Study On Acellular Dermal Matrix Scaffold Combined With Bone Marrow Stem Cells To Construct Tissue Engineering Anterior Cruciate Ligament

Objective: With the development of tissue engineering anterior cruciate ligament (ACL)technique, the transforming growth factor β1(TGF-β1) and basic fibroblast growth factor(bFGF) have become a hot issue in the ACL healing research. Acellular dermal matrix(ADM) is a kind of tissue repair material, and it has been widely applied for repair oftissue defect. The purpose of this study is to explore the influence of specificconcentration of TGF-β1and bFGF on the adhesion, proliferation and differentiation ofbone marrow stromal cell (BMSCs) cultured in vitro. Reconstructed rabbits’ ACL wasused as a model and comparisons were undertaken in the tendon-bone healing, collagencontent and biomechanical strength after6weeks with or without growth factorstimulation above, so as to provide the experimental basis for the construction of tissueengineering ACL.Methods:1. The third generation of rabbit BMSCs were inoculated on the ADM andcultured using the general culture medium (control group) and TGF-β1(concentration10ng/ml) and bFGF(concentration25ng/ml) culture medium (experimental group) respectively. The MTT curve was drawn respectively on the1,3,5,7,9,11day of cellproliferation. On the7d, the content of alkaline phosphatase(ALP) was measured.Fluorescence microscopy and scanning electron microscope were used to observe the twogroup cells’ proliferation, differentiation and adhesion in ADM scaffolds.2. Rabbits’ ACLwere reconstructed by ADM scaffold with4strands braided column (experimental group)and4shares of beam shape(control group), then the growth of cell, the secretion of type I,III collagen and tendon-bone healing were tested by HE staining, Sirius red staining andbiomechanical testing.3. All the data were analyzed by SPSS12.0and P<0.05was definedas statistical difference.Results:1.Compared with the control group, significant higher BMSCs adhered toscaffold in experimental group evidenced by MTT curve and fluorescencestaining(P<0.05). ALP staining showed that TGF-β1(concentration10ng/ml) andbFGF(concentration25ng/ml) can promote BMSCs to secrete more ALP (P<0.05).Laserconfocal scanning microscopy showed that more cells adhered to scaffold and the cellform was even better in the experimental group.2. At6,12weeks after ACLreconstruction, HE staining on tendon-bone conjunction and Sirius red staining on ACLshowed that the healing times of tendon to bone in the experimental group was faster thanin the control group but he secretion of type I, III collagen in both groups was similar. At12weeks, the results of biomechanical properties in the experimental group weresignificant better than that in control group (P<0.05).Conclusions:1.TGF-β(concentration10ng/ml) and bFGF(concentration25ng/ml) factorhave obvious stimulative effectiveness on the growth, adhesion and differentiation ofBMSCs on the ADM.2. Braided ADM scaffolds provided certain biomechanical strengthand4strands braided column scaffold can promote the BMSCs to secrete collagen type I,III in rabbits and enhance tendon-bone healing procedure in some degree.