Hydroxyapatite-reinforced pectin hydrogel films PEC/PVA/APTES/HAp: doxycycline loading for sustained drug release and wound healing applications.

Doxycycline (DOXY)-loaded hydroxyapatite (HAp) pectin hydrogel films were prepared for sustained drug release and wound healing application. A series of pectin-based, DOXY-loaded hydrogels were synthesized via a solution casting method. HAp at varying amounts was used as a filler to synthesize PEC/PVA/APTES/HAp (PPC-5, -10, -15, -20) hydrogels. SEM, FTIR, TGA, and XRD analyses verified the porous morphology, structural integrity, thermal stability and amorphous nature of the hydrogels, respectively. A biodegradation study of the hydrogel was conducted using phosphate buffer saline (PBS) and proteinase-K enzymatic solutions. Cell viability was evaluated using the MTT assay with HEK293 cells. Moreover, drug-loaded hydrogel dressings were developed and subjected to in vivo wound healing studies on albino mice. Excision wound infliction was created to produce a 5-6 mm wide and 2-3 mm deep cutaneous wound. Swelling of the hydrogel films was found to be inversely related to the concentrations of HAp. The hydrogels exhibited significant swelling profiles in distilled water with a maximum swelling of 2519% in 140 min, while the highest swelling was observed at pH 6 in both buffer and non-buffer solutions. Antibacterial studies indicated bactericidal activity of hydrogels against both Gram-positive (S. aureus) and Gram-negative (E. coli) bacteria. In vitro release of DOXY from the hydrogel matrix (PPC-10) revealed 88.57% drug release in PBS solution within 3.5 h. Wound healing studies exhibited exceptional healing tendency, with complete excision wound healing achieved in 8 days. In conclusion, the remarkable biocompatible, biodegradable and nontoxic pectin-based hydrogel systems are suitable for drug delivery, tissue engineering, wound healing, and other medico-biological applications.