Biodegradable microparticles loaded with thrombin receptor agonist peptide for gastric ulcer treatment in rats

The aim of the current paper was to elaborate an immobilization method of thrombin receptor agonist peptide (TRAP-6) in biodegradable biocompatible poly(d,l)-lactide-co-glycolide (PLGA) microparticles and to demonstrate the effect of the entrapped peptide for tissue repair, namely for a gastric ulcer treatment in rats. TRAP-6 was entrapped in polymer using w/o/w double emulsion-evaporation technique. The morphology of empty and TRAP-6 loaded microparticles was evaluated by light and scanning electron microscopy (SEM). In vitro release kinetics profile of TRAP-6 from microparticles was studied by HPLC. To investigate gastric mucosal protection effect in vivo, TRAP-6-loaded microparticles were administered in a rat stomach after a previous mucosal injury (a gastric ulcer). Microparticles with entrapped TRAP-6 were found to reduce both an inflammation and proliferation phases of wound healing, and thus accelerated tissue repair in rats.