Synthesis of thermoresponsive composite hydrogel from Pluronic F127 reinforced by oil palm empty fruit bunches-extracted cellulose for silver sulfadiazine drug delivery

Hydrogels are modern dermal drug-delivery media which can hold a huge amount of water and modify their structure to enable spontaneous response to temperature change and are thus attractive to overcome the limitations of conventional drug-delivery media. In this study, a sustainable method was developed to synthesize thermoresponsive Pluronic F127 (PF127) composite hydrogel reinforced by cellulose extracted from oil palm empty fruit bunches (OPEFBs). The thermoresponsive cellulose/PF127 composite hydrogels were formulated by dissolving OPEFB-extracted cellulose in aqueous sodium hydroxide/urea solution prior to mixing with PF127 polymer at low temperature. The performance of the synthesized thermoresponsive cellulose/PF127 composite hydrogels was evaluated in terms of their swelling ratio, percentage of degradation, and in vitro silver sulfadiazine (AgSD) drug release. PCT20 thermoresponsive cellulose/PF127 composite hydrogel with 20 w/v% PF127 and 3 w/v% OPEFB cellulose showed high mechanical strength (storage modulus and complex viscosity values of 20.90 kPa and 2.09 kPa s, respectively), relatively high swelling ratio (3.63 ± 0.43), and prolonged release of AgSD (t_50% value of 4 h) compared with PCT17-PCT19 thermoresponsive cellulose/PF127 composite hydrogels. Besides, AgSD-loaded thermo-responsive cellulose/PF127 composite hydrogels showed relatively good inhibitory activity against the Staphylococcus aureus, Escherichia coli, Enterococcus faecalis, Enterococcus faecium, Streptococcus pyogenes, and Klebsiella pneumoniae bacteria. The exploration of thermoresponsive cellulose/PF127 composite hydrogel from OPEFBs can promote sustainable, environment-friendly, and cost-effective drug delivery systems by using abundant agricultural biomass.