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

Abstract

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.