W. Shi (Beijing, CN)
Institute of Sports Medicine;Beijing Key Laboratory of Sports Injuries;Peking University Third Hospital Institute of Sports MedicinePresenter Of 1 Presentation
16.2.4 - Structurally and Functionally Optimized Silk Fibroin-Gelatin Scaffold using 3DP to Repair Cartilage Injury
Abstract
Purpose
We want to design a structurally and functionally optimized scaffold for recruiting more autologous BMSCs and providing suitable microenvironment for cartilage regeneration in the knee joint.
Methods and Materials
We designed a structurally and functionally optimized scaffold by integrating silk fibroin with gelatin(SFG) in combination of BMSC-specific affinity peptide(SFG-E7) using three-dimensional printing (3DP) technology. In vitro experiments, we tested the viability and morphology of the BMSCs seeded on the SFG or SFG-E7 scaffolds, measured the recruitment capacity and chondrogenic differentiation of different scaffolds. In animal experiments, there were three groups : MF, MF+SFG and MF+SFG-E7. Then we evaluated the chondrogenic capacity of different groups by staining with hematoxylin and eosin (H&E), toluidine blue, immunostaining of collagen type II antibody and biomechanical analysis of repair cartilage after the rabbits were sacrificed at 6,12,24 weeks.
Results
The scaffolds with mass ratio of 1:2 (6.9 w/v %) were selected which might match the previously reported requirements of tissue engineered cartilage scaffold. In vitro, BMSCs grew well on the fashioned scaffolds and the typical fusiform morphology of BMSCs was observed the scaffolds. Also SFG-E7 scaffolds had higher chondrogenic capacity than SFG scaffolds, as evidenced by more HYP and GAG production and collagen type II expression in vitro. In vivo,SFG group had a better repair effect than MF group and neo-cartilage in SFG-E7 group was more similar to normal cartilage than SFG group through a series of assessment including gross observation, MRI, histology, SEM and biomechanics evaluation.
Conclusion
This dually optimized scaffold has shown superior performance for cartilage repair in knee joint. It appears to be a promising biomaterial for knee cartilage repair, and is worthy of further investigation in large animal studies and preclinical applications. Beyond knee cartilage, this dually optimized scaffold may also serve as an ideal biomaterial for the regeneration of other joint cartilages.