Bombyx mori derived scaffolds and their use in cartilage regeneration: a systematic review.

For the last two decades, silk has been extensively used as scaffolds in tissue engineering because of its remarkable properties. Unfortunately, the aneural property of cartilage limits its regenerative potential which can be achieved using tissue engineering approach. A lot of research has been published searching for the optimization of silk fibroin (SF) and its blends in order to get the best cartilage mimicking properties. However, according to our best knowledge, there is no systematic review available regarding the use of Bombyx mori derived biomaterials limited to cartilage related studies. This systematic review highlights the in vitro and in vivo work done for the past 7 years on structural and functional properties of B. mori derived biomaterials together with different parameters for cartilage regeneration. PubMed database was searched focusing on in vitro and in vivo studies using the search thread "silk fibroin" and "cartilage". A total of 40 articles met the inclusion criteria. All the articles were deeply studied for cell types, scaffold types and animal models used along with study design and results. Five types of cells were used for in vitro while seven types of cells were used for in vivo studies. Three types of animal models were used for scaffold implantation purpose. Moreover, different types of scaffolds either seeded with cells or supplemented with various factors were explored and discussed in detail. Results suggest the suitability of silk as a better biomaterial because of its cartilage mimicking properties.

Vitamin E protects rat mesenchymal stem cells against hydrogen peroxide-induced oxidative stress in vitro and improves their therapeutic potential in surgically-induced rat model of osteoarthritis.

OBJECTIVE: Oxidative stress is a major obstacle against cartilage repair in osteoarthritis (OA). Anti-oxidant agents can play a vital role in addressing this issue. We evaluated the effect of Vitamin E preconditioning in improving the potential of mesenchymal stem cells (MSCs) to confer resistance against oxidative stress prevailing during OA. METHODS: Vitamin E pretreated MSCs were exposed to oxidative stress in vitro by hydrogen peroxide (H2O2) and also implanted in surgically-induced rat model of OA. Analysis was done in terms of cell proliferation, apoptosis, cytotoxicity, chondrogenesis and repair of cartilage tissue. RESULTS: Vitamin E pretreatment enabled MSCs to counteract H2O2-induced oxidative stress in vitro. Proliferative markers, proliferating cell nuclear antigen (PCNA) and Ki67 were up-regulated, along with the increase in the viability of MSCs. Expression of transforming growth factor-beta (TGFß) was also increased. Reduction of apoptosis, expression of vascular endothelial growth factor (VEGF) and caspase 3 (Casp3) genes, and lactate dehydrogenase (LDH) release were also observed. Transplantation of Vitamin E pretreated MSCs resulted in increased proteoglycan contents of cartilage matrix. Increased expression of chondrogenic markers, Aggrecan (Acan) and collagen type-II alpha (Col2a1) accompanied by decreased expression of collagen type-I alpha (Col1a1) resulted in increased differentiation index that signifies the formation of hyaline cartilage. Further, there was an increased expression of PCNA and TGFß genes along with a decreased expression of Casp3 and VEGF genes with increased histological score. CONCLUSION: Taken together results of this study demonstrated that Vitamin E pretreated MSCs have an improved ability to impede the progression of OA and thus increased potential to treat OA.