Effects of soft segment characteristics on the properties of biodegradable amphiphilic waterborne polyurethane prepared by a green process

Traditional 3D printing materials are not suitable for tissue engineering due to their toxicity, low degradability and poor biocompatibility. In this study, a new amphiphilic biodegradable waterborne polyurethane (WBPU) was developed by a green and sustainable process without any organic solvents, catalysts or cross-linkers. The soft segments of this kind of WBPU were formed by replacing hydrophobic poly(ε-caprolactone) diol with hydrophilic poly(ethylene glycol) (PEG). Different block lengths of PEG were used for this purpose. The combination of ester and ether groups endowed WBPU with amphiphilic characteristics, which is important for regeneration and maintenance of tissue. The effects of composition and content of soft segments on the phase separation, thermal properties, mechanical properties, water absorption, biodegradability and cytotoxicity of WBPU were investigated. The results showed that the desired properties of WBPU could be achieved by tuning the block length of PEG and content of soft segments. The present work provided a new approach to prepare WBPUs with amphiphilic and biodegradable characteristics, which are promising candidates for 3D printing materials for tissue engineering scaffolds.