| Abstract
Introduction: Stimuli-responsive hydrogels,
which indicate a significant response to the
environmental change (e.g., pH, temperature,
light, …), have potential applications for
tissue engineering, drug delivery systems, cell
therapy, artificial muscles, biosensors, etc.
Among the temperature-responsive materials,
poly (N-isopropylacrylamide) (PNIPAAm)
based hydrogels have been widely developed
and their properties can be easily tailored by
manipulating the properties of the hydrogel
and the composite material. Graphene oxide (GO), as a multifunctional and biocompatible
nanosheet, can efficiently improve the mechanical strength and response rate of PNIPAAmbased
hydrogels. Here, hydrogel composites (HCs) of PNIPAAm with GO was developed using
the modified starch as a biodegradable cross-linker.
Methods: Micro/nanohydrogel composites were synthesized by free radical polymerization of
NIPAAm in the suspension of different feed ratio of GO using maleate-modified starch (St-
MA) as cross-linker and Tetrakis (hydroxymethyl) phosphonium chloride (THPC) as a strong
oxygen scavenger. The HCs were characterized by FT-IR, DSC, TGA, SEM, and DLS. Also, the
phase transition, swelling/deswelling behavior, hemocompatibility and biocompatibility of the
synthesized HCs were investigated.
Results: The thermal stability, phase transition temperature and internal network crosslinking
of HCs increases with increasing of the GO feed ratio. Also, the swelling/deswelling, hemolysis,
and MTT assays studies confirmed that the HCs are a fast response, hemocompatible and
biocompatible materials.
Conclusion: The employed facile approach for the synthesis of HCs yields an intelligent material
with great potential for biomedical applications. |