A novel thermo-responsive hydrogel based on salecan and poly(N-isopropylacrylamide): Synthesis and characterization

Salecan is a novel microbial polysaccharide produced by Agrobacterium sp. ZX09. The salt-tolerant strain was isolated from a soil sample in our laboratory and the 16S rDNA sequence was deposited in the GenBank database under the accession number GU810841 . Salecan is suitable to fabricate hydrogel for biomedical applications due to the excellent hydrophilicity and biocompatibility. Here, salecan has been introduced into poly(N-isopropylacrylamide) (PNIPAm) network to form novel thermo-sensitive semi-interpenetrating polymer networks (semi-IPNs). The structure of salecan/PNIPAm semi-IPNs was confirmed by Fourier transformation infrared spectroscopy (FTIR) and X-ray diffraction (XRD). Thermogravimetric analysis (TGA) proved the stability of the semi-IPNs. Rheological and compressive tests revealed an elastic solid-like behavior and good mechanical properties of the hydrogels. Swelling behavior test showed the hydrogels possessed high water content at room temperature. An excellent thermo-sensitive property of fast response rates to temperature had been demonstrated as well. In vitro degradation measurements ensured the semi-IPNs were degradable. Cytotoxicity and cell adhesion study suggested the synthesized salecan/PNIPAm hydrogels were non-toxic and biocompatibility. The results indicated the novel thermo-responsive hydrogels could be a suitable candidate for biomedical applications.