Highly porous tissue scaffolds based on cyclic acetals with tunable hydrophilicity and degradation behavior

Biodegradable cyclic acetal-based porous scaffolds without acidic by-products upon hydrolytic degradation are very promising in tissue engineering. However, most cyclic acetal based crosslinked polymer networks mainly utilized (meth) acrylates as reactive moieties for crosslinking. Development of cyclic acetal based crosslinked polymer networks without (meth) acrylate terminal groups and fabrication of cyclic acetal based high-porous scaffolds are still challenging. In this study, a novel cyclic acetal monomer with carbonic acid allyl ester terminal groups was synthesized and a series of high-porous scaffolds with tunable swelling ability and degradation rate were fabricated by thiol-ene photopolymerization combined with low-temperature phase-separation method. The obtained scaffolds exhibited high porosity of 78%-89%. The average pore size and porosity of porous scaffolds increased with the increase of solvent content during scaffold fabrication. The introduction of PEG chains into scaffolds had a slight influence on the pore size, but can significantly enhance the swelling ability and hydrolytic degradation rate of resulted scaffolds. MTT assay and cell adhesion experiments indicated that the scaffolds are non-toxic toward L929 cells and had good in vitro biocompatibility. The proposed cyclic acetal based high porous scaffolds with tunable hydrophilicity and degradation behavior have great potential in tissue engineering application.

Automated summary

A novel cyclic acetal monomer with carbonic acid allyl ester terminal groups was synthesized, and a series of high-porous scaffolds with tunable swelling ability and degradation rate were fabricated using a specific method. The scaffolds showed non-toxicity towards cells and good in vitro biocompatibility, suggesting great potential in tissue engineering applications.