Objective: To prepare collagen-chitosan/nano-hydroxyapatite-collagen-polylactic acid (Col-CS/nHAC-PLA) biomimetic scaffold and to examine its biocompatibility so as to lay the foundation for its application on the treatment of osteochondral defect.
Methods: PLA was dissolved in dioxane for getting final concentration of 8%, and the nHAC power was added at a weight ratio of nHAC to PLA, 1 : 1. The solution was poured into a mold and frozen. CS and Col were dissolved in 2% acetum for getting the final concentrations of 2% and 1% respectively, then compounded at a weight ratio of CS to Col, 20 : 1. The solution was poured into the frozen mold containing nHAC-PLA, and then biomimetic osteochondral scaffold of Col-CS/nHAC-PLA was prepared by freeze-drying. Acute systemic toxicity test, intracutaneous stimulation test, pyrogen test, hemolysis test, cytotoxicity test, and bone implant test were performed to evaluate its biocompatibility.
Results: Col-CS/nHAC-PLA had no acute systemic toxicity. Primary irritation index was 0, indicating that Col-CS/nHAC-PLA had very slight skin irritation. In pyrogen test, the increasing temperature of each rabbit was less than 0.6 degrees C, and the increasing temperature sum of 3 rabbits was less than 1.3 degrees C, which was consistent with the evaluation criteria. Hemolytic rate of Col-CS/nHAC-PLA was 1.38% (far less than 5%). The toxicity grade of Col-CS/nHAC-PLA was classified as grade I. Bone implant test showed that Col-CS/nHAC-PLA had good biocompatibility with the surrounding tissue.
Conclusion: Col-CS/nHAC-PLA scaffold has good biocompatibility, which can be used as an alternative osteochondral scaffold.