Joseph Azumah

• Azumah, Joseph; Vasilic, Danijela; Smistad, Gro & Hiorth, Marianne (2025). Preparation of sodium hyaluronate coated liposomes: effect of polymer molecular weight, coating concentration, amount of charged lipids and type of hydration medium on the stability. Journal of liposome research. ISSN 0898-2104. 35(2), s. 159–172. doi: 10.1080/08982104.2025.2456194. Fulltekst i vitenarkiv Vis sammendrag

  In this study, liposomes consisting of soybean phosphatidyl choline (SoyPC) and different molar concentrations (10 mol% and 20 mol%) of dioleoyl trimethylammoniumpropane (DOTAP) were prepared by the thin film hydration method and coated with sodium hyaluronate (NaHA) of different MWs (8–15 kDa, 30–50 kDa and 90–130 kDa) and concentrations (0.01–0.2% w/w) using phosphate buffer (PB) or glycerol phosphate buffer (G-PB) as the hydration medium. These NaHA coated liposomes could have a potential in the treatment of dry mouth since glycerol and NaHA are known for their lubricating and hydrating properties. The liposomes composed of SoyPC-DOTAP 20 mol%, and coated with NaHA MW 90–130 kDa, 0.05% w/w were found to be most stable during storage. The liposomes with 20 mol% DOTAP coated with NaHA MW 30–50 kDa, 0.05% w/w showed promising results as these stayed stable for at least two weeks. However, the liposomes coated with NaHA MW 8–15 kDa were generally unstable irrespective of the combinations of the investigated parameters. When the stable liposomes were introduced into artificial saliva (AS), aggregation rapidly occurred. Sodium alginate (NaAlg) coated liposomes that were prepared for comparison were found to be stable in AS. The study has demonstrated the influence of the amount of charged lipid which must be high, the polymer MW which must lay in the area 30 kDa-130 kDa and coating concentration which should be intermediate 0.05% w/w in preparing stable NaHA coated liposomes. Further studies need to be conducted to understand the instability exhibited by the NaHA coated liposomes in AS.

• Azumah, Joseph; Smistad, Gro & Hiorth, Marianne (2022). Preparation of stable polymer-liposome complexes by a novel approach employing a one-pot method. Colloids and Surfaces A: Physicochemical and Engineering Aspects. ISSN 0927-7757. 653. doi: 10.1016/j.colsurfa.2022.129924. Fulltekst i vitenarkiv Vis sammendrag

  The purpose of this study was to prepare stable polymer-liposome complexes using a new, improved one-pot method. Complexes prepared by the conventional method were used as reference. The one-pot method combines the vesicle formation and complexation with the polymer in a single step allowing for fewer steps compared to the conventional thin-film method followed by coating. This has the possibility of complexing the polymer on the surface and within the aqueous core of the liposomes. Soya phosphatidylcholine (SoyPC) in combination with different amounts of either dioleoyl trimethylammoniumpropane (DOTAP, positively charged) or egg phosphatidylglycerol (Egg PG, negatively charged) were complexed with alginate or chitosan, respectively. All the alginate-liposome complexes were larger compared to the naked liposomes and the zeta potential changed from positive to negative after complexation with the polymer. Polydispersity index (PDI) analysis showed narrow size distributions implying homogenous populations. The best stability was obtained by employing 20 mol% DOTAP in the membrane. This formulation was stable during the whole four months period when the stability test was performed. The chitosan-liposome complexes were generally difficult to extrude and were larger than the alginate-liposome complexes due to the need for a larger pore size in the membrane during extrusion. Based on these results, the one-pot method can be used for preparing stable alginate-liposome complexes. For the chitosan-liposome complexes alternative methods for size reduction should be investigated.

Se alle arbeider i NVA

• Hiorth, Marianne; Azumah, Joseph & Smistad, Gro (2019). The potential of polymer-coated liposomes for dental care. Fulltekst i vitenarkiv
• Azumah, Joseph; Hiorth, Marianne; Smistad, Gro & Martinsen, Ørjan Grøttem (2019). Development of alginate and chitosan coated liposomes intended to use in the treatment of xerostomia. Fulltekst i vitenarkiv
• Azumah, Joseph; Hiorth, Marianne; Smistad, Gro & Martinsen, Ørjan Grøttem (2019). Alginate and chitosan coated liposomes intended for treatment of dry mouth. Fulltekst i vitenarkiv
• Azumah, Joseph; Smistad, Gro; Martinsen, Ørjan Grøttem & Hiorth, Marianne (2019). Development of alginate coated liposomes with potential of being used in treatment of dry mouth. Fulltekst i vitenarkiv

Se alle arbeider i NVA