Influence of PEG‐PLGA nanoparticles on the pore structure of injectable and self‐healing hydrogels based on carboxymethyl chitosan/aldehyde sodium hyaluronate for prolonged sustained release of valsartan

Abstract Valsartan is almost insoluble, resulting in very low bioavailability. Preparing prolonged sustained‐release systems to achieve valsartan drug delivery is essential. Herein, two types of poly(ethylene glycol)‐b‐poly(lactide‐co‐glycolide) (PEG‐PLGA) nanoparticles loading valsartan and carboxymethyl chitosan/aldehyde sodium hyaluronate hydrogels were prepared. The nanoparticles and hydrogel composites(NPs@Gel) were obtained by physical mixing. The NPs@Gel composites have swelling ratios within the scope from 157.87% to 206.51% and mass loss within the scope from 12.85% to 17.32%, influenced by incorporating PEG‐PLGA nanoparticles. Moreover, the NPs@Gel composites had properties of self‐healing and injection proven by rheological measurements. Importantly, adding nanoparticles could significantly reduce the swelling ratios of the hydrogels by shrinking the void fraction and enhancing the mechanical properties. Meanwhile, NPs@Gel composites also present excellent biocompatibility as evidenced by hemolysis test and MTT assay. Therefore, a potential prolonged sustained‐release system of NPs@Gel for the delivery of valsartan was achieved.