Cartilage Repair Using Clematis Triterpenoid Saponin Delivery Microcarrier, Cultured in a Microgravity Bioreactor Prior to Application in Rabbit Model

Abstract

Cartilage tissue engineering provides a promising method for the repair of articular cartilage defects, requiring appropriate biological scaffolds and necessary growth factors to enhance the efficiency of cartilage regeneration. Here, a silk fibroin (SF) microcarrier and a clematis triterpenoid saponin delivery SF (CTS-SF) microcarrier were prepared by the high-voltage electrostatic differentiation and lyophilization method, and chondrocytes were carried under the simulated microgravity condition by a rotating cell culture system. SF and CTS-SF microspheres were relatively uniform in size and had a porous structure with good swelling and cytocompatibility. Further, CTS-SF microcarriers could sustainably release CTSs in the monitored 10 days. Compared with the monolayer culture, chondrocytes under the microgravity condition maintained a better chondrogenic phenotype and showed better proliferation ability after culture on microcarriers. Moreover, the sustained release of CTS from CTS-SF microcarriers upregulated transforming growth factor-β, Smad2, and Smad3 signals, contributing to promote chondrogenesis. Hence, the biophysical effects of microgravity and bioactivities of CTS-ST were used for chondrocyte expansion and phenotype maintenance in vitro. With prolonged expansion, SF- and CTS-SF-based microcarrier–cell composites were directly implanted in vivo to repair rabbit articular defects. Gross evaluations, histopathological examinations, and biochemical analysis indicated that SF- and CTS-SF-based composites exhibited cartilage-like tissue repair compared with the nontreated group. Further, CTS-SF-based composites displayed superior hyaline cartilage-like repair that integrated with the surrounding cartilage better and higher cartilage extracellular matrix content. In conclusion, these results provide an alternative preparation method for drug-delivered SF microcarrier and a culture method for maintaining the chondrogenic phenotype of seed cells based on the microgravity environment. CTS showed its bioactive function, and the application of CTS-SF microcarriers can help repair and regenerate cartilage defects.

Mechanisms of vascular invasion after cartilage injury and potential engineering cartilage treatment strategies

“…Clematis total saponins is the extract of Willingin, which can significantly inhibit inflammation, reduce oxidative stress damage, and protect chondrocytes from apoptosis, thereby promoting cartilage tissue damage repair, and has long been used to treat OA 132–134 . We prepared a silk fibroin microsphere loaded with wellingxian saponins that can carry chondrocytes, implanted it into a rabbit model of full‐thickness cartilage injury, and found that it showed good cartilage repair and no obvious vascular invasion at the regenerated cartilage site 135 …”

“…[132][133][134] We prepared a silk fibroin microsphere loaded with wellingxian saponins that can carry chondrocytes, implanted it into a rabbit model of full-thickness cartilage injury, and found that it showed good cartilage repair and no obvious vascular invasion at the regenerated cartilage site. 135 Numerous TCM extracts that are used to treat cartilage injuries also possess anti-angiogenic effects, such as ginsenosides, 136 artemisinin, 137 dihydroartemisinin, 138 betaine, 139 and baicalin. 140 Notably, in the treatment of diseases with TCM, compound herbal formulations are often used as the main approach.…”

Advances in Microgravity Directed Tissue Engineering

“…Following the implantation of microcarrier–cell composites at the injury site of rabbit articular defects, the treatment groups exhibited cartilage‐like tissue repair. [ 78 ] Promising cell carrier–cartilage ECM‐derived particles have good cellular compatibility with adipose‐derived stem cells. Under mimic microgravity conditions in RCCS, MSCs differentiated into a chondrogenic phenotype with no need for exogenous growth factors.…”

CD62E- and ROS-Responsive ETS Improves Cartilage Repair by Inhibiting Endothelial Cell Activation through OPA1-Mediated Mitochondrial Homeostasis

“…Fibrin, a natural polymer, has good biocompatibility and morphological plasticity and is widely used in CTE [ 27 ]. Studies have shown that silk fibroin (SF) scaffolds loaded with CS can promote cartilage regeneration in a rabbit knee cartilage defect model [ 28 ]. SF, as a kind of biomaterial with good biocompatibility, degradability and modifiability, has been widely used in CTE.…”