Niosomes encapsulated in biohydrogels for tunable delivery of phytoalexin resveratrol†
A series of biohydrogels based on mixtures of kappa-carrageenan (κ-carrageenan, κ-C) and gelatin were evaluated as potential soft delivery vehicles for the encapsulation and subsequent release of non-ionic surfactant vesicles (niosomes) loaded with resveratrol (RSV). The niosomes were prepared using a mixture of amphiphilic lipids Tween 80 and Span 80 in water. The results showed that RSV-niosomes did not significantly affect the hydrogelation properties of the biopolymer mixture. Moreover, in vitro drug release experiments from biohydrogels containing RSV-niosomes were successfully carried out under simulated gastrointestinal conditions. The RSV-niosomal liberation profiles from hydrogels were fitted using first order kinetics, Higuchi, Korsmeyer–Peppas and Weibull drug release models, showing the prevalence of diffusion mechanisms in each case. In addition, the RSV release was easily tuned by adjusting the total concentration of κ-C : gelatin. Interestingly, the niosomal-hydrogel system was also found to prevent the trans-to-cis photoisomerization of RSV.