Tissue engineering for cartilage repair: growth and proliferation of hBM-MSCs on scaffolds composed of Collagen I and Heparan Sulphate

Abstract

proteoglycan content was found decreased by histomorphometry (score decline-64%) and biochemical analysis of GAG (-75%) and total collagen (-30%) content. Gene expression of catabolic enzymes (MMP13, MMP1, MMP2), and genes involved in inflammatory response (IL8, CCL2, CCL4 CXCL2) was significantly increased (>4-fold) and genes related to ECM formation (COL2A1, COMP, Aggrecan, COL8A1, COL11A1) were decreased (<-4-fold). Whereas histological and biochemical characteristics of the TNF-alpha induced model match with observations known from human OA cartilage, gene expression analysis revealed contrary gene expression pattern related to ECM formation (COL2A1, COL11A1, COMP) and to hypertrophic bone formation (COL10A1). The addition of TGF-b1 and PRP during TNF-alpha stimulation led to reduced GAG loss (both 40%) whereas IL1b enhanced the GAG loss by further 10% demonstrating responsiveness of the model to test substances. Conclusions: The use of porcine chondrocytes in micromasses and the addition of TNF-alpha resulted in the induction of some typical features of OA such as extensive ECM loss and induction of genes related to catabolic activity and inflammatory response. In contrast to human OA, ECM formation was inhibited, which might be a consequence of the exclusive use of TNF-alpha, which is only one of many impacting factors in OA. Although not all characteristics of human OA could be demonstrated, the presented test system was suitable to detect effects of test substances. TNF-alpha induced porcine micromasses can be a useful supplement to existing preclinical tests in OA and an alternative to the use of human tissue in vitro.

Directing the osteoblastic and chondrocytic differentiations of mesenchymal stem cells: matrix vs. induction media

“…The results suggested a HA-collagen matrix-driven osteoblastic differentiation for MSCs, likely through a series of coordinated cellular events. The collagen-based materials have been reported to promote both the osteoblastic and chondrocytic differentiations [ 51 , 52 ]. Nevertheless, the HA-collagen matrix selected in this study, while having a structure far from the ideal hierarchical structure from the natural bone, did imitate the natural composition of bone in a simple manner and likely provided the proper physical microenvironment and chemical microenvironment favoring the osteoblastic differentiation, a highly robust process as occurred in natural bone development and regeneration.…”

An artificial-vision- and statistical-learning-based method for studying the biodegradation of type I collagen scaffolds in bone regeneration systems

“…The qualitative analysis is currently performed on images obtained by biomedical imaging techniques such as transmission electron microscopy and scanning electron microscopy. This analysis is often based on examining (in a subjective way) the electrodensity of related objects that appear in the obtained images (cells, cell nuclei, cytoplasm, biomaterials such as type I collagen, and extracellular material, among others) (Sanjurjo-Rodríguez et al, 2017; Sanjurjo-Rodríguez et al, 2014; Sanjurjo-Rodríguez et al, 2016; Sanjurjo-Rodríguez et al, 2013; Martínez-Sánchez et al, 2013; Gashti et al, 2012). Therefore, the information obtained with this type of microanalytical techniques is largely of a qualitative nature (elements observed in a certain area of the image are analyzed by specialized personnel) (Gashti et al, 2012).…”

Peer Review #1 of "An artificial-vision- and statistical-learning-based method for studying the biodegradation of type I collagen scaffolds in bone regeneration systems (v0.1)"

“…The qualitative analysis is currently performed on images obtained by biomedical imaging techniques such as transmission electron microscopy and scanning electron microscopy. This analysis is often based on examining (in a subjective way) the electrodensity of related objects that appear in the obtained images (cells, cell nuclei, cytoplasm, biomaterials such as type I collagen, and extracellular material, among others) (Sanjurjo-Rodríguez et al, 2017, 2016aMartínez-Sánchez et al, 2013;Gashti et al, 2012). Therefore, the information obtained with this type of microanalytical techniques is largely of a qualitative nature (elements observed in a certain area of the image are analyzed by specialized personnel) (Gashti et al, 2012).…”