Dual pH- and thermal-responsive nanocomposite hydrogels for controllable delivery of hydrophobic drug baicalein: Dual pH- and thermal-responsive nanocomposite hydrogels

Hydrogels have been widely used as mild biomaterials due to their bio-affinity, high drug loading capability and controllable release profiles. However, hydrogel-based carriers are greatly limited for the delivery of hydrophobic payloads due to the lack of hydrophobic binding sites. Herein, nano-liposome micelles were embedded in semi-interpenetrating poly[(N-isopropylacrylamide)-co-chitosan] (PNIPAAm-co-CS) and poly[(N-isopropylacrylamide)-co-(sodium alginate)] (PNIPAAm-co-SA) hydrogels which were responsive to both temperature and pH, thereby establishing tunable nanocomposite hydrogel delivery systems. Nano-micelles formed via the self-assembly of phospholipid could serve as the link between hydrophobic drug and hydrophilic hydrogel due to their special amphiphilic structure. The results of transmission and scanning electron microscopies and infrared spectroscopy showed that the porous hydrogels were successfully fabricated and the liposomes encapsulated with baicalein could be well contained in the network. In addition, the experimental results of response release in vitro revealed that the smart hydrogels showed different degree of sensitiveness under different pH and temperature stimuli. The results of the study demonstrate that combining PNIPAAm-co-SA and PNIPAAm-co-CS hydrogels with liposomes encapsulated with hydrophobic drugs is a feasible method for hydrophobic drug delivery and have potential application prospects in the medical field. (c) 2018 Society of Chemical Industry