Low-Intensity Nanosecond Pulsed Electric Field Accelerates Osteogenic Transformation of Human Dermal Fibroblasts by Enhancing Cell Pluripotency.

Autologous human fibroblasts have the potential to differentiate into the osteogenic lineage under specific conditions and can be utilized for bone regeneration. However, their efficiency is currently unsatisfactory. Recently, low-intensity nanosecond pulsed electric field (nsPEF) stimulation has been demonstrated to enhance cell pluripotency by activating epigenetic regulatory pathways. In this study, human dermal fibroblasts were exposed to different intensities of nsPEF to assess whether these exposures resulted in changes in proliferation rate, calcium salt deposition, and expression of differentiation-related markers in different experimental groups. The results showed a significant increase in cell proliferation, pluripotency, bone marker expression, and osteogenic differentiation efficiency when stimulating cells with 5 kV/cm of nsPEF. However, cell proliferation and differentiation significantly decreased at 25 kV/cm. Additionally, the proliferation and efficiency of osteogenic differentiation were reduced when the nsPEF intensity was increased to 50 kV/cm. Treatment with a 5 kV/cm of nsPEF led to increased and concentrated expression of Yes-Associated Protein (YAP) in the nucleus. These observations suggest that human dermal fibroblasts possess a heightened potential to differentiate into osteogenic cells when activated with nsPEF at 5 kV/cm. Consequently, the nsPEF strengthening strategy shows promise for fibroblast-based tissue-engineered bone repair research.

Enhancing osteogenic differentiation in adipose-derived mesenchymal stem cells with Near Infra-Red and Green Photobiomodulation.

Worldwide, osteoporosis is the utmost predominant degenerative bone condition. Stem cell regenerative therapy using adipose-derived mesenchymal stem cells (ADMSCs) is a promising therapeutic route for osteoporosis. Photobiomodulation (PBM) has sparked considerable international appeal due to its' ability to augment stem cell proliferation and differentiation properties. Furthermore, the differentiation of ADMSCs into osteoblast cells and cellular proliferation effects have been established using a combination of osteogenic differentiation inducers and PBM. This in vitro study applied dexamethasone, ß-glycerophosphate disodium, and ascorbic acid as differentiation inducers for osteogenic induction differentiation media. In addition, PBM at a near-infrared (NIR) wavelength of 825 nm, a green (G) wavelength of 525 nm, and the novel combination of both these wavelengths using a single fluence of 5 J/cm2 had been applied to stimulate proliferation and differentiation effectivity of immortalised ADMSCs into early osteoblasts. Flow cytometry and ELISA were used to identify osteoblast antigens using early and late osteoblast protein markers. Alizarin red Stain was employed to identify calcium-rich deposits by cells within culture. The morphology of the cells was examined, and biochemical assays such as an EdU proliferation assay, MTT proliferation and viability assay, Mitochondrial Membrane Potential assay, and Reactive Oxygen Species assay were performed. The Central Scratch Test determined the cells' motility potential. The investigative outcomes revealed that a combination of PBM treatment and osteogenic differentiation inducers stimulated promising early osteogenic differentiation of immortalised ADMSCs. The NIR-Green PBM combination did appear to offer great potential for immortalised ADMSC differentiation into early osteoblasts amongst selected assays, however, further investigations will be required to establish the effectivity of this novel wavelength combination. This research contributes to the body of knowledge and assists in the establishment of a standard for osteogenic differentiation in vitro utilising PBM.

Therapeutic effects of isoquercetin on ovariectomy-induced osteoporosis in mice.

Bone marrow mesenchymal stem cells (BMSCs) are non-hematopoietic multipotent stem cells capable of differentiating into mature cells. Isoquercetin, an extract from natural sources, has shown promise as a potential treatment for osteoporosis. To investigate the therapeutic effects of isoquercetin on osteoporosis, bone marrow mesenchymal stem cells (BMSCs) were cultured in vitro, and osteogenesis or adipogenesis was induced in the presence of isoquercetin for 14 days. We evaluated cell viability, osteogenic and adipogenic differentiation, as well as mRNA expression levels of Runx2, Alpl, and OCN in osteoblasts, and mRNA expression levels of Pparγ, Fabp4, and Cebpα in adipocytes. The results showed that isoquercetin dose-dependently increased cell viability and promoted osteogenic differentiation, as evidenced by Alizarin Red and alkaline phosphatase staining and mRNA expression levels of Runx2, Alpl, and OCN in osteoblasts (P < 0.05). In contrast, isoquercetin inhibited adipogenic differentiation and decreased the mRNA expression levels of Pparγ, Fabp4, and Cebpα in adipocytes (P < 0.05). In vivo, isoquercetin treatment increased bone quantity and density in an osteoporosis model mice group, as determined by µCT scanning and immunohistochemistry (P < 0.05). These findings suggest that isoquercetin may have therapeutic potential for osteoporosis by promoting the proliferation and differentiation of BMSCs towards osteoblasts while inhibiting adipogenic differentiation.

Research and analysis of the properties of bredigite-based 3D-printed bone scaffolds.

The use of bone tissue-engineered scaffolds for repairing bone defects has become extremely common. Bone tissue-engineered scaffolds should have good mechanical properties, a pore structure similar to that of natural bone, appropriate biodegradability, and good biocompatibility to provide attachment sites for growth factors and seed cells. They also need to exhibit special functions such as osteoconductivity and osteoinduction. In this study, the mechanical, degradation, and biological properties of bredigite were studied by using a triply periodic minimal surface (TPMS) model structure. Pressure tests on bone tissue-engineered scaffolds showed that the mechanical properties of TPMS scaffolds were significantly better than those of open-rod scaffolds with the same porosity. By analyzing the biological properties, we found that the TPMS model had better protein adsorption ability than the open-rod model, the cells could better adsorb on the surface of the TPMS scaffold, and the proliferation number and proliferation rate of the TPMS model were higher than those of the open-ended rod model.

A Cartilaginous Construct with Bone Collar Exerts Bone-Regenerative Property Via Rapid Endochondral Ossification.

Three-dimensional clumps of mesenchymal stem cells (MSCs)/extracellular matrix (ECM) complexes (C-MSCs) can be implanted into tissue defects with no artificial scaffolds. In addition, the cellular properties and characteristics of the ECM in C-MSCs can be regulated in vitro. Most bone formation in the developmental and healing process is due to endochondral ossification, which occurs after bone collar formation surrounding cartilage derived from MSCs. Thus, to develop a rapid and reliable bone-regenerative cell therapy, the present study aimed to generate cartilaginous tissue covered with a mineralized bone collar-like structure from human C-MSCs by combining chondrogenic and osteogenic induction. Human bone marrow-derived MSCs were cultured in xeno-free/serum-free (XF) growth medium. Confluent cells that formed cellular sheets were detached from the culture plate using a micropipette tip. The floating cellular sheet contracted to round clumps of cells (C-MSCs). C-MSCs were maintained in XF-chondro-inductive medium (CIM) and XF-osteo-inductive medium (OIM). The biological and bone-regenerative properties of the generated cellular constructs were assessed in vitro and in vivo. C-MSCs cultured in CIM/OIM formed cartilaginous tissue covered with a mineralized matrix layer, whereas CIM treatment alone induced cartilage with no mineralization. Transplantation of the cartilaginous tissue covered with a mineralized matrix induced more rapid bone reconstruction via endochondral ossification in the severe combined immunodeficiency mouse calvarial defect model than that of cartilage generated using only CIM. These results highlight the potential of C-MSC culture in combination with CIM/OIM to generate cartilage covered with a bone collar-like structure, which can be applied for novel bone-regenerative cell therapy.

Biological evaluation and osteogenic potential of polyhydroxybutyrate-keratin/Al2O3 electrospun nanocomposite scaffold: A novel bone regeneration construct.

In this study, the effect of alumina nanowire on the physical and biological properties of polyhydroxybutyrate-keratin (PHB-K) electrospun scaffold was investigated. First, PHB-K/alumina nanowire nanocomposite scaffolds were made with an optimal concentration of 3 wt% alumina nanowire by using the electrospinning method. The samples were examined in terms of morphology, porosity, tensile strength, contact angle, biodegradability, bioactivity, cell viability, ALP activity, mineralization ability, and gene expression. The nanocomposite scaffold provided a porosity of >80 % and a tensile strength of about 6.72 MPa, which were noticeable for an electrospun scaffold. AFM images showed an increase in surface roughness with the presence of alumina nanowires. This led to an improvement in the degradation rate and bioactivity of PHB-K/alumina nanowire scaffolds. The viability of mesenchymal cells, alkaline phosphatase secretion, and mineralization significantly increased with the presence of alumina nanowire compared to PHB and PHB-K scaffolds. In addition, the expression level of collagen I, osteocalcin, and RUNX2 genes in nanocomposite scaffolds increased significantly compared to other groups. In general, this nanocomposite scaffold could be a novel and interesting construct for osteogenic induction in bone tissue engineering.

Chemically-induced osteogenic cells for bone tissue engineering and disease modeling.

Cell reprogramming can satisfy the demands of obtaining specific cell types for applications such as tissue regeneration and disease modeling. Here we report the reprogramming of human fibroblasts to produce chemically-induced osteogenic cells (ciOG), and explore the potential uses of ciOG in bone repair and disease treatment. A chemical cocktail of RepSox, forskolin, and phenamil was used for osteogenic induction of fibroblasts by activation of RUNX2 expression. Following a maturation, the cells differentiated toward an osteoblast phenotype that produced mineralized nodules. Bulk and single-cell RNA sequencing identified a distinct ciOG population. ciOG formed mineralized tissue in an ectopic site of immunodeficiency mice, unlike the original fibroblasts. Osteogenic reprogramming was modulated under engineered culture substrates. When generated on a nanofiber substrate ciOG accelerated bone matrix formation in a calvarial defect, indicating that the engineered biomaterial promotes the osteogenic capacity of ciOG in vivo. Furthermore, the ciOG platform recapitulated the genetic bone diseases Proteus syndrome and osteogenesis imperfecta, allowing candidate drug testing. The reprogramming of human fibroblasts into osteogenic cells with a chemical cocktail thus provides a source of specialized cells for use in bone tissue engineering and disease modeling.

Inhibitory Effect of Periodontitis through C/EBP and 11ß-Hydroxysteroid Dehydrogenase Type 1 Regulation of Betulin Isolated from the Bark of Betula platyphylla.

Periodontitis is an infectious inflammatory disease of the tissues around the tooth that destroys connective tissue and is characterized by loss of periodontal ligaments and alveolar bone. Currently, surgical methods for the treatment of periodontitis have limitations and new treatment strategies are needed. Therefore, this study evaluated the efficacy of the compound betulin isolated from bark of Betula platyphylla on the inhibition of periodontitis in vitro and in vivo periodontitis induction models. In the study, betulin inhibited pro-inflammatory mediators, such as tumor necrosis factor, interleukin-6, inducible nitric oxide synthase, and cyclooxygenase-2, in human periodontal ligament cells stimulated with Porphyromonas gingivalis lipopolysaccharide (PG-LPS). In addition, it showed an anti-inflammatory effect by down-regulating 11ß-hydroxysteroid dehydrogenase type 1 and transcription factor C/EBP ß produced by PG-LPS. Moreover, PG-LPS inhibited the osteogenic induction of human periodontal ligament cells. The protein and mRNA levels of osteogenic markers, such as inhibited osteopontin (OPN) and runt-related transcription factor 2 (RUNX2), were regulated by betulin. In addition, the efficacy of betulin was demonstrated in a typical in vivo model of periodontitis induced by PG-LPS, and the results showed through hematoxylin & eosin staining and micro-computed tomography that the administration of betulin alleviated alveolar bone loss and periodontal inflammation caused by PG-LPS. Therefore, this study proved the efficacy of the compound betulin isolated from B. platyphylla in the inhibition of periodontitis and alveolar bone loss, two important strategies for the treatment of periodontitis, suggesting the potential as a new treatment for periodontitis.

Circ_0087960 stabilizes KDM5B by reducing SKP2 mediated ubiquitination degradation and promotes osteogenic differentiation in periodontal ligament stem cells.

BACKGROUND: Periodontitis is a common chronic oral disease among the world. Periodontal ligament stem cells (PDLSCs) has been proved to be a promising tool for the treatment of periodontitis due to their capability of generating periodontal tissues. Circ_0087960 and KDM5B have been shown to participate in the process of osteogenic differentiation with unclear function and mechanism. METHODS: Circ_0087960 and KDM5B expressions were detected during the osteogenic induction of PDLSCs. The functions of circ_0087960 and KDM5B were validated by manipulating their expression with shRNA. ChIP and luciferase reporter assays were used to prove the KDM5B-based osteogenic gene regulation. Co-IP assay was used to determine the interaction between SKP2 and KDM5B. In vivo ubiquitination assay was used to test the modification of KDM5B by SKP2. RNA pull-down was used to demonstrate the interaction between circ_0087960 and KDM5B. RESULTS: Circ_0087960 and KDM5B were found to be upregulated in the osteogenic differentiation of PDLSCs and promote the expression of related genes. KDM5B could directly bind and promote the expression of Runx2, ALP and OCN. KDM5B protein level in PDLSCs was controlled by SKP2-mediated protein ubiquitination and degradation. Circ_0087960 was identified to bind to KDM5B protein and protect it against SKP2-induced protein degradation, leading to the upregulation of osteogenic genes. CONCLUSION: Circ_0087960 and KDM5B could be applied as promising therapeutic methods to stimulate the osteogenic differentiation of PDLSCs, expanding their capability in the treatment of periodontitis.

Management of the Cavity After Removal of Giant Cell Tumor of the Bone.

Purpose: To find out the most appropriate management scheme through the analysis and comparison of different inactivation methods and filling materials. Method: A systematic literature search was performed using the terms, anhydrous ethanol, phenol, hypertonic saline, cryotherapy, thermal therapy, bone reconstruction, GCTB, and etc., Selected articles were studied and summarized. The mechanism, clinical effects, and influence on bone repair of various methods are presented. Recent developments and perspectives are also demonstrated. Recent Findings: Compared to curettage alone, management of the residual cavity can effectively reduce the recurrence of giant cell tumours of bone. It is a complex and multidisciplinary process that includes three steps: local control, cavity filling, and osteogenic induction. In terms of local control, High-speed burring can enlarge the area of curettage but may cause the spread and planting of tumour tissues. Among the inactivation methods, Anhydrous ethanol, and hyperthermia therapy are relatively safe and efficient. The combination of the two may achieve a better inactivation effect. When inactivating the cavity, we need to adjust the approach according to the invasion of the tumour. Filling materials and bone repair should also be considered in management.

Moringa oleifera leaf extracts protect BMSC osteogenic induction following peroxidative damage by activating the PI3K/Akt/Foxo1 pathway.

OBJECTIVE: We aimed to investigate the therapeutic effects of Moringa oleifera leaf extracts on osteogenic induction of rat bone marrow mesenchymal stem cells (BMSCs) following peroxidative damage and to explore the underlying mechanisms. METHODS: Conditioned medium was used to induce osteogenic differentiation of BMSCs, which were treated with H2O2, Moringa oleifera leaf extracts-containing serum, or the phosphatidyl inositol-3 kinase (PI3K) inhibitor wortmannin, alone or in combination. Cell viability was measured using the MTT assay. Cell cycle was assayed using flow cytometry. Expression levels of Akt, phosphorylated (p)Akt, Foxo1, and cleaved caspase-3 were analyzed using western blot analysis. The mRNA levels of osteogenesis-associated genes, including alkaline phosphatase (ALP), collagen І, osteopontin (OPN), and Runx2, were detected using qRT-PCR. Reactive oxygen species (ROS) and malondialdehyde (MDA) levels, as well as superoxide dismutase (SOD), glutathione peroxidase (GSH-PX), and ALP activity were detected using commercially available kits. Osteogenic differentiation capability was determined using alizarin red staining. RESULTS: During osteogenic induction of rat BMSCs, H2O2 reduced cell viability and proliferation, inhibited osteogenesis, increased ROS and MDA levels, and decreased SOD and GSH-PX activity. H2O2 significantly reduced pAkt and Foxo1 expression, and increased cleaved caspase-3 levels in BMSCs. Additional treatments with Moringa oleifera leaf extracts partially reversed the H2O2-induced changes. Wortmannin partially attenuated the effects of Moringa oleifera leaf extracts on protein expression of Foxo1, pAkt, and cleaved caspase-3, as well as mRNA levels of osteogenesis-associated genes. CONCLUSION: Moringa oleifera leaf extracts ameliorate peroxidative damage and enhance osteogenic induction of rat BMSCs by activating the PI3K/Akt/Foxo1 pathway.

The Adipo-Fascial ALT Flap in Lower Extremities Reconstruction Gustillo IIIC-B Fractures. An Osteogenic Inducer?

RESULTS: Mean time from injury to flap coverage was 72 hours. The mean size of bone defects was 4-7,6 cm. All flaps were Antero Lateral Tight flaps, and the fracture sites did not have any evidence of infection. None of the patients was a smoker. A solid bone union was reached, and full wearing was in a mean of 11 (4-20) weeks after the injury. The lower limb was saved in 100% of the cases. CONCLUSION: Despite the goods results, further studies applied on a large number of patients are needed to confirm authors theory, however, we can consider the fascial ALT flap as a valid help for bone healing in 3B-C open tibial fractures.

Expansion of Human Dental Pulp Cells In Vitro Under Different Cryopreservation Conditions.

BACKGROUND/AIM: To optimize the expansion of human dental pulp cells in vitro by exploring several cryopreservation methodologies. MATERIALS AND METHODS: The intra-dental pulp tissues from healthy subjects were extracted and divided into three separate tissue segments, which were randomly divided into the three following groups; the fresh group, the 5% DMSO group, and the 10% DMSO group. In the fresh group, dental pulp cells were directly cultivated as primary cultures, whereas in the DMSO groups, the dental pulp cells were cultivated from cryopreserved pulp tissue segments one month later. RESULTS: The cell yield and the time it took for the cells to grow out of the pulp tissue and attach to the culture plate varied among the three groups; the 5% DMSO group was inferior to the fresh group but superior to the 10% DMSO group (p<0.05). Moreover, no differences were found at the 1st passage amongst the three groups regarding the following aspects (p>0.05); colony formation rate and cell survival rate. Furthermore, no differences were noted at the 3rd passage regarding the following aspects (p>0.05); proliferation ability, cell growth curve and surface marker expression of dental pulp cells. CONCLUSION: Five percent DMSO may be the most optimal condition for tissue storage to preserve stem cells in situ.

Biological properties of bone marrow stem cells and adipose-derived stem cells derived from T2DM rats: a comparative study.

BACKGROUND: Patients with type 2 diabetes mellitus (T2DM), especially those with poor glycemic control, are characterized by low bone mass and destruction of bone microstructure. Nowadays, autologous mesenchymal stem cells (auto-MSCs) have been used to repair defects and promote tissue regeneration due to handy source, low immunogenicity and self-renewing and multi-differentiating potential. However, T2DM changed the biological properties of auto-MSCs, and investigating the most suitable auto-MSCs for T2DM patients becomes a focus in tissue engineering. RESULTS: In this research, we compared the biological characteristics of adipose-derived stem cells (ASCs) and bone marrow stem cells (BMSCs) derived from T2DM rats. These results demonstrated that ASCs had a higher proliferation rate, colony-formation and cell-sheet forming ability, while BMSCs got better osteogenesis-related staining, expression of osteogenesis-related genes and proteins, and osteogenic capacity in vitro. CONCLUSIONS: As it turned out, ASCs from T2DM had a higher proliferation, while BMSCs had significantly higher osteogenetic ability no matter in vitro and in vivo. Therefore, we should take into account the specific and dominated properties of MSC according to different needs to optimize the protocols and improve clinical outcomes for tissue regeneration of T2DM patients.

Physical Properties and Biofunctionalities of Bioactive Root Canal Sealers In Vitro.

Calcium silicate-based bioactive glass has received significant attention for use in various biomedical applications due to its excellent bioactivity and biocompatibility. However, the bioactivity of calcium silicate nanoparticle-incorporated bioactive dental sealer is not much explored. Herein, three commercially available bioactive root canal sealers (Endoseal MTA (EDS), Well-Root ST (WST), and Nishika Canal Sealer BG (NBG)) were compared with a resin-based control sealer (AH Plus (AHP)) in terms of physical, chemical, and biological properties. EDS and NBG showed 200 to 400 nm and 100 to 200 nm nanoparticle incorporation in the SEM image, respectively, and WST and NBG showed mineral deposition in Hank's balanced salt solution after 28 days. The flowability and film thickness of all products met the ISO 3107 standard. Water contact angle, linear dimensional changes, and calcium and silicate ion release were significantly different among groups. All bioactive root canal sealers released calcium ions, while NBG released ~10 times more silicon ions than the other bioactive root canal sealers. Under the cytocompatible extraction range, NBG showed prominent cytocompatibility, osteogenecity, and angiogenecity compared to other sealers in vitro. These results indicate that calcium silicate nanoparticle incorporation in dental sealers could be a potential strategy for dental periapical tissue regeneration.

Effects of PRP and LyPRP on osteogenic differentiation of MSCs.

Platelet-rich plasma (PRP) is rich in a variety of growth factors and plays an important role in the proliferation and differentiation of mesenchymal stem cells (MSCs). It has been reported that the preparation of freeze-dried platelets (lyophilized platelets [LyPRP]) from platelets could be an effective strategy to preserve the bioactivity of platelets for a long time. In this study, the osteogenic induction effects of PRP and LyPRP on MSCs were evaluated. The rabbit arterial blood was drawing to preparation of PRP by secondary centrifugation. Whole blood was prepared by lyophilization buffer to prepare LyPRP, which were activated by chloride and their surface morphology was observed. It was observed using a scanning electron microscope that platelets were evenly distributed on the surface of PRP and LyPRP. Growth factors were slowly released from PRP and LyPRP during the first 7 days and detected by the enzyme-linked immunosorbent assay kit. Cell proliferation assays and fluoresceindiacetate/propidium iodide (FDA/PI) staining demonstrated that PRP and LyPRP could promote cell proliferation. PRP and LyPRP were also shown to promote osteogenic differentiation of MSCs in vitro by osteogenesis characteristic staining and qPCR quantitative detection of osteogenic related gene expression. Both PRP and LyPRP could promote the proliferation and osteogenic differentiation of MSCs effectively. Moreover, PRP exhibited a better osteogenic induction effect on MSC than LyPRP.

Effect of Testudinis Carapax et Plastrum Aqueous Extract Regulating NF-κB Inflammation Microenvironment on Osteogenic Differentiation of MC3T3-E1 / 中国实验方剂学杂志

Objective::To investigate the role and mechanism of Testudinis Carapax et Plastrum aqueous extract in promoting osteogenic differentiation of mouse preosteoblast cell line(MC3T3-E1) by regulating nuclear transcription factor-κB(NF-κB) inflammation microenvironment. Method::MC3T3-E1 cells were cultured in vitro, and osteogenic induction (OI) was performed. Testudinis Carapax et Plastrum was prepared and treated the cells. Cells were devided into control group, osteogenic induction group and Testudinis Carapax et Plastrum (20 mg·L-1)with osteogenic induction group. The proliferation of MC3T3-E1 was detected by cell counting kit-8 (CCK-8), and the optimum concentration of intervention was determined. MC3T3-E1 differentiation and osteogenic mineralization were assayed using alkaline phosphatase (ALP) and Alizarin red staining (ARS), respectively. The expressions of NF-κB p65, NF-κB p105, interleukin-6(IL-6), ALP and Collagen-Ⅰ(COL-Ⅰ) mRNA were detected by Real-time PCR. Result::The results of CCK-8 showed that the proliferation of MC3T3-E1 did not change statistically with time, but it showed an upward trend, while the proliferation at 20 mg·L-1 was more obvious than other groups. The ALP and ARS showed that the positive staining rate of osteogenic induction group and Testudinis Carapax et Plastrum with osteogenic induction group were higher than control group.Real-time PCR results showed that on the 7th day in culture, the expression of NF-κB p105 and IL-6 mRNA in Testudinis Carapax et Plastrum with osteogenic induction group was significantly lower than that in control group (P<0.01), and the expression of ALP and COL-Ⅰ mRNA was significantly upregulated(P<0.05), on the 14th day, the expression of NF-κB p65, NF-κB p105 and IL-6 mRNA in Testudinis Carapax et Plastrum with osteogenic induction group was significantly lower than that in control group (P<0.01). The expression of ALP and COL-Ⅰ mRNA was significantly increased (P<0.05, P<0.01). Conclusion::Testudinis Carapax et Plastrum aqueous extract can promote osteogenic differentiation of MC3T3-E1 via a mechanism associated with the regulation of inhibition of NF-κB inflammatory microenvironment.

Knockoutof nipbl gene down-regulates the abilities of proliferation and osteogenic differentiation in mouse bone marrow mesenchymal stem cells / 中国组织工程研究

BACKGROUND: Cornelia de Lange syndrome is a genetic disease with multiple developmental defects, of which NIPBL is the main pathogenic gene. OBJECTIVE: To investigate the effect of NIPBL gene on the proliferation and osteogenic differentiation of bene marrow mesenchymal stem cells. METHODS: The NIPBL+/- mice were constructed by NIPBL-Loxp and Cre mice and used as experimental group, and the wild-type NIPBL+/+ mice served as control group. Mouse bone marrow mesenchymal stem cells were isolated and cultured in the two groups. Cell proliferation was detected using cell counting kit-8 assay when thecells were passed to the third generation. Osteoblastic differentiation was then compared between two groups after osteogenesis induction. RESULTS AND CONCLUSION: The proliferation capacity of bone marrow mesenchymal stem cells in the experimental group was lower than that in the control group (P < 0.05). The activity of alkaline phosphatase in the experimental group was significantly lower than that in the control group on the 7th day of osteogenic induction (P < 0.05). The expression levels of osteogenic genes and proteins (Runx2 and OCN) in the experimental group were lower than those in the control group after osteogenic induction (P < 0.05). On the 21st day of osteogenic induction, results from alizarin red staining indicated there were more red calcium nodules in the control group than the experimental group under inverted microscope. These findings suggest that NIPBL gene knockout can reduce the proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells.

Osteogenesis of bone marrow mesenchymal stem cells on hydroxyapatite/icariin/poly(Lactic-co-glycolic acid) scaffolds / 中国组织工程研究

BACKGROUND: Bone tissue engineering has provided a novel ideal for treating bone defects in clinic. This study is the first to combine traditional Chinese medicine with the nanostructures of tissue-engineered scaffolds in order to explore and construct a new bone tissue substitute material for the treatment of bone defects. OBJECTIVE: To investigate the osteogenic activity of icariin (ICA)/hydroxyapatite (HA)/poly(lactic-co-glycolic acid) (PLGA) composite scaffolds. METHODS: A HA/PLGA composite scaffold was prepared by physical blending of HA and PLGA, and was then soaked in ICA solution of different concentrations to obtain the HA/ICA/PLGA scaffold. Rabbit bone marrow mesenchymal stem cells were used to evaluate the cell adhesion, proliferation, osteogenesis and cytotoxicity of the composite scaffold. The cell adhesion, proliferation and cytotoxicity were detected by MTT method. The activities of alkaline phosphatase and osteocalcin were detected by ELISA. The expression levels of osteogenic genes and proteins were detected by fluorescence quantitative PCR and western blot assay, respectively. RESULTS AND CONCLUSION: Adding appropriate amount of HA into PLGA could improve the mechanical strength of the scaffold, and 10% HA had the best effect with tensile strength of (1.67±0.37) MPa, and compression modulus of (4.17±1.62) MPa, and nanostructure would be formed on the surface of the scaffold. The nanostructure could promote the adhesion of bone marrow mesenchymal stem cells on the surface of the scaffold. ICA did not affect the proliferation of bone marrow mesenchymal stem cells on the composite scaffold. However, the HA/PLGA composite scaffold soaked in 1.00 µmol/L ICA aqueous solution had the optimal osteogenic differentiation function, and the expression levels of alkaline phosphatase, osteocalcin, osteogenic related genes and proteins (Runx-2 and COL I) were increased. The ICA/HA/PLGA scaffold had no cytotoxicity. These results suggest that HA (10%)/ICA (1.00 µmol/L)/PLGA scaffold has good mechanical properties, osteogenesis and biocompatibility, which has the potential to be a favorable scaffold for bone tissue engineering.