Noninvasive Evaluation of Injectable Chitosan/Nano-Hydroxyapatite/Collagen Scaffold via Ultrasound

Abstract

To meet the challenges of designing anin situforming scaffold and regenerating bone with complex three-dimensional (3D) structures, anin situforming hydrogel scaffold based on nano-hydroxyapatite (nHA), collagen (Col), and chitosan (CS) was synthesized. Currently, only a limited number of techniques are available to mediate and visualize the injection process of the injectable biomaterials directly and noninvasively. In this study, the potential of ultrasound for the quantitativein vivoevaluation of tissue development in CS/nHAC scaffold was evaluated. The CS/nHAC scaffold was injected into rat subcutaneous tissue and evaluated for 28 days. Quantitative measurements of the gray-scale value, volume, and blood flow of the scaffold were evaluated using diagnostic technique. This study demonstrates that ultrasound can be used to noninvasively and nondestructively monitor and evaluate thein vivocharacteristics of injectable bone scaffold. In comparison to the CS, the CS/nHAC scaffold showed a greater stiffness, less degradation rate, and better blood supply in thein vivoevaluation. In conclusion, the diagnostic ultrasound method is a good tool to evaluate thein vivoformation of injectable bone scaffolds and facilitates the broad use to monitor tissue development and remodeling in bone tissue engineering.