Application of mesenchymal stem cell therapy for the treatment of osteoarthritis of the knee: A concise review

Background: Due to their intrinsic properties, stem cells are promising tools for new developments in tissue engineering and particularly for cartilage tissue regeneration. Although mesenchymal stromal/stem cells from bone marrow (BM-MSC) have long been the most used stem cell source in cartilage tissue engineering, they have certain limits. Thanks to their properties such as low immunogenicity and particularly chondrogenic differentiation potential, mesenchymal stromal/stem cells from Wharton’s jelly (WJ-MSC) promise to be an interesting source of MSC for cartilage tissue engineering. Methods: In this study, we propose to evaluate chondrogenic potential of WJ-MSC embedded in alginate/hyaluronic acid hydrogel over 28 days. Hydrogels were constructed by the original spraying method. Our main objective was to evaluate chondrogenic differentiation of WJ-MSC on three-dimensional scaffolds, without adding growth factors, at transcript and protein levels. We compared the results to those obtained from standard BM-MSC. Results: After 3 days of culture, WJ-MSC seemed to be adapted to their new three-dimensional environment without any detectable damage. From day 14 and up to 28 days, the proportion of WJ-MSC CD73⁺, CD90⁺, CD105⁺ and CD166⁺ decreased significantly compared to monolayer marker expression. Moreover, WJ-MSC and BM-MSC showed different phenotype profiles. After 28 days of scaffold culture, our results showed strong upregulation of cartilage-specific transcript expression. WJ-MSC exhibited greater type II collagen synthesis than BM-MSC at both transcript and protein levels. Furthermore, our work highlighted a relevant result showing that WJ-MSC expressed Runx2 and type X collagen at lower levels than BM-MSC. Conclusions: Once seeded in the hydrogel scaffold, WJ-MSC and BM-MSC have different profiles of chondrogenic differentiation at both the phenotypic level and matrix synthesis. After 4 weeks, WJ-MSC, embedded in a three-dimensional environment, were able to adapt to their environment and express specific cartilage-related genes and matrix proteins. Today, WJ-MSC represent a real alternative source of stem cells for cartilage tissue engineering.

A series of chitosan-modified zein composite films were fabricated from zein and chitosan by a process involving blending, solution casting and evaporation. Effects of chitosan content on the structure and physical properties of the composite films were investigated by Fourier transform infrared spectroscopy, differential scanning calorimetry, scanning electron microscopy, tensile testing, water absorption measurement and water contact angle measurement. The results showed that the zein/chitosan composite films were fabricated successfully due to the formation of hydrogen bonds between zein and chitosan, and the thermal stability, water absorption, hydrophilicity, tensile strength, flexibility of the composite films increased with an increase in chitosan content from 0 to 50%. The cytotoxicity and cytocompatibility of the composite films were evaluated by 3-[45-dimethyl-2-thiazoly1]-25-diphenyl-2H-tetrazolium bromide (MTT) assay and in vitro cell culture, which showed that the films have non- or low-cytotoxicity, and chitosan promoted the growth, adhesion and proliferation of the cells. These results indicated that chitosan-modified zein composite films might have potentials applications as biomaterials.

Therapeutic prospects of mesenchymal stem/stromal cells in COVID-19 associated pulmonary diseases: From bench to bedside

: The outbreak of coronavirus disease 2019 (COVID-19) triggered by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become a widespread pandemic globally and seriously threatened public health. Patients with COVID-19 infection, and in particular, those with severe pneumonia-associated acute respiratory distress syndrome (ARDS) manifested rapid disease progression and the resultant high mortality and morbidity. Advances in fundamental and clinical studies have suggested the feasibility of mesenchymal stem/stromal cell (MSC)-based therapy as an inspiring alternative for ARDS administration. However, the systematic characteristics of the MSC-based cytotherapy and underlying mechanism for COVID-19 associated ARDS by bibliometric analyses are still unknowable. Herein, we took advantage of visual analyses to reveal the overview of ARDS-associated updates, core authors and focused issues, as well as to summarize the comprehensive knowledge of the keywords, authors, institutions with the aid of indicated software. Meanwhile, we have provided a brief overview on the molecular mechanisms and discussed the safety and efficacy of MSC-based therapy for ARDS on the basis of clinical trials.