Proliferation Of Bone Marrow Mesenchymal Stem Cells Research Articles

Thermodynamic 2D Silicene for Sequential and Multistage Bone Regeneration.

Bone healing is a multistage process involving the recruitment of cells, revascularization, and osteogenic differentiation, all of which are modulated in the temporal sequence to maximize cascade bone regeneration. However, insufficient osteoblast cells, poor blood supply, and limited bone induction at the site of critical-sized bone defect broadly impede bone repair. 2D SiO2 -silicene@2,2'-,azobis(2-[2-imidazolin-2-yl] propane) (SNSs@AIPH) with inherent thermodynamic property and osteoinductive activity is therefore designed and engineered for sequentially efficient bone repair. By means of controllable NIR-II irradiation, the integrated SNSs@AIPH stimulates the generation of appropriate intracellular reactive oxygen species, which accelerates early bone marrow mesenchymal stem cells (BMSCs) proliferation and angiogenesis remarkably. Importantly, as silicon-based 2D nanoparticles, the engineered SNSs@AIPH with high biocompatibility features distinct bioactivity to significantly promote BMSCs osteogenesis differentiation by activating TGFβ and BMP pathways. In a rat cranial defect model, SNSs@AIPH-NIR-II leads to a comparable increase of BMSCs proliferation and local vascularization at an early stage, followed by significant osteogenic differentiation, synergically resulting in a highly effective bone repair. Collectively, the fascinating characteristics and exceptional bone repair efficiency of NIR-II-mediated SNSs@AIPH allow it to be a promising bionic-oriented strategy for bone regeneration, broadening a new perspective in the application of cell-instructive biomaterials in bone tissue engineering.

Silk-Inorganic Nanoparticle Hybrid Hydrogel as an Injectable Bone Repairing Biomaterial.

Silk fibroin is regarded as a promising biomaterial in various areas, including bone tissue regeneration. Herein, Laponite® (LAP), which can promote osteogenic differentiation, was introduced into regenerated silk fibroin (RSF) to prepare an RSF/LAP hybrid hydrogel. This thixotropic hydrogel is injectable during the operation process, which is favorable for repairing bone defects. Our previous work demonstrated that the RSF/LAP hydrogel greatly promoted the osteogenic differentiation of osteoblasts in vitro. In the present study, the RSF/LAP hydrogel was found to have excellent biocompatibility and significantly improved new bone formation in a standard rat calvarial defect model in vivo. Additionally, the underlying biological mechanism of the RSF/LAP hydrogel in promoting osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) was extensively explored. The results indicate that the RSF/LAP hydrogels provide suitable conditions for the adhesion and proliferation of BMSCs, showing good biocompatibility in vitro. With the increase in LAP content, the alkaline phosphatase (ALP) activity and mRNA and protein expression of the osteogenic markers of BMSCs improved significantly. Protein kinase B (AKT) pathway activation was found to be responsible for the inherent osteogenic properties of the RSF/LAP hybrid hydrogel. Therefore, the results shown in this study firmly suggest such an injectable RSF/LAP hydrogel with good biocompatibility (both in vitro and in vivo) would have good application prospects in the field of bone regeneration.

Mechanosensitive miR-99b mediates the regulatory effect of matrix stiffness on bone marrow mesenchymal stem cell fate both in vitro and in vivo.

Mechanical signals from extracellular matrix stiffness are important cues that regulate the proliferation and differentiation of bone marrow mesenchymal stem cells (BMSCs). However, the incorporation of BMSCs into soft hydrogels and the dominance of soft matrices for BMSC growth and differentiation limit the directed differentiation of BMSCs incorporated into hydrogels for tissue engineering, especially osteogenesis. Here, we found that the expression of miR-99b increased with increasing hydrogel stiffness and that miR-99b regulated the proliferation and differentiation of BMSCs seeded on the surface of substrates with different stiffnesses. Furthermore, miR-99b significantly promoted the migration of BMSCs in 3D hydrogels. Mechanistically, we demonstrated that matrix stiffness-sensitive miR-99b targets the mammalian target of the rapamycin signaling pathway to regulate the adipogenic and osteogenic differentiation of BMSCs. In addition, by modulating the expression of miR-99b, the osteogenic differentiation of BMSCs in soft 3D hydrogels was promoted. Consistently, the flexible BMSC-GelMA hydrogel transfected with miR-99b significantly promoted bone regeneration in the rat calvarial defect area. These results suggest that miR-99b plays a key role in the mechanotransduction and phenotypic transformation of BMSCs and may inspire new tissue engineering applications with MSCs as key components.

Bacterial cellulose membrane combined with BMSCs promotes wound healing by activating the notch signaling pathway.

The bacterial cellulose membrane (BCM) has been widely studied and applied as a new biomaterial for wound healing, but causes pain with frequent dressing changes. Local application of bone marrow mesenchymal stem cells (BMSCs) requires a niche. Furthermore, the effect and mechanism of the BCM combined with BMSCs have not been reported. Morphological and chemical identifications of BCMs were investigated by porosity analyses, scanning electron microscopy, and Fourier-transform infrared spectroscopy. Biological wound dressings (BWDs) were prepared by the BCM in combination with BMSCs. The biological effects of BWDs on human dermal fibroblast (HDF) and VEGF-A in human vascular endothelial cells (HuVECs) were detected in vitro, and the effect of BWDs on acute wounds in mice was detected in vivo. Collagen and angiogenesis were evaluated through hematoxylin-eosin staining and Masson staining. The expressions of COL-1 and VEGF-A and the activation of the Notch signaling pathway in vivo and in vitro were detected by quantitative reverse-transcriptase polymerase chain reaction. The BCM had a nanoscale structure and provided a partial niche for the survival and proliferation of BMSCs. BWDs were successfully prepared and regulated the biological behaviors of wound healing-related cells in vitro and upregulated the expressions of COL-1 in HDF and VEGF-A in HuVECs. BWDs promoted wound healing by increasing collagen type I synthesis and angiogenesis in acute wounds in mice. BWDs prepared by the combination of nanomaterial BCMs and BMSCs facilitated acute wound healing, which may be regulated by activating the Notch signaling pathway.

Engineered periosteum-diaphysis substitutes with biomimetic structure and composition promote the repair of large segmental bone defects

The repair of large segmental bone defects remains a big challenge due to limited self-healing capacity of bone. Digging into the structure and composition of natural long bone let us realize that the periosteum cambium on the surface of diaphysis plays a crucial role in bone repair. In this study, we explored the feasibility of using a tissue-engineered periosteum-diaphysis substitute to repair the large segmental bone defects. To create an artificial periosteum cambium, bone marrow mesenchymal stem cells (BMSCs) and endothelial progenitor cells (EPCs) were co-cultured on electrospun silk fibroin (SF) fibrous membranes for mimicking the cellular composition and microstructure of cambium layer of the native periosteum. These SF membranes supported the adhesion and proliferation of both BMSCs and EPCs. In addition, we found that a 1:1 ratio of BMSCs and EPCs supported osteogenesis and angiogenesis optimally. This biomimetic periosteum layer was integrated with artificial diaphysis made of tubular SF scaffolds to construct a biomimetic periosteum-diaphysis substitute. Animal studies confirmed that the biomimetic periosteum-diaphysis substitutes promoted the repair of critical-size bone defects of rabbit radius. Furthermore, the transplanted biomimetic periosteum-diaphysis substitute could prevent the growth of fibrous tissues in the bone defect, and thus reduce the occurrence of nonunion. This study described a promising tissue engineering strategy for the repair of large segmental bone defects.

COX-2/PGE2/VEGF signaling promotes ERK-mediated BMSCs osteogenic differentiation under hypoxia by the paracrine action of ECs.

Understanding the crosstalk between endothelial cells (ECs) and bone-marrow mesenchymal stem cells (BMSCs) in response to hypoxic environments and deciphering of the underlying mechanisms are of great relevance for better application of BMSCs in tissue engineering. Here, we demonstrated that hypoxia promoted BMSCs proliferation, colony formation, osteogenic markers expression, mineralization, and extracellular signal-regulated protein kinase (ERK) phosphorylation, and that PD98059 (ERK inhibitor) blocked hypoxia-induced osteogenic differentiation. Hypoxia enhanced ECs migration, cyclooxygenase 2 (COX-2) and integrin αvβ3 expression, and prostaglandin E2 (PGE2), vascular endothelial growth factor (VEGF) secretion. NS398 (selective COX-2 inhibitor) and LM609 (integrin αvβ3 specific inhibitor) impaired the ECs response to hypoxia, and exogenous PGE2 partially reversed the effects of NS398. BMSCs: ECs co-culture under hypoxia upregulated BMSCs osteogenesis and ERK phosphorylation, as well as ECs migration, integrin αvβ3 expression, and PGE2 and VEGF secretion. NS398 (pretreated ECs) lessened PGE2, VEGF concentrations of the co-culture system. NS398-treated ECs and AH6809 (combined EP1/2 antagonist)/L-798106 (selective EP3 antagonist)/L-161982 (selective EP4 antagonist)/SU5416 [VEGF receptor (VEGFR) inhibitor]-treated BMSCs impaired the co-cultured ECs-induced enhancement of BMSCs osteogenic differentiation. In conclusion, hypoxia enhances BMSCs proliferation and ERK-mediated osteogenic differentiation, and augments the COX-2-dependent PGE2 and VEGF release, integrin αvβ3 expression, and migration of ECs. COX-2/PGE2/VEGF signaling is involved in intercellular BMSCs: ECs communication under hypoxia.

Graphene/hydroxyapatite coating deposit on titanium alloys for implant application.

Titanium (Ti) implants are widely used in medicine. Meanwhile, surface modification of Ti can strengthen the osseointegration of implants. In this study, we modified Ti implant surfaces, which was coated with GO, HA, HA-2wt%GO and HA-5wt%GO via electrophoresis deposition, to investigate their mechanisms and biological activity. Uncoated Ti was used as the control. Further, we examined the biological behavior and osteogenic performance of mouse bone marrow mesenchymal stem cells (BMSCs) cultured on coatings in vitro. We found that the HA-GO nanocomposite coating improved the roughness and hydrophilicity of the Ti surface. Compared with the uncoated Ti or Ti modified by HA or GO alone, cell adhesion and diffusion were enhanced on HA-GO-modified Ti surfaces. In addition, the proliferation and osteogenic differentiation of BMSCs in vitro were significantly improved on HA-GO-modified surfaces, whereas osteogenesis-related gene expression and alkaline phosphatase activity were slightly enhanced. Furthermore, we noted that bone regeneration was improved in the HA-2wt%GO group in vivo. Thus, the HA-2wt%GO nanocomposite coating might have potential applications in the field of dental implants.

Retinol-Loaded Poly(vinyl alcohol)-Based Hydrogels as Suitable Biomaterials with Antimicrobial Properties for the Proliferation of Mesenchymal Stem Cells

Polyvinyl alcohol (PVA) hydrogels are well-known biomimetic 3D systems for mammalian cell cultures to mimic native tissues. Recently, several biomolecules were intended for use in PVA hydrogels to improve their biological properties. However, retinol, an important biomolecule, has not been combined with a PVA hydrogel for culturing bone marrow mesenchymal stem (BMMS) cells. Thus, for the first time, the effect of retinol on the physicochemical, antimicrobial, and cell proliferative properties of a PVA hydrogel was investigated. The ability of protein (3.15 nm) and mineral adsorption (4.8 mg/mL) of a PVA hydrogel was improved by 0.5 wt.% retinol. The antimicrobial effect of hydrogel was more significant in S. aureus (39.3 mm) than in E. coli (14.6 mm), and the effect was improved by increasing the retinol concentration. The BMMS cell proliferation was more upregulated in retinol-loaded PVA hydrogel than in the control at 7 days. We demonstrate that the respective in vitro degradation rate of retinol-loaded PVA hydrogels (RPH) (75-78% degradation) may promote both antibacterial and cellular proliferation. Interestingly, the incorporation of retinol did not affect the cell-loading capacity of PVA hydrogel. Accordingly, the fabricated PVA retinol hydrogel proved its compatibility in a stem cell culture and could be a potential biomaterial for tissue regeneration.

Proteomics reveals the potential mechanism of Tanshinone IIA in promoting the ExVivo expansion of human bone marrow mesenchymal stem cells.

Bone marrow mesenchymal stem cells (BMSCs) are a promising cell type for tissue engineering, however, the application of BMSCs is largely hampered by the limited number harvested from bone marrow cells. The methods or strategies that focused on promoting the capacity of BMSCs expansion exvivo become more and more important. Tanshinone IIA (Tan IIA), the main active components of Danshen, has been found to promote BMSCs proliferation, but the underlying mechanism is still unclear. The aim of this study is to explore the effect and underlying mechanism of Tan IIA on the expansion capacity of hBMSCs exvivo. In this present study, the effect of Tan IIA on the expansion capacity of BMSCs from human was investigated, and quantitative proteome analysis was applied furtherly to identify the differentially expressed proteins (DEPs) and the molecular signaling pathways in Tan IIA-treated hBMSCs. Finally, molecular biology skills were employed to verify the proposed mechanism of Tan IIA in promoting hBMSCs expansion. The results showed that a total of 84 DEPs were identified, of which 51 proteins were upregulated and 33 proteins were downregulated. Besides, Tan IIA could promote hBMSCs proliferation by regulating the progression of S phase via increasing the release of fibroblast growth factor 2 (FGF2), FGF-mediated PI3K/AKT signaling pathways may play an important role in Tan IIA's effect on hBMSCs expansion. This study employed molecular biology skills combined with quantitative proteome analysis, to some extent, clarified the mechanism of Tan IIA's effect on promoting hBMSCs proliferation, and will give a hint that Tan IIA may have the potential to be used for BMSCs applications in cell therapies in the future.

MiR-145 inhibits the differentiation and proliferation of bone marrow stromal mesenchymal stem cells by GABARAPL1 in steroid-induced femoral head necrosis

Steroid-induced osteonecrosis of femoral head (SANFH) involves impaired differentiation of bone marrow mesenchymal stem cells (BMSC), the mechanism of which is regulated by multiple microRNAs. Studies have shown that miR-145 is a key regulatory molecule of BMSC cells, but its mechanism in steroid-induced femur head necrosis remains unclear. The present study mainly explored the specific mechanism of miR-145 involved in SANFH. In this study dexamethasone, a typical glucocorticoid, was used to induce osteogenic differentiation of BMSC cells. Western blot, qPCR, CCK8 and flow cytometry were used to investigate the effects of miR-145 on the proliferation and differentiation of BMSC. The relationship between miR-145 and GABA Type A Receptor Associated Protein Like 1(GABARAPL1) was identified using dual luciferase reports and the effects of the two molecules on BMSC were investigated in vitro. The results showed that miR-145 was up-regulated in SANFH patients, while GABARAPL1 was down-regulated. Inhibition of miR-145 can improve apoptosis and promote proliferation and activation of BMSC. GABARAPL1 is a downstream target gene of miR-145 and is negatively regulated by miR-145. In conclusion, miR-145 regulates the proliferation and differentiation of glucocorticoid-induced BMSC cells through GABARAPL1 and pharmacologically inhibit targeting miR-145 may provide new aspect for the treatment of SANFH.

Tuning the Poisson's ratio of poly(ethylene glycol) diacrylate/cellulose nanofibril aerogel scaffold precisely for cultivation of bone marrow mesenchymal stem cell.

Tissue engineering (TE) scaffolds with appropriate Poisson's ratio (PR) are suitable for mimicking the environment of native tissues on which cells could survive and thrive better. Herein, cellular structured scaffolds are made by a new composite poly(ethylene glycol) diacrylate/cellulose nanofibril aerogel, with prototypes of the hexagonal, reentrant, and semireentrant models. Scaffolds with different geometry parameters (l, t, α) are designed and simulated by COMSOL to enable precise regulation of their PR. Then, nine groups of scaffolds with different PRs ranging from -0.5 to 0.85 are designed by adjusting geometry parameters and fabricated by using stereolithography and freeze-drying techniques. Subsequently, bone marrow mesenchymal stem cells (BMSc) are cultured on these scaffolds for 21 days, during which CCK8 assay, fluorescence microscope observation, and real-time polymerase chain reaction experiments are performed to characterize the proliferation and differentiation of BMSc. The results reflect that the scaffolds with different PR can provide various stress environments for cells, and the scaffold with zero PR is the most suitable for BMSc differentiating into chondrocytes during early culture experiments. This study suggests that tuning PR precisely is an attractive and effective strategy to provide a cells-suitable environment for scaffold fabrication for TE.

Stromal Cell-Derived Factor 1 (SDF-1) Regulates the Proliferation of Bone Marrow Mesenchymal Stem Cells (BMSCs) and Affects Myocardial Cell Injury

Acute myocardial infarction (AMI) is a serious disease with a high mortality. Stromal cell-derived factor 1 (SDF-1) can recruit circulating progenitor cell populations into damaged tissues. Bone marrow mesenchymal stem cells (BMSCs) have a variety of cellular functions. We studied the ability of SDF-1 to repair ischemia/reperfusion injury (IRI)-induced heart injury via regulating BMSCs proliferation in rats. Mouse BMSCs were isolated and expanded. Cell proliferation and apoptotic factors were analyzed. The rats were assigned into control group, BMSCs group or SDF-1-BMSCs group. SDF-1 expression was analyzed by ELISA. Rat heart function changes, the expression of various related factors, and the secretion of TNF- α were analyzed. SDF-1 stimulated BMSCs proliferation and decreased Caspase 3 activity ( P <0.05). Rats in BMSCs group and SDF-1-BMSCs group showed significantly improved cardiac function, higher expressions of Bcl-2 and VEGF, and lower levels of TNF- α ( P < 0.05), while the improvement in SDF-1-BMSCs group was the most significant ( P <0.05). In conclusion, SDF-1 promotes the repair of IRI via promoting the proliferation of BMSCs and inhibiting apoptosis.

MiR-21 Overexpression Ameliorates the Myocardial Injury and Inflammation and Oxidative Stress

This study assessed the effect of miR-21 overexpression on the myocardial injury and inflammation and oxidative stress. Bone marrow mesenchymal stem cells (BMSCs) of rats and lentivirus with pLVX- miR-21 were isolated and assigned into control group, model group, BMSCs group and group of over presentation of miR-21 followed by analysis of the proliferative and apoptotic activity of damaged myocardial cells, miR-21 by RT-PCR and the level of Bcl-2, Bax and VEGF, SOD activity and ROS generation as well as the secretion of IL-6 and TNF- α . H/R group showed significantly upregulated miR-21 expression, decreased cell proliferation, increased Caspase3 activity, reduced Bcl-2, increased Bax as well as decreased VEGF and SOD activity, increased ROS generation and IL-6 and TNF- α secretion. However, BMSC group and miR-21-BMSC group showed the opposite changes of the above mentioned parameters with more changes in miR-21-BMSC group. In conclusion, the proliferation of BMSC is prompted and apoptosis is restrained with the overexpression of miR-21, leading to accelerated recovery of cardiac injury caused by IRI.

Decellularized tympanic membrane scaffold with bone marrow mesenchymal stem cells for repairing tympanic membrane perforation.

Tympanic membrane perforation (TMP) is a common disease in otology, and few acellular techniques have been reported for repairing this condition. Decellularized extracellular matrix (ECM) scaffolds have been used in organ reconstruction. This study on tissue engineering aimed to develop a tympanic membrane (TM) scaffold prepared using detergent immersion and bone marrow mesenchymal stem cells (BMSCs) as repair materials to reconstruct the TM. General structure was observed that the decellularized TM scaffold with BMSCs retained the original intact anatomical ECM structure, with no cell residue, as observed using scanning electron microscopy (SEM), and exhibited low immunogenicity. Therefore, we seeded the decellularized TM scaffold with BMSCs for recellularization. Histology and eosin staining, SEM and immunofluorescence in vivo showed that the recellularized TM patch had a natural ultrastructure and was suitable for the migration and proliferation of BMSCs. The auditory brainstem response (ABR) evaluated after recellularized TM patch repair was slightly higher than that of the normal TM, but the difference was not significant. The synthetic ECM scaffold provides temporary physical support for the three-dimensional growth of cells during the tissue developmental stage. The scaffold stimulates cells to secrete their own ECM required for tissue regeneration. The recellularized TM patch shows potential as a natural, ultrastructure biological material for TM reconstruction.

Berberine Encapsulated in Exosomes Derived from Platelet-Rich Plasma Promotes Chondrogenic Differentiation of the Bone Marrow Mesenchymal Stem Cells via the Wnt/β-Catenin Pathway.

Cartilage regenerative medicine, wherein the stem cells from adults exert a crucial role, has high potential in the treatment of defective articular cartilage. Recently, Bone marrow mesenchymal stem cells (BMSCs) are being increasingly recognized as an alternative source of adult stem cells, which are capable of differentiating into several cell types (e.g., adipocytes, chondrocytes, and osteoblasts). However, their proliferative properties and tendency to dedifferentiate restrict their use in clinical settings. Recently, a possible bioactive material PRP-exos (exosomes derived from platelet-rich plasma), has emerged, which can effectively facilitate the differentiation and proliferation of cells. Recent studies have reported that berberine (Ber), known to have anti-inflammatory properties, plays a role in osteogenesis. Since biological molecules are used in combinations, we attempted to assess the effect of Exos-Ber (PRP-exos in combination with Ber) on the chondrogenic differentiation of BMSCs in vitro. In this study, Exos-Ber was observed to promote the proliferation of BMSCs and cause their chondrogenic differentiation in vitro. Additionally, Exos-Ber could promote the migration of BMSCs and increase the protein expression of the chondrogenic genes (Collagen II, SOX9, Aggrecan). After treatment with Exos-Ber, significant induction of β-catenin expression was observed, which could be repressed successfully by adding β-catenin inhibitor XAV-939. Interestingly, the repression of the Wnt/β-catenin axis also resulted in reduced gene expression levels of Collagen II, SOX9, and Aggrecan. These observations indicated that Exos-Ber facilitated the differentiation of chondrogenic BMSCs by modulating the Wnt/β-catenin axis, which offers innovative insights into the reconstruction of cartilage.

Antifouling poly(PEGMA) grafting modified titanium surface reduces osseointegration through resisting adhesion of bone marrow mesenchymal stem cells

As an alternative strategy to achieve the desired bone augmentation, tenting screw technology (TST) has considerably broadened the indications for implant treatment. Titanium tenting screws are typically used in TST to maintain the space for bone regeneration. However, a high degree of osteogenic integration complicate titanium tenting screw removal and impact the bone healing micro-environment. Previous efforts have been focused on modifying titanium surfaces to enhance osseointegration while ignoring the opposite process. Due to the vital role of bone marrow mesenchymal stem cells (BMSCs) in bone regeneration, it might be feasible to reduce osseointegration around titanium tenting screws by resisting the adhesion of BMSCs. Herein, poly(ethylene glycol)methyl ether methacrylate (poly(PEGMA)) with an optimal length of PEG chain was incorporated with a Ti surface in terms of surface-initiated activators regenerated by electron transfer atom transfer radical polymerization (SI-ARGET ATRP). The cell apoptosis analysis showed that the new surface would not induce the apoptosis of BMSCs. Then, the adhesive and proliferative behaviors of BMSCs on the surface were analyzed which indicated that the poly(PEGMA) surface could inhibit the proliferation of BMSCs through resisting the adhesion process. Furthermore, in vivo experiments revealed the presence of the poly(PEGMA) on the surface resulted in a lower bone formation and osseointegration compared with the Ti group. Collectively, this dense poly(PEGMA) surface of Ti may serve as a promising material for clinical applications in the future. Statement of significanceThe poly(ethylene glycol)methyl ether methacrylate (poly(PEGMA)) with an optimal length of PEG chain was grafted onto a Ti surface by surface-initiated activators regenerated by electron transfer atom transfer radical polymerization (SI-ARGET ATRP). The PEGMA surface could reduce the osteogenic integration by preventing the adhesion of cells, resulting in a lower pullout force of the modified implant and thereby desirable and feasible applications in dental surgery.

Low-level laser therapy with different irradiation methods modulated the response of bone marrow mesenchymal stem cells in vitro.

Low-level laser therapy (LLLT) also known as photobiomodulation is a treatment to change cellular biological activity. The exact effects of LLLT remain unclear due to the different irradiation protocols. The purpose of this study was to investigate the effects of LLLT by three different irradiation methods on the proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) in vitro. BMSCs were inoculated in 24-well plates and then irradiated or not (control) with a laser using three different irradiation methods. The irradiation methods were spot irradiation, covering irradiation, and scanning irradiation according to different spot areas (0.07 cm2 or 1.96 cm2) and irradiation areas (0.35 cm2 or 1.96 cm2), respectively. The laser was applied three times at energy densities of 4J/cm2. The cell proliferation by CCK-8. ALP activity assay, alizarin red, and quantitative real-time polymerase chain reaction (RT-PCR) were performed to assess osteogenic differentiation and mineralization. Increases in cell proliferation was obvious following irradiation, especially for covering irradiation. The ALP activity was significantly increased in irradiated groups compared with non-irradiated control. The level of mineralization was obviously improved following irradiation, particularly for covering irradiation. RT-PCR detected significantly higher expression of ALP, OPN, OCN, and RUNX-2 in the group covering than in the others, and control is the lowest. The presented results indicate that the biostimulative effects of LLLT on BMSCs was influenced by t he irradiation method, and the covering irradiation is more favorable method to promote the proliferation and osteogenic differentiation of BMSCs.

A silk fibroin/chitosan/nanohydroxyapatite biomimetic bone scaffold combined with autologous concentrated growth factor promotes the proliferation and osteogenic differentiation of BMSCs and repair of critical bone defects.

PurposeWith the goal of increasing the translational efficiency of bone tissue engineering for practical clinical applications, biomimetic composite scaffolds combined with autologous endogenous growth factors for repairing bone defects have become a current research hotspot. In this study, we prepared a silk fibroin/chitosan/nanohydroxyapatite (SF/CS/nHA) composite biomimetic scaffold and then combined it with autologous concentrated growth factor (CGF) to explore the effect of this combination on the proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) and the efficiency of repairing critical radial defects.MethodsThree kinds of SF/CS/nHA composite biomimetic scaffolds with mass fractions of 3%, 4%, and 5% were prepared by vacuum freeze-drying and chemical cross-linking methods, and the characteristics of the scaffolds were evaluated. In vitro, BMSCs were seeded on SF/CS/nHA scaffolds, and then CGF was added. The morphology and proliferation of BMSCs were evaluated by live-dead staining, phalloidin staining, and CCK-8 assays. ALP staining, alizarin red staining, cellular immunofluorescence, RT–PCR, and Western blotting were used to detect the osteogenic differentiation of BMSCs. In vivo, a rabbit radius critical bone defect model was constructed, and the SF/CS/nHA-BMSC scaffold cell complex combined with CGF was implanted. The effect on bone defect repair was evaluated by 3D CT scanning, HE staining, Masson staining, and immunohistochemistry.ResultsThe characteristics of 4% SF/CS/nHA were the most suitable for repairing bone defects. In vitro, the SF/CS/nHA combined CGF group showed better adhesion, cell morphology, proliferation, and osteogenic differentiation of BMSCs than the other groups (P < 0.05 for all). In vivo imaging examination and histological analysis demonstrated that the SF/CS/nHA scaffold combined with CGF had better efficiency in bone defect repair than the other scaffolds (P < 0.05 for all).ConclusionsA SF/CS/nHA composite biomimetic bone scaffold combined with autologous CGF promoted the proliferation and osteogenic differentiation of BMSCs in vitro and improved the repair efficiency of critical bone defects in vivo. This combination may have the potential for clinical translation due to its excellent biocompatibility.

MiR-29b Modulates Bone Marrow Mesenchymal Stem Cells (BMSCs) Differentiation and Induces Nerve Repair in Diabetic Retina Rat Model

microRNAs are involved in diabetic retinopathy (DR). This study intends to analyze miR-29b’s role in bone marrow mesenchymal stem cells (BMSCs) differentiation in DR rat models to induce nerve repair. BMSCs from DR rat models were cultured and transfected with miR-29b mimics and inhibitors followed by measuring miR-29b level, cell proliferation and apoptosis. Retinal ganglion cells (RGC) were treated with high glucose for 24 h, and BMSCs and si-miR-29b-BMSC were cocultured for 24 h, respectively followed by assessing cell proliferation and apoptosis, inflammatory cytokines by ELISA, MDA, SOD, brain-derived neurotrophic factor (BDNF) and ciliary neurotrophic factor (CNTF) level by ELISA. MiR-29b was up-regulated in BMSCs of DR rats. miR-29b mimics significantly up-regulated miR-29b, inhibited cell proliferation and promoted apoptosis (P &lt; 0.05), which were reversed by miR-29b inhibitor (P &lt; 0.05). Co-culture of BMSCs with si-miR-29b-BMSC promoted RGC proliferation, inhibited apoptosis and IL-6 secretion, decreased MDA, increased SOD, BDNF and CNTF expression (P &lt; 0.05) with more significant changes in si-miR-29b-BMSC group (P &lt; 0.05). In conclusion, down-regulation of miR-29b promotes BMSCs proliferation in DR rat models, inhibits BMSCs apoptosis, and promotes the recovery of retinal ganglion cell function.

Taohong Siwu decoction promotes the process of fracture healing by activating the VEGF-FAK signal pathway and systemically regulating the gut microbiota.

This study aimed to explore the effect of Taohong Siwu Decoction (THSWD) on bone marrow mesenchymal stem cells (BMSCs) at the cellular level and the possible mechanism of systemic regulation of gut microbiota on fracture recovery. Cell Counting Kit-8 (CCK-8) experiments show that THSWD effectively promotes the proliferation of BMSCs. Transwell and wound healing assays show that THSWD effectively promotes the invasion and migration of BMSCs. Alizarin red staining showed that the THSWD model enhanced the osteogenic differentiation of BMSCs. Moreover, the effect of THSWD on BMSCs is time- and concentration-dependent. RT-qPCR and western blot results showed that THSWD treatment up-regulated the expression of vascular endothelial growth factor (VEGF) and focal adhesion kinase (FAK) at mRNA and protein levels, respectively. Haematoxylin-eosin and crocin O-quick green staining showed that after 14 days of THSWD treatment, the area of callus and cartilage regeneration at the fracture site increased significantly in rats with right femoral shaft fractures. Gut microbiota was changed in fractured rats, such as the abundance of Bacteroidetes and Firmicutes was increased. THSWD showed positive regulation of both to a certain extent. THSWD up-regulates VEGF and activates the FAK signalling pathway to enhance the development and differentiation of BMSCs, and systematically regulates the gut microbiota to promote fracture healing. This study provides new insights on the cellular and systemic level to understand the mechanism of THSWD in the treatment of fractures.