A novel method for providing scaffold: Decellularization of parathyroid capsule

This study aimed to generate a novel biomatrix from the decellularized human parathyroid capsule using different methods and to compare the efficiency of decellularization in the means of cell removal, structural integrity and extracellular matrix preservation. The parathyroid capsules, which were carefully dissected from the parathyroid tissue, were randomly divided into four groups and then decellularized using three different protocols: freeze-thaw only, sodium dodecyl sulphate and Triton X-100 treatments after freeze-thawing. Quantitative DNA analysis, agarose gel electrophoresis, sulphated glycosaminoglycan assay, histological analysis, immunohistochemistry and scanning electron microscopy were used to observe the efficiency of parathyroid capsule decellularization and preservation of extracellular matrix components. Considering all the results, it can be said that only freeze-thawing is not an effective method in parathyroid capsule decellularization. When the tissue was treated with a detergent agent in addition to freeze-thawing, the amount of DNA decreased by 90% while sulphated glycosaminoglycan amount maintained 50% compared to untreated tissue. Comparing the effects of the two detergents on the preservation of extracellular matrix such as collagen and sulphated glycosaminoglycan, it was seen that the integrity of tissues treated with Triton X-100 was preserved more than tissues treated with sodium dodecyl sulphate. It is concluded that Triton X-100 treatment with freeze-thawing is the most suitable and effective method for decellularizing the human parathyroid capsule. The biomatrix obtained with this method can be applied in the transplantation of parathyroid tissue and other endocrine tissue types in the body.

Sodium hyaluronate supplemented culture medium combined with joint-simulating mechanical loading improves chondrogenic differentiation of human mesenchymal stem cells

In vitro models aim to recapitulate the in vivo situation. To more closely mimic the knee joint environment, current in vitro models need improvements to reflect the complexity of the native tissue. High molecular weight hyaluronan (hMwt HA) is one of the most abundant bioactive macromolecules in healthy synovial fluid, while shear and dynamic compression are two joint-relevant mechanical forces. The present study aimed at investigating the concomitant effect of joint-simulating mechanical loading (JSML) and hMwt HA-supplemented culture medium on the chondrogenic differentiation of primary human bone-marrow-derived mesenchymal stem cells (hBM-MSCs). hBM-MSC chondrogenesis was investigated over 28 d at the gene expression level and total DNA, sulphated glycosaminoglycan, TGF-β1 production and safranin O staining were evaluated. The concomitant effect of hMwt HA culture medium and JSML significantly increased cartilage-like matrix deposition and sulphated glycosaminoglycan synthesis, especially during early chondrogenesis. A stabilisation of the hBM-MSC-derived chondrocyte phenotype was observed through the reduced upregulation of the hypertrophic marker collagen X and an increase in the chondrogenic collagen type II/X ratio. A combination of JSML and hMwt HA medium better reflects the complexity of the in vivo synovial joint environment. Thus, JSML and hMwt HA medium will be two important features for joint-related culture models to more accurately predict the in vivo outcome, therefore reducing the need for animal studies. Reducing in vitro artefacts would enable a more reliable prescreening of potential cartilage repair therapies.