Human stem cells and articular cartilage regeneration.

The regeneration of articular cartilage damaged due to trauma and posttraumatic osteoarthritis is an unmet medical need. Current approaches to regeneration and tissue engineering of articular cartilage include the use of chondrocytes, stem cells, scaffolds and signals, including morphogens and growth factors. Stem cells, as a source of cells for articular cartilage regeneration, are a critical factor for articular cartilage regeneration. This is because articular cartilage tissue has a low cell turnover and does not heal spontaneously. Adult stem cells have been isolated from various tissues, such as bone marrow, adipose, synovial tissue, muscle and periosteum. Signals of the transforming growth factor beta superfamily play critical roles in chondrogenesis. However, adult stem cells derived from various tissues tend to differ in their chondrogenic potential. Pluripotent stem cells have unlimited proliferative capacity compared to adult stem cells. Chondrogenesis from embryonic stem (ES) cells has been studied for more than a decade. However, establishment of ES cells requires embryos and leads to ethical issues for clinical applications. Induced pluripotent stem (iPS) cells are generated by cellular reprogramming of adult cells by transcription factors. Although iPS cells have chondrogenic potential, optimization, generation and differentiation toward articular chondrocytes are currently under intense investigation

Comparative study of the osteogenic potential of mesenchymal stem cells derived from different sources

Mesenchymal stem cells (MSCs) can regenerate missing tissues and treat diseases. Hence, the current work aimed to compare the proliferation rate and the osteogenic differentiation potential of bone marrow MSCs (BMSCs), gingival MSCs (GMSCs) and submandibular MSCs (SMSCs). MSCs derived from bone marrow, gingiva and submandibular salivary gland were isolated and cultured from rats. The proliferation capacity was judged by MTT proliferation Assay. Osteogenic differentiation was assessed by Alzarin red stain and quantitative RT-PCR was performed for Runx-2 and MMP-13. The highest significant proliferation was estimated in the BMSCs compared to GMSCs and SMSCs (p-value was < 0.01). All studied cell types formed mineralized nodules as stained with Alizarin Red stain at the 3rd passage of differentiation. However, BMSCs seemed to generate the highest level of mineralization compared to GMSCs and SMSCs. RT-PCR revealed that the expression of Runx-2 and MMP-13 mRNAs was significantly increased in the BMSCs compared to GMSCs and SMSCs (p-value was < 0.01). BMSCs displayed maximum osteogenesis results followed by the GMSCs and lastly by the SGSCs. Thus, it could be recommended that GMSCs can be used as a second choice after BMSCs when bone tissue reconstruction is needed

The Fas/Fap-1/Cav-1 Complex Regulates IL-1RA Secretion in Mesenchymal Stem Cells to Accelerate Wound Healing

Mesenchymal stem cells (MSCs) are capable of secreting exosomes, extracellular vesicles, and cytokines to regulate cell and tissue homeostasis. However, it is unknown whether MSCs use a specific exocytotic fusion mechanism to secrete exosomes and cytokines. We show that Fas binds with Fas-associated phosphatase–1 (Fap-1) and caveolin-1 (Cav-1) to activate a common soluble N-ethylmaleimide–sensitive factor (NSF) attachment protein receptor (SNARE)–mediated membrane fusion mechanism to release small extracellular vesicles (sEVs) in MSCs. Moreover, we reveal that MSCs produce and secrete interleukin-1 receptor antagonist (IL-1RA) associated with sEVs to maintain rapid wound healing in the gingiva via the Fas/Fap-1/Cav-1 cascade. Tumor necrosis factor–α (TNF-α) serves as an activator to up-regulate Fas and Fap-1 expression via the nuclear factor κB pathway to promote IL-1RA release. This study identifies a previously unknown Fas/Fap-1/Cav-1 axis that regulates SNARE-mediated sEV and IL-1RA secretion in stem cells, which contributes to accelerated wound healing

Synergistic contribution of activated carbon and PEDOT:PSS in hybrid electrodes for high-performance planar micro-supercapacitors

The high-performance miniaturized micro-supercapacitors exhibit great potential due to their inherent properties of high-power density, fast charge–discharge rates, long cycle life, and wide working temperature range. However, there is a need to further enhance the energy density of micro-supercapacitors. In this study, we investigate a hybrid electrode material combination comprising activated carbon (AC) and polymer poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) to fabricate symmetric micro-supercapacitors (SMSCs) and employ the advanced Microplotter technique for the effective loading of active materials onto microelectrodes. The combination of AC and PEDOT:PSS is fine-tuned to attain optimal charge storage. This involves leveraging the synergistic impact of electrical double-layer capacitance from AC and pseudocapacitance from PEDOT:PSS, resulting in enhanced charge storage performance. Additionally, PEDOT:PSS acts as a mixed ion–electron conducting adhesive, effectively binding AC particles together and facilitating the rapid transport of both ions and electrons. As a result, the AC-PEDOT:PSS SMSCs demonstrate an impressive charge storage performance compared to AC SMSCs. At 1 mA/cm2, the measured areal capacitance (device areal capacitances) is 29.5 mF/cm2 (11.8 mF/cm2) for AC-PEDOT:PSS and 15.7 mF/cm2 (6.3 mF/cm2) for AC SMSCs. Furthermore, the areal energies and powers, considering active materials, are found to be 2.79 µWh/cm2 at 0.8 mW/cm2, and considering the device area of the SMSC, they are 1.12 µWh/cm2 at 0.32 mW/cm2. Notably, the AC-PEDOT:PSS SMSCs exhibit a stable long-term capacitance with 85% capacitance retention even after 5000 cycles. This work highlights the significant potential of hybrid materials in improving energy storage performance and showcases the innovative application of the Microplotter technique

Fgf Signaling in Cranial Suture Development and Related Diseases

Suture mesenchymal stem cells (SMSCs) are a heterogeneous stem cell population with the ability to self-renew and differentiate into multiple cell lineages. The cranial suture provides a niche for SMSCs to maintain suture patency, allowing for cranial bone repair and regeneration. In addition, the cranial suture functions as an intramembranous bone growth site during craniofacial bone development. Defects in suture development have been implicated in various congenital diseases, such as sutural agenesis and craniosynostosis. However, it remains largely unknown how intricate signaling pathways orchestrate suture and SMSC function in craniofacial bone development, homeostasis, repair and diseases. Studies in patients with syndromic craniosynostosis identified fibroblast growth factor (FGF) signaling as an important signaling pathway that regulates cranial vault development. A series of in vitro and in vivo studies have since revealed the critical roles of FGF signaling in SMSCs, cranial suture and cranial skeleton development, and the pathogenesis of related diseases. Here, we summarize the characteristics of cranial sutures and SMSCs, and the important functions of the FGF signaling pathway in SMSC and cranial suture development as well as diseases caused by suture dysfunction. We also discuss emerging current and future studies of signaling regulation in SMSCs

Влияние инкапсуляции в альгинатные микросферы на жизнеспособность мезенхимальных стромальных клеток после экспозиции с проникающими криопротекторами

В работе изучено влияние инкапсуляции в альгинатные микросферы (АМС) на жизнеспособность мезенхимальных стромальных клеток (МСК) после экспозиции в течение 1,5 и 5 мин с растворами проникающих криопротекторов диметилсульфоксида (ДМСО), этиленгликоля (ЭГ) и 1,2-пропандиола (1,2-ПД) в концентрациях от 1,5 до 9 М. Установлено, что показатель жизнеспособности МСК в виде суспензии и АМС снижается с увеличением концентрации криопротекторов и времени экспозиции, а инкапсуляция в АМС существенно уменьшает токсическое повреждение клеток криопротекторами. Так, если 5-минутная экспозиция МСК в виде суспензии с 9 М ДМСО, ЭГ и 1,2-ПД приводила к гибели практически всех клеток в суспензии, то жизнеспособность МСК в составе АМС после экспозиции в аналогичных условиях составляла 60, 80 и 52% соответственно. Установлено, что исследованные проникающие криопротекторы обладают разной цитотоксичностью по отношению к МСК, которая снижается в ряду ДМСО > 1,2-ПД > ЭГ. Полученные результаты могут быть использованы при разработке многокомпонентных витрифицирующих растворов.У роботі вивчено вплив інкапсуляції в альгінатні мікросфери (АМС) на життєздатність мезенхімальних стромальних клітин (МСК) після експозиції протягом 1,5 і 5 хв із розчинами проникних кріопротекторів диметилсульфоксиду (ДМСО), етиленгліколю (ЕГ) і 1,2-пропандіолу (1,2-ПД) у концентраціях від 1,5 до 9 М. Встановлено, що показник життєздатності МСК у суспензії та АМС знижується зі збільшенням концентрації кріопротекторів та часу експозиції, а інкапсуляція в АМС суттєво зменшує токсичне пошкодження кріопротекторами клітин. Так, якщо 5-хвилинна експозиція з 9 М ДМСО, ЕГ і 1,2-ПД призводила до загибелі практично всіх клітин у суспензії, то життєздатність МСК у складі АМС після експозиції в аналогічних умовах становила 60, 80 і 52% відповідно. Доведено, що досліджені проникні кріопротектори мають різну цитотоксичність по відношенню до МСК, яка знижується у ряду ДМСО > 1,2-ПД > ЕГ. Отримані результати можуть бути використані під час розробки багатокомпонентних розчинів для вітрифікації.The effect of encapsulation into alginate microspheres (AMS) on viability of mesenchymal stromal cells (MSCs) after exposure to the solutions of penetrating cryoprotectants dimethyl sulfoxide (DMSO), ethylene glycol (EG) and 1,2-propane diol (1,2-PD) with concentrations varying from 1.5 to 9 M during 1.5 and 5 min was studied. It was shown that the viability of MSCs both as a suspension and encapsulated in AMS decreased with a rise in cryoprotectant concentration and exposure time. Encapsulation into AMS significantly protected the cells from cytotoxic damage of the cryoprotectants, e. g. if the 5-min exposure to 9 M DMSO, EG and 1,2-PD resulted in the death of quite all the cells in the suspension, the viability of encapsulated MSCs after exposure under similar conditions made 60, 80 and 52% respectively. It was found that the studied penetrating cryoprotectants had a various cytotoxicity to MSCs, and it decreased in the row DMSO > 1,2-PD > EG. The findings can be used to develop a multi-component vitrifying solution

The Fas/Fap-1/Cav-1 complex regulates IL-1RA secretion in mesenchymal stem cells to accelerate wound healing

Mesenchymal stem cells (MSCs) are capable of secreting exosomes, extracellular vesicles, and cytokines to regulate cell and tissue homeostasis. However, it is unknown whether MSCs use a specific exocytotic fusion mechanism to secrete exosomes and cytokines. We show that Fas binds with Fas-Associated phosphatase-1 (Fap-1) and caveolin-1 (Cav-1) to activate a common soluble N-ethylmaleimide-sensitive factor (NSF) attachment protein receptor (SNARE)-mediated membrane fusion mechanism to release small extracellular vesicles (sEVs) in MSCs. Moreover, we reveal that MSCs produce and secrete interleukin-1 receptor antagonist (IL-1RA) associated with sEVs to maintain rapid wound healing in the gingiva via the Fas/Fap-1/Cav-1 cascade. Tumor necrosis factor-? (TNF-?) serves as an activator to up-regulate Fas and Fap-1 expression via the nuclear factor ?B pathway to promote IL-1RA release. This study identifies a previously unknown Fas/Fap-1/Cav-1 axis that regulates SNARE-mediated sEV and IL-1RA secretion in stem cells, which contributes to accelerated wound healing. © 2018 The Authors, Some Rights Reserved

Basic fibroblast growth factor promotes meniscus regeneration through the cultivation of synovial mesenchymal stem cells via the CXCL6–CXCR2 pathway

Objective: To investigate the efficacy of basic fibroblast growth factor (bFGF) in promoting meniscus regeneration by cultivating synovial mesenchymal stem cells (SMSCs) and to validate the underlying mechanisms. Methods: Human SMSCs were collected from patients with osteoarthritis. Eight-week-old nude rats underwent hemi-meniscectomy, and SMSCs in pellet form, either with or without bFGF (1.0 × 106 cells per pellet), were implanted at the site of meniscus defects. Rats were divided into the control (no transplantation), FGF (−) (pellet without bFGF), and FGF (+) (pellet with bFGF) groups. Different examinations, including assessment of the regenerated meniscus area, histological scoring of the regenerated meniscus and cartilage, meniscus indentation test, and immunohistochemistry analysis, were performed at 4 and 8 weeks after surgery. Results: Transplanted SMSCs adhered to the regenerative meniscus. Compared with the control group, the FGF (+) group had larger regenerated meniscus areas, superior histological scores of the meniscus and cartilage, and better meniscus mechanical properties. RNA sequencing of SMSCs revealed that the gene expression of chemokines that bind to CXCR2 was upregulated by bFGF. Furthermore, conditioned medium derived from SMSCs cultivated with bFGF exhibited enhanced cell migration, proliferation, and chondrogenic differentiation, which were specifically inhibited by CXCR2 or CXCL6 inhibitors. Conclusion: SMSCs cultured with bFGF promoted the expression of CXCL6. This mechanism may enhance cell migration, proliferation, and chondrogenic differentiation, thereby resulting in superior meniscus regeneration and cartilage preservation.Goshima A., Etani Y., Hirao M., et al. Basic fibroblast growth factor promotes meniscus regeneration through the cultivation of synovial mesenchymal stem cells via the CXCL6–CXCR2 pathway. Osteoarthritis and Cartilage , (2023); https://doi.org/10.1016/j.joca.2023.07.010

Advanced Porous Gold-PANI Micro-Electrodes for High-Performance On-Chip Micro-Supercapacitors

The downsizing of microscale energy storage devices is crucial for powering modern on-chip technologies by miniaturizing electronic components. Developing high-performance microscale energy devices, such as micro-supercapacitors, is essential through processing smart electrodes for on-chip structures. In this context, we introduce porous gold (Au) interdigitated electrodes (IDEs) as current collectors for micro-supercapacitors, using polyaniline as the active material. These porous Au IDE-based symmetric micro-supercapacitors (P-SMSCs) show a remarkable enhancement in charge storage performance, with a 187% increase in areal capacitance at 2.5 mA compared to conventional flat Au IDE-based devices, despite identical active material loading times. Our P-SMSCs achieve an areal capacitance of 60 mF/cm2, a peak areal energy density of 5.44 μWh/cm2, and an areal power of 2778 μW/cm2, surpassing most reported SMSCs. This study advances high-performance SMSCs by developing highly porous microscale planar current collectors, optimizing microelectrode use, and maximizing capacity within a compact footprint