Osteoblast Gene Research Articles

GWAS-Informed data integration and non-coding CRISPRi screen illuminate genetic etiology of bone mineral density.

Over 1,100 independent signals have been identified with genome-wide association studies (GWAS) for bone mineral density (BMD), a key risk factor for mortality-increasing fragility fractures; however, the effector gene(s) for most remain unknown. Informed by a variant-to-gene mapping strategy implicating 89 non-coding elements predicted to regulate osteoblast gene expression at BMD GWAS loci, we executed a single-cell CRISPRi screen in human fetal osteoblasts (hFOBs). The BMD relevance of hFOBs was supported by heritability enrichment from stratified LD-score regression involving 98 cell types grouped into 15 tissues. 23 genes showed perturbation in the screen, with four (ARID5B, CC2D1B, EIF4G2, and NCOA3) exhibiting consistent effects upon siRNA knockdown on three measures of osteoblast maturation and mineralization. Lastly, additional heritability enrichments, genetic correlations, and multi-trait fine-mapping revealed unexpectedly that many BMD GWAS signals are pleiotropic and likely mediate their effects via non-bone tissues. Extending our CRISPRi screening approach to these tissues could play a key role in fully elucidating the etiology of BMD.

In vitro comparison of the effects of titanium-prepared platelet-rich fibrin and leukocyte platelet-rich fibrin on osteoblast behavior and their gen expression

ObjectiveTo compare the effects of titanium-prepared platelet-rich fibrin (T-PRF) and leukocyte platelet-rich fibrin (L-PRF) on osteoblasts.MethodsVenous blood samples were collected from ten volunteer patients to obtain T-PRF and L-PRF. The T-PRF group was labelled as Group T, the L-PRF group as Group L, and the control group, which includes only osteoblasts, was Group K. PRF samples were added to cultured osteoblast cells and cell proliferation was assessed using an MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide) assay. The effect of different groups on osteoblast proliferation was observed for 72 h and the results were analysed statistically. Additionally, real-time polymerase chain reaction (RT-PCR) was conducted to evaluate gene expression levels of COL1A1, ALP, OCN, and RUNX2 within 48 h.ResultsWe found that the MTT results at 24 h were significantly lower than those at 48 and 72 h (p = 0.036 and p < 0.001, respectively). L-PRF levels showed an increase from 24 to 48 h followed by a decrease from 48 to 72 h. T-PRF levels were seen to increase at both the 24–48 h and 48–72-hour intervals. The changes in the COLA1, OCN, ALP, and RUNX2 genes at 24 h and 48 h did not significantly differ among the groups (p > 0.05).ConclusionsIn this study, we investigated the effects of T-PRF and L-PRF on osteoblast proliferation over a 72-hour period. Both groups improved osteoblast proliferation, however T-PRF group showed a consistent increase in osteoblast proliferation up to 72 h, in contrast to the L-PRF group. No differences in gene expression were found. However, osteoblastic marker genes can be significantly expressed over longer time periods. Therefore, long-term studies are needed.

Impact of microgravity and lunar gravity on murine skeletal and immune systems during space travel

Long-duration spaceflight creates a variety of stresses due to the unique environment, which can lead to compromised functioning of the skeletal and immune systems. However, the mechanisms by which organisms respond to this stress remain unclear. The present study aimed to investigate the impact of three different gravitational loadings (microgravity, 1/6 g [lunar gravity], and 1 g) on the behavior, bone, thymus, and spleen of mice housed for 25–35 days in the International Space Station. The bone density reduction under microgravity was mostly recovered by 1 g but only partially recovered by 1/6 g. Both 1 g and 1/6 g suppressed microgravity-induced changes in some osteoblast and osteoclast marker gene expression. Thymus atrophy induced by microgravity was half recovered by both 1 g and 1/6 g, but gene expression changes were not fully recovered by 1/6 g. While no histological changes were observed due to low gravity, alterations in gene expression were noted in the spleen. We found that in bone and thymus, lunar gravity reduced microgravity-induced histological alterations and partially reversed gene expression changes. This study highlighted organ-specific variations in responsiveness to gravity, serving as an animal test for establishing a molecular-level gravity threshold for maintaining a healthy state during future spaceflight.

Evaluation of Potential Roles of Zinc Finger Homeobox 3 (Zfhx3) Expressed in Chondrocytes and Osteoblasts on Skeletal Growth in Mice.

Bone formation is tightly modulated by genetically encoded molecular proteins that interact to regulate cellular differentiation and secretion of bony matrix. Many transcription factors are known to coordinate these events by controlling gene transcription within networks. However, not all factors involved are known. Here, we identified a novel function forZinc Finger Homeobox 3(Zfhx3), a gene encoding a transcription factor, as a regulator of bone metabolism. We knocked outZfhx3conditionally in mice in either chondrocytes or osteoblasts and characterized their bones by micro-CT in 12-week-old mice. We observed a negative effect in linear bone growth in both knockout mice but reduced bone mass only in mice withZfhx3deleted in osteoblasts. Loss of Zfhx3 expression in osteoblasts affected trabecular bone mass in femurs and vertebrae in both sexes but influenced cortical bone volume fraction only in females. Moreover, transcriptional analysis of femoral bones in osteoblastZfhx3conditional knockout mice revealed a reduced expression of osteoblast genes, and histological evaluation of trabecular bones suggests that Zfhx3 causes changes in bone formation and not resorption. The loss of Zfhx3 causes reductions in trabecular bone area and osteoid volume, but no changes in the expression of osteoclast differentiation markers or number of TRAP stained osteoclasts. These studies introduce Zfhx3 as a relevant factor toward understanding gene regulatory networks that control bone formation and development of peak bone mass.

Combined Effects of Cyclic Hypoxic and Mechanical Stimuli on Human Bone Marrow Mesenchymal Stem Cell Differentiation: A New Approach to the Treatment of Bone Loss.

Background: The prevention and treatment of bone loss and osteoporotic fractures is a public health challenge. Combined with normobaric hypoxia, whole-body vibration has a high clinic potential in bone health and body composition. The effect of this therapy may be mediated by its action on bone marrow mesenchymal stem cells (MSCs). Objectives: Evaluate the effects of cyclic low-vibration stimuli and/or hypoxia on bone marrow-derived human MSC differentiation. Methods: MSCs were exposed four days per week, two hours/day, to hypoxia (3% O2) and/or vibration before they were induced to differentiate or during differentiation into osteoblasts or adipocytes. Gene and protein expression of osteoblastic, adipogenic, and cytoskeletal markers were studied, as well as extracellular matrix mineralization and lipid accumulation. Results: early osteoblastic markers increased in undifferentiated MSCs, pretreated in hypoxia and vibration. This pretreatment also increased mRNA levels of osteoblastic genes and beta-catenin protein in the early stages of differentiation into osteoblasts without increasing mineralization. When MSCs were exposed to vibration under hypoxia or normoxia during osteoblastic differentiation, mineralization increased with respect to cultures without vibrational stimuli. In MSCs differentiated into adipocytes, both in those pretreated as well as exposed to different conditions during differentiation, lipid formation decreased. Changes in adipogenic gene expression and increased beta-catenin protein were observed in cultures treated during differentiation. Conclusions: Exposure to cyclic hypoxia in combination with low-intensity vibratory stimuli had positive effects on osteoblastic differentiation and negative ones on adipogenesis of bone marrow-derived MSCs. These results suggest that in elderly or frail people with difficulty performing physical activity, exposure to normobaric cyclic hypoxia and low-density vibratory stimuli could improve bone metabolism and health.

The effects of all-trans retinoic acid on prednisolone-induced osteoporosis in zebrafish larvae

Glucocorticoids (GCs) are extensively used as anti-inflammatory and immunosuppressive medications in the long-term treatment of rheumatic disorders, respiratory diseases, renal diseases, and organ transplantation. Prolonged use of GCs can reduce bone mineral density, leading to osteoporosis (Glucocorticoid Induced Osteoporosis, GIOP) and fracture. All-trans retinoic acid (ATRA) is an active vitamin A metabolite that regulates embryonic development and adult organ function. ATRA has been found in studies to enhance osteogenesis. To examine the interventional effects of ATRA on GIOP and the mechanisms of ATRA activities, we first performed bioinformatic analysis to identify potential gene targets of ATRA. Zebrafish larvae were recruited as experimental animals, and the frequently used GC, prednisolone, was administered to larvae to construct a GIOP model. We evaluated the influence of exogenous ATRA on the activities of bone metabolic enzymes, the expression of genes linked to osteoblasts and osteoclasts, and the restoration of bone mineral density and bone mass in GIOP zebrafish larvae. Furthermore, we studied the influence of RBM14, a transcriptional coactivator and negative reciprocal factor of ATRA, on the regulation of osteoblastic gene expression during the anti-GIOP process of ATRA using the morpholino knockdown approach. The findings of bone metabolic enzyme activity (alkaline phosphatase, ALP and tartrate-resistant acid phosphatase, TRAP) and expression assays of osteoblastic marker genes (Runx2a, Runx2b, SP7, Csf1a, RANKL, and CTSK) indicated that ATRA had bidirectional effects on osteogenesis. However, in the GIOP model, ATRA reversed the GIOP-induced osteoporosis phenotype by inhibiting the GIOP-induced suppression of osteoblastic metabolic enzyme (ALP) activities and osteoblastic marker gene expression (Runx2a, Runx2b, and SP7), and this antagonism was concentration-dependent. We also observed that ATRA inhibited RBM14 expression in zebrafish larvae, while ATRA alone and RBM14 knockdown showed a consistent induction of osteoblast marker gene expression, implying that ATRA's inhibitory effect on RBM14 expression may underlie ATRA's osteogenic effects. Based on these data, we postulated that ATRA may ameliorate GIOP by decreasing RBM14 expression, thereby enhancing osteoblastic marker gene expression.

Osteo-modulatory potential of biologically synthesized cis-resveratrol passivated gold nanoparticles

Resveratrol, a stilbene, particularly trans-isomer, shows significant osteogenic potential but experiences high instability and poor bioavailability. However, cis-isomer (cRes) is not explored yet due to its instability. Our study investigates the osteoinductive potential of cRes for the first time by stabilizing it onto the surface of gold nanoparticles. cRes capped GNPs (cRGNPs) presented no toxic effects on the MC3T3-E1 cells with increased levels of alkaline phosphatase and calcium deposition. The nanoparticles presented a 2.6-fold increase in cell number compared to the control. The pro-migratory effect of the cRGNPs was also significantly higher (97.21 ± 0.99 % migration) in 4 days. The osteoinductivity was further confirmed by enhanced expression of osteoblastic genes like RUNX2, OPN, OCN, BMP, OPG, and Col1A. The stability provided to cRes upon conjugating to GNPs allowed exploration of its potential in aiding proliferation, migration, and differentiation of the pre-osteoblasts, which will be beneficial in repairing bone defects.

SGCAL: An Algorithm to Identify Sensitive Gene Combinations in the Mouse Osteoblast Gene Network

Osteoblasts originate from mesenchymal stem cells (MSCs) and their maturation is regulated by numerous genes. However, specific genes that play decisive roles in osteoblast maturation are not completely understood. Herein, we propose a new algorithm called SGCAL to identify sensitive gene combinations during osteoblast development and decode the regulatory roles of sensitive gene combinations in cell development. In contrast to conventional gene identification algorithms, the SGCAL algorithm, which is based on a combination of ARNN-LNE iterative cycles, quantitatively evaluates the sensitivity of genes by analyzing the average network entropy before and after gene perturbation. We verified that osteoblast development is fundamentally regulated by an overall sensitive network formed by specific genes. Moreover, we explored the roles of these sensitive genes and their combinations in the transition time point of the initial state of network change. Our algorithm was validated on two independent mouse osteoblast development datasets, successfully identifying sensitive genes and their combinations in both datasets and revealing that gene combinations containing Col1a1 can exhibit significant sensitivity. This study demonstrated the universality of cell fate and network regulation, offering new insights and a theoretical basis for the treatment and repair of bone diseases

Mn2+ vs Co2+ substitution into β-TCP: Structural details and bone cells response

This work investigated the range of substitution of two biologically relevant ions, namely Mn2+ and Co2+, into the structure of β-tricalcium phosphate, as well as their influence on bone cells response. To this aim, β-TCP was synthesized by solid state reaction in the presence of increasing amount of the substituent ions. The results of the X-ray diffraction analysis reveal that just limited amounts of these ions can enter into the β-TCP structure: 15 at% and 20 at% for cobalt and manganese, respectively. Substitution provokes aggregation of the micrometric particles and reduction of the lattice constants. In particular, the dimension of the c-parameter exhibits a discontinuity at about 10 at% for both cations, although with different trend. Moreover, Rietveld refinement demonstrates a clear preference of both manganese and cobalt for the octahedral site (V). The influence of these ions on cell response was tested on osteoblast, osteoclast and endothelial cells. The results indicate that the presence of manganese promotes a good osteoblast viability, significantly enhances the expression of osteoblast key genes and the angiogenic process of endothelial cells, while inhibiting osteoclast resorption. At variance, osteoblast viability appears reduced in the presence of Co samples, on which osteoblast genes reach higher expression than on β-TCP just in a few cases. On the other hand, the results clearly show that cobalt significantly stimulates the angiogenic process and inhibits osteoclast resorption.

The antioxidant protective effect of resveratrol on long-term exposure to acrylamide-induced skeletal toxicity in female mice.

Acrylamide (AA) is a toxic substance formed when cooking starch-based foods at high temperatures. Studies have shown that AA can cause neurotoxicity, reproductive toxicity and so on. However, there remains limited understanding of the potential skeletal toxicity of AA. The aim of this study was to investigate the potential skeletal toxicity of AA, as well as the potential bone protective effects of Resveratrol (RVT). Based on the daily intake of adult women, adult female mice was treated with AA at 0, 0.01, 0.1, 1 mg/kg/d or AA/RVT (1 mg/kg/d AA +10 mg/kg/d RVT) for 8 weeks, and skeletal toxicity were evaluated by RT-qPCR and histopathological techniques. The results found that exposure to AA (0.1 or 1 mg/kg/d) after 8 weeks, osteogenesis exhibited pathological damage characteristics such as inhibition of growth plate function, and reduction of fibrous tissue, and cartilage exhibited pathological damage characteristics such as irregular cell morphology and arrangement, and damage to the tidal line. The results of cellular functional gene testing showed a decrease in the expression of functional genes in osteoblasts and chondrocytes. Meanwhile, after further co-treatment with AA (1 mg/kg/d) and resveratrol (RVT) (10 mg/kg/d), we found that RVT restored AA-induced damage to osteogenesis and cartilage, and reduced the high apoptosis and oxidative stress levels in osteogenesis/cartilage after AA exposure. In summary, this study confirmed the skeletal toxicity of AA on female adult mice, and further clarified the antioxidant protective effect of RVT on this toxicity.

Synergistic Interaction between Polysaccharide-Based Extracellular Matrix and Mineralized Osteoblast-Derived EVs Promotes Bone Regeneration via miRNA-mRNA Regulatory Axis.

Extracellular vesicles (EVs) derived from bone progenitor cells are advantageous as cell-free and non-immunogenic cargo delivery vehicles. In this study, EVs are isolated from MC3T3-E1 cells before (GM-EVs) and after mineralization for 7 and 14 days (DM-EVs). It was observed that DM-EVs accelerate the process of differentiation in recipient cells more prominently. The small RNA sequencing of EVs revealed that miR-204-5p, miR-221-3p, and miR-148a-3p are among the highly upregulated miRNAs that have an inhibitory effect on the function of mRNAs, Sox11, Timp3, and Ccna2 in host cells, which is probably responsible for enhancing the activity of osteoblastic genes. To enhance the bioavailability of EVs, they are encapsulated in a chitosan-collagen composite hydrogel that serves as a bioresorbable extracellular matrix (ECM). The EVs-integrated scaffold (DM-EVs + Scaffold) enhances bone regeneration in critical-sized calvarial bone defects in rats within 8 weeks of implantation by providing the ECM cues. The shelf life of DM-EVs + Scaffold indicates that the bioactivity of EVs and their cargo in the polymer matrix remains intact for up to 30 days. Integrating mineralized cell-derived EVs into an ECM represents a bioresorbable matrix with a cell-free method for promoting new bone formation through the miRNA-mRNA regulatory axis.

Hepatocyte growth factor and insulin-like growth factor-1 were used to repair bone-cartilage defects in bone marrow mesenchymal stem cells in a rabbit model of postmenopausal

In postmenopausal osteoporosis (PMOP), an imbalance exists in the differentiation of bone marrow mesenchymal stem cells (BMSCs), with a decrease in osteogenic differentiation and an increase in adipogenic differentiation. This imbalance leads to bone marrow adiposity, bone loss, bone fragility, and a substantial rise in fracture risk. After a patient experiences an osteochondral defect due to trauma, it struggles to heal naturally, presenting a clinical challenge for treatment. Our study delved into the abnormal differentiation of BMSCs in PMOP by conducting transcriptome sequencing on BMSCs from a PMOP model (PMOP-BMSCs) and a healthy control model (Normal-BMSCs). We identified insulin-like growth factor 1 (IGF-1) and hepatocyte growth factor (HGF) genesas significantly low-expressed protein-coding genes during the osteogenic cartilage differentiation process of PMOP-BMSCs. Due to the downregulation of its expression, it leads to the deletion of the proteins it encodes IGF-1 and HGF. In order to verify the sequencing results, the feasibility of co-culture the above two growth factors with PMOP-BMSCs to repair osteochondral defects was discussed. The findings indicated that the inclusion of elements enhanced the DNA replication activity and extracellular matrix mineralization of PMOP-BMSCs. It also promoted the construction of tissue-engineered bone in vitro and the up- regulation of Runx2, BMP4, OCN, ACAN, collagen type Ⅰ, II, and Sox9 osteochondral differentiation markers. In the rabbit model of knee osteochondral injury with PMOP, the group treated with both growth factors and PMOP-BMSCs showed superior outcomes in repairing cartilage and subchondral bone defects compared to the other groups. We suggest that the addition of HGF and IGF-1 increases the expression of osteoblast and cartilage-related genes and proteins, promoting the proliferation and differentiation of osteochondrous bone in PMOP-BMSCs. These findings could offer a novel cell therapy strategy for treating postmenopausal osteoporosis, utilizing growth factors.

Biocompatibility of Subperiosteal Dental Implants: Changes in the Expression of Osteogenesis-Related Genes in Osteoblasts Exposed to Differently Treated Titanium Surfaces.

The use of endosseous dental implants may become unfeasible in the presence of significant maxillary bone atrophy; thus, surgical techniques have been proposed to promote bone regeneration in such cases. However, such techniques are complex and may expose the patient to complications. Subperiosteal implants, being placed between the periosteum and the residual alveolar bone, are largely independent of bone thickness. Such devices had been abandoned due to the complexity of positioning and adaptation to the recipient bone site, but are nowadays witnessing an era of revival following the introduction of new acquisition procedures, new materials, and innovative manufacturing methods. We have analyzed the changes induced in gene and protein expression in C-12720 human osteoblasts by differently surface-modified TiO2 materials to verify their ability to promote bone formation. The TiO2 materials tested were (i) raw machined, (ii) electropolished with acid mixture, (iii) sand-blasted + acid-etched, (iv) AlTiColorTM surface, and (v) anodized. All five surfaces efficiently stimulated the expression of markers of osteoblastic differentiation, adhesion, and osteogenesis, such as RUNX2, osteocalcin, osterix, N-cadherin, β-catenin, and osteoprotegerin, while cell viability/proliferation was unaffected. Collectively, our observations document that presently available TiO2 materials are well suited for the manufacturing of modern subperiosteal implants.

Resorbable engineered barrier membranes for oral surgery applications.

Population aging, reduced economic capacity, and neglecting the treatments for oral pathologies, are the main causal factors for about 3 billion individuals who are suffering from partial/total edentulism or alveolar bone resorption: thus, the demand for dental implants is increasingly growing. To achieve a good prognosis for implant-supported restorations, adequate peri-implant bone volume is mandatory. The Guided Bone Regeneration (GBR) technique is one of the most applied methods for alveolar bone reconstruction and treatment of peri-implant bone deficiencies. This technique involves the use of different types of membranes in association with some bone substitutes (autologous, homologous, or heterologous). However, time for bone regeneration is often too long and the bone quality is not simply predictable. This study aims at engineering and evaluating the efficacy of modified barrier membranes, enhancing their bioactivity for improved alveolar bone tissue regeneration. We investigated membranes functionalized with chitosan (CS) and chitosan combined with the peptide GBMP1α (CS + GBMP1α), to improve bone growth. OsseoGuard® membranes, derived from bovine Achilles tendon type I collagen crosslinked with formaldehyde, were modified using CS and CS + GBMP1α. The functionalization, carried out with 1-ethyl-3-(3 dimethylaminopropyl)carbodiimide and sulfo-N-Hydroxysuccinimide (EDC/sulfo-NHS), was assessed through FT-IR and XPS analyses. Biological assays were performed by directly seeding human osteoblasts onto the materials to assess cell proliferation, mineralization, gene expression of Secreted Phosphoprotein 1 (SPP1) and Runt-Related Transcription Factor 2 (Runx2), and antibacterial properties. Both CS and CS + GBMP1α functionalizations significantly enhanced human osteoblast proliferation, mineralization, gene expression, and antibacterial activity compared to commercial membranes. The CS + GBMP1α functionalization exhibited superior outcomes in all biological assays. Mechanical tests showed no significant alterations of membrane biomechanical properties post-functionalization. The engineered membranes, especially those functionalized with CS + GBMP1α, are suitable for GBR applications thanks to their ability to enhance osteoblast activity and promote bone tissue regeneration. These findings suggest a potential advancement in the treatment of oral cavity problems requiring bone regeneration.

Assessing the effects of probiotic supplementation, single strain versus mixed strains, on femoral mineral density and osteoblastic gene mRNA expression in rats.

Osteoporosis is a significant health concern characterized by weak and porous bones, particularly affecting menopausal women aged 50 and above, leading to increased risk of hip fractures and associated morbidity and mortality. We conducted a study to assess the efficacy of single-strain versus mixed-strain probiotic supplementation on bone health using an ovariectomy (OVX) rat model of induced bone loss. The probiotics evaluated were Lactobacillus helveticus (L. helveticus), Bifidobacterium longum (B. longum), and a combination of both. Rats were divided into five groups: SHAM (Control negative), OVX (Control positive), OVX +L. helveticus, OVX + B. longum, and OVX + mixed L. helveticus and B. longum. Daily oral administration of probiotics at 10^8-10^9 CFU/mL began two weeks post-surgery and continued for 16 weeks. Both single-strain and mixed-strain probiotic supplementation upregulated expression of osteoblastic genes (BMP- 2, RUNX-2, OSX), increased serum osteocalcin (OC) levels, and improved bone formation parameters. Serum C-terminal telopeptide (CTX) levels and bone resorption parameters were reduced. However, the single-strain supplementation demonstrated superior efficacy compared to the mixed-strain approach. Supplementation with B. longum and L. helveticus significantly reduces bone resorption and improves bone health in OVX rats, with single-strain supplementation showing greater efficacy compared to a mixed-strain combination. These findings highlight the potential of probiotics as a therapeutic intervention for osteoporosis, warranting further investigation in human studies.

Influence of metallic particles and TNF on the transcriptional regulation of NLRP3 inflammasome-associated genes in human osteoblasts.

The release of mature interleukin (IL-) 1β from osteoblasts in response to danger signals is tightly regulated by the nucleotide-binding oligomerization domain leucine-rich repeat and pyrin-containing protein 3 (NLRP3) inflammasome. These danger signals include wear products resulting from aseptic loosening of joint arthroplasty. However, inflammasome activation requires two different signals: a nuclear factor-kappa B (NF-κB)-activating priming signal and an actual inflammasome-activating signal. Since human osteoblasts react to wear particles via Toll-like receptors (TLR), particles may represent an inflammasome activator that can induce both signals. Temporal gene expression profiles of TLRs and associated intracellular signaling pathways were determined to investigate the period when human osteoblasts take up metallic wear particles after initial contact and initiate a molecular response. For this purpose, human osteoblasts were treated with metallic particles derived from cobalt-chromium alloy (CoCr), lipopolysaccharides (LPS), and tumor necrosis factor-alpha (TNF) alone or in combination for incubation times ranging from one hour to three days. Shortly after adding the particles, their uptake was observed by the change in cell morphology and spectral data. Exposure of osteoblasts to particles alone increased NLRP3 inflammasome-associated genes. The response was not significantly enhanced when cells were treated with CoCr + LPS or CoCr + TNF, whereas inflammation markers were induced. Despite an increase in genes related to the NLRP3 inflammasome, the release of IL-1β was unaffected after contact with CoCr particles. Although CoCr particles affect the expression of NLRP3 inflammasome-associated genes, a single stimulus was not sufficient to prime and activate the inflammasome. TNF was able to prime the NLRP3 inflammasome of human osteoblasts.

Silk sericin-based functional food for osteoporosis prevention and therapy

The development of new functional foods that can potentially reduce the risk of diseases, such as osteoporosis, has received increasing attention in recent years. Here we demonstrated that silk sericin-based functional food (SSBF) exerted preventive and therapeutic effects against bone loss. Sericin isolated at 70 °C for 60 min from the cocoon of Bombyx mori stimulated osteoblast differentiation by increasing osteoblastic gene expression while inhibiting receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclast differentiation in vitro. Micro-computed tomography analysis revealed that pre- and post-oral administration of SSBF increased bone mass in ovariectomized mouse model in vivo. Furthermore, dynamic bone histomorphometry analysis revealed that SSBF enhanced osteoblast activity and suppressed bone resorption by reducing the number of osteoclasts. These findings indicated the potential role of SSBF in preventing and being a therapeutic candidate for osteoporosis.

The design of natural hybrid biomaterial to promote osteogenic differentiation, collagen i and II expression and relief of musculoskeletal pains: Bone tissue-engineering applications (in-vitro and clinical studies)

This research aimed to fabricate a natural hybrid biomaterial and assess its physicochemical/biological properties to study the role of the therapeutic biomaterial in the growth of human monocytes, synoviocytes, chondrocytes, expression of type-I/II collagen, and osteogenic differentiation for bone tissue engineering applications, as well as to assess effects of bio-ointment derived from this biomaterial on relief of musculoskeletal pains. Hence, an oily formula [turmeric:ginger:chili pepper:rose oils (1:1:1:1w/w)] was mixed with the base oil [sesame:black seed:olive oils (1:0.4:0.6w/w)] in 3 wt ratios of 1:6(H1), 1.5:5.5(H2), and 2:5(H3). Accordingly, H2 indicated a better performance in cell growth and decrease of inflammatory mediators and led to the highest expression of osteoblastic genes of RUNX2, OCN, and OPN, as well as collagen I and II (COL1A1,COL2A) respectively 1.3-fold, 1.7-fold, and 1.4-fold, as well as %87 % and ∼ 60 % higher than H1, and ∼ 2-fold, 2.1-fold, and 3.4-fold, and ∼ 19 % and ∼ 16 % higher than H3. A clinical study on H2 was also performed on 50 patients with musculoskeletal pains. H2-based bio-ointment could relieve pain in less than 10 min for 40 % of patients and after 30 min from use for 35 %. Moreover, the analgesia period for 60 % and 36 % of patients lasted for longer than 3 h and between 2 h and 3 h, respectively. 76 % also stated that bio-ointment possesses stronger effects than other treatments along with moderate warming functions. Finally, although 6 % of patients reported mild effectiveness in pain relief, 92 % of users stated this therapeutic method has resulted in more effects on their pain relief and damaged organ performance recovery.

Bioprinting Macroporous Hydrogel with Aqueous Two‐Phase Emulsion‐Based Bioink: In Vitro Mineralization and Differentiation Empowered by Phosphorylated Cellulose Nanofibrils

AbstractAqueous two‐phase emulsion (ATPE)‐based bioinks, a creative innovation for bioprinting, enable the fabrication of complex 3D cell‐laden hydrogels with macroporous structure, which promote cellular activities within the scaffold. However, these bioinks intrinsically lack stability and specific biofunctionality, potentially limiting their application for targeted tissue engineering. This study proposes a new perspective by introducing less than 0.1% phosphorylated cellulose nanofibrils (pCNF), a 1D nanofibril top‐down produced from natural biomasses, into a dextran/methacrylated gelatin (GelMA)‐based ATPE system for extrusion‐based bioprinting of preosteoblastic cells, aiming to fabricate macroporous hydrogels with osteogenic differentiation potential. The pCNF that is selectively partitioned in the GelMA phase can not only improve the emulsion stability and alter the rheological behaviors of the ATPE‐based bioink, but also enhance the damping capacity and mineralization ability of the crosslinked hydrogels. Furthermore, macroporous hydrogels with pCNF demonstrate increased cell activity and higher viability in post‐printing, along with higher alkaline phosphatase activity and osteoblastic gene expression. Importantly, the organized interfaces within the hydrogel facilitate the formation of macroscopic biomineralized nodules in vitro. The incorporation of multifunctional pCNF in the ATPE system significantly boosts the physiochemical and biological performance of the macropore‐forming bioink, transforming them into a suitable platform for engineering in vitro bone models.

Multilayer Electrospun Scaffolds of Opposite-Charged Chitosans.

Chitosan (CS) is a polysaccharide obtainable by the deacetylation of chitin, which is highly available in nature and is consequently low-cost. Chitosan is already used in the biomedical field (e.g., guides for nerve reconstruction) and has been proposed as a biomaterial for tissue regeneration in different body districts, including bone tissue. The interest in chitosan as a biomaterial stems from its ease of functionalization due to the presence of reactive groups, its antibacterial properties, its ease of processing to obtain porous matrices, and its inherent similarity to polysaccharides that constitute the human extracellular matrix, such as hyaluronic acid (HA). Here, chitosan was made to react with succinic anhydride to develop a negatively charged chitosan (SCS) that better mimics HA. FT-IR and NMR analyses confirmed the presence of the carboxylic groups in the modified polymer. Four different electrospun matrices were prepared: CS, SCS, a layer-by-layer matrix (LBL), and a matrix with both CS and SCS simultaneously electrospun (HYB). All the matrices containing SCS showed increased human osteoblast proliferation, mineralization, and gene expression, with the best results obtained with HYB compared to the control (CS). Moreover, the antibacterial potential of CS was preserved in all the SCS-containing matrices, and the pure SCS matrix demonstrated a significant reduction in bacterial proliferation of both S. aureus and E. coli.