Immobilized Lentivirus Vector on Chondroitin Sulfate-Hyaluronate Acid-Silk Fibroin Hybrid Scaffold for Tissue-Engineered Ligament-Bone Junction

Abstract

The lack of a fibrocartilage layer between graft and bone remains the leading cause of graft failure after anterior cruciate ligament (ACL) reconstruction. The objective of this study was to develop a gene-modified silk cable-reinforced chondroitin sulfate-hyaluronate acid-silk fibroin (CHS) hybrid scaffold for reconstructing the fibrocartilage layer. The scaffold was fabricated by lyophilizing the CHS mixture with braided silk cables. The scanning electronic microscopy (SEM) showed that microporous CHS sponges were formed around silk cables. Each end of scaffold was modified with lentiviral-mediated transforming growth factor-β3 (TGF-β3) gene. The cells on scaffold were transfected by bonded lentivirus. In vitro culture demonstrated that mesenchymal stem cells (MSCs) on scaffolds proliferated vigorously and produced abundant collagen. The transcription levels of cartilage-specific genes also increased with culture time. After 2 weeks, the MSCs were distributed uniformly throughout scaffold. Deposited collagen was also found to increase. The chondral differentiation of MSCs was verified by expressions of collagen II and TGF-β3 genes in mRNA and protein level. Histology also confirmed the production of cartilage extracellular matrix (ECM) components. The results demonstrated that gene-modified silk cable-reinforced CHS scaffold was capable of supporting cell proliferation and differentiation to reconstruct the cartilage layer of interface.

Strategies to engineer tendon/ligament-to-bone interface: Biomaterials, cells and growth factors

“…Sun et al[161] coupled a TGF-β3-expressing lentiviral vector to a silk scaffold reinforced with chondroitin sulfate for the fabrication of an interface-like construct. MSCs were cultured on the scaffold and continuously transfected with the coupled lentivirus.…”

Structural Design, Fabrication and Evaluation of Resorbable Fiber-Based Tissue Engineering Scaffolds

“…Sun et al fabricated a gene-modified scaffold by lyophilizing the CHS mixture with braided silk cables for fibrocartilage application [87]. The scaffold, seeded with mesenchymal stem cells (MSCs), showed vigorous cell proliferation and differentiation to reconstruct the cartilage.…”

Current Status of Tissue-engineered Scaffolds for Rotator Cuff Repair

“…76 For engineering of the interface between tendon and bone, immobilization of a TGF- β3 expressing lentiviral vector onto a scaffold induced a chondrogenic phenotype by mesenchymal stem cells. 77 Not all studies to evaluate the efficacy of growth factors are as successful when applied to animal models as in vitro studies would suggest. For example, adipose stem cells transduced with BMP-2 and seeded onto aligned PLGA scaffolds in an attempt to improve tendon-bone healing had reduced trabecular bone at the tendon-bone interface and reduced mechanical properties compared to scaffolds not producing BMP-2 in a rat model, therefore use of BMP-2 for enhanced tendon-bone repair at the rotator cuff was not recommended; these results were consistent with several similar studies previously reported, but also in contrast to other studies suggesting a positive effect of BMP-2 in tendon-bone or ligament-bone healing.…”