Pterocarpus marsupium Roxburgh heartwood extract/chitosan nanoparticles loaded hydrogel as an innovative wound healing agent in the diabetic rat model

•PM-CNPsH-1 showed therapeutic properties in vivo in diabetic and non-diabetic group of rats.•PM-CNPsH-1 showed maximum zone of inhibition against Gram-positive and Gram-negative bacteria.•PM-CNPsH-1 application on wounds accelerated healing of complicated surgical wounds even on diabetic rats.•PM-CNPsH-1 reduced infiltration of inflammatory cells in granulation tissues and improved angiogenesis.