A facile method to obtain hydrophilic-hydrophobic hyaluronic acid- polylactic acid bilayer films

Fostering cell attachment is essential for tissue engineering. However, unwanted cellular interactions increase the risk of post-operative adhesions which can hinder tissue regeneration. Thus, cell-adhesion-promoting and cell-adhesion-inhibitory functions need to be regulated simultaneously. We develop a stably joined bilayer film composed of a thin polylactic acid film (cell interactive side) obtained by solvent casting coated with hyaluronic acid (cell antifouling side) crosslinked with divinyl sulphone, seeking to reduce post-operative adhesions after surgery. Both layers were bonded together by a biocompatible nitrocellulose-base adhesive forming a long-term stable bilayer due to the reaction between their chemical groups and the formation of a semi-interpenetrating polymeric network on the amorphous regions of the polylactic acid film. A thorough physicochemical characterisation (morphology, composition, swelling ratio and stability) of this novel type of scaffold was carried out to ensure a comprehensive understanding of its structural properties and performance characteristics. Schwann cell culture on the bilayer film proved that the polylactic acid surface was cell-friendly and promoted cell attachment and proliferation whereas the hyaluronic acid surface prevented initial cell adhesion. [Display omitted]