The Preliminary Experimental Study On The Fabrication Of Tissue-engineered Anterior Cruciate Ligament Using The Braided Polyvinyl Alcohol Materials

Objective: To fabricate the braided anterior cruciate ligament scaffold materials using the polyvinyl alcohol (PVA) fibers and observe the adhesion, proliferation and growth of hACL cells seeded onto the scaffolds surface, and to investigate the feasibility of the fabrication of tissue-engineered ACL using the PVA fibers in vitro.Methods: Firstly, two kinds of PVA fibers were made from the polyvinyl alcohol solution by spinning technique, and two braided ACL scaffold materials were made from PVA fibers by different three-dimensional braiding technique. The swelling ratio and mechanical properties of the braided scaffold materials were measured respectively. Secondly, human ACL cells were isolated and cultured by tissue implant and collagenase digestive methods, the morphologic characteristics of hACL cells were observed, and typeⅠandⅢcollagen secreted by hACL cells were detected by immunohistochemistry method. Thirdly, hACL cells were expanded in vitro and seeded onto the surface of the braided PVA scaffold materials, the adhesion, proliferation and three-dimensional growth of hACL cells on the scaffold were observed by SEM.Results: Two kinds of PVA fibers with different diameter and size can be made from the polyvinyl alcohol solution by spinning technique. The swelling ratio of the different PVA fiber was similar. The swelling properties of the braided scaffold materials were also similar. Two kinds of braided scaffold materials were prepared for mechanical testing; all specimens failed by pulling apart in the midsubstance and demonstrated the characteristic non-linear tensile loading stress-strain curve, commonly reported for anterior cruciate ligament. The ultimate tensile strength and Young's modulus of the scaffold materials braided by loop fibers were 13.97±1.87MPa and 199.63±24.1MPa respectively. The ultimate tensile strength and Young's modulus of the scaffold materials braided by parallel fibers were significantly increasing, reached 52.21±2.88MPa and 435.57±43.99MPa respectively. Human ACL cells exhibited morphological characteristics of the ligament fibroblasts, hACL cells synthesized rich typeⅠandⅢcollagen protein in vitro. The braided scaffold materials had no cytotoxicity; hACL cells adhered, grew and proliferated well both on the surface and in the holes of the braided ligament scaffold materials.Conclusions: 1. The tissue-engineering ligament scaffold materials can be made from the PVA fibers by three-dimensional braiding technique. 2. Human ACL cells can powerfully proliferate and richly synthesis typeⅠandⅢcollagen protein in vitro, and can be used as cell source for anterior cruciate ligament tissue engineering. 3. The scaffold materials exhibit certain mechanical properties and good cell compatibility; it may become an ideal scaffold material for constructing tissue-engineering ACL, if the mechanical properties can be further improved.