Effect of Nano Encapsulated Chitosan- Collagen Hydrogel on Healing of Injured Achilles Tendon in a Rabbit Model

Tendon injuries pose a significant clinical challenge due to their limited intrinsic healing capacity, often resulting in fibrotic scar formation and impaired mechanical function.This study investigates the efficacy of nano encapsulated chitosan-collagen hydrogel (NECCH) compared to untreated tendon in enhancing the healing process of injured Achilles tendons in a rabbit model.A total of 40 adult male rabbits were used and divided into two groups: (A) control (untreated), (B) NECCH-treated.The experimental model involved standardized Achilles tenotomy followed by tenorrhaphy using the modified Kessler technique.The nano encapsulated chitosan-collagen (0.3 ml of chitosan (2 w/v%) and collagen-I (4 mg/ml) hydrogel were locally applied at the repair site to assess their regenerative potential.Postoperative evaluations included clinical examinations, ultrasonography, macroscopic and histopathological assessments, over 12 weeks.The results demonstrated that the treatment group exhibited superior tendon healing compared to the control group, as evidenced by reduced inflammatory response, enhanced tendon gliding, and more organized collagen deposition following NECCH treatment.Ultrasound imaging confirmed enhanced tendon integrity and reduced adhesion formation in the treated groups.These findings suggest that NECCH offers a promising therapeutic strategy for tendon repair, providing a biocompatible scaffold that facilitates tissue regeneration and functional restoration.