ObjectiveTo review the chondrocyte survival microenvironment and the research progress of the application of microfluidic chips in constructing the chondrocyte microenvironment. MethodsRecent literature about the role of microenvironment in the regulation of chondrocytes and the application of microfluidic chips in constructing the chondrocyte microenvironment was reviewed and analyzed. ResultsRegulating the microenvironment of chondrocyte mainly involves extracellular matrix microenvironment, mechanical microenvironment, electric microenvironment, and hypoxic microenvironment. Currently, the related research of chondrocyte microenvironment based on microfluidic system mainly involves biochemical stimuli, mechanical stimuli, production of biomimetic scaffold materials, and so on. ConclusionIt will be helpful for constructing cartilage tissue being closer to the physiological function in the future to deeply understand chondrocyte survival environment and to mimic the microenvironment in vivo required by chondrocyte development as possible by using microfluidic chips.
ObjectiveTo review the relative researches about mechanical stimulation of stem cells differentiation in stem cells microenvironment in vitro. MethodsThe recent related literature about stem cells differentiation in vitro was reviewed and summarized. ResultsThe mechanical loads (including shear stress, mechanical strain, and stress), substrates stiffness, substrates nanotopography, and cell shape were the 4 important aspects of mechanical factors regulating stem cells differentiation. The mechanical stimulation can simulate the in vivo microenvironment, which can alter the size, shape, alignment, and differentiation state of stem cells, can change the expression of their differentiation markers, and can affect the lineage commitment of stem cells. ConclusionMechanical stimulation play an important role in regulating stem cells differentiation and cells morphology in addition to chemical and biological factors.
ObjectiveTo review the research progress of microenvironment for the treatment of peripheral nervous injuries. MethodsThe recent literature concerning the treatment mechanism of peripheral nervous injuries was extensively consulted, and the microenvironment response involved in the treatment of peripheral nervous injuries was reviewed. ResultsThe complex microenvironment for treatment of peripheral nervous injuries is dependent on nerve regeneration chamber, the formation of neurotrophic factors, inflammation response, regulation of hormones, signaling pathways, and related enzymes in regulation. In-depth study will help us have a clearer understanding on the distal and proximal neurons axons at the cellular and molecular levels after peripheral nervous injuries. ConclusionIn recent years, the researches of microenvironment for the treatment of peripheral nervous injuries have achieved obvious progress. With the current nanotechnology, materials science, genetic engineering, and stem cell transplantation technology, it will provide new ideas and corresponding basis for clinical treatment.
ObjectiveTo investigate the differentiation potential of human umbilical cord mesenchymal stem cells (HUCMSCs) into hepatocytes induced by rat fibrotic liver tissue extracts. MethodsLiver fibrosis was induced in the Sprague Dawley rats (weighting, 180-220 g) by repeated intraperitoneal injections of 3% thioacetamide-saline at a dose of 200 mg/kg twice a week for 4 weeks;fibrotic liver tissues were used to prepare liver homogenate supernatants. The HUCMSCs at passage 3 were cultured in DMEM/F12 with 10% fetal bovine serum (FBS) (control group) and in DMEM/F12 with 10%FBS and 50 g/L liver homogenate supernatants (experimental group) for 7 days. The morphological changes of the cells were recorded;the protein levels of cytokeratin 18 (CK18), alpha fetoprotein (AFP), and CYP3A4 were measured using Western blot. The glycogen storing ability of the cells was detected by periodic acid-schiff (PAS) staining. Furthermore, the synthesis of albumin (ALB) and blood urea nitrogen (BUN) was measured. ResultsIn experimental group, after 1 day of induction, the stem cells of fusiform shape began to lose sharp edges and progressively shrunk, and then they changed into hepatocyte-like cells with round and irregular shape at 7 days. Positive expressions of AFP, CK18, and CYP3A4 were observed in the experimental group, but negative expression in the control group. The concentrations of BUN and ALB were (0.43±0.07) mmol/L and (8.08±0.41) μg/mL in the control group and were (2.52±0.20) mmol/L and (41.48±4.11) μg/mL in the experimental group, showing significant differences (t=24.160, P=0.000;t=19.810, P=0.000). PAS staining results showed navy blue nucleus and lavender cytoplasm in the control group, but dark purple cell body and visible nucleus in the experimental group. ConclusionHUCMSCs could differentiate into hepatocyte-like cells induced by rat fibrotic liver tissue extracts, which have hepatocyte biomarkers (AFP, CK18, and CYP3A4) and hepatocyte-specific functions of glycogen storage, urea production and ALB secretion, so they could partially replace the function of hepatocytes, that may be one of the therapeutic mechanisms of stem cell transplantation.
Uveal melanoma (UM) is an aggressive and lethal tumor in the eye. The complexity and heterogeneity of UM and its microenvironment leads to a lack of strategies for early prevention and treatment of metastases. Single-cell sequencing technologies provide critical insights into deciphering the complexity of intratumor heterogeneity and the microenvironment by enabling genomic, transcriptomic, and epigenetic analysis at the single-cell level. With the help of bioinformatics analysis combined with artificial intelligence algorithms, molecular indicator systems related to prognosis as well as therapeutic targets can be found, which can provide a basis for guiding the selection of clinical treatment plans. However, the single-cell sequencing technology also has certain limitations, such as high sample requirements, expensive and time-consuming sequencing. It is believed that with the improvement of science and technology and the update of analytical methods, these shortcomings can be gradually solved, and this rare tumor will eventually be overcome in the future, and the goal of long-term survival of UM patients will be achieved.
Stem cells have been regarded with promising application potential in tissue engineering and regenerative medicine due to their self-renewal and multidirectional differentiation abilities. However, their fate is relied on their local microenvironment, or niche. Recent studied have demonstrated that biophysical factors, defined as physical microenvironment in which stem cells located play a vital role in regulating stem cell committed differentiation. In vitro, synthetic physical microenvironments can be used to precisely control a variety of biophysical properties. On this basis, the effect of biophysical properties such as matrix stiffness, matrix topography and mechanical force on the committed differentiation of stem cells was further investigated. This paper summarizes the approach of mechanical models of artificial physical microenvironment and reviews the effects of different biophysical characteristics on stem cell differentiation, in order to provide reference for future research and development in related fields.