Aligned poly(butylene adipate-co-terephthalate)/type I collagen fibers promote tendon-bone healing after anterior cruciate ligament rupture
Hu Qiuyu1, Yang Long2, Yang Yong2, Song Shenchao1
1School of Public Health, Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education, Guizhou Medical University, Guiyang 550025, Guizhou Province, China; 2Department of Orthopedics, Affiliated Hospital of Guizhou Medical University, Guiyang 550004, Guizhou Province, China
Abstract: BACKGROUND: The micro/nano structure on the surface of the material has a regulatory effect on the behavior of the cells. The tendon tissue is mainly composed of parallel collagen fibers, so the aligned fiber structure has a certain promotion effect on tendon-bone healing.
OBJECTIVE: To explore the biocompatibility and osteoinductive activity of poly(butylene adipate-co-terephthalate) (PBAT)/type I collagen aligned fiber scaffolds.
METHODS: Electrospinning technology was used to prepare random PBAT, aligned PBAT, and aligned PBAT/type I collagen fiber scaffold materials. The static contact angle and mechanical properties of the three stents were characterized. The three scaffolds were co-cultured with rat bone marrow mesenchymal stem cells to detect cell adhesion rate and proliferation. DAPI staining and Live/Dead fluorescent staining were used to observe cell adhesion and survival on the scaffold. Alkaline phosphatase staining and type I collagen immunohistochemical staining were used to detect the osteoinductive activity of oriented fiber scaffolds.
RESULTS AND CONCLUSION: (1) The static contact angle of oriented PBAT/type I collagen fiber scaffold was lower than that of random PBAT and aligned PBAT fiber scaffolds (P < 0.05). (2) The strain degree of the two aligned scaffolds was better than that of the aligned PBAT scaffold (P < 0.05), and the tensile strength of the aligned PBAT scaffold was better than that of the random PBAT group (P < 0.05). There was no significant difference in the elastic modulus of the three groups of scaffolds (P > 0.05). (3) The cell adhesion and proliferation on the aligned PBAT/type I collagen fiber scaffold were better than those of the other two scaffolds. (4) DAPI staining and Live/Dead fluorescent staining showed that bone marrow mesenchymal stem cells could adhere and proliferate on the three groups of scaffolds, and the number of cells on the aligned PBAT/type I collagen fiber scaffold was the largest. (5) Alkaline phosphatase staining and type I collagen immunohistochemical staining showed that the osteoinductive activity of the aligned PBAT/type I collagen fiber scaffold was stronger than that of the aligned PBAT fiber scaffold. (6) The results show that the PBAT/type I collagen aligned fiber scaffold has good biocompatibility and osteoinductive activity and can effectively promote cell proliferation and adhesion.
Key words: poly(butylene adipate-co-terephthalate), type I collagen, tissue engineering, aligned fibers, stem cells, electrospinning, biomaterials