Collagen matrices containing poly(vinyl alcohol) microcapsules with retinyl palmitate – Structure, stability, mechanical and swelling properties

The aim of this study was to obtain and investigate new materials for cosmetic or dermatological applications. Microcapsules typically have a particle size from 1 to 1000 μm in diameter and they consist of an inner core containing an active agent, covered by a layer of polymer. Encapsulation technology have been used for improving the long-term stability of active substances and enhancing and prolonging the effectiveness of active ingredients. Microcapsules were obtained by coacervation/cross-linking method. The core was made of retinyl palmitate and was coated with poly(vinyl alcohol). In the next step, different quantities of microcapsules were incorporated into polymer matrices, which were prepared from collagen isolated from fish scales of Esox lucius in our laboratory. Polymer matrices were cross-linked with EDC/NHS (1-ethyl-3(3-dimethylaminopropyl) carbodiimide/N-hydroxysuccinimide) mixture. The Scanning Electron Microscopy confirmed the porous structure of the obtained materials with the presence of microcapsules. The highest values of Young's modulus were observed for the collagen matrices with incorporated larger amount of PVA microcapsules. All the matrices had high swelling properties. Based on the analysis, it was found that collagen matrices with incorporated retinyl palmitate-loaded PVA microcapsules are a promising material for the cosmetic or pharmaceutical industry.