Bo Ørjan Gunnar Nystrøm

• Azizi, Marzieh; Kiaie, Seyed Hossein; Yazdian, Fatemeh; Sheibani, Mohammad; Nystrøm, Bo Ørjan Gunnar & Ghourchian, Hedayatollah (2025). A Combination Delivery of Silver and Paclitaxel in Albumin Nanoparticles for Breast Cancer Cells. Pharmaceutical Sciences. ISSN 1735-403X. 31(4), p. 425–439. doi: 10.34172/PS.025.40979. Full text in Research Archive
• Mahdieh, Athar; Motasadizadeh, Hamidreza; Maghsoudian, Samane; Sabzevari, Alireza; Khalili, Fereshte & Yeganeh, Hamid [Show all 7 contributors for this article] (2024). Novel polyurethane-based ionene nanoparticles electrostatically stabilized with hyaluronic acid for effective gene therapy. Colloids and Surfaces B: Biointerfaces. ISSN 0927-7765. 236. doi: 10.1016/j.colsurfb.2024.113802. Full text in Research Archive Show summary

  Gene therapy is considered to be a valuable strategy for effective cancer treatment. However, the development of effective delivery systems that can specifically deliver gene materials, such as siRNA to tumor tissues plays a critical role in cancer therapy. In the present study, we have developed a novel complex that is based on an electrostatic interaction between cationic polyurethane ionene (CPUI) nanoparticles and an anti-signal transducer and activator of transcription 3 (STAT3) siRNA. For active targeting, hyaluronic acid (HA) was used to coat the complexes, which significantly reduced the cytotoxicity of the blank nanocarriers while demonstrating high transport efficiency of the siRNA via the CD44-mediated endocytosis pathway in MCF-7 breast cancer cells. The targeted nanocarriers (HA/CPUI/siRNA) showed significantly higher cellular internalization in flow cytometry and confocal microscopy compared with the non-targeted system (CPUI/siRNA). In addition, the incorporation of HA on the surface of the complexes resulted in significantly greater suppression of the STAT3 gene compared to the corresponding non-targeted formulation. Whole-body fluorescence images showed more significant tumor accumulation of the targeted nanocarriers in 4T1 breast tumor-bearing mice. Therefore, HA/CPUI/siRNA nanocarriers are an interesting option for the siRNA-targeted treatment of breast cancer cells.

• Mahdieh, Athar; Yeganeh, Hamid; Sande, Sverre Arne & Nyström, Bo (2023). Design of novel polyurethane-based ionene nanocarriers for cancer therapy: Synthesis, in-vitro, and in-vivo studies. International Journal of Pharmaceutics. ISSN 0378-5173. 635. doi: 10.1016/j.ijpharm.2023.122768. Full text in Research Archive
• Tan, Julia Jianwei; Gjerde, Natalie; Giudice, Alessandra Del; Knudsen, Kenneth Dahl; Galantini, Luciano & Du, Guanqun [Show all 9 contributors for this article] (2023). Interactions in Aqueous Mixtures of Cationic Hydroxyethyl Cellulose and Different Anionic Bile Salts. Journal of Agricultural and Food Chemistry. ISSN 0021-8561. 71(8), p. 3732–3741. doi: 10.1021/acs.jafc.3c00076. Full text in Research Archive Show summary

  It is known that the reduction of blood cholesterol can be accomplished through foods containing a large number of dietary fibers; this process is partially related to the binding of bile salt to fibers. To gain new insights into the interactions between dietary fibers and bile salts, this study investigates the interactions between cationic hydroxyethyl cellulose (catHEC) and sodium deoxycholate (NaDC) or sodium cholate (NaC), which have a similar structure. Turbidity measurements reveal strong interactions between catHEC and NaDC, and under some conditions, macroscopic phase separation occurs. In contrast, the interactions with NaC are weak. At a catHEC concentration of 2 wt %, incipient phase separation is approached at concentrations of NaC and NaDC of 32.5 and 19.3 mM, respectively. The rheological results show strong interactions and a prominent viscosification effect for the catHEC/NaDC system but only moderate interactions for the catHEC/NaC system. Both cryogenic transmission electron microscopy and small-angle X-ray scattering results display fundamental structural differences between the two systems, which may explain the stronger interactions in the presence of NaDC. The surmise is that the extended structures formed in the presence of NaDC can easily form connections and entanglements in the network.

• Li, Yuhan; Zhu, Kaizheng; Bu, Huaitian; Fu, Zhenyu; Kjøniksen, Anna-Lena & Nyström, Bo [Show all 7 contributors for this article] (2023). Miktoarm PEG–PCL Star Copolymer (AB6) Blend Composite Solid Electrolyte for All-Solid-State Lithium Metal Battery. Macromolecules. ISSN 0024-9297. 56(19), p. 7921–7930. doi: 10.1021/acs.macromol.3c01621. Full text in Research Archive Show summary

  A series of AB6 type-7 miktoarm star copolymers consisting of poly(ethylene glycol) (PEG) as the A arm and poly(ε-caprolactone) (PCL) as the B arm are synthesized by controlled ring-opening polymerization of the ε-caprolactone monomer. The chemical structure is confirmed and characterized by nuclear magnetic resonance (NMR) and Fourier transform infrared (FT-IR) spectroscopies. The synthesized PEG–PCL star copolymers (PAB6) (Mn = 8400, 16,820, and 32,480) with arms of different lengths are introduced into the poly(ethylene oxide)-based solid electrolyte system. Moreover, the electrochemical, mechanical, and thermochemical properties of composite solid polymer electrolytes are enhanced by adding three miktoarm PEG–PCL star copolymers (referred to as PAB6–1, PAB6–2, and PAB6–3). The unique low-molecular-weight miktoarm copolymers with a central etheroxy group and branched carboxyl groups interact with poly(ethylene oxide) segments and lithium ions, enhancing the segment mobility of the polymer and lithium-ion transfer. Therefore, all-solid-state lithium metal batteries by the serial miktoarm star copolymer composite electrolytes display a high capacity retention of 128.1 mAh g–1 after 390 cycles.

• Mahdieh, Athar; Yeganeh, Hamid; Motasadizadeh, Hamidreza; Nekoueifard, Effat; Maghsoudian, Samane & Ghahremani, Mohammad Hossein [Show all 8 contributors for this article] (2023). Waterborne polyurethane magnetic nanomicelles with magnetically governed functions for breast cancer therapy. International Journal of Pharmaceutics. ISSN 0378-5173. 645. doi: 10.1016/j.ijpharm.2023.123356. Full text in Research Archive
• Gjerde, Natalie Solfrid; Giudice, Alessandra Del; Zhu, Kaizheng; Knudsen, Kenneth Dahl; Galantini, Luciano & Schillén, Karin [Show all 7 contributors for this article] (2023). Synthesis and Characterization of a Thermoresponsive Copolymer with an LCST-UCST-like Behavior and Exhibiting Crystallization. ACS Omega. 8(34), p. 31145–31154. doi: 10.1021/acsomega.3c03162. Full text in Research Archive Show summary

  In this work, the diblock copolymer methoxy-poly(ethylene glycol)-block-poly(ε-caprolactone) (MPEG–b-PCL) was synthesized with a block composition that allows this polymer in aqueous media to possess both an upper critical solution temperature (UCST) and a lower critical solution temperature (LCST) over a limited temperature interval. The value of the UCST, associated with crystallization of the PCL-block, depended on heating (H) or cooling (C) of the sample and was found to be CPUCSTH = 32 °C and CPUCSTC = 23 °C, respectively. The LCST was not affected by the heating or cooling scans; assumed a value of 52 °C (CPLCSTH = CPLCSTC). At intermediate temperatures (e.g., 45 °C), dynamic light scattering (DLS), small-angle X-ray scattering (SAXS), and cryogenic transmission electron microscopy (cryo-TEM) showed that the solution consisted of a large population of spherical core–shell particles and some self-assembled rodlike objects. At low temperatures (below 32 °C), differential scanning calorimetry (DSC) and wide-angle X-ray scattering (WAXS) in combination with SAXS disclosed the formation of crystals with a cylindrical core–shell structure. Cryo-TEM supported a thread-like appearance of the self-assembled polymer chains. At temperatures above 52 °C, incipient phase separation took place and large aggregation complexes of amorphous morphology were formed. This work provides insight into the intricate interplay between UCST and LCST and the type of structures formed at these conditions in aqueous solutions of MPEG–b-PCL diblock copolymers.

• Mahdieh, Athar; Motasadizadeh, Hamidreza; Yeganeh, Hamid; Nyström, Bo & Dinarvand, Rassoul (2022). Redox-responsive waterborne polyurethane nanocarriers for targeted doxorubicin delivery. International Journal of Pharmaceutics. ISSN 0378-5173. 628. doi: 10.1016/j.ijpharm.2022.122275. Full text in Research Archive
• Nazemoroaya, Zahra; Sarafbidabad, Mohsen; Mahdieh, Athar; Zeini, Darya & Nyström, Bo (2022). Use of Saponinosomes from Ziziphus spina-christi as Anticancer Drug Carriers. ACS Omega. 7(32), p. 28421–28433. doi: 10.1021/acsomega.2c03109. Full text in Research Archive Show summary

  Saponins are plant glycosides with different structures and biological activities, such as anticancer effects. Ziziphus spina-christi is a plant rich in saponin, and this compound is used to treat malignant melanoma in the present study. Nanophytosomes can be used as an advantageous nanodrug delivery system for plant extracts. The aim of this work is to use the saponin-rich fraction (SRF) from Z. spina-christi and prepare SRF-loaded nanophytosomes (saponinosomes) and observe the in vitro and in vivo effects of these carriers. First, the SRF was obtained from Z. spina-christi by a solvent–solvent fractionation method. Then, Fourier transform infrared (FTIR) analyses were performed to confirm the presence of saponins in the extracted material. Subsequently, the saponinosomes were prepared by the solvent injection method (ether injection method) using a 1:1:1 ratio of lecithin/cholesterol/SRF in the mixture. Characterization of the prepared saponinosomes was performed by FTIR, dynamic light scattering (DLS), field-emission scanning electron microscopy (FE-SEM), and atomic force microscopy (AFM) analyses. In addition, a UV–vis spectrophotometer was used to determine the entrapment efficiency (EE) and in vitro release of the SRF. Finally, cell cytotoxicity of the different formulations was evaluated using a 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) assay on both mouse melanoma cells (B16F10) and fibroblasts (L929). Using DLS, AFM, and FE-SEM analyses, the particle size was determined to be 58 ± 6 nm with a zeta potential of −32 ± 2 mV. The calculated EE was 85 ± 3%. The results of the in vitro release profile showed that 68.2% of the SRF was released from the saponinosome after 48 h. The results of the MTT assay showed that the SRF and saponinosomes have high toxicity on B16F10 melanoma cells, but saponinosomes showed a significant decrease in cytotoxicity on L929 fibroblast cells compared with that of the SRF. Our results indicate that the SRF from Z. spina-christi has anticancer activity, and the saponinosomes prepared in this work can control tumor growth, improve therapeutic efficacy, and reduce the side effects of saponins.

• Zeini, Darya; Glover, Joel C.; Knudsen, Kenneth Dahl & Nyström, Bo (2021). Influence of Lysine and TRITC Conjugation on the Size and Structure of Dextran Nanoconjugates with Potential for Biomolecule Delivery to Neurons. ACS Applied Bio Materials (AABM). 4(9), p. 6832–6842. doi: 10.1021/acsabm.1c00544. Full text in Research Archive Show summary

  As a potent nonviral system for biomolecular delivery to neurons via their axons, we have studied molecular characteristics of lysinated fluorescent dextran nanoconjugates with degrees of conjugation of 0.54–15.2 mol lysine and 0.25–7.27 mol tetramethyl rhodamine isothiocyanate (TRITC) per mol dextran. We studied the influence of conjugation with lysine and TRITC on the size and structure of different molecular weight dextrans and their mobility within axons. Dynamic light scattering (DLS) and small-angle neutron scattering (SANS) experiments revealed significant differences in the size and structure of unmodified and modified dextrans. Unexpectedly, lower-molecular-weight conjugated dextrans exhibited higher molecular volumes, which we propose is due to fewer intramolecular interactions than in higher-molecular-weight conjugated dextrans. Assessment of retrograde and anterograde movement of lysine- and TRITC-conjugated dextrans in axons in the lumbar spinal cord of chicken embryos showed that lower-molecular-weight dextrans translocate more efficiently than higher-molecular-weight dextrans, despite having larger molecular volumes. This comparative characterization of different molecular weight dextrans will help define optimal features for intracellular delivery.

• Du, Guanqun; Belić, Domagoj; Giudice, Alessandra Del; Alfredsson, Viveka; Carnerup, Anna M. & Zhu, Kaizheng [Show all 10 contributors for this article] (2021). Condensed Supramolecular Helices: The Twisted Sisters of DNA. Angewandte Chemie International Edition. ISSN 1433-7851. p. 1–9. doi: 10.1002/anie.202113279. Full text in Research Archive Show summary

  Condensation of DNA helices into hexagonally packed bundles and toroids represents an intriguing example of functional organization of biological macromolecules at the nanoscale. The condensation models are based on the unique polyelectrolyte features of DNA, however here we could reproduce a DNA-like condensation with supramolecular helices of small chiral molecules, thereby demonstrating that it is a more general phenomenon. We show that the bile salt sodium deoxycholate can form supramolecular helices upon interaction with oppositely charged polyelectrolytes of homopolymer or block copolymers. At higher order, a controlled hexagonal packing of the helices into DNA-like bundles and toroids could be accomplished. The results disclose unknown similarities between covalent and supramolecular non-covalent helical polyelectrolytes, which inspire visionary ideas of constructing supramolecular versions of biological macromolecules. As drug nanocarriers the polymer–bile salt superstructures would get advantage of a complex chirality at molecular and supramolecular levels, whose effect on the nanocarrier assisted drug efficiency is a still unexplored fascinating issue.

• Nasrollah, Seyyed Ahmad Seyyed; Najmoddin, Najmeh; Mohammadi, Mohsen; Fayyaz, Abdolali & Nyström, Bo (2021). Three dimensional polyurethane/ hydroxyapatite bioactive scaffolds: The role of hydroxyapatite on pore generation. Journal of Applied Polymer Science. ISSN 0021-8995. 138(11), p. 1–14. doi: 10.1002/app.50017. Full text in Research Archive
• Carmona, Pierre; Tasici, Anca Maria; Sande, Sverre Arne; Knudsen, Kenneth Dahl & Nyström, Bo (2021). Glyceraldehyde as an efficient chemical crosslinker agent for the formation of chitosan hydrogels. Gels. 7(4). doi: 10.3390/gels7040186. Full text in Research Archive Show summary

  The rheological changes that occur during the chemical gelation of semidilute solutions of chitosan in the presence of the low-toxicity agent glyceraldehyde (GCA) are presented and discussed in detail. The entanglement concentration for chitosan solutions was found to be approximately 0.2 wt.% and the rheological experiments were carried out on 1 wt.% chitosan solutions with various amounts of GCA at different temperatures (25 °C and 40 °C) and pH values (4.8 and 5.8). High crosslinker concentration, as well as elevated temperature and pH close to the pKa value (pH ≈ 6.3–7) of chitosan are three parameters that all accelerate the gelation process. These conditions also promote a faster solid-like response of the gel-network in the post-gel region after long curing times. The mesh size of the gel-network after a very long (18 h) curing time was found to contract with increasing level of crosslinker addition and elevated temperature. The gelation of chitosan in the presence of other chemical crosslinker agents (glutaraldehyde and genipin) is discussed and a comparison with GCA is made. Small angle neutron scattering (SANS) results reveal structural changes between chitosan solutions, incipient gels, and mature gels.

• Zhu, Kaizheng; Pamies, Ramon Francisco Porras; Al-Manasir, Nodar; Cifre, José G. Hernández; Torre, José Garcia De la & Nyström, Bo [Show all 7 contributors for this article] (2020). The Effect of Number of Arms on the Aggregation Behavior of Thermoresponsive Poly(N‐isopropylacrylamide) Star Polymers. ChemPhysChem. ISSN 1439-4235. 21(12), p. 1258–1271. doi: 10.1002/cphc.202000273. Full text in Research Archive Show summary

  The thermoresponsive nature of aqueous solutions of poly(N‐isopropylacrylamide) (PNIPAAM) star polymers containing 2, 3, 4, and 6 arms has been investigated by turbidity, dynamic light scattering, rheology, and rheo‐SALS. Simulations of the thermosensitive nature of the single star polymers have also been conducted. Some of the samples form aggregates even at temperatures significantly below the lower critical solution temperature (LCST) of PNIPAAM. Increasing concentration and number of arms promotes associations at low temperatures. When the temperature is raised, there is a competition between size increase due to enhanced aggregation and a size reduction caused by contraction. Monte Carlo simulations show that the single stars contract with increasing temperature, and that this contraction is more pronounced when the number of arms is increased. Some samples exhibit a minimum in the turbidity data after the initial increase at the cloud point. The combined rheology and rheo‐SALS data suggest that this is due to a fragmentation of the aggregates followed by re‐aggregation at even higher temperatures. Although the 6‐arm star polymer aggregates more than the other stars at low temperatures, the more compact structure renders it less prone to aggregation at temperatures above the cloud point.

• Du, Guanqun; Giudice, Alessandra Del; Alfredsson, Viveka; Carnerup, Anna M.; Pavel, Nicolae V. & Loh, Watson [Show all 10 contributors for this article] (2020). Effect of temperature on the association behavior in aqueous mixtures of an oppositely charged amphiphilic block copolymer and bile salt. Polymer. ISSN 0032-3861. 206. doi: 10.1016/j.polymer.2020.122871. Full text in Research Archive Show summary

  The association in aqueous mixtures of a thermoresponsive cationic diblock copolymer composed of poly(N-isopropylacrylamide) (PNIPAM) and poly(3-acrylamidopropyl)-trimethylammonium-chloride (PAMPTMA(+)) and the oppositely charged bile salt sodium deoxycholate (NaDC) is investigated at different compositions by light and X-ray scattering, calorimetry, and electrophoretic mobility measurements. Clouding reveals aggregation upon heating. The addition of NaDC to the copolymer solution lowers the temperature of the transition and increases its cooperativity. At high temperature and low NaDC fractions, mixed aggregates with a dehydrated PNIPAM-rich interior and a PAMPTMA(+)-rich shell partially neutralized by DC– anions are formed. At high NaDC fractions, the aggregates present internal regularly spaced segregated nanoregions of dehydrated PNIPAM and PAMPTMA(+)/DC– (microphase separation). The results suggest that the mixed aggregates have appealing composition-controlled thermoresponse. The system phase separates at body temperature and the highest NaDC fractions investigated, meaning in conditions accomplished when the use of the polymer as a bile salt sequestrant is hypothesized.

• Dashtimoghadam, Erfan; Salimikenari, Hamed; Nasseri, Rasool; Knudsen, Kenneth Dahl; Mirzadeh, Hamid & Nyström, Bo (2020). Tunable viscoelastic features of aqueous mixtures of thermosensitive ethyl(hydroxyethyl)cellulose and cellulose nanowhiskers. Colloids and Surfaces A: Physicochemical and Engineering Aspects. ISSN 0927-7757. 590. doi: 10.1016/j.colsurfa.2020.124489. Full text in Research Archive Show summary

  Ethyl(hydroxyethyl) cellulose (EHEC) is known to form reversible hydrogels in water at elevated temperatures in the presence of an ionic surfactant. However, the toxicity of common ionic surfactants (like SDS and CTAB) hampers pharmaceutical and biomedical applications of EHEC-based thermogels. Addition of a nature-based material to EHEC solutions - in the form of negatively charged cellulose nanowhiskers (CNWs) - will introduce an internal electrostatic repulsion that could also produce the balanced swelling necessary for forming a stable gel at elevated temperatures (ca. 37 °C). This may therefore be an alternative way of designing low toxicity thermoresponsive hydrogels of high mechanical strength for pharmaceutical and biomedical applications without the use of ionic surfactants. The properties of the temperature-induced gelling systems (EHEC/CNW and EHEC/SDS/CNW) were characterized by rheological methods and rheo-small angle light scattering (rheo-SALS), whereas the structure and morphology of CNWs were examined by transmission electron microscope (TEM) and small angle neutron scattering (SANS). Oscillatory shear results for the EHEC/CNW system showed that the gel temperature (ca. 37 °C) was virtually unaffected by the amount of added CNWs, while the fractal dimension values (2.2–2.3) suggested the evolution of a tighter incipient gel network with increasing level of added CNWs. Furthermore, a threefold increase of the gel strength parameter was observed with increasing concentration of CNWs. For the EHEC/CNW/SDS system, a more open network evolved with increasing amount of CNWs, and for this system, higher values of the gel strength parameter were found. Pronounced shear-thinning, even at very low shear rates, was observed for the EHEC/CNW system at all levels of CNW addition, whereas for the EHEC/CNW/SDS system, Newtonian-like behavior was detected at low shear rates.

• Schillén, Karin; Galantini, Luciano; Du, Guanqun; Giudice, Alessandra Del; Alfredsson, Viveka & Carnerup, Anna M. [Show all 9 contributors for this article] (2019). Block copolymers as bile salt sequestrants: Intriguing structures formed in a mixture of an oppositely charged amphiphilic block copolymer and bile salt. Physical Chemistry, Chemical Physics - PCCP. ISSN 1463-9076. 21(23), p. 12518–12529. doi: 10.1039/c9cp01744e. Full text in Research Archive
• Pandya, Abhilash D.; Jäger, Eliézer; Fam, Shahla Bagheri; Höcherl, Anita; Jäger, Alessandro & Sincari, Vladimir [Show all 12 contributors for this article] (2019). Paclitaxel-loaded biodegradable ROS-sensitive nanoparticles for cancer therapy. International Journal of Nanomedicine. ISSN 1176-9114. 14, p. 6269–6285. doi: 10.2147/IJN.S208938. Full text in Research Archive Show summary

  <i>Background</i>: Reactive oxygen species (ROS), such as hydrogen peroxide and superoxide, trigger biodegradation of polymer-based nanoparticles (NPs) bearing pinacol-type boronic ester groups. These NPs may selectively release their cargo, in this case paclitaxel (PTX), at the high levels of ROS present in the intracellular environment of inflamed tissues and most tumors.<p> <p><i>Purpose</i>: The main objective was to determine anti-tumor efficacy of PTX-loaded ROS-sensitive NPs and to examine whether macrophage infiltration had any impact on treatment efficacy.<p> <p><i>Methods</i>: NPs were synthesized and their characteristics in the presence of H₂O₂ were demonstrated. Both confocal microscopy as well as flow cytometry approaches were used to determine degradation of ROS-sensitive NPs. HeLa cells were cultured in vitro and used to establish tumor xenografts in nude mice. In vivo experiments were performed to understand toxicity, biodistribution and anti-tumor efficacy of the NPs. Moreover, we performed immunohistochemistry on tumor sections to study infiltration of M1 and M2 subsets of macrophages.<p> <p><i>Results</i>: We demonstrated that PTX delivered in NPs containing a ROS-sensitive polymer exhibits a better anti-tumor efficacy than PTX in NPs containing ROS-non-sensitive polymer, free PTX or Abraxane® (nab-PTX). The biodistribution revealed that ROS-sensitive NPs exhibit retention in liver, spleen and lungs, suggesting a potential to target cancer metastasizing to these organs. Finally, we demonstrated a correlation between infiltrated macrophage subsets and treatment efficacy, possibly contributing to the efficient anti-tumor effects.<p> <p><i>Conclusion</i>: Treatment with ROS-sensitive NPs containing PTX gave an improved therapeutic effect in HeLa xenografts than their counterpart, free PTX or nab-PTX. Our data revealed a correlation between macrophage infiltration and efficiency of the different antitumor treatments, as the most effective NPs resulted in the highest infiltration of the anti-tumorigenic M1 macrophages.

• Schlachet, Inbar; Trousil, Jiri; Rak, Dmytro; Knudsen, Kenneth Dahl; Pavlova, Ewa & Nyström, Bo [Show all 7 contributors for this article] (2019). Chitosan-graft-poly(methyl methacrylate) amphiphilic nanoparticles: Self-association and physicochemical characterization. Carbohydrate Polymers. ISSN 0144-8617. 212, p. 412–420. doi: 10.1016/j.carbpol.2019.02.022. Full text in Research Archive
• Motlaq, Vahid Forooqi; Momtazi, Leva; Zhu, Kaizheng; Knudsen, Kenneth Dahl & Nyström, Bo (2019). Differences in self‐assembly features of thermoresponsive anionic triblock copolymers synthesized via one‐pot or two‐pot by atom transfer radical polymerization. Journal of Polymer Science Part B: Polymer Physics. ISSN 0887-6266. 57(9), p. 524–534. doi: 10.1002/polb.24808. Full text in Research Archive Show summary

  The self‐assembly process in aqueous solutions of the methoxyl‐poly(ethylene glycol)‐block ‐poly(2‐acrylamido‐2‐methyl‐1‐propanesulfonic sodium)‐block ‐poly(N ‐isopropyl acrylamide) (PNIPAAM) triblock copolymer, synthesized via two different atomic transfer radical polymerization methods, namely “one‐pot” (P3‐sample) and “two‐pot” (P2‐sample), was studied by various experimental techniques. The “one‐pot” procedure leads to a copolymer (P3) where the PNIPAAM block is contaminated with a minor quantity of 2‐acrylamido‐2‐methyl‐1‐propane sulfonate (AMPS) residuals and this sample does not form micelles over the considered temperature region, but unimers and temperature‐induced aggregates coexist in the presence of a small amount of salt. The P2 polymer forms micelles and intermicellar structures, but the former moieties disappear at high temperatures, whereas the latter species contract with increasing temperature. Small‐angle neutron scattering results revealed correlation peaks, both for P3 and P2, and no micelle formation for P3, but a pronounced upturn of the scattered intensity at low wavevector values at elevated temperatures for the P2 copolymer. The findings from this study clearly show that the spurious AMPS residuals have a drastic influence on the self‐assembly and micelle formation of the triblock copolymer. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2019 , 57 , 524–534

• Gjerde, Natalie Solfrid; Zhu, Kaizheng; Knudsen, Kenneth Dahl & Nyström, Bo (2019). Influence of poly(ε-caprolactone) end-groups on the temperature-induced macroscopic gelation of Pluronic in aqueous media. European Polymer Journal. ISSN 0014-3057. 112, p. 493–503. doi: 10.1016/j.eurpolymj.2019.01.033. Full text in Research Archive Show summary

  Temperature-induced gelation of amphiphilic copolymers in aqueous media has attracted a great deal of interest in recent years. We have investigated phase behavior, gelation, rheology, and structure of modified versions of the water-soluble copolymer of type PEO-PPO-PEO (Pluronic, F127) with short (PCL(5)) or long (PCL(11)) poly(caprolactone) blocks at both ends. By visual inspection of the studied semidilute and concentrated polymer samples at various temperatures, gelation and phase separation could be mapped and the length of the PCL blocks had a strong impact on the observed features. By using oscillatory shear experiments, the gel points of the systems were determined and an interesting anomaly of the complex viscosity was observed at high frequencies where the moieties were kinetically arrested. This irregularity was strengthened for the PCL(11) copolymer and this was ascribed to bridging of the micelles due to the long PCL blocks. The mesoscopic structure of the systems was studied by using small angle neutron scattering. The position and amplitude of the observed correlation peak, which discloses vital intermicellar correlations in the scattering function depends on temperature, concentration, and the length of the PCL blocks. Frequently the scattering function could be portrayed by a spherical core-shell micelle model with hard sphere interaction between them. The estimated aggregation number (Nagg) was substantially affected by the PCL content of the polymer and a significant influence of polymer concentration and temperature on the value of Nagg was found.

• Feher, Bence; Zhu, Kaizheng; Nyström, Bo; Varga, Imre & Pedersen, Jan Skov (2019). Effect of Temperature and Ionic Strength on Micellar Aggregates of Oppositely Charged Thermoresponsive Block Copolymer Polyelectrolytes. Langmuir. ISSN 0743-7463. doi: 10.1021/acs.langmuir.9b01896. Full text in Research Archive
• Pooch, Fabian; Sliepen, Marjolein; Knudsen, Kenneth Dahl; Nyström, Bo; Tenhu, Heikki & Winnik, Françoise M. (2019). Poly(2-isopropyl-2-oxazoline)-b-poly(lactide) (PiPOx-b-PLA) Nanoparticles in Water: Interblock van der Waals Attraction Opposes Amphiphilic Phase Separation. Macromolecules. ISSN 0024-9297. 52(3), p. 1317–1326. doi: 10.1021/acs.macromol.8b02558. Full text in Research Archive
• Halamish, Hen Moshe; Trousil, Jiří; Rak, Dmytro; Knudsen, Kenneth Dahl; Pavlova, Ewa & Nyström, Bo [Show all 8 contributors for this article] (2019). Self-assembly and nanostructure of poly(vinyl alcohol)-graft-poly(methyl methacrylate) amphiphilic nanoparticles. Journal of Colloid and Interface Science. ISSN 0021-9797. 553, p. 512–523. doi: 10.1016/j.jcis.2019.06.047. Full text in Research Archive
• Diget, Jakob Stensgaard; Lund, Reidar; Nyström, Bo; Wintgens, Veronique; Amiel, Catherine & Wimmer, Reinhard [Show all 7 contributors for this article] (2019). Self-assembled nanoparticles based on cyclodextrin-modified pullulan: Synthesis, and structural characterization using SAXS. Carbohydrate Polymers. ISSN 0144-8617. 213, p. 403–410. doi: 10.1016/j.carbpol.2019.01.106. Full text in Research Archive
• Skottvoll, Frøydis Sved; Berg, Henriette Engen; Bjørseth, Kamilla; Lund, Kaja; Roos, Norbert & Bekhradnia, Sara [Show all 13 contributors for this article] (2018). Ultracentrifugation versus kit exosome isolation: nanoLC-MS and other tools reveal similar performance biomarkers, but also contaminations. Future science OA. 5(1). doi: 10.4155/fsoa-2018-0088. Full text in Research Archive Show summary

  Aim: For isolation of exosomes, differential ultracentrifugation and an isolation kit from a major vendor were compared. Materials & methods: ‘Case study’ exosomes isolated from patient-derived cells from glioblastoma multiforme and a breast cancer cell line were analyzed. Results: Transmission electron microscopy, dynamic light scattering, western blotting, and so forth, revealed comparable performance. Potential protein biomarkers for both diseases were also identified in the isolates using nanoLC–MS. Western blotting and nanoLC–MS also revealed negative exosome markers regarding both isolation approaches. Conclusion: The two isolation methods had an overall similar performance, but we hesitate to use the term ‘exosome isolation’ as impurities may be present with both isolation methods. NanoLC–MS can detect disease biomarkers in exosomes and is useful for critical assessment of exosome enrichment procedures.

• Gjerde, Natalie Solfrid; Zhu, Kaizheng; Nyström, Bo & Knudsen, Kenneth Dahl (2018). Effect of PCL end-groups on the self-assembly process of Pluronic in aqueous media. Physical Chemistry, Chemical Physics - PCCP. ISSN 1463-9076. 20(4), p. 2585–2596. doi: 10.1039/c7cp07240f. Full text in Research Archive
• Salimi-Kenari, Hamed; Mollaie, Faeze; Dashtimoghadam, Erfan; Imani, Mohammad & Nyström, Bo (2018). Effects of chain length of the cross-linking agent on rheological and swelling characteristics of dextran hydrogels. Carbohydrate Polymers. ISSN 0144-8617. 181, p. 141–149. doi: 10.1016/j.carbpol.2017.10.056. Full text in Research Archive
• Motlaq, Vahid Forooqi; Knudsen, Kenneth Dahl & Nyström, Bo (2018). Effect of PEGylation on the stability of thermoresponsive nanogels. Journal of Colloid and Interface Science. ISSN 0021-9797. 524, p. 245–255. doi: 10.1016/j.jcis.2018.04.024. Full text in Research Archive
• Dashtimoghadam, Erfan; Salimi-Kenari, Hamed; Motlaq, Vahid Forooqi; Hasani-Sadrabad, Mohammad Mahdi; Mirzadeh, Hamid & Zhu, Kaizheng [Show all 8 contributors for this article] (2017). Synthesis and temperature-induced self-assembly of a positively charged symmetrical pentablock terpolymer in aqueous solutions. European Polymer Journal. ISSN 0014-3057. 97, p. 158–168. doi: 10.1016/j.eurpolymj.2017.10.008. Full text in Research Archive
• Kaczmarek, Daria; Diget, Jakob Stensgaard; Nyström, Bo; Gyulai, Gergő; Mészáros, R. & Gilányi, Tibor [Show all 7 contributors for this article] (2017). Response of Block Copolyelectrolyte Complexes to Addition of Ionic Surfactants. Colloids and Surfaces A: Physicochemical and Engineering Aspects. ISSN 0927-7757. 532, p. 290–296. doi: 10.1016/j.colsurfa.2017.04.078. Full text in Research Archive
• Nielsen, Josefine Eilsø; Zhu, Kaizheng; Sande, Sverre Arne; Kováčik, Lubomír; Cmarko, Dusan & Knudsen, Kenneth [Show all 7 contributors for this article] (2017). Structural and Rheological Properties of Temperature-Responsive Amphiphilic Triblock Copolymers in Aqueous Media. Journal of Physical Chemistry B. ISSN 1520-6106. 121(18), p. 4885–4899. doi: 10.1021/acs.jpcb.7b01174. Full text in Research Archive
• Bayati, Solmaz; Bergquist, Karl-Erik; Zhu, Kaizheng; Nyström, Bo; Pedersen, Jan Skov & Galantini, Luciano [Show all 7 contributors for this article] (2017). Mixed micelles of oppositely charged poly(N-isopropylacrylamide) diblock copolymers. Journal of Polymer Science Part B: Polymer Physics. ISSN 0887-6266. 55(19), p. 1457–1470. doi: 10.1002/polb.24403. Full text in Research Archive
• Trousil, Jiří; Filippov, Sergey K.; Hrubý, Martin; Mazel, Tomáš; Syrová, Zdeňka & Cmarko, Dusan [Show all 15 contributors for this article] (2017). System with embedded drug release and nanoparticle degradation sensor showing efficient rifampicin delivery into macrophages. Nanomedicine: Nanotechnology, Biology and Medicine. ISSN 1549-9634. 13, p. 307–315. doi: 10.1016/j.nano.2016.08.031. Full text in Research Archive
• Moghaddam, Saeed Z..; Zhu, Kaizheng; Nyström, Bo & Thormann, Esben (2017). Thermo-responsive diblock and triblock cationic copolymers at the silica/aqueous interface: A QCM-D and AFM study. Journal of Colloid and Interface Science. ISSN 0021-9797. 505, p. 546–555. doi: 10.1016/j.jcis.2017.06.044. Full text in Research Archive
• Azizi, Marzieh; Ghourchian, Hedayatoallah; Yazdian, Fatemeh; Fam, Shahla Bagheri; Bekhradnia, Sara & Nyström, Bo (2017). Anti-cancerous effect of albumin coated silver nanoparticles on MDA-MB 231 human breast cancer cell line. Scientific Reports. 7(1), p. 5178–5196. doi: 10.1038/s41598-017-05461-3. Full text in Research Archive Show summary

  With the aim of making specific targeting of silver nanoparticles as a drug for tumor cells and developing new anticancer agents, a novel nano-composite was developed. Albumin coated silver nanoparticles (ASNPs) were synthesized, and their anti-cancerous effects were evaluated against MDA-MB 231, a human breast cancer cell line. The synthesized ASNPs were characterized by spectroscopic methods. The morphological changes of the cells were observed by inverted, florescent microscopy and also by DNA ladder pattern on gel electrophoresis; the results revealed that the cell death process occurred through the apoptosis mechanism. It was found that ASNPs with a size of 90 nm and negatively charged with a zeta-potential of about −20 mV could be specifically taken up by tumor cells. The LD50 of ASNPs against MDA-MB 231 (5 μM), was found to be 30 times higher than that for white normal blood cells (152 μM). The characteristics of the synthesized ASNPs included; intact structure of coated albumin, higher cytotoxicity against cancer cells than over normal cells, and cell death based on apoptosis and reduction of gland tumor sizes in mice. This work indicates that ASNPs could be a good candidate for chemotherapeutic drug.

• Lazzara, Giuseppe; Campbell, Richard A; Bayati, Solmaz; Zhu, Kaizheng; Nyström, Bo & Nylander, Tommy [Show all 7 contributors for this article] (2017). On the formation of inclusion complexes at the solid/liquid interface of anchored temperature-responsive PNIPAAM diblock copolymers with γ-cyclodextrin. Colloid and Polymer Science. ISSN 0303-402X. 295(8), p. 1327–1341. doi: 10.1007/s00396-017-4052-6. Full text in Research Archive Show summary

  The thermal responsive behavior of adsorbed layers of diblock copolymers of poly(N-isopropylacrylamide) (PNIPAAM) and poly((3-acrylamidopropyl)trimethylammonium chloride) (PAMPTMA(+)) with γ-cyclodextrin (γ-CD) at the solid/liquid interface has been investigated using three in situ techniques: null ellipsometry, quartz–crystal microbalance with dissipation monitoring, and neutron reflectometry. The measurements provided information about the adsorbed amounts, the layer thickness, hydration and viscoelastic properties, and the interfacial structure and composition. The copolymers adsorb to silica with the cationic PAMPTMA(+) blocks sitting as anchors in a flat conformation and the PNIPAAM chains extending into the solution. The copolymer system alone exhibits reversible collapse above the lower critical solution temperature of PNIPAAM. The addition of γ-CD to pre-adsorbed copolymer layers results in a highly extended conformation as well as some loss of copolymer from the surface, which we discuss in terms of the formation of surface-invoked lateral steric repulsion of formed inclusion complexes.

• Bandyopadhyay, Sulalit; Alvi, Muhammad Awais Ashfaq; Sharma, Anuvansh; Zhu, Kaizheng; Kjøniksen, Anna-Lena & Nyström, Bo [Show all 7 contributors for this article] (2017). Influence of polymer coating on release of L-dopa from core-shell Fe@Au nanoparticle systems. Colloid and Polymer Science. ISSN 0303-402X. 295(2), p. 391–402. doi: 10.1007/s00396-017-4015-y. Full text in Research Archive Show summary

  We report on the effect of different stimuli-responsive polymer shells on Fe@Au core-shell nanoparticles (NPs) with respect to thermoresponse as well as loading and release characteristics. The hybrid NP systems were investigated using a wide array of characterization techniques including dynamic light scattering, electrophoretic mobility, UV-visible spectroscopy, and scanning transmission electron microscopy. Three different polymeric shells were selected for loading and release of l-dopa: thiolated polyethylene glycol (PEG), poly(N-isopropylacrylamide-co-acrylic acid) (PNIPAAM_AAc) microgel crosslinked with N,N′-methylenebis(acrylamide) (BIS), and finally concomitant PEG and PNIPAAM_AAc microgel (Fe@Au_PEG_Microgel). All three shells were found to exhibit high loading (∼10%) and encapsulation efficiencies up to 100 μg l-dopa/mg. Although the loading efficiencies are comparable for the three systems, Fe@Au_PEG_Microgel has the highest release (87%) at elevated temperature and acidic conditions. The attenuated release from the PEG-based systems can be attributed to stronger dipole-dipole interactions between the carboxyl group of PEG and the amino group of l-dopa.

• Medel, Sandra; Syrova, Zdenka; Kováčik, Lubomír; Hrdy, Jiri; Hornacek, Matus & Jager, Eliezer [Show all 12 contributors for this article] (2017). Curcumin-bortezomib loaded polymeric nanoparticles for synergistic cancer therapy. European Polymer Journal. ISSN 0014-3057. 93, p. 116–131. doi: 10.1016/j.eurpolymj.2017.05.036. Full text in Research Archive
• Smistad, Gro; Nyström, Bo; Zhu, Kaizheng; Grønvold, Marte; Røv-Johnsen, Anne & Hiorth, Marianne (2017). Liposomes coated with hydrophobically modified hydroxyethyl cellulose: Influence of hydrophobic chain length and degree of modification. Colloids and Surfaces B: Biointerfaces. ISSN 0927-7765. 156, p. 79–86. doi: 10.1016/j.colsurfb.2017.04.061. Full text in Research Archive Show summary

  Nanoparticulate systems with an uncharged hydrophilic surface may have a great potential in mucosal drug delivery. In the present study liposomes were coated with hydrophobically modified hydroxyethyl cellulose (HM-HEC) to create a sterically stabilized liposomal system with an uncharged surface. The aim was to clarify the influence of the amount of hydrophobic modification of HEC and the length of the hydrophobic moiety, on the stability of the system and on the release properties. HM-HEC with different degrees of hydrophobic modification (1 and 2 mol%) and hydrophobic groups with different chain lengths (C8, C12, C16) were included in the study, as well as fluid phase and gel phase liposomes. Both types of liposomes were successfully coated with HM-HEC containing 1 mol% of hydrophobic groups, while 2 mol% did not work for the intended pharmaceutical applications. The polymer coated gel phase liposomes were stable (size, zeta potential, leakage) for 24 weeks at 4 °C, with no differences between the C8 and C16 HM-HEC coating. For the fluid phase liposomes a size increase was observed after 24 weeks at 4 °C for all formulations; the C8 HM-HEC coated liposomes increased the most. No differences in the leakage during storage at 4 °C or in the release at 35 °C were observed between the fluid phase formulations. To conclude; HM-HEC with a shorter hydrophobic chain length resulted in a less stable product for the fluid phase liposomes, while no influence of the chain length was observed for the gel phase liposomes (1 mol% HM).

• Khorshid, Neda Kahmed; Zhu, Kaizheng; Knudsen, Kenneth Dahl; Bekhradnia, Sara; Sande, Sverre Arne & Nyström, Bo (2016). Novel Structural Changes during Temperature-Induced Self-Assembling and Gelation of PLGA-PEG-PLGA Triblock Copolymer in Aqueous Solutions. Macromolecular Bioscience. ISSN 1616-5187. 16(12), p. 1838–1852. doi: 10.1002/mabi.201600277. Full text in Research Archive
• Dashtimoghadam, Erfan; Bahlakeh, Ghasem; Salimi-Kenari, Hamed; Hasani-Sadrabad, Mohammad Mahdi; Mirzadeh, Hamid & Nyström, Bo (2016). Rheological Study and Molecular Dynamics Simulation of Biopolymer Blend Thermogels of Tunable Strength. Biomacromolecules. ISSN 1525-7797. 17(11), p. 3474–3484. doi: 10.1021/acs.biomac.6b00846. Full text in Research Archive
• Claro, Barbara; Zhu, Kaizheng; Fam, Shahla Bagheri; Silva, Sandra G.; Griffiths, Gareth Wyn & Knudsen, Kenneth [Show all 8 contributors for this article] (2016). Phase behavior, microstructure and cytotoxicity in mixtures of a charged triblock copolymer and an ionic surfactant. European Polymer Journal. ISSN 0014-3057. 75, p. 461–473. doi: 10.1016/j.eurpolymj.2016.01.018. Full text in Research Archive
• Mirsharghi, Sahar; Knudsen, Kenneth; Fam, Shahla Bagheri; Nyström, Bo & Boas, Ulrik (2016). Preparation and self-assembly of amphiphilic polylysine dendrons. New Journal of Chemistry. ISSN 1144-0546. 40(4), p. 3597–3611. doi: 10.1039/c5nj02690c. Full text in Research Archive
• Pamies, Ramon Francisco Porras; Zhu, Kaizheng; Kjøniksen, Anna-Lena & Nyström, Bo (2016). Temperature effects on the stability of gold nanoparticles in the presence of a cationic thermoresponsive copolymer. Journal of nanoparticle research. ISSN 1388-0764. 18(11). doi: 10.1007/s11051-016-3627-3. Full text in Research Archive
• Plazzotta, Beatrice; Diget, Jakob Stensgaard; Zhu, Kaizheng; Nyström, Bo & Pedersen, Jan Skov (2016). Small-Angle X-ray Scattering as a Useful Supplementary Technique to Determine Molecular Masses of Polyelectrolytes in Solution. Journal of Polymer Science Part B: Polymer Physics. ISSN 0887-6266. 54, p. 1913–1917. doi: 10.1002/polb.24107. Full text in Research Archive
• Fam, Shahla Bagheri; Griffiths, Gareth Wyn; Mælandsmo, Gunhild; Nyström, Bo; Hasirci, Vasif & Hasirci, Nesrin (2015). Poly(sebacic anhydride) nanocapsules as carriers: effects of preparation parameters on properties and release of doxorubicin. Journal of Microencapsulation. ISSN 0265-2048. 32(2), p. 166–174. doi: 10.3109/02652048.2014.973073. Full text in Research Archive
• Calejo, Maria Teresa Rebelo; Hasirci, Nesrin; Fam, Shahla Bagheri; Lund, Reidar & Nyström, Bo (2015). Stimuli-responsive structures from cationic polymers for biomedical applications. RSC Polymer Chemistry Series. ISSN 2044-0790. 2015-January(13), p. 149–177. doi: 10.1039/9781782620105-00149. Full text in Research Archive
• Bekhradnia, Sara; Iram, Naz; Lund, Reidar; Effenberg, Christiane; Appelhans, Dietmar & Sande, Sverre Arne [Show all 7 contributors for this article] (2015). Characterization of oligosaccharide-functionalized hyperbranched poly(ethylene imine) and their complexes with retinol in aqueous solution. Journal of Colloid and Interface Science. ISSN 0021-9797. 458, p. 178–186. doi: 10.1016/j.jcis.2015.07.042. Full text in Research Archive
• Kahnamouei, Farinaz; Zhu, Kaizheng; Lund, Reidar; Knudsen, Kenneth Dahl & Nyström, Bo (2015). Self-assembly of a hydrophobically end-capped charged amphiphilic triblock copolymer: effects of temperature and salinity. RSC Advances. 5(58), p. 46916–46927. doi: 10.1039/c5ra07657a. Full text in Research Archive
• Laskookalayeh, Golnaz Isapour; Lund, Reidar; Zhu, Kaizheng; Quan, Zhilong; Knudsen, Kenneth Dahl & Nyström, Bo (2015). Schizophrenic micellization in aqueous solutions of the pH- and temperature responsive pentablock terpolymer PDEAEMAx-b- PNIPAAMy-b-PEGz-b-PNIPAAMy-b-PDEAEMAx. European Polymer Journal. ISSN 0014-3057. 70, p. 79–93. doi: 10.1016/j.eurpolymj.2015.07.007. Full text in Research Archive
• Ciepluch, Karol; Nyström, Bo; Appelhans, Dietmar; Zablocka, M.; Bryszewska, Malgorzata Anita & Majoral, JP (2015). Effect of dendritic polymers on a simple model biological membrane. Journal of polymer research. ISSN 1022-9760. 22(9). doi: 10.1007/s10965-015-0825-0. Full text in Research Archive
• Fam, Shahla Bagheri; Skjeldal, Frode Miltzow; Griffiths, Gareth Wyn; Mælandsmo, Gunhild; Engebråten, Olav & Nyström, Bo [Show all 8 contributors for this article] (2015). pH-Responsive Nano Carriers for Doxorubicin Delivery. Pharmaceutical Research. ISSN 0724-8741. 32(4), p. 1249–1263. doi: 10.1007/s11095-014-1530-0. Full text in Research Archive
• Ayoubi, Mehran Asad; Almdal, Krisrtoffer; Zhu, Kaizheng; Nyström, Bo; Olsson, Ulf & Piculell, Lennart (2015). Self-assembly of block copolymer-based ionic supramolecules based upon multi-tail amphiphiles. RSC Advances. 5, p. 31091–31103. Full text in Research Archive
• Bekhradnia, Sara; Diget, Jakob Stensgaard; Zinn, Thomas; Zhu, Kaizheng; Sande, Sverre Arne & Nyström, Bo [Show all 7 contributors for this article] (2015). Charged star diblock copolymers in dilute solutions: Synthesis, structure, and chain conformations. Macromolecules. ISSN 0024-9297. 48(8), p. 2637–2646. doi: 10.1021/ma502488u. Full text in Research Archive
• Kjøniksen, Anna-Lena; Calejo, Maria Teresa Rebelo; Zhu, Kaizheng; Nyström, Bo & Sande, Sverre Arne (2015). Stabilization of Pluronic Gels by Hydrophobically Modified Hydroxyethylcellulose. International Journal of Polymeric Materials and Polymeric Biomaterials. ISSN 0091-4037. 64(2), p. 76–83. doi: 10.1080/00914037.2014.886245. Full text in Research Archive
• Lyngsø, Jeppe; Al-Manasir, Nodar; Behrens, Manja Annette; Zhu, Kaizheng; Kjøniksen, Anna-Lena & Nyström, Bo [Show all 7 contributors for this article] (2015). Small-Angle X-ray Scattering Studies of Thermoresponsive Poly(N-isopropylacrylamide)Star Polymers in Water. Macromolecules. ISSN 0024-9297. 48(7), p. 2235–2243. doi: 10.1021/acs.macromol.5b00057. Full text in Research Archive
• Momtazi, Leva; Fam, Shahla Bagheri; Singh, Gurvinder; Hofgaard, Antje; Hakkarainen, Minna & Glomm, Wilhelm [Show all 10 contributors for this article] (2014). Synthesis, characterization, and cellular uptake of magnetic nanocarriers for cancer drug delivery. Journal of Colloid and Interface Science. ISSN 0021-9797. 433, p. 76–85. doi: 10.1016/j.jcis.2014.07.013. Full text in Research Archive Show summary

  Hypothesis The absence of targetability is the primary inadequacy of conventional chemotherapy. Targeted drug delivery systems are conceptualized to overcome this challenge. We have designed a targetable magnetic nanocarrier consisting of a superparamagnetic iron oxide (SPIO) core and biocompatible and biodegradable poly(sebacic anhydride)-block-methyl ether poly(ethylene glycol) (PSA-mPEG) polymer shell. The idea is that this type of carriers should facilitate the targeting of cancer cells.

• Fenaroli, Federico; Westmoreland, David; Benjaminsen, Jørgen; Kolstad, Terje R Selnes; Skjeldal, Frode Miltzow & Meijer, Annemarie H. [Show all 12 contributors for this article] (2014). Nanoparticles as Drug Delivery System against Tuberculosis in Zebrafish Embryos: Direct Visualization and Treatment. ACS Nano. ISSN 1936-0851. 8(7), p. 7014–7026. doi: 10.1021/nn5019126. Full text in Research Archive
• Cardoso, Ana Maria S.; Calejo, Maria Teresa Rebelo; Morais, Catarina M.; Cardoso, Ana Luisa; Cruz, Rita & Zhu, Kaizheng [Show all 9 contributors for this article] (2014). Application of thermoresponsive PNIPAAM-b-PAMPTMA diblock copolymers in siRNA delivery. Molecular Pharmaceutics. ISSN 1543-8384. 11(3), p. 819–827. doi: 10.1021/mp400510a. Full text in Research Archive
• Calejo, Maria Teresa Rebelo; Kjøniksen, Anna-Lena; Maleki, Atoosa; Nyström, Bo & Sande, Sverre Arne (2014). Microparticles based on hydrophobically modified chitosan as drug carriers. Journal of Applied Polymer Science. ISSN 0021-8995. 131(7). doi: 10.1002/app.40055. Full text in Research Archive
• Ulanova, Lilia; Laskookalayeh, Golnaz Isapour; Maleki, Atoosa; Fanaian, Shirin; Zhu, Kaizheng & Hofgaard, Antje [Show all 10 contributors for this article] (2014). Development of methods for encapsulation of viruses into polymeric nano- and microparticles for aquaculture vaccines. Journal of Applied Polymer Science. ISSN 0021-8995. 131(17), p. 8785–8796. doi: 10.1002/app.40714. Full text in Research Archive
• Ayoubi, Mehran Asad; Almdal, Kristoffer; Zhu, Kaizheng; Nyström, Bo; Olsson, Ulf & Piculell, Lennart (2014). Lamellar Microdomains of Block-Copolymer-Based Ionic Supramolecules Exhibiting a Hierarchical Self-Assembly. Macromolecules. ISSN 0024-9297. 47(10), p. 3428–3435. doi: 10.1021/ma500232y. Full text in Research Archive
• Bekhradnia, Sara; Zhu, Kaizheng; Knudsen, Kenneth Dahl; Sande, Sverre Arne & Nyström, Bo (2014). Structure, swelling, and drug release of thermoresponsive poly(amidoamine) dendrimer-poly(N-isopropylacrylamide) hydrogels. Journal of Materials Science. ISSN 0022-2461. 49(17), p. 6102–6110. doi: 10.1007/s10853-014-8340-y. Full text in Research Archive
• Kjøniksen, Anna-Lena; Calejo, Maria Teresa Rebelo; Zhu, Kaizheng; Nyström, Bo & Sande, Sverre Arne (2014). Stabilization of Pluronic Gels in the Presence of Different Polysaccharides. Journal of Applied Polymer Science. ISSN 0021-8995. 131(13). doi: 10.1002/app.40465. Full text in Research Archive
• Dashtimoghadam, Erfan; Mirzadeh, Hamid; Taromi, Faramarz Afshar & Nyström, Bo (2014). Thermoresponsive biopolymer hydrogels with tunable gel characteristics. RSC Advances. 4(74), p. 39386–39393. doi: 10.1039/c4ra05246c. Full text in Research Archive
• Behrens, Manja Annette; Lopez, Montse; Kjøniksen, Anna-Lena; Zhu, Kaizheng; Nyström, Bo & Pedersen, Jan Skov (2014). The effect of cationic and anionic blocks on temperature-induced micelle formation. Journal of Applied Crystallography. ISSN 0021-8898. 47, p. 22–28. doi: 10.1107/S1600576713030033. Full text in Research Archive
• Kjøniksen, Anna-Lena; Calejo, Maria Teresa Rebelo; Zhu, Kaizheng; Cardoso, Ana Maria S.; Lima, Maria C. Pedroso de & Jurado, Amália S. [Show all 8 contributors for this article] (2014). Sustained release of naltrexone from poly(N-isopropylacrylamide) microgels. Journal of Pharmaceutical Sciences. ISSN 0022-3549. 103(1), p. 227–234. doi: 10.1002/jps.23780. Full text in Research Archive
• Calejo, Maria Teresa Rebelo; Cardoso, Ana Maria S.; Kjøniksen, Anna-Lena; Zhu, Kaizheng; Morais, Catarina M. & Sande, Sverre Arne [Show all 10 contributors for this article] (2013). Temperature-Responsive Cationic Block Copolymers as Nanocarriers for Gene Delivery. International Journal of Pharmaceutics. ISSN 0378-5173. 448(1), p. 105–114. doi: 10.1016/j.ijpharm.2013.03.028. Full text in Research Archive
• Dashtimoghadam, Erfan; Mirzadeh, Hamid; Taromi, Faramarz Afshar & Nyström, Bo (2013). Microfluidic self-assembly of polymeric nanoparticles with tunable compactness for controlled drug delivery. Polymer. ISSN 0032-3861. 54(18), p. 4972–4979. doi: 10.1016/j.polymer.2013.07.022. Full text in Research Archive

View all works in NVA

• Nyström, Bo (2018). Self-assembling of charged copolymers and formation of intricate nanostructures. Full text in Research Archive
• Nyström, Bo (2017). Structural and Rheological Properties of Temperature-Responsive Amphiphilic Triblock Copolymers in Aqueous Media. Full text in Research Archive
• Nyström, Bo (2017). Self-assembling and formation of nanostructures for medical applications. Full text in Research Archive
• Nyström, Bo (2017). Small-angle scattering (SAS) in the study of supramolecular structures and polymers. Full text in Research Archive
• Nyström, Bo (2016). Adsorption and polyelectrolyte bridging of amphiphilic polymers and copolymers onto planar and curved surfaces. Full text in Research Archive
• Nyström, Bo (2016). Novel structural changes during temperature-induced self-assembling and gelation of PLGA-PEG-PLGA triblock copolymer in aqueous solutions. Full text in Research Archive
• Nyström, Bo (2016). Self-Assembled Structures of Polymers for Medical Applications. Full text in Research Archive
• Nyström, Bo (2016). Self-Assembled Structures of Polymers and Formation of Nanoparticles for Medical Applications. Full text in Research Archive
• Nyström, Bo (2016). Rheological and Scattering Techniques in the Study of Self-Assembling Polymeric Systems and Hydrogels. Full text in Research Archive
• Nyström, Bo (2015). Rheological and Scattering Techniques in the Study of Specially Designed Aqueous Polymer Systems for drug delivery. Full text in Research Archive
• Nyström, Bo (2015). Rheological and Scattering Techniques in the Study of Self-Assembling in Polymeric Systems and Hydrogels. Full text in Research Archive
• Nyström, Bo; Bekhradnia, Sara; Naz, Iram; Lund, Reidar; Appelhans, Dietmar & Sande, Sverre Arne (2015). Structural features of maltose-functionalized hyperbranched poly(ethylene imine) and their complexes. Full text in Research Archive
• Kjøniksen, Anna-Lena; Pamies, Ramon Francisco Porras; Al-Manasir, Nodar; Zhu, Kaizheng & Nyström, Bo (2015). Thermoresponsive Poly(N-Isopropylacrylamide) Star Polymers. Full text in Research Archive
• Alvi, Muhhamad Awais Ashfaq; Bandyopadhyay, Sulalit; Zhu, Kaizheng; Nyström, Bo & Glomm, Wilhelm (2015). Controlled Release from Nanoparticles (NPs) for Theranostic Applications. Full text in Research Archive
• Nyström, Bo (2014). Self-Assembled Structures of Specially designed Nanoparticles. Full text in Research Archive
• Nyström, Bo (2014). Physico-chemical aspects of polymers at molecular level. Full text in Research Archive
• Nyström, Bo (2014). Scattering Methods in the Study of Polymer Systems. Full text in Research Archive
• Nyström, Bo (2014). Self-Assembled Polymeric Nanostructures for Medical Applications. Full text in Research Archive
• Nyström, Bo (2014). Self-Assembled Structures of Polymers and Formation of Nanoparticles in Aqueous Solutions. Full text in Research Archive
• Nyström, Bo (2014). Stability of Charged Nanostructures. Full text in Research Archive
• Nyström, Bo (2013). Self-Assembled Structures of Responsive Polymers and Nanoparticles in Aqueous Solutions, Marie Curie Workshop in Aarhus. Full text in Research Archive
• Nyström, Bo (2013). Intensity and Dynamic Light Scattering Methods in the Study of Polymer Systems, Marie Curie Workshop in Aarhus, Denmark. Full text in Research Archive
• Kjøniksen, Anna-Lena; Calejo, Maria Teresa Rebelo; Zhu, Kaizheng; Sande, Sverre Arne; Nyström, Bo & Cardoso, Ana Maria S. [Show all 10 contributors for this article] (2013). Temperature-Responsive Polymers as Nanocarriers for Gene Delivery. Full text in Research Archive
• Nyström, Bo (2013). Presentation of the Polymer Research Group in Oslo. Full text in Research Archive
• Nyström, Bo (2013). Rheological properties of complex fluids and gels. Full text in Research Archive
• Diget, Jakob Stensgaard; Nyström, Bo & Lund, Reidar (2022). In Pursuit of Well-Defined Organic Polymers - Controlled Synthesis and Accurate Characterization. Department of Chemistry, Faculty of Mathematics and Natural Sciences, University of Oslo. Full text in Research Archive Show summary

  Polymers are large (macro) molecules consisting of parts, or repeating units. The immense importance is reflected by the action of polynucleotides, e.g., DNA and RNA. As a result of their perfectly defined molecular structure, they direct the synthesis of all organic life forms. Well-defined synthetic polymers are gaining traction in fields such as biomedical science and the coatings industry, where their specific properties lead to more sophisticated materials. Not surprisingly, some of the most daunting and prestigious goals of polymer chemists, are to control the polymer molecular structure via synthesis and establish structure-property relationships. In this thesis, focus is on functional polyelectrolytes (charged chains) and polysaccharides (sugar chains), for potential use in biomedical science where specific and predictable properties are important. For the polymers in question, however, there is a lack of reliable controlled synthesis procedures and accurate characterization methods. The primary objective of the studies presented in this thesis has therefore been to establish such procedures and methods. As a secondary objective, specific scenarios (e.g., self-assembly and response to stimuli) have been investigated, and structure-property relationships thus elucidated. These new procedures and studies are expected to aid researchers in obtaining well-defined polymers with specific and predictable properties that may be used in, e.g., imaging, drug - and gene delivery systems, to combat diseases such as cancer.

• Motlaq, Vahid Forooqi; Nyström, Bo & Bagherifam, Shahla (2017). Effect of PEGylation on Physical and Biological Behavior of Temperature-Responsive Nanogels. Universitetet i Oslo. Full text in Research Archive
• Gjerde, Natalie; Nyström, Bo & Medel, Sandra (2017). Dynamical and Structural Properties of Hydrophobically Modified Pluronic PCL-F127-PCL. Universitetet i Oslo. Full text in Research Archive Show summary

  In this thesis, structural and dynamic features of thermoresponsive amphiphilic pentablock copolymers have been studied for their potential use for drug delivery application. The copolymers are amphiphilic poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO), also known as Pluronic, modified with hydrophobic poly(caprolactone) (PCL) to give the pentablock terpolymer PCL-PEO-PPO-PEO-PCL (PCLn-Pluronic-PCLn). The effects of the PCL length (n = 5 and 11) on the self-assembly properties of PCL-Pluronic-PCL in aqueous solutions have been investigated at various temperatures and both in the dilute and the semidilute concentration regimes. Turbidity measurements revealed a lower critical solution temperature, where the cloud point decreased with PCL length. Through dynamic light scattering (DLS) measurements, the polymers were found to form a mixture of micelles and intermicellar aggregates. A longer PCL length resulted in larger intermicellar aggregates. Small angle neutron scattering (SANS) measurements revealed that the polymers with a short PCL length formed spherical flower-like micelles, whereas the polymers with a long PCL length formed elongated cylindrical micelles. In the semidilute concentration region, the polymers form thermoreversible hydrogels at elevated temperatures. The gel window in the phase diagrams for these polymers greatly depends on the PCL length, where a longer PCL length decreases the concentration and temperature needed for gelation. The dynamic properties of the gels were characterized by rheology. SANS measurements revealed a tight ordering of the micelles in these systems, and demonstrated interesting conformational differences between the systems.

• Momtazi, Leva; Nyström, Bo & Bagherifam, Shahla (2014). Synthesis and Characterization of Magnetic Nanocarriers for Cancer Drug Delivery. Universitetet i Oslo. Full text in Research Archive
• Kahnamouei, Farinaz; Nyström, Bo & Lund, Reidar (2014). Effects of Temperature and Salt Addition on the Self-assembling Behavior of a Hydrophobically End-capped Charged Amphiphilic Triblock Copolymer. Universitetet i Oslo. Full text in Research Archive Show summary

  In this study, association properties of aqueous solutions of anionic thermo-responsive hydrophobically end-capped amphiphilic triblock terpolymer n-octadecyl-poly(ethylene glycol)-poly(N-isopropyl acrylamide)-block-poly(2-acrylamido- 2-methyl-1-propanesulfonic sodium), abbreviated as C18-PEG10-b-PNIPAAm54-b-PAMPS10, have been studied by means of zeta potential measurements, turbidimetry, dynamic light scattering (DLS), densitometry and small angle light scattering (SANS) at various temperatures, polymer concentrations, and salinities. This polymer exhibits lower critical solution temperature (LCST) owing to its PNIPAAm block. Increasing the ionic strength of the aqueous solutions leads to a decrease in the cloud point (CP) of the solutions which is an indication of enhanced aggregation due to the screening of Coulomb repulsions. The dynamic light scattering (DLS) data gives a detailed information about the interactions between intra-chain and inter-chain associations. The zeta-potential is augmented through temperatures due to increase in charge density. The effect of ionic strength induced by adding different amounts of NaCl on solutions of the applied triblock terpolymer has been examined by means of turbidimetry, dynamic light scattering , densitometry and small angle neutron scattering (SANS). By increasing the amount of added salt, the electrostatic interactions are screened out and increasing the temperature promotes the formation of large aggregates. It has been demonstrated by turbidimetry experiments that CP is depressed when the ionic strength is increased. The results from DLS and SANS also confirm that higher salt concentration result in the formation of large aggregates at elevated temperatures.

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