Liposomes Entrapped in Biopolymer Hydrogels Can Spontaneously Release into the External Solution

• DOI: 10.1021/acs.langmuir.0c00596
• Publication Date: 2020-06-16T14:43:06Z
• Authors: Benjamin R. Thompson; Brady C. Zarket; E. Hunter Lauten; Samiul Amin; Sivaramakrishnan ...; Srinivasa R. Ragh...
• Keywords: Biopolymer; Gelatin; Agarose; Aqueous two-phase system

Hydrogels of biopolymers such as agar and gelatin are widely used in many applications, cases, the gels loaded with nanoparticles. The polymer chains these cross-linked by physical bonds into three-dimensional networks, mesh size networks typically being 10–100 nm. One class "soft" nanoparticles liposomes, which have an aqueous core surrounded a lipid bilayer. Solutes encapsulated liposomal can be delivered externally over time. In this paper, we create liposomes diameters ∼150 nm from unsaturated phospholipid (lecithin) embed them (the phase also contains 0–50% glycerol, is active ingredient cosmetic products). Upon placing gel quiescent water, find that release out water period 1–3 days, even though remains intact. This surprising result runs contrary to our expectation would simply remain immobilized gel. We show rate tuned several variables: for example, increases concentration lowered steadily temperature. addition agar, occurs other including those agarose gelatin. However, made saturated do not any gels. discuss possible mechanism release, involves intact deforming squeezing through transient large pores arise agar. Our findings relevance transdermal delivery: they suggest possibility systematically delivering actives matrix.