Human Osteoblastic Cells Research Articles

Optimising degradation and mechanical performance of additively manufactured biodegradable Fe–Mn scaffolds using design strategies based on triply periodic minimal surfaces

Additively manufactured lattices based on triply periodic minimal surfaces (TPMS) have attracted significant research interest from the medical industry due to their good mechanical and biomorphic properties. However, most studies have focussed on permanent metallic implants, while very little work has been undertaken on manufacturing biodegradable metal lattices. In this study, the mechanical properties and in vitro corrosion of selective laser melted Fe–35%Mn lattices based on gyroid, diamond and Schwarz primitive unit-cells were comprehensively evaluated to investigate the relationships between lattice type and implant performance. The gyroid-based lattices were the most readily processable scaffold design for controllable porosity and matching the CAD design. Mechanical properties were influenced by lattice geometry and pore volume. The Schwarz lattices were stronger and stiffer than other designs with the 42% porosity scaffold exhibiting the highest combination of strength and ductility, while diamond and gyroid based scaffolds had lower strength and stiffness and were more plastically compliant. The corrosion behaviour was strongly influenced by porosity, and moderately influenced by geometry and geometry-porosity interaction. At 60% porosity, the diamond lattice displayed the highest degradation rate due to an inherently high surface area-to-volume ratio. The biodegradable Fe–35Mn porous scaffolds showed a good cytocompatibility to primary human osteoblasts cells. Additive manufacturing of biodegradable Fe–Mn alloys employing TPMS lattice designs is a viable approach to optimise and customise the mechanical properties and degradation response of resorbable implants toward specific clinical applications for hard tissue orthopaedic repair.

Surface Morphology and Human MG-63 Osteoblasic Cell Line Response of 316L Stainless Steel after Various Surface Treatments

In this study, the effects of three distinct surface treatment techniques on 316L stainless steel were investigated: low-temperature immersion corrosion, shot peening followed by immersion corrosion, and electrochemical corrosion. These techniques were selected with a focus on their potential implications for biomedical implant applications, as research gaps persist in understanding the influence of these treatments. A comprehensive examination of surface alterations was conducted using scanning electron microscopy, Raman spectroscopy, and α-step thin-film thickness profiling. Furthermore, human MG-63 osteoblastic cell line adhesion was evaluated using Liu’s stain and metallographic optical microscopy. Notable differences in cell-adhesion behavior based on the chosen surface treatment methods were observed. Specifically, weak cell adhesion was observed after low-temperature immersion and shot peening followed by immersion corrosion. In contrast, electrochemical corrosion, especially when conducted with a high current density and low corrosive-solution concentration, resulted in a uniformly corroded surface, which, in turn, promoted dense cell adhesion. Porous oxide layers were generated using all three techniques, but the efficacy of shot peening (applied at 1 kg/cm2 for 20 s) and electrochemical corrosion (using 0.5 M HCl) as promising processes were highlighted by our experimental results. Uniformly dense corrosion pits were produced through electrochemical corrosion, while semicircular grooves with small corrosion pits were the result of shot peening, both of which were found to be favorable for cell adhesion. The superior cell adhesion observed with electrochemical corrosion further emphasizes its suitability for biomedical applications.

Preosteoclast plays a pathogenic role in syndesmophyte formation of ankylosing spondylitis through the secreted PDGFB — GRB2/ERK/RUNX2 pathway

ObjectivesAnkylosing spondylitis (AS) is a chronic inflammatory disease that mainly affects the sacroiliac joint and spine. However, the real mechanisms of immune cells acting on syndesmophyte formation in AS are not well identified. We aimed to find the key AS-associated cytokine and assess its pathogenic role in AS.MethodsA protein array with 1000 cytokines was performed in five AS patients with the first diagnosis and five age- and gender-matched healthy controls to discover the differentially expressed cytokines. The candidate differentially expressed cytokines were further quantified by multiplex protein quantitation (3 AS-associated cytokines and 3 PDGF-pathway cytokines) and ELISA (PDGFB) in independent samples (a total of 140 AS patients vs 140 healthy controls). The effects of PDGFB, the candidate cytokine, were examined by using adipose-derived stem cells (ADSCs) and human fetal osteoblast cell line (hFOB1.19) as in vitro mesenchymal cell and preosteoblast models, respectively. Furthermore, whole-transcriptome sequencing and enrichment of phosphorylated peptides were performed by using cell models to explore the underlying mechanisms of PDGFB. The xCELLigence system was applied to examine the proliferation, chemotaxis, and migration abilities of PDGFB-stimulated or PDGFB-unstimulated cells.ResultsThe PDGF pathway was observed to have abnormal expression in the protein array, and PDGFB expression was further found to be up-regulated in 140 Chinese AS patients. Importantly, PDGFB expression was significantly correlated with BASFI (Pearson coefficient/p value = 0.62/6.70E − 8) and with the variance of the mSASSS score (mSASSS 2 years − baseline, Pearson coefficient/p value = 0.76/8.75E − 10). In AS patients, preosteoclasts secreted more PDGFB than the healthy controls (p value = 1.16E − 2), which could promote ADSCs osteogenesis and enhance collagen synthesis (COLI and COLIII) of osteoblasts (hFOB 1.19). In addition, PDGFB promoted the proliferation, chemotaxis, and migration of ADSCs. Mechanismly, in ADSCs, PDGFB stimulated ERK phosphorylation by upregulating GRB2 expression and then increased the expression of RUNX2 to promote osteoblastogenesis of ADSCs.ConclusionPDGFB stimulates the GRB2/ERK/RUNX2 pathway in ADSCs, promotes osteoblastogenesis of ADSCs, and enhances the extracellular matrix of osteoblasts, which may contribute to pathological bone formation in AS.

Cytocompatibility, antibacterial, and corrosion properties of chitosan/polymethacrylates and chitosan/poly(4-vinylpyridine) smart coatings, electrophoretically deposited on nanosilver-decorated titania nanotubes.

The development of novel implants subjected to surface modification to achieve high osteointegration properties at simultaneous antimicrobial activity is a highly current problem. This study involved different surface treatments of titanium surface, mainly by electrochemical oxidation to produce a nanotubular oxide layer (TNTs), a subsequent electrochemical reduction of silver nitrate and decoration of a nanotubular surface with silver nanoparticles (AgNPs), and finally electrophoretic deposition (EPD) of a composite of chitosan (CS) and either polymethacrylate-based copolymer Eudragit E 100 (EE100) or poly(4-vinylpyridine) (P4VP) coating. The effects of each stage of this multi-step modification were examined in terms of morphology, roughness, wettability, corrosion resistance, coating-substrate adhesion, antibacterial properties, and osteoblast cell adhesion and proliferation. The results showed that the titanium surface formed nanotubes (inner diameter of 97 ± 12 nm, length of 342 ± 36 nm) subsequently covered with silver nanoparticles (with a diameter of 88 ± 8 nm). Further, the silver-decorated nanotubes were tightly coated with biopolymer films. Most of the applied modifications increased both the roughness and the surface contact angle of the samples. The deposition of biopolymer coatings resulted in reduced burst release of silver. The coated samples revealed potent antimicrobial activity against both Gram-positive and Gram-negative bacteria. Total elimination (99.9%) of E. coli was recorded for a sample with CS/P4VP coating. Cytotoxicity results using hFOB 1.19, a human osteoblast cell line, showed that after 3 days the tested modifications did not affect the cellular growth according to the titanium control. The proposed innovative multilayer antibacterial coatings can be successful for titanium implants as effective postoperative anti-inflammation protection.

Development and Characterization of Electrospun Composites Built on Polycaprolactone and Cerium-Containing Phases.

The current study reports on the fabrication of composite scaffolds based on polycaprolactone (PCL) and cerium (Ce)-containing powders, followed by their characterization from compositional, structural, morphological, optical and biological points of view. First, CeO2, Ce-doped calcium phosphates and Ce-substituted bioglass were synthesized by wet-chemistry methods (precipitation/coprecipitation and sol-gel) and subsequently loaded on PCL fibres processed by electrospinning. The powders were proven to be nanometric or micrometric, while the investigation of their phase composition showed that Ce was present as a dopant within the crystal lattice of the obtained calcium phosphates or as crystalline domains inside the glassy matrix. The best bioactivity was attained in the case of Ce-containing bioglass, while the most pronounced antibacterial effect was visible for Ce-doped calcium phosphates calcined at a lower temperature. The scaffolds were composed of either dimensionally homogeneous fibres or mixtures of fibres with a wide size distribution and beads of different shapes. In most cases, the increase in polymer concentration in the precursor solution ensured the achievement of more ordered fibre mats. The immersion in SBF for 28 days triggered an incipient degradation of PCL, evidenced mostly through cracks and gaps. In terms of biological properties, the composite scaffolds displayed a very good biocompatibility when tested with human osteoblast cells, with a superior response for the samples consisting of the polymer and Ce-doped calcium phosphates.

Evaluation of ethanol-induced chitosan aerogels with human osteoblast cells

The following article provides an insight into the production of chitosan aerogels as potential materials for tissue engineering. Chitosan aerogels were prepared following two different protocols: formation in ethanol and formation in sodium hydroxide in an ethanol solution. The main objective was to apply a new route to obtain chitosan aerogels with no external cross-linkers and compare the mentioned preparation approaches. Forming chitosan aerogels in ethanol implies a simple, environmentally friendly, and efficient method. The prepared materials showed specific surface areas of up to 450 m2/g, highly porous networks and great mechanical properties. In vitro degradation studies revealed high stability for up to 10 weeks. The differences between the samples were significant. While the chitosan aerogels prepared in ethanol showed superior textural, morphological and mechanical properties, the chitosan aerogels prepared in the sodium hydroxide solution proved that a considerable influence on end properties could be made simply by adjusting the ageing medium. In vitro cell analysis with primary human osteoblasts showed good biocompatibility and pointed towards the potential use of these aerogels for orthopedic applications. This testing showed further that adjustments in structural properties by sodium hydroxide also come with a cost regarding their suitability to host bone cells.

Structural, cell culture, antibacterial and in vitro bioactivity analysis of highly-ordered Al2O3 nanotube coating with decorated Ag2O nanoparticles on Ti-6Al-4V

The alumina nanotubular arrays (Al2O3 NTs) are a promising candidate for application in bone and dental implants for their better mechanical and chemical behavior in the human body compared to titanium. Nevertheless, the biocompatibility and antibacterial activity of Al2O3 NTs still need further improvement to meet the requirements of safe implants. In this research, Al2O3 NTs coating was proposed on Ti-6Al-4 V via magnetron sputtering pure aluminum followed by an anodization and sealing process, then heat treated for 1 h at 450 °C. After that, Ag2O nanoparticles (NPs) were decorated on the nanotubular walls under controlled conditions using magnetron sputtering. The findings demonstrated that the proposed Al2O3 NTs-Ag2O NPs promoted in-vitro bioactivity alongside excellent antibacterial activity against E.coli and S.aureus bacteria within 4 h and 6 h, respectively. Additionally, the cell-culture showed healthy growth of the human osteoblast cells (HOb) on the Al2O3 NTs-Ag2O NPs. The new design of coating also shows that the total cumulative Ag+released after 14 days is significantly low which is safe and provides the long-term antibacterial activity. It is illustrated that Al2O3 NTs-Ag2O NPs have promising biomedical properties to enhance the biofunctionality of biomedical-grade Ti-6Al-4 V implants.

The evaluation of the osteopromoting capabilities of composites based on biopolymers and gold/silver nanoparticles doped bioactive glasses on an experimental rat bone defect

The most important concept behind using bone scaffolds is the biocompatibility of the material to avoid a local inflammatory response and must have the following properties: osteoinduction, osteoconductivity, angiogenesis, and mechanical support for cell growth. Gold nanoparticles/gold and silver nanoparticles -containing bioactive glasses in biopolymer composites have been used to enhance bone regeneration. These composites were tested in vitro on fibroblast and osteoblast cell lines using MTT tests, immunofluorescence, scanning electron microscopy analysis, and in vivo in an experimental bone defect in Sprague-Dawley rats. Both composites promoted adequate biological effects on human fibroblastic BJ (CRL 2522TM) cell lines and human osteoblastic cells isolated from the human patella in terms of cell proliferation, morphology, migration, and attachment. Most importantly, they did not cause cellular apoptosis and necrosis. According to the histological and immunohistochemical results, both composites were osteoinductive and promoted new bone formation at 60 d. Evidence from this study suggests that the small amount of silver content does not influence negatively the in vitro or in vivo results. In addition, we obtained accurate results proving that the existence of apatite layer and proteins on the surface of the recovered composite, supports the validity of in vitro bioactivity research.

Biomineralization of carboxymethyl cellulose-sodium alginate infused with cellulose nanocrystals for bone regeneration

The development of novel tissue constructs from both natural and synthetic biopolymers has attracted widespread attention among researchers, prior to its excellent outcomes in bone tissue regeneration. This research aims to investigate the biocompatibility of carboxymethyl cellulose (CMC)/sodium alginate (SA) embedded with cellulose nanocrystals (CNC) and its surface response due to the biomineralization process as potential implant material. The CMC/SA were prepared with and without CNC using water as the only solvent. It was then freeze-dried for up to 72 h before being further immersed in simulated body fluid (SBF) for comparative studies. Morphological observation by scanning electron microscope (SEM) showed that CMC/SA/CNC (SBF) displayed a spherical apatite structure amid interconnected porous materials with an average particle diameter between 95 and 148 nm. The apatite crystal indicated the existence of calcium (Ca) and phosphorus (P) elements, which was confirmed by energy dispersive X-ray analysis (EDX). All scaffolds showed a porosity of up to 90.13% with a moderate degradation rate and a water absorption value of up to 1100%. Overall, all scaffolds had open, interconnected pore sizes ranging from 40 to 400 µm. Attenuated total reflection – Fourier Transform Infrared (ATR-FTIR) spectroscopy and thermogravimetric analysis (TGA) curve showed a new existing peak and lower decomposition rate, respectively, for SBF-treated scaffolds. Stress-strain curve disclosed the highest tensile stress of CMC/SA/CNC (SBF) at 16.2 MPa and 15.75% strain effect. Preliminary in vitro cytotoxicity studies performed with human foetal osteoblast (hFOB) cells showed that cytocompatibility was more evident on CMC/SA/CNC (SBF) scaffolds. This study showed that scaffold-embedded CNC with SBF treatment could be hit upon as material selection for bone tissue engineering.

Icariin, a phytoestrogen, exerts rapid estrogenic actions through crosstalk of estrogen receptors in osteoblasts.

Icariin, a flavonoid glycoside derived from Epimedium brevicornum Maxim, exerts bone protective effects via estrogen receptors (ERs). This study aimed to investigate the role of ER-α66, ER-α36, and GPER in bone metabolism in osteoblasts following treatment with icariin. Human osteoblastic MG-63 cells and osteoblast-specific ER-α66 knockout mice were employed. The ERs crosstalk in the estrogenic action of icariin was evaluated in ER-α66-negative human embryonic kidney HEK293 cells. Icariin, like E2, regulated ER-α36 and GPER protein expression in osteoblasts by downregulating them and upregulating ER-α66. ER-α36 and GPER suppressed the actions of icariin and E2 in bone metabolism. However, the in vivo administration of E2 (2 mg/kg/day) or icariin (300 mg/kg/day) restored bone conditions in KO osteoblasts. ER-α36 and GPER expression increased significantly and rapidly activated and translocated in KO osteoblasts after treatment with E2 or icariin. ER-α36 overexpression in KO osteoblasts further promoted the OPG/RANKL ratio induced by E2 or icariin treatment. This study showed icariin and E2 elicit rapid estrogenic responses in bone through recruiting ER-α66, ER-α36, and GPER. Notably, in osteoblasts lacking ER-α66, ER-α36, and GPER mediate the estrogenic effects of icariin and E2, while in intact osteoblasts, ER-α36 and GPER act as negative regulators of ER-α66.

Fabrication of Zr-Ti-Si glassy metallic overlay on 3D printed Ti-6Al4V implant prototypes for enhanced biocompatibility

Implantable materials with enhanced corrosion resistance and bioactivity are highly desired for biomedical application. A 3D metal printed prototype surface was coated with amorphous alloy components of elements Zr, Ti and Si (Zr54Ti35 Si11) as a novel biomedical grade ternary system for the implants. A DC magnetron sputtering technique was used to sputter the films on Ti-6Al-4 V implant prototypes, exhibiting a smooth and denser coating with root means square surface roughness of 1.4 nm. Surface morphology and structural integrity of the thin film metallic glass (TFMG) was studied from electron microscopic techniques and X-ray diffraction analysis. The TFMG is thermally stable with a large supercooled liquid region (∆Tx) of 81.2 °C. Mechanical characteristics of the coatings were studied using the nanoindentation method to correlate the hardness and modulus of the implant materials. Under the simulated body fluid condition, Ti-6Al-4 V implant with 500 nm thickness coatings (Zr54Ti35Si11) exhibited the superior corrosion resistance rate 1 × 10−6 mpy with a charge transfer resistance of 34 kΩ promising for practical application. Electrochemical impedance spectra and Tafel analysis revealed that the corrosion resistance was prominent in the 500 nm thickness TFMG system than the 250 nm and uncoated bare counterparts. The in-vitro biocompatibility and cytotoxicity studies of the as-coated 3D printed implants were studied using the human osteoblast and L929 fibroblast cell lines, respectively. A hemocompatibility study on the implant materials revealed that erythrocytes remain biconcave without aggregation, platelet activation and thrombogenesis, supporting the biocompatibility of the implants. The integration of such unique properties makes these TFMG system ideal candidates for biomedical implants.

CD44 expression is correlated with osteosarcoma cell progression and immune infiltration and affects the Wnt/β-catenin signaling pathway

CD44 is associated with a variety of human diseases and plays a potential role in tumorigenesis, however, the mechanism of its role in osteosarcoma remains unclear. We analyzed the expression of CD44 in the Cancer Genome Atlas (TCGA) and genotype-tissue expression pan-cancer data and found that it was highly expressed in most tumors, including sarcoma. The expression of CD44 in osteosarcoma cell lines was higher than that in human osteoblast cell line in the results of the Western blot and Immunohistochemical staining assay. The results of colony formation assay and CCK 8 showed that CD44 improved the proliferation capacity of osteosarcoma cells, transwell assay and wound healing assay showed that CD44 improved the migration capacity of osteosarcoma cells. Further studies revealed that CD44 exerts its influence on the biological behavior of osteosarcoma cells through the Wnt/β-catenin signaling pathway. Since CD44 may be involved in the immune response, we analyzed the correlation between CD44 expression and immune cell infiltration in TCGA database using the previous cluster analyzer R software package, TIMER2.0 database and, GEPIA2 database, and found its involvement in the immune infiltration of osteosarcoma. Therefore, we believe that CD44 could be a potential target for the treatment of osteosarcoma patients and may be a candidate biomarker for immune infiltration-related prognosis.

Effects of extract solution from magnesium alloys supplemented with different compositions of rare earth elements on in vitro epithelial and osteoblast progenitor cells.

Background: Magnesium alloys (Mg-alloys) have gained significant attention in recent years as a potential bioactive material for clinical applications. The incorporation of rare earth elements (REEs) into Mg-alloys has been of particular interest due to their potential to improve both mechanical and biological properties. Although there are diverse results in terms of cytotoxicity and biological effects of REEs, investigating the physiological benefits of Mg-alloys supplemented with REEs will help in the transition from theoretical to practical applications. Methods: In this study, two culture systems were used to evaluate the effects of Mg-alloys containing gadolinium (Gd), dysprosium (Dy), and yttrium (Y): human umbilical vein endothelial cells (HUVEC) and mouse osteoblastic progenitor cells (MC3T3-E1). Different compositions of Mg-alloys were assessed, and the effects of the extract solution on cell proliferation, viability, and specific cell functions were analyzed. Results: Within the range of weight percentages tested, the Mg-REE alloys did not exhibit any significant negative impacts on either cell line. Interestingly, moderate compositions (Mg-1.5Gd-1.5Dy-0.825Y-0.5Zr and Mg-2Gd-2Dy-1.1Y-0.5Zr) demonstrated a tendency to enhance osteoblastic activity and promote the vascularization process in both HUVEC and MC3T3-E1 cell lines. Discussion: The results of this study provide valuable insights into the potential benefits of REE-supplemented Mg-alloys for clinical applications. The observed enhancement in osteoblastic activity and promotion of vascularization processes suggest that optimizing the compositions of REEs in Mg-alloys could lead to the development of novel, more effective bioactive materials. Further investigations are required to understand the underlying mechanisms and to refine the alloy compositions for improved biocompatibility and performance in clinical settings.

Interaction gene set between osteoclasts and regulatory CD4+ T cells can accurately predict the prognosis of patients with osteosarcoma.

Osteoclasts (OCs) and regulatory CD4+ T cells (CD4+ Tregs) are important components in the tumor microenvironment (TME) of osteosarcoma. In this study, we collected six osteosarcoma samples from our previous study (GSE162454). We also integrated a public database (GSE152048), which included single cell sequencing data of 11 osteosarcoma patients. We obtained 138,192 cells and then successfully identified OCs and CD4+ Tregs. Based on the interaction gene set between OCs and CD4+ Tregs, patients from GSE21257 were distinguished into two clusters by consensus clustering analysis. Both the tumor immune microenvironment and survival prognosis between the two clusters were significantly different. Subsequently, five model genes were identified by protein-protein interaction network based on differentially upregulated genes of cluster 2. Quantitative RT-PCR was used to detect their expression in human osteoblast and osteosarcoma cells. A prognostic model was successfully established using these five genes. Kaplan-Meier survival analysis found that patients in the high-risk group had worse survival (p = 0.029). Therefore, our study first found that cell-cell communication between OCs and CD4+ Tregs significantly alters TME and is connected to poor prognosis of OS. The model we constructed can accurately predict prognosis for osteosarcoma patients.

Monitoring Cell Adhesion on Polycaprolactone-Chitosan Films with Varying Blend Ratios by Quartz Crystal Microbalance with Dissipation.

A detailed understanding of the cell adhesion on polymeric surfaces is required to improve the performance of biomaterials. Quartz crystal microbalance with dissipation (QCM-D) as a surface-sensitive technique has the advantage of label-free and real-time monitoring of the cell-polymer interface, providing distinct signal patterns for cell-polymer interactions. In this study, QCM-D was used to monitor human fetal osteoblastic (hFOB) cell adhesion onto polycaprolactone (PCL) and chitosan (CH) homopolymer films as well as their blend films (75:25 and 25:75). Complementary cell culture assays were performed to verify the findings of QCM-D. The thin polymer films were successfully prepared by spin-coating, and relevant properties, i.e., surface morphology, ζ-potential, wettability, film swelling, and fibrinogen adsorption, were characterized. The adsorbed amount of fibrinogen decreased with an increasing percentage of chitosan in the films, which predominantly showed an inverse correlation with surface hydrophilicity. Similarly, the initial cell sedimentation after 1 h resulted in lesser cell deposition as the chitosan ratio increased in the film. Furthermore, the QCM-D signal patterns, which were measured on the homopolymer and blend films during the first 18 h of cell adhesion, also showed an influence of the different interfacial properties. Cells fully spread on pure PCL films and had elongated morphologies as monitored by fluorescence microscopy and scanning electron microscopy (SEM). Corresponding QCM-D signals showed the highest frequency drop and the highest dissipation. Blend films supported cell adhesion but with lower dissipation values than for the PCL film. This could be the result of a higher rigidity of the cell-blend interface because the cells do not pass to the next stages of spreading after secretion of their extracellular matrix (ECM) proteins. Variations in the QCM-D data, which were obtained at the blend films, could be attributed to differences in the morphology of the films. Pure chitosan films showed limited cell adhesion accompanied by low frequency drop and low dissipation.

Multifunctional Zn and Ag co-doped bioactive glass nanoparticles for bone therapeutic and regeneration

Bone cancer has traditionally been treated using surgery, radiotherapy, and/or chemotherapy. The nonspecific distribution of chemotherapy and implantable infections are significant risk factors for the failure of the bone to heal. Multifunctional zinc and silver co-doped bioactive glass nanoparticles (yAg–xZn-BGNPs) with a diameter of 150 ± 30 nm were successfully synthesized using modified sol–gel and two-step post-functionalization processes, tailored to provide antibacterial and anticancer activity whilst maintaining osteogenesis ability. Co-doped BGNPs with Zn and Ag did not significantly alter physicochemical properties, including size, morphology, glass network, and amorphous nature. Apatite-like layer was observed on the surface of yAg–xZn-BGNPs and resorbed in the simulated body fluid solution, which could increase their bioactivity. Human fetal osteoblast cell line (hFOB 1.19) treated with particles showed calcified tissue formation and alkaline phosphatase activity in the absence of osteogenic supplements in vitro, especially with 0.5Ag–1Zn-BGNPs. Moreover, these particles preferentially disrupted the metabolic activity of bone cancer cells (MG-63) and had an antibacterial effect against B. subtilis, E. coli, and S. aureus via the disc diffusion method. This novel 0.5Ag–1Zn-BGNP and 1Ag–1Zn-BGNPs, with wide-ranging ability to stimulate bone regeneration, to inhibit bone cancer cell proliferation, and to prevent bacterial growth properties, may provide a feasible strategy for bone cancer treatment. The 0.5Ag–1Zn-BGNPs and 1Ag–1Zn-BGNPs can be applied for the preparation of scaffolds or filler composites using in bone tissue engineering.

FeMn and FeMnAg biodegradable alloys: An in vitro and in vivo investigation

Iron-based biodegradable metal bone graft substitutes are in their infancy but promise to fill bone defects that arise after incidents such as trauma and revision arthroplasty surgery. Before clinical use however, a better understanding of their in vivo biodegradability, potential cytotoxicity and biocompatibility is required. In addition, these implants must ideally be able to resist infection, a complication of any implant surgery. In this study there was significant in vitro cytotoxicity caused by pure Fe, FeMn, FeMn1Ag and FeMn5Ag on both human foetal osteoblast (hFOB) and mouse pre-osteoblast (MC3T3-E1) cell lines. In vivo experiments on the other hand showed no signs of ill-effect on GAERS rats with the implanted FeMn, FeMn1Ag and FeMn5Ag pins being removed largely uncorroded. All Fe-alloys showed anti-bacterial performance but most markedly so in the Ag-containing alloys, there is significant bacterial resistance in vitro.

Evaluation of decellularization process for developing osteogenic bovine cancellous bone scaffolds in-vitro.

Current immunological issues in bone grafting regarding the transfer of xenogeneic donor bone cells into the recipient are challenging the industry to produce safer acellular natural matrices for bone regeneration. The aim of this study was to investigate the efficacy of a novel decellularization technique for producing bovine cancellous bone scaffold and compare its physicochemical, mechanical, and biological characteristics with demineralized cancellous bone scaffold in an in-vitro study. Cancellous bone blocks were harvested from a bovine femoral head (18-24 months old) subjected to physical cleansing and chemical defatting, and further processed in two ways. Group I was subjected to demineralization, while Group II underwent decellularization through physical, chemical, and enzymatic treatments. Both were then freeze-dried, and gamma radiated, finally producing a demineralized bovine cancellous bone (DMB) scaffold and decellularized bovine cancellous bone (DCC) scaffold. Both DMB and DCC scaffolds were subjected to histological evaluation, scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDS), fourier-transform infrared spectroscopy (FTIR), quantification of lipid, collagen, and residual nucleic acid content, and mechanical testing. The osteogenic potential was investigated through the recellularization of scaffolds with human osteoblast cell seeding and examined for cell attachment, proliferation, and mineralization by Alizarin staining and gene expression. DCC produced a complete acellular extracellular matrix (ECM) with the absence of nucleic acid content, wider pores with extensive interconnectivity and partially retaining collagen fibrils. DCC demonstrated a higher cell proliferation rate, upregulation of osteogenic differentiation markers, and substantial mineralized nodules production. Our findings suggest that the decellularization technique produced an acellular DCC scaffold with minimal damage to ECM and possesses osteogenic potential through the mechanisms of osteoconduction, osteoinduction, and osteogenesis in-vitro.

Abstract 3609: Interaction of interleukin-6/8/18 with prostate cancer cell secreted growth factors are crucial for osteoblast proliferation and differentiation

Abstract There is currently no effective therapy for bone metastatic prostate cancer, which is the main cause of mortality in people with prostate cancer. Poor prognosis of bone metastasis has limitations in current therapeutics mainly due to the complexity of microenvironment. Our focus was on the interactions between prostate cancer cells and the bone microenvironment, including osteoclasts and osteoblasts in regard to growth factors and cytokines, as the bone microenvironment plays a significant role in this process. The present study shows the downstream effects of Stavudine (KB-S); a known antiviral compound along with 5-fluoro-1-((1R,4R)-4-((tetrahydro-2H-pyran-2-yl)oxy)cyclopent-2-en-1-yl)pyrimidine-2,4(1H,3H)-dione (KB-G) and 1-((1R,4R)-4-hydroxycyclopent-2-en-1-yl)-5-methylpyrimidine-2,4(1H,3H)-dione (KB-H) on bone metastatic prostate cancer. Effects of KB-G/H and S on HEK-293 control cells were determined as moderate under tested conditions. A series of KB-G/H and S (10, 25, 50, 75 and 100 µM) was given for a 4-day period (with 24 h intervals) and the prostate cancer cell population was determined at the end of the 4-day treatment period. Preliminary results indicated that all 3 compounds significantly decreased DU-145 and PC-3 cell population compared to the effects on HEK-293 cells. Results suggested that all 3 compounds can decrease the prostate cancer cell progression by enhancing apoptosis. Our data also suggested that all 3 compounds downregulated interleukin (IL)-18, IL-8, IL-6 and C-X-C motif ligand-1(CXCL-1) in prostate cancer cells (PC-3 and DU-145). A human osteoblast cell line (hFOB 1.19) is being used to study the effect of cytokines in relation to transforming growth factor β (TGFβ), insulin-like growth factor (IGF) and platelet-derived growth factor (PDGF) that are secreted by prostate cancer cells. In-vitro migration/invasion assays, immunoprecipitation (IP), immunofluorescence microscope, cytokine profile array, real time qPCR and Western blot techniques are being used in this study to further analyze role of cytokines and growth factors on osteoblast differentiation. Our preliminary results suggest that all 3 compounds can be used to disrupt the main steps of prostate cancer bone metastasis. Results suggested that KB-G/H and S can be targeted to develop customized, tailored therapies for bone metastatic prostate cancer which merit further research. Citation Format: Aaron Jeshua Todman, Wishrawana S. Ratnayake, Luke Lajmi, Sloan Breedy, Kirpal Bisht, Mildred Acevedo-Duncan. Interaction of interleukin-6/8/18 with prostate cancer cell secreted growth factors are crucial for osteoblast proliferation and differentiation. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3609.

Primary human osteoblast and mesenchymal stem cell responses to apatite/tricalcium phosphate bone cement modified with polyacrylic acid and bioactive glass.

In this work, three different modified cements, control apatite/beta-tricalcium phosphate cement (CPC), polymeric CPC (p-CPC), and bioactive glass added polymeric cement (p-CPC/BG) were evaluated regarding their physical properties and the responses of primary human osteoblast cells (HObs) and mesenchymal stem cells (MSCs). Although polyacrylic acid (PAA) increased compressive strength and Young's modulus of the cement, it could cause poor apatite phase formation, a prolonged setting time, and a lower degradation rate. Consequently, bioactive glass (BG) was added to PAA/cement to improve its physical properties, such as compressive strength, Young's modulus, setting time, and degradation. For in vitro testing, HObs viability was assessed under two culture systems with cement-preconditioned medium (indirect) and with cement (direct). HObs viability was examined in direct contact with cements treated by different prewashing conditions. HObs presented a more well spread morphology on cement soaked in medium overnight, as compared to other cements with no treatment and washing in PBS. In addition, the proliferation, differentiation, and total collagen production of both HObs and MSCs adhered to the cement were detected. Cells showed excellent proliferation on PAA/cement and PAA/BG/cement. Furthermore, the higher released Si ion and lower acidosis of PAA/BG/cement-conditioned medium resulted in an increase in osteogenic differentiation (HObs and MSCs) and enhanced collagen production (HObs in osteogenic medium and MSCs in control medium). Therefore, our findings suggest that BG incorporated PAA/apatite/β-TCP cement could be a promising formula for bone repair applications.