Rabbit Bone Marrow Mesenchymal Stem Research Articles

Diatomite-incorporated hierarchical scaffolds for osteochondral regeneration

Osteochondral regeneration involves the highly challenging and complex reconstruction of cartilage and subchondral bone. Silicon (Si) ions play a crucial role in bone development. Current research on Si ions mainly focuses on bone repair, by using silicate bioceramics with complex ion compositions. However, it is unclear whether the Si ions have important effect on cartilage regeneration. Developing a scaffold that solely releases Si ions to simultaneously promote subchondral bone repair and stimulate cartilage regeneration is critically important. Diatomite (DE) is a natural diatomaceous sediment that can stably release Si ions, known for its abundant availability, low cost, and environmental friendliness. Herein, a hierarchical osteochondral repair scaffold is uniquely designed by incorporating gradient DE into GelMA hydrogel. The adding DE microparticles provides a specific Si source for controlled Si ions release, which not only promotes osteogenic differentiation of rBMSCs (rabbit bone marrow mesenchymal stem cells) but also enhances proliferation and maturation of chondrocytes. Moreover, DE-incorporated hierarchical scaffolds significantly promoted the regeneration of cartilage and subchondral bone. The study suggests the significant role of Si ions in promoting cartilage regeneration and solidifies their foundational role in enhancing bone repair. Furthermore, it offers an economic and eco-friendly strategy for developing high value-added osteochondral regenerative bioscaffolds from low-value ocean natural materials.

Synergistic large segmental bone repair by 3D printed bionic scaffolds and engineered ADSC nanovesicles: Towards an optimized regenerative microenvironment

Achieving sufficient bone regeneration in large segmental defects is challenging, with the structure of bone repair scaffolds and their loaded bioactive substances crucial for modulating the local osteogenic microenvironment. This study utilized digital laser processing (DLP)-based 3D printing technology to successfully fabricate high-precision methacryloylated polycaprolactone (PCLMA) bionic bone scaffold structures. Adipose-derived stem cell-engineered nanovesicles (ADSC-ENs) were uniformly and stably modified onto the bionic scaffold surface using a perfusion device, constructing a conducive microenvironment for tissue regeneration and long bone defect repair through the scaffold's structural design and the vesicles' biological functions. Scanning electron microscopy (SEM) examination of the scaffold surface confirmed the efficient loading of ADSC-ENs. The material group loaded with vesicles (PCLMA-BAS-ENs) demonstrated good cell compatibility and osteogenic potential when analyzed for the adhesion and osteogenesis of primary rabbit bone marrow mesenchymal stem cells (BMSCs) on the material surface. Tested in a 15 mm critical rabbit radial defect model, the PCLMA-BAS-ENs scaffold facilitated near-complete bone defect repair after 12 weeks. Immunofluorescence and proteomic results indicated that the PCLMA-BAS-ENs scaffold significantly improved the osteogenic microenvironment at the defect site in vivo, promoted angiogenesis, and enhanced the polarization of macrophages towards M2 phenotype, and facilitated the recruitment of BMSCs. Thus, the PCLMA-BAS-ENs scaffold was proven to significantly promote the repair of large segmental bone defects. Overall, this strategy of combining engineered vesicles with highly biomimetic scaffolds to promote large-segment bone tissue regeneration holds great potential in orthopedic and other regenerative medicine applications.

Ocu-miR-10a-5p promotes the chondrogenic differentiation of rabbit BMSCs by targeting BTRC-mediated Wnt/β-catenin signaling pathway.

MicroRNAs (miRNAs) play an important role in articular cartilage damage in osteoarthritis (OA). However, the biological role of miRNAs in the chondrogenic differentiation of bone marrow mesenchymal stem cell (BMSC) remains largely unclear. Rabbit bone marrow mesenchymal stem cells (rBMSCs) were isolated, cultured, and identified. Afterwards, rBMSCs were induced to chondrogenic differentiation, examined by Alcian Blue staining. Differentially expressed miRNAs were identified in rBMSCs between induced and non-induced groups by miRNA sequencing analysis, part of which was validated via PCR assay. Cell viability and apoptosis were assessed by CCK-8 assay and Hoechst staining. Saffron O staining was utilized to assess chondrocyte hyperplasia. The expression of specific chondrogenic markers, including COL2A1, SOX9, Runx2, MMP-13, Aggrecan, and BMP-2, were measured at mRNA and protein levels. The association between beta-transducin repeat containing E3 ubiquitin protein ligase (BTRC) and miR-10a-5p in the miRNA family from rabbit (ocu-miR-10a-5p) was determined by luciferase reporter assay. A total of 76 differentially expressed miRNAs, including 52 downregulated and 24 upregulated miRNAs, were identified in rBMSCs from the induced group. Inhibition of ocu-miR-10a-5p suppressed rBMSC viability and chondrogenic differentiation, as well as downregulated the expression of β-catenin, SOX9, COL2A1, MMP-13, and Runx2. BTRC was predicted and confirmed as a target of ocu-miR-10a-5p. Overexpression of BTRC rescued the promoting impacts of overexpressed ocu-miR-10a-5p on chondrogenic differentiation of rBMSCs and β-catenin expression. Taken together, our data suggested that ocu-miR-10a-5p facilitated rabbit BMSC survival and chondrogenic differentiation by activating Wnt/β-catenin signaling through BTRC.

Cartilage-like protein-polysaccharide hybrid hydrogel for enhancing chondrogenic differentiation of bone marrow mesenchymal stem cells

The regeneration of articular cartilage posed a formidable challenge due to the restricted treatment efficacy of existing therapies. Scaffold-based tissue engineering emerges as a promising avenue for cartilage reconstitution. However, most scaffolds exhibit inadequate mechanical characteristics, poor biocompatibility, or absent cell adhesion sites. In this study, cartilage-like protein-polysaccharide hybrid hydrogel based on DOPA-modified hyaluronic acid, bovine type I collagen (Col I), and recombinant humanized type II collagen (rhCol II), denoted as HDCR. HDCR hydrogels possessed the advantage of injectability and in situ crosslinking through pH adjustment. Moreover, HDCR hydrogels exhibited a manipulable degradation rate and favorable biocompatibility. Notably, HDCR hydrogels significantly induced chondrogenic differentiation of rabbit bone marrow mesenchymal stem cells in vitro, as demonstrated by the upregulation of crucial chondrogenic genes (type II collagen, aggrecan) and the abundant accumulation of glycosaminoglycan. This approach presented a strategy to manufacture injectable, biodegradable scaffolds based on cartilage-like protein-polysaccharide polymers, offering a minimally invasive solution for cartilage repair.Graphical abstract

Effect of exosomes derived from rabbit bone marrow mesenchymal stem cells on the expression of collagen, aggrecan, and tumor necrosis factor-alpha genes in nucleus pulposus cells

Effect of exosomes derived from rabbit bone marrow mesenchymal stem cells on the expression of collagen, aggrecan, and tumor necrosis factor-alpha genes in nucleus pulposus cells

Viscoelasticity microenvironment constructed by self-crosslinking hyaluronan hybrid hydrogels regulates chondrogenic differentiation of mesenchymal stem cells

Chondrogenic differentiation of stem cells can be regulated by mechanical properties of biomaterials. Here, hybrid hydrogels, composed of sulfhydrylated hyaluronan (HA-SH) with different molecular weight and collagen I (Col Ⅰ), were designed to investigate chondrogenic differentiation of rabbit bone marrow mesenchymal stem cells (rBMSCs). The enhanced molecular weight of HA-SH decreased the mechanical properties of hybrid hydrogels, but improved viscosity and degradation resistance, which could modulate cell spreading and morphological changes, thereby influencing chondrogenic differentiation. Furthermore, 1 MDa HA-SH combined with Col Ⅰ (1M-HAC) with adequate viscoelasticity was beneficial to the circularity and nuclear chromatin condensation of rBMSCs, which induced significant chondrocyte aggregation, increased glycosaminoglycans and collagen Ⅱ stainings, and reduced collagen Ⅹ staining. This was conducive to preserve a hyaline cartilage's phenotype and reducing inflammation and degeneration. Subcutaneous implantation studies revealed that 1M-HAC also facilitated specific matrix secretion, chondrogenic gene expression and potentially anti-inflammatory and anti-degenerative effects.

3D printing of polylactic acid/boron nitride bone scaffolds: Mechanical properties, biomineralization ability and cell responses

Polylactic acid (PLA) has been widely utilized as a bone scaffold material; however, it exhibits inadequate mechanical performance, biomineralization ability, and cell response, leading to limitations in its practical application. In this study, we utilized boron nitride (BN) nanosheets with favorable mechanical and biological properties to improve the performances of PLA, and prepared PLA/BN composite scaffolds by FDM 3D printing technology. Then, the PLA/BN composite scaffolds with varying BN contents (0–4 wt%) were investigated in terms of microstructure, mechanical performance, biomineralization ability, and cell response. The results showed that the FDM printed PLA/BN scaffolds have an orderly and interconnected porous structure. The mechanical tests showed that the tensile and compression properties (strength and modulus) increased first and then decreased with the content of BN gradually increasing from 0 wt% to 4 wt%, with the optimum mechanical properties occurring at 1 wt%, as an appropriate content of BN could be well-dispersed in the PLA matrix with forming a good interfacial bond, while an excessive content of BN would lead to obvious agglomeration. The simulated body fluid (SBF) soaking experiments showed that BN improved the biomineralization of the PLA scaffold through promoting the formation and deposition of apatite on the scaffold surface by accelerating ion exchange. Besides, an appropriate content of BN promoted the adhesion, proliferation, and osteogenic differentiation of rabbit bone marrow mesenchymal stem cells (BMSCs). These results indicated that BN could be used as a versatile filler for improving the comprehensive performances of polymers, especially for bone tissue engineering.

Preparation of gum tragacanth/poly (vinyl alcohol)/halloysite hydrogel using electron beam irradiation with potential for bone tissue engineering

Nanocomposite hydrogels based on tyramine conjugated gum tragacanth, poly (vinyl alcohol) (PVA), and halloysite nanotubes (HNTs) were prepared by electron beam irradiation and characterized. The FTIR, 1H NMR, and TGA results confirmed the chemical incorporation of HNTs into gum tragacanth. Gel content and swelling of hydrogels decreased with HNTs loading up to 20 % wt. The mechanical strength of hydrogels increased by increasing HNTs content up to 10 % with 371 kPa fracture stress at 0.95 fracture strain, compared to 312 kPa stress at 0.79 strain for gum tragacanth/PVA hydrogel. Hydrogel's biocompatibility and osteogenic activity were tested by seeding rabbit bone marrow mesenchymal stem cells. The cell viability was >85 % after 7 days of culture. In vitro secretion of ALP and calcium deposition on hydrogels in alizarin red assay after 21 days of culture indicated hydrogel potential for bone tissue engineering.

Impact of in-vivo Low-Level Laser therapy combined with Rabbit Bone Marrow Mesenchymal Stem Cells to promote Bone Regeneration. Morphological and Gene Expression Assessments.

Impact of in-vivo Low-Level Laser therapy combined with Rabbit Bone Marrow Mesenchymal Stem Cells to promote Bone Regeneration. Morphological and Gene Expression Assessments.

Accelerating bone regeneration using poly(lactic-co-glycolic acid)/hydroxyapatite scaffolds containing duck feet-derived collagen

Collagen, with low antigenicity and excellent cell adhesion, is a biomaterial mainly used for regenerating bone, cartilage, and skin, owing to its biocompatibility and biodegradability. Results from a previous study confirmed that a scaffold mixed with duck feet-derived collagen (DC) and Poly(lactic-co-glycolic acid) (PLGA) reduced inflammatory reaction and increased bone regeneration. To develop an optimal bone substitute we included hydroxyapatite (HAp), a key osteoconductive material, in a DC and PLGA mixture. We fabricated 0, 10, 20, 40, 60, and 80 wt% DC/PLGA/HAp scaffolds and studied their potential for bone tissue engineering. Characteristic analysis of the scaffold and seeding of rabbit bone marrow mesenchymal stem cells (rBMSCs) on the scaffold were conducted to investigate cell proliferation, osteogenic differentiation, and bone formation. We confirmed that increasing DC concentration not only improved the compressive strength of the DC/PLGA/HAp scaffold but also cell proliferation and osteogenic differentiation. It was found through comparison with previous studies that including HAp in the scaffold also promotes osteogenic differentiation. Our study thus shows through in vivo results that the 80 wt% DC/PLGA/HAp scaffold promotes bone mineralization and collagen deposition while reducing the inflammatory response. Hence, 80 wt% DC/PLGA/HAp has excellent potential as a biomaterial for bone regeneration applications.

Selective Polyetheretherketone Implants Combined with Graphene Cause Definitive Cell Adhesion and Osteogenic Differentiation.

Polyetheretherketone (PEEK) has good biosafety and chemical stability for bone repair. However, PEEK is biologically inert and cannot promote bone apposition. This study investigated whether graphene-modified PEEK (G-PEEK) could improve cell adhesion and osteogenic differentiation. G-PEEK was prepared by melted blending and was characterized. In vitro, the biocompatibility of G-PPEK and the ability to promote cell adhesion and osteogenic differentiation in rabbit bone marrow mesenchymal stem cells (rBMSCs) were examined using live and dead cell double staining, the cell counting kit-8 (CCK-8) assay, immunofluorescence and quantitative real-time PCR (qRT‒PCR). An in vivo rabbit extra-articular graft-to-bone healing model was established. At 4 and 12 weeks after surgery, CT analysis and histological evaluation were performed. In vitro, G-PEEK significantly improved the adhesion and proliferation of rBMSCs, with good biocompatibility. In vivo, G-PEEK promoted new bone formation at the site of the bone defect. G-PEEK showed excellent osteogenesis performance, which promises new applications in implant materials.

Circular Patterns of Dynamic Covalent Hydrogels with Gradient Stiffness for Screening of the Stem Cell Microenvironment.

As extracellular matrix (ECM) mimetic materials, hydrogels have been widely used for broad biomedical applications. However, with so many physical or chemical cues in the matrix that regulate cell behaviors or functions, it remains challenging to design a customizable hydrogel with the desired properties on demand. In the current study, we aim to establish a circular-patterned hydrogel model with gradient stiffness for screening the most favorable ECM environment for specific cells or certain application purposes. First, six types of hydrogels with a wide stiffness range of 1.2-28.9 kPa were prepared by dynamic covalent cross-linking between gelatin derivatives and oxidized hyaluronic acid. Taking advantage of their instantaneous self-healing property from dynamic chemistry, the hydrogels were further spliced into one whole piece of circular-patterned hydrogel. When rabbit bone marrow mesenchymal stem cells were seeded in the center, the influences of matrix stiffness on the regulation of stem cell adhesion, migration, and differentiation were directly observed and compared under one visual field. In addition, these hydrogels all possessed good biocompatibility, degradability, and injectability, showing great potential for tissue-engineering-related applications.

The Antibacterial Activity Comparison between Novel Carbon-Based Nanofilm Coated Titanium Alloy and Co-Cr-Mo Alloy.

Objective The purpose of this study was to reveal the antibacterial activity of carbon-based nanofilm titanium alloy. Methods The experiments were performed both in vitro and in vivo of animals using two circular-piece test specimens of the same specification, which were made from carbon-based nanofilm coated titanium alloy and commonly used in artificial joints Co-Cr-Mo alloy, respectively. In the in vitro experiments, the two test specimens were cocultured with standard strains of Staphylococcus aureus and Escherichia coli, and the antibacterial properties of the two test specimens were evaluated via inhibition zone size, scanning electron microscopy, fluorescence staining, colony forming unit count, and others; the cytotoxicities of the two test specimens were evaluated by coculturing and them with rabbit bone marrow mesenchymal stem cells (BMSCs). In the in vivo experiments, the two test specimens were implanted in the muscle tissue of experimental rabbits to evaluate their histocompatibilities. Results Both in vitro cocultures of the carbon-based nanofilm titanium alloy and the Co-Cr-Mo alloy with Staphylococcus aureus and Escherichia coli failed to form inhibition zone. However, some biofilms were observed on the surface of the Co-Cr-Mo alloy. Fewer bacteria adhered to the carbon-based nanofilm titanium alloy can be observed via scanning electron microscopy and fluorescence staining techniques. Meanwhile, the colony forming counts showed that, compared with the Co-Cr-Mo alloy, the carbon-based nanofilm titanium alloy had fewer bacteria adhered (P < 0.05). After coculture of the two test specimens with rabbit BMSCs, there was no significant difference in cell count, and both cell counts showed no cytotoxicity. In the in vivo experiment of animals, there are relatively fewer giant cells and better histocompatibility in tissues near the carbon-based nanofilm titanium alloy. Conclusion Compared with Co-Cr-Mo alloy, the novel carbon-based nanofilm titanium alloy enjoys stronger in vitro antibacterial activity and better in vivo histocompatibility.

Efficiency of Nanohydroxyapatite on Repairing Type II Diabetes Dental Implant-Bone Defect.

The purpose of this study was to see how a nanohydroxyapatite (n-HA) composite polyamide 66 (PA66) affected the repair of bone defects in diabetics with titanium implants, as well as to develop experimental materials for the creation of the interface between bone tissue and titanium implants. Rabbit bone marrow mesenchymal stem cells (MSCs) were isolated using n-HA/PA66 composite material, and the effect of coculture with the material on cell proliferation was analyzed after induction of mineralization. Bone defect models of diabetic experimental rabbits and titanium implants were prepared. Normal rabbits with bone defects were used as control (NC group, N = 8). After the diabetic bone defect (DM group, N = 8) and the implantation of n-HA/PA66 composite material (n-HA/PA66 group, N = 8), the differences in body weight, blood glucose, scanning electron microscopy of the implant-bone interface, bone mineral density, new bone trabecular parameters, histomorphology, and biomechanical properties of the implant-bone interface were compared and analyzed. In vitro test results showed that MSC cell growth could be promoted by mineralization induction, the cell growth condition was good after coculture with n-HA/PA66, and the proliferation activity of MSCs was not affected by the material. In vivo test results showed that the body weight of the DM group and n-HA/PA66 group was considerably inferior to that of the NC group, and the blood glucose was dramatically superior to that of the NC group (P < 0.05). However, the body weight of the n-HA/PA66 group was dramatically superior to that of the DM group (P < 0.05). The bone mineral density, bone volume fraction (BV/TV), bone surface area fraction (BS/BV), bone trabecular thickness (Tb.Th), bone trabecular number (Tb.N), bone trabecular area, and biomechanical properties in the DM group were considerably inferior to those in the NC group and n-HA/PA66 group (P < 0.05). The trabecular space (Tb.Sp) in the NC group and n-HA/PA66 group was dramatically superior to that in the NC group (P < 0.05). The bone mineral density, BV/TV, BS/BV, Tb.Th, Tb.N, trabecular area, and biomechanical properties of the n-HA/PA66 group were dramatically superior to those of the NC group (P < 0.05), while Tb.Sp was considerably inferior to that of the NC group (P < 0.05). These findings showed that the n-HA/PA66 material had good biocompatibility and minimal cytotoxicity, and that filling the space between the surrounding bone and the titanium implant can enhance bone repair. This research paved the way for future research into the tissue-engineered bone in the field of oral surgery.

Icariin promotes the repair of bone marrow mesenchymal stem cells in rabbit knee cartilage defects via the BMP/Smad pathway.

BackgroundIcariin (ICA) has been widely used in the treatment of osteoporosis. However, the potential mechanism of its critical role in repairing knee cartilage damage still needs to be further clarified.MethodsFirst, rabbit bone marrow mesenchymal stem cells (BMSCs) were isolated, cultured, and identified. Subsequently, BMSCs were treated with different concentrations of ICA. Cell Counting Kit 8 (CCK-8) and 5-ethynyl-2'-deoxyuridine (EdU) were used to evaluate the cell proliferation in each group. Alcian Blue staining, immunofluorescence, and western blotting were used to evaluate the ability of BMSCs to differentiate cartilage. In addition, a rabbit knee cartilage injury model was established. Evaluation of cartilage defects in each group was performed according to the classification system outlined by the International Cartilage Repair Society (ICRS). Hematoxylin and eosin (HE), Alcian Blue, and immunohistochemistry were used to analyze the pathological status of knee cartilage.ResultsIn vitro, the results showed that ICA promoted the cartilage differentiation of BMSCs as well as cell proliferation. In addition, ICA promoted the expression of type II collagen (COL2A1), aggrecan, and bone morphogenetic protein 2 (BMP2) in BMSCs, while BMP-Smad inhibitor (Noggin) reversed the repair effect of ICA on BMSCs. In vivo, our results showed that the ICRS score of the BMSC and ICA treatment group was higher. Moreover, BMSC and ICA treatment promoted the proliferation of chondrocytes and repaired the cartilage-like tissue on the surface of cartilage defect.ConclusionsThe combined application of ICA and BMSCs can repair rabbit knee cartilage injury by regulating the BMP/Smads pathway, indicating that ICA and BMSCs may be a viable clinical treatment strategy for knee cartilage damage.

In vitro and in vivo Repair Effects of the NCF-Col-NHA Aerogel Scaffold Loaded With SOST Monoclonal Antibody and SDF-1 in Steroid-Induced Osteonecrosis.

In the current study, we synthesized nanocellulose (NCF)-collagen (Col)-nano hydroxyapatite (NHA) organic-inorganic hybrid aerogels loaded with stromal cell derived factor-1 (SDF-1) and sclerostin monoclonal antibody (SOST McAb) and investigated their ability to repair steroid-induced osteonecrosis. Rabbit bone marrow mesenchymal stem cells (BMSCs) and human vascular endothelial cells (HUVECs) were used for the in vitro study. A rabbit steroid-induced osteonecrosis model was used for the in vivo study. The best elastic modulus reached 12.95 ± 4.77 MPa with a mean compressive property of 0.4067 ± 0.084 MPa for the scaffold containing 100% mass fraction. The average pore diameter of the aerogel was 75 ± 18 µm with a porosity of more than 90% (96.4 ± 1.6%). The aerogel-loaded SDF-1 and SOST were released at 40–50% from the material within the initial 3 h and maintained a stable release for more than 21 days. The in vitro study showed osteogenesis and vascularization capabilities of the scaffold. The in vivo study showed that rabbits received implantation of the scaffold with SOST McAb and SDF-1 showed the best osteogenesis of the osteonecrosis zone in the femoral head. Imaging examination revealed that most of the necrotic area of the femoral head was repaired. These results suggest that this hybrid aerogel scaffold could be used for future steroid-induced osteonecrosis repair.

Effect of Ce-doped bioactive glass/collagen/chitosan nanocomposite scaffolds on the cell morphology and proliferation of rabbit’s bone marrow mesenchymal stem cells-derived osteogenic cells

BackgroundCerium-containing materials have wide applications in the biomedical field, because of the mimetic catalytic activities of cerium. The study aims to deeply estimate the biocompatibility of different scaffolds based on Ce-doped nanobioactive glass, collagen, and chitosan using the first passage of rabbit bone marrow mesenchymal stem cells (BM-MSCs) directed to osteogenic lineage by direct and indirect approach. One percentage of glass filler was used (30 wt. %) in the scaffold, while the percentage of CeO2 in the glass was ranged from 0 to 10 mol. %. Cytotoxicity was evaluated by monitoring of cell morphological changes and reduction in cell proliferation activity of BMMSCs maintained under osteogenic condition using proliferation assays, MTT assay for the direct contact of cells/scaffolds twice in a week, trypan blue and hemocytometer cell counting for indirect contact of cells/scaffolds extracts at day 7. Cell behaviors growth, morphology characteristics were monitored daily under a microscope and cell counting were conducted after 1 week of the incubation of the cells with the extracts of the four composite scaffolds in the osteogenic medium at the end of the week. ResultsShowed that at 24 h after direct contact with composite scaffold, all scaffolds showed proliferation of cells > 50% and increased in cell density on day 7. The scaffold of the highest percentage of CeO2 in bioactive glass nanoparticles (sample CL/CH/C10) showed the lowest inhibition of cell proliferation (< 25%) at day 7. Moreover, the indirect cell viability test showed that all extracts from the four composite scaffolds did not demonstrate a toxic effect on the cells (inhibition value < 25%). ConclusionThe addition of CeO2 to the glass composition improved the biocompatibility of the composite scaffold for the proliferation of rabbit bone marrow mesenchymal stem cells directed to osteogenic lineage.

In Vitro Biological Evaluation of a Fabricated Polycaprolactone/Pomegranate Electrospun Scaffold for Bone Regeneration.

Different scaffold biomaterials are being investigated as a solution for bone loss due to disease or trauma. The aim of this study is the fabrication, characterization, and in vitro biological evaluation of a novel polycaprolactone (PCL) nanoscaffold incorporating pomegranate peel extract (PG) for bone regeneration. Using electrospinning, three groups of scaffolds were prepared: the control group PCL and two groups of PCL with PG concentrations (11 and 18 weight %). The antioxidant activity and the total phenolic content (TPC) of the fabricated nanoscaffolds were evaluated, in addition to the porosity and degradation measurement. Cultured osteoblasts derived from rabbit bone marrow mesenchymal stem cells were used for the assessment of cell proliferation and attachment on the scaffold’s surface. Scaffolds’ characterization showed uniform nanofibers (NFs) with a fiber diameter range of 149–168 nm. Meanwhile, higher antioxidant activity and TPC of the PG groups were detected. Furthermore, total porosities of 59 and 62% were determined for the PCL–PG scaffolds. An increased degradation rate and significant improvement in cell proliferation and cell attachment were revealed for the PCL–PG fabricated scaffolds. Such incorporation of natural food waste, PG, in PCL NFs offered novel PCL–PG scaffolds as a promising candidate for bone regeneration applications.

Inhibition of PPARγ Gene Particle Downregulates the Differentiation of Rabbit Bone Marrow Mesenchymal Stem Cells into Adipocytes

This study aims to evaluate the effect of peroxisome proliferator-activated receptor (PPAR) γ gene inhibition on the adipogenic differentiation of rabbit bone marrow mesenchymal stem cells (BMSCs). Primary BMSCs were isolated from rabbit bone marrow, cultured, and the markers of BMSCs on cell’s surface were analyzed using flow cytometry. The experiment involved five groups, namely, control: untreated BMSCs; model: BMSCs treated with ethanol; empty siRNA: BMSCs treated with ethanol + empty siRNA; PPARγ: BMSCs treated with ethanol + PPARγ siRNA; and PPARγ inhibitor: BMSCs treated with ethanol + T0070907. RT-PCR and Western blotting were used to detect changes in the expression level of PPARγ, PETALA2 (AP2), lipoprotein lipase (LPL), fatty acid transport protein (FATP) 1, and fatty acid transporter (FAT). Adipocyte count and triacylglycerol content of the model and the empty siRNA groups were considerably greater than the control group ( P &lt; 0.01 ). After the inhibition with PPARγ or T0070907, adipocyte count and triacylglycerol content of the PPARγ and T0070907 groups were significantly reduced ( P &lt; 0.01 ), with no statistically significantly difference than the control group ( P &gt; 0.05 ). The expression levels of PPARγ gene and protein in the model and empty siRNA groups were ominously enhanced than the control group ( P &lt; 0.01 ), and after inhibition with PPARγ or T0070907, the PPARγ gene or protein expression level of PPARγ and T0070907 groups significantly reduced ( P &lt; 0.01 ), with no statistically significance difference compared to the control group ( P &gt; 0.05 ). The expression levels of Ap2, LPL, FATP1, and FAT genes in the model and empty siRNA groups were considerably greater compared to the control group ( P &lt; 0.01 ). Inhibition with PPARγ or T0070907 in the PPARγ and T0070907 groups, respectively, lead to significantly reduced expression levels of adipogenic genes ( P &lt; 0.01 ), with no statistically significance difference compared to the control ( P &gt; 0.05 ). Inhibition of PPARγ gene downregulates the differentiation of BMSCs into adipocytes, indicating its putative role in the expression of adipogenic genes.

Regulation of Inflammatory Response and Osteogenesis to Citrate-Based Biomaterials through Incorporation of Alkaline Fragments.

A proper pH microenvironment is crucial to mobilizing regeneration function of biomaterials. Neutralizing the acidity in bone defects with alkaline substances is a promising strategy to create favorable environments for cell proliferation and bone repair. In this study, to neutralize the acidity and reduce the inflammation caused by the rapid release of citric acid, a novel citrate-based biodegradable elastomeric poly(citric acid-1,8-octanediol-1,4-bis(2-hydroxyethyl)piperazine (BHEp)) (POPC) is synthesized with the introduction of the alkaline fragment BHEp, and then POPC/β-tricalcium phosphate (β-TCP) porous scaffolds are fabricated by 3D printing technique. The results reveal that the alkaline fragment BHEp effectively corrects the acid environment and improves the biocompatibility, cells affinity and promoted cell adhesion, and proliferation of POPC. Furthermore, the improved pH of POPC15/β-TCP (PTCP15) enhances the adhesion and the proliferation of rabbit bone marrow mesenchymal stem cells, and the expression of osteogenesis-related genes. Moreover, PTCP15 scaffolds relieve inflammatory response and switch RAW 264.7 toward a prohealing extreme. The rat femoral defect model further demonstrates good biocompatibility and enhanced bone regeneration of PTCP15. In conclusion, the results offer a promising approach for biodegradable polymers to address the degradation acidity issue. Meanwhile, a positive regulation strategy is provided for biopolymer to enhance cell proliferation, osteogenic differentiation, and bone repair.