Polysaccharide-based microgels are effective vectors for biopharmaceutics delivery and functional components in tissue engineering due to their bioactivity and biocompatibility. Currently, the synthesis of chemically crosslinked microgels typically requires long reaction times, high energy input and are low yielding due to low volumes of water phase used. Herein, we report the synthesis of norbornene-derivatized chitosan (CS-nbn-COOH), which can undergo rapid gelation in the presence of a thiolated crosslinker through the highly efficient thiol-ene photoclick reaction. This water-soluble photocrosslinkable derivative, synthesized on scale via a single step from native chitosan and commercially available carbic anhydride, represents the first example of a norbornene-functionalised CS to the best of our knowledge. Microgels with controlled cross-linking densities and diameters varying between 100 and 400 nm were obtained via a low energy water-in-oil nano-emulsion templating method at room temperature, with photo-crosslinking initiated in a flow reactor powered with a domestic UV-A lamp, a method that is suitable for scale-up synthesis of the microgels. We also demonstrate that the resulting microgels were non-toxic to human dermofibroblasts (HDF) cell lines and that residual norbornene groups could be reacted in a late stage through tetrazine ligation, highlighting the potential of these microgels as scaffolds for functional nanomaterials with biomedical applications.
- BCS and TECS CDTs