ABSTRACT
In tissue engineering, the decellularization of organs and tissues as a biological scaffold plays a critical role in the repair of neurodegenerative diseases. Various protocols for cell removal can distinguish the effects of treatment ability, tissue structure, and extracellular matrix (ECM) ability. Despite considerable progress in nerve regeneration and functional recovery, the slow regeneration and recovery potential of the central nervous system (CNS) remains a challenge. The success of neural tissue engineering is primarily influenced by composition, microstructure, and mechanical properties. The primary objective of restorative techniques is to guide existing axons properly toward the distal end of the damaged nerve and the target organs. However, due to the limitations of nerve autografts, researchers are seeking alternative methods with high therapeutic efficiency and without the limitations of autograft transplantation. Decellularization scaffolds, due to their lack of immunogenicity and the preservation of essential factors in the ECM and high angiogenic ability, provide a suitable three-dimensional (3D) substrate for the adhesion and growth of axons being repaired toward the target organs. This study focuses on mentioning the types of scaffolds used in nerve regeneration, and the methods of tissue decellularization, and specifically explores the use of decellularized nerve tissues (DNT) for nerve transplantation.
ABSTRACT
Human adipose-derived stem cells (hADSCs) are widely used in regenerative medicine and affected by many biochemical and biophysical stimuli in vivo. Betaine has been reported to be a type of osteogenic stimulating biochemical factor. This study aimed to investigate the effects of betaine; on osteogenic differentiation of cultured hADSCs in osteogenesis differentiation medium. Mesenchymal stem cells were extracted from women undergoing liposuction after obtaining written consent and cultured in vitro. The cells at passage 4 were confirmed by flow cytometry and differentiated into osteocytes and adipocytes. Experimental groups were the cells cultured in osteogenesis differentiation medium (control), cultured in α-MEM and 10% serum-containing Betaine (BET) ,and cultured in osteogenesis differentiation medium containing 10 mM Betaine (OD+BET). After 14 and 21 days of treatment, osteogenic differentiation and the expression of RUNX2 and OCN genes were assessed by qualitative and quantitative Alizarin red staining and real-time PCR. There were significant increases in the calcium matrix deposits, alkaline phosphatase activity ,and expression of RUNX2 and OCN genes in the OD+BET group compared to the BET group. At the end of day 14, the calcium matrix formation was significantly decreased the in BET group compared to the control. Treatment of hADSCs with Betaine, and osteogenesis differentiation medium leads to increased alkaline phosphatase activity, matrix calcium deposits and expression of RUNX2 and OCN genes and finally stimulated osteogenesis. This kind of treatment could be used to support bone regeneration in the future of tissue engineering.
ABSTRACT
Human adipose tissue-derived mesenchymal stem cells (hADSCs) due to easy extraction, relative abundance, in vitro expansion and differentiation potential, frozen storage capability, and ability to secrete cytokines, compared to other stem cells, are appropriate candidate in regenerative medicine. Extremely low-frequency electromagnetic fields (ELF-EMF) and betaine are two safe factors in bone lesions repair. This study was designed to assess the osteogenic differentiation potential of these factors on hADSCs. The samples were collected from women undergoing liposuction after obtaining written consent. The hADSCs were extracted and treated with osteogenesis differentiation medium (OD) as the positive control, with OD and betaine (BET group), with OD and EMF (EMF group), and with OD and betaine and EMF (BET+EMF group) for 21 d; the negative control consisted of cells without treatment. Betaine 10 mM and EMF with 50-Hz frequency, 1-mT intensity (8 h daily), and in the form of sinus wave were used. Osteogenic differentiation was evaluated by Alizarin Red staining, alkaline phosphatase activity, calcium deposition, and real-time PCR. A significant increase in calcium deposition in the BET+EMF group was observed compared to the other groups. The activity of alkaline phosphatase in the positive control and BET groups was increased significantly compared to EMF and BET + EMF groups and a significant increase of this enzyme activity in the BET + EMF compared to EMF group was observed. The expression of RUNX2 and OCN genes in the EMF-treated groups were significantly reduced compared to the non-EMF-treated groups, and BET+EMF showed a significant increase of RUNX2 gene expression as compared the EMF group. The ELF-EMF leads to a decrease in the osteogenic differentiation and the expression RUNX2 and OCN genes in hADSCs. But osteogenic differentiation and RUNX2 gene expression were increased post-induction by betaine. The synergic effect of betaine and EMF on the osteogenic differentiation and related genes expression of hADSCs was higher than EMF.
