Osteoblastic Cells Research Articles

Improved visualisation of ACP-engineered osteoblastic spheroids: a comparative study of contrast-enhanced micro-CT and traditional imaging techniques.

This study investigates osteoblastic cell spheroid cultivation methods, exploring flat-bottom, U-bottom, and rotary flask techniques with and without amorphous calcium phosphate (ACP) supplementation to replicate the 3D bone tissue microenvironment. ACP particles derived from eggshell waste exhibit enhanced osteogenic activity in 3D models. However, representative imaging of intricate 3D tissue-engineered constructs poses challenges in conventional imaging techniques due to notable scattering and absorption effects in light microscopy, and hence limited penetration depth. We investigated contrast-enhanced micro-CT as a methodological approach for comprehensive morphological 3D-analysis of the in-vitro model and compared the technique with confocal laser scanning microscopy (CLSM), scanning electron microscopy (SEM) and classical histology. Phosphotungstic acid (PTA) and iodine-based contrast agents were employed for micro-CT imaging in laboratory and synchrotron micro-CT imaging. Results revealed spheroid shape variations and structural integrity influenced by cultivation methods and ACP particles. The study underscores the advantage of 3D spheroid models over traditional 2D cultures in mimicking bone tissue architecture and cellular interactions, emphasising the growing demand for novel imaging techniques to visualise 3D tissue-engineered models. Contrast-enhanced micro-CT emerges as a promising non-invasive imaging method for tissue-engineered constructs containing ACP particles, offering insights into sample morphology, enabling virtual histology before further analysis.

Bone Healing via Carvacrol and Curcumin Nanoparticle on 3D Printed Scaffolds.

Carvacrol is a potent antimicrobial and anti-inflammatory agent, while curcumin possesses antioxidant, anti-inflammatory, and anticancer properties. These phytochemicals have poor solubility, bioavailability, and stability in their free form. Nanoencapsulation can reduce these limitations with enhanced translational capability. Integrating nanocarriers with 3D-printedcalcium phosphate (CaP)scaffolds presents a novel strategy for bone regeneration. Carvacrol and curcumin-loaded nanoparticles (CC-NP) synthesized with melt emulsification produced negatively charged, monodispersed particles with a hydrodynamic diameter of ≈127nm. Their release from the scaffold shows a biphasic release under physiological and acidic conditions. At pH 5.0, the CC-NP exhibits a 53% release of curcumin and nearly 100% release of carvacrol, compared to 19% and 36% from their respective drug solutions. At pH 7.4, ≈40% of curcumin and 76% of carvacrol releases, highlighting their pH-sensitive release mechanism. In vitro studies demonstrate a 1.4-fold increase in osteoblast cell viability with CC-NP treatment. CC-NP exhibit cytotoxic effects against osteosarcoma cells, reducing cell viability by ≈2.9-fold. The antibacterial efficacy of CC-NP evaluated against Staphylococcus aureus (SA) and Pseudomonas aeruginosa (PA) exhibiting 98% antibacterial efficacy. This approach enhances therapeutic outcomes and minimizes the potential side effects associated with conventional treatments, paving the way for innovative applications in regenerative medicine.

Screening of active components of melastoma dodecandrum lour. against diabetic osteoporosis using cell membrane chromatography-mass spectrometry

BackgroundMelastoma dodecandrum Lour. (MD), a traditional botanical drug known for its hypoglycemic, antioxidant, and anti-inflammatory properties, is commonly used to treat diabetes, osteoarthritis, and osteoporosis. However, its specific active components against diabetic osteoporosis remain unclear.PurposeThis study aimed to identify the key active components in MD using cell membrane chromatography coupled with mass spectrometry and validate their effects in vitro.MethodsAn AGEs-induced osteoblast injury model was established. MTT assays measured cell viability, and ALP activity was assessed using a biochemical kit. Western blotting was employed to detect the expression levels of osteoblast-related proteins OCN and RUNX2 and the AGE receptor protein RAGE. ELISA was used to determine the levels of SOD, MDA, CAT, and GPx. PCR quantified TNF-α expression to evaluate the protective effects and potential mechanisms of MD. The AGEs-induced osteoblast cell membrane chromatography-mass spectrometry method facilitated the rapid identification of potentially active compounds based on their affinity for the osteoblast cell membrane. Cell experiments further validated the activity of the characteristic component isovitexin.ResultsMD significantly improved cell viability in AGEs-damaged osteoblasts, enhanced ALP, SOD, CAT, and GPx activities, reduced MDA levels, increased OCN and RUNX2 protein expression, and decreased TNF-α mRNA and RAGE protein expression. Cell membrane chromatography identified 20 chemical constituents, including 13 flavonoids, 4 organic acids, 1 phenylpropanoids, 1 terpenoids, and 1 alkaloid. Cell experiments have confirmed that isovitexin has significant protective activity against osteoblasts and can inhibit the expression of specific receptor RAGE on the osteoblast membrane, consistent with the effect of MD.ConclusionMD and its active component, isovitexin, provide protective effects against AGEs-induced osteoblast injury, offering a basis for subsequent drug development.

Zibibbo Grape Seeds’ Polyphenolic Profile: Effects on Bone Turnover and Metabolism

Background: The consumption of seeds as food has become increasingly common due to their numerous health benefits. Among these, the seeds of the Zibibbo grape from Pantelleria, a native species of southern Italy, remain largely unexplored and are usually considered waste material from viticulture. Nevertheless, Zibibbo grape seeds may offer health benefits, particularly for the elderly and people with metabolic disorders, due to their potential content of beneficial compounds such as polyphenols. Methods: The Zibibbo grape seeds extract (ZSE) was characterized using UV-visible spectrophotometry and HPLC chromatography. The antioxidant activity of ZSE was measured by different colorimetric assays and Electronic Paramagnetic Resonance (EPR). Additionally, specific in vitro tests were conducted on human osteoblast cell lines (Saos-2 and MG63) aiming to evaluate the ZSE’s effects on bone turnover and metabolism. Western blotting was used to assess the impact on specific proteins and pathways related to bone health. Results: The ZSE contained almost ~3 mg/mL of carbohydrates and phenolic compounds, including rutin (~6.4 ppm) and hesperidin (~44.6 ppm). The extracts exhibited an antioxidant activity greater than 90% across all tests performed. Moreover, the Zibibbo seed extracts exerted a significant proliferative effect on the Saos-2 cell human osteoblast-like cell line, also modulating the phosphorylation of specific kinases involved in cell health and metabolism. Conclusions: Zibibbo grape seeds are rich in phenolic compounds, especially flavonoids with strong antioxidant and free radical scavenging properties. ZSE demonstrated beneficial effects on bone metabolism and osteoblast proliferation, suggesting potential for counteracting osteodegenerative conditions like osteoporosis. If confirmed through further studies, Zibibbo grape seed phenolic compounds could serve as an adjunctive therapy for osteoporosis, helping to slow aging and bone degeneration.

Enhanced bipolar electrode electrochemiluminescence biosensor for ultrasensitive monitoring of alkaline phosphatase activity during osteoblast differentiation by integrating electrocatalytic and enzymatic strategies

Alkaline phosphatase (ALP) is an important biomarker that reflects osteoblast activity and bone growth. Accurately detecting ALP activity is of pivotal clinical significance for the diagnosis and differentiation of bone system diseases. In this work, an enhanced bipolar electrode electrochemiluminescence (BPE-ECL) biosensor based on enzyme catalysis and electrocatalysis was proposed for ultrasensitive detection of ALP in osteoblasts. Carbon nitride nanosheets (CNNS) were utilized as electrocatalysts to facilitate the electrochemical reaction of bipyridine ruthenium (Ru(bpy)32+) and tripropylamine (TPrA) in the reporting cell. Meanwhile, in the sensing cell, the target ALP catalyzed the conversion of p-aminophenyl phosphate monohydrate into p-aminophenol (p-AP). The p-AP was subsequently oxidized at the anode of the driving electrode, producing electrons and increasing the Faradaic current of BPE. The dual-signal amplification strategy, combining electrocatalysis and enzyme catalysis, resulted in a 10-fold enhancement of the ECL intensity of Ru(bpy)32+/TPrA. The BPE-ECL biosensor achieved ultrasensitive detection of ALP with a detection limit as low as 1.9×10−6 U/L, and was successfully applied to monitor ALP activity in osteoblast cells. Additionally, a portable smartphone imaging was developed for the visual detection of ALP. This research introduces an innovative BPE-ECL biosensor for the monitoring of ALP activity and point-of-care testing (POCT) in osteoblasts in clinical settings.

Fabrication and comprehensive evaluation of Zr-based bulk metallic glass matrix composites for biomedical applications

AbstractThe aim of this study is to fabricate Zr-based bulk metallic glass matrix composites (BMG-MCs) for biomedical usage and subject them to a comprehensive and farreaching analysis with respect to their mechanical properties, biocorrosion resistance, biocompatibility, and interactions with biofilms that all may arise from their chemical compositions and unusual disordered internal structure. In this study, we fabricate Zr40Ti15Cu10Ni10Be25, Zr50Ti15Cu10Ni10Be25, and Zr40Ti15Cu10Ni5Si5Be25 alloys and confirm their glassy matrix nature through differential scanning calorimetry (DSC) and scanning electron microscopy (SEM) analyses. The mechanical properties, assessed via nanoindentation, demonstrate the high hardness, strength, and elasticity of the produced materials. Corrosion resistance is investigated in simulated body fluid, with Zr-based BMG-MCs exhibiting superior performance compared to conventional biomedical materials, including 316L stainless steel and Ti6Al4V alloy. Biocompatibility is assessed using human fetal osteoblastic cell line hFOB 1.19, revealing low levels of cytotoxicity. The study also examines the potential for biofilm formation, a critical factor in the success of biomedical implantation, where bacterial infection is a major concern. Our findings suggest, as never reported before, that Zr-based BMG-MCs, with their unique composite glassy structure and excellent physicochemical properties, are promising candidates for various biomedical applications, potentially offering improved performance over traditional metallic biomaterials.

Low toxicity of dissolved silver from silver-coated titanium dental implants to human primary osteoblast cells

Objectivesthe controlled release of silver as a biocide from Ag-coated medical implants is desirable. However, the biocompatibility of Ag leachates is poorly understood. This study investigated the toxicity of silver released from the silver plated titanium implants to human primary osteoblast cells; and the effect of cell culture medium on the silver speciation and bioavailability. Methods: Ti6Al4V discs were coated with Ag nanoparticles (NPs), silver plus hydroxyapatite (HA) nanoparticles (Ag+nHA), or Ag NPs plus microparticles (Ag+mHA). Primary human osteoblast cells were exposed to the leachates from the various discs for up to 7 days. Results: the total Ag concentrations released as leachate from the silver-plated titanium discs were 0.7–1.6 mg L−1, regardless of treatment. Cumulative silver release over 7 days was approximately 3 mg L−1 in all treatments. The concentration of total Ag in the cell homogenates from all the Ag-containing treatments was modest, ∼ 0.1 µg mg protein−1 or less at day 7. Cells showed normal healthy morphology with no appreciable leak of LDH or ALP activity into the external media compared to the reference control. Similarly, there was no significant differences (Kruskal Wallis, p > 0.05) in the LDH or ALP activity in the cell homogenate between treatments. Conclusions: overall, there was a controlled release of Ag into the external media, but this remained biocompatible with no deleterious effects on the osteoblast cells, which means that the released silver to the peri-implant environment is not toxic making the coating potential for clinical use

Expression of osteopontin and osteocalcin in Osteoblast cells exposed to a combination of polymethylmethacrylate (PMMA) and hydroxyapatite (HAp): A prospective observational study.

The success of implant placement will depend on the ability of the implant material to integrate with the surrounding tissue. Polymethylmethacrylate (PMMA) has been used as an implant material, but it has several fallback properties in its interaction with bone tissue. The addition of hydroxyapatite (HAp) to PMMA is expected to produce reinforced bioceramic polymers with better mechanical and biological properties. The purpose of this study was to evaluate the expression of osteopontin and osteocalcin in cultured osteoblasts when exposed to two implant candidate materials: PMMA-HApGMP, derived from bovine bone and processed under Good Manufacturing Practice by a Tissue Bank, and PMMA-HApBBK, sourced from limestone (CaCO3) and processed by Balai Besar Keramik. Twenty-four fetal rat calvariae osteoblast cell cultures were randomly divided into 6 groups: 7- and 14-day control group, 7 and 14 days PMMA-HApGMP group, 7 and 14 days PMMA-HApBBK group. The expression of osteopontin and osteocalcin was seen by immunocytochemical examination. The results showed that the average expression of osteopontin and osteocalcin in the treatment group on the 7th and 14th days was higher than the control group. The expression of osteopontin and osteocalcin in the PMMA-HApGMP group increased significantly (P < .05) on day 14. The PMMA-HAp combination material can accelerate the process of osteoblast differentiation which is characterized by an increase in osteopontin and osteocalcin which are markers of bone formation. This will support in increasing osseointegration.

Exploring the Impact of Catechins on Bone Metabolism: A Comprehensive Review of Current Research and Future Directions.

Background/Objectives: Degenerative musculoskeletal diseases represent a global health problem due to the progressive deterioration of affected individuals. As a bioactive compound, catechins have shown osteoprotective properties by stimulating osteoblastic cells and inhibiting bone resorption. Thus, this review aimed to address the mechanism of action of catechins on bone tissue. Methods: The search was applied to PubMed without limitations in date, language, or article type. Fifteen articles matched the topic and objective of this review. Results: EGCG (epigallocatechin gallate) and epicatechin demonstrated action on the osteogenic markers RANKL, TRAP, and NF-κβ and expression of BMPs and ALP, thus improving the bone microarchitecture. Studies on animals showed the action of EGCG in increasing calcium and osteoprotegerin levels, in addition to regulating the transcription factor NF-ATc1 associated with osteoclastogenesis. However, it did not show any effect on osteocalcin and RANK. Regarding human studies, EGCG reduced the risk of fracture in a dose-dependent manner. In periodontal tissue, EGCG reduced IL-6, TNF, and RANKL in vitro and in vivo. Human studies showed a reduction in periodontal pockets, gingival index, and clinical attachment level. The action of EGCG on membranes and hydrogels showed biocompatible and osteoinductive properties on the microenvironment of bone tissue by stimulating the expression of osteogenic growth factors and increasing osteocalcin and alkaline phosphate levels, thus promoting new bone formation. Conclusions: EGCG stimulates cytokines related to osteogenes, increasing bone mineral density, reducing osteoclastogenesis factors, and showing great potential as a therapeutic strategy for reducing the risk of bone fractures.

Fabrication and in vitro biological properties of hydroxyapatite-sodium potassium niobate-barium titanate piezoelectric bioceramics

The utilization of piezoelectric materials in bone implants is appealing due to the inherent piezoelectric property of natural bone. The intrinsic electrical characteristics of piezoelectric biomaterials enhance antibacterial activities, biocompatibility, and bioactivity properties. This study delves into investigating the antibacterial properties, biocompatibility, and bioactivity of three-component biocomposites: sodium potassium niobate (KNN)-barium titanate (BT)-hydroxyapatite (HA). The combination of sodium potassium niobate and barium titanate, possessing suitable piezoelectric properties, with hydroxyapatite, known for its favorable biological properties, enhances the requisite properties for a bone implant. Among the various compositions studied, the combination comprising 70 wt% of the piezoelectric component (KNN-BT) and 30 wt% hydroxyapatite, labeled as 30HKB, emerged as the most optimal blend in terms of density, morphotropic phase boundary, and other biological tests conducted. Following polarization, the antibacterial efficacy of 30HKB against S. aureus bacteria cells increased by 61 %. Furthermore, the growth and adhesion of MC3T3-E1 osteoblast cells suggest enhanced biocompatibility of the 30HKB composite attributed to surface polarization. The surface charges generated by polarization facilitated the absorption of Ca2+ ions, as well as the interaction of HPO4 - and OH- ions with the precipitated Ca2+ ions, leading to the formation of the CaP layer. Hence, polarized piezoelectric ceramics exhibit heightened bioactivity compared to their non-polarized counterparts.

The Role of Mitochondrial Permeability Transition in Bone Metabolism, Bone Healing, and Bone Diseases.

Bone is a dynamic organ with an active metabolism and high sensitivity to mitochondrial dysfunction. The mitochondrial permeability transition pore (mPTP) is a low-selectivity channel situated in the inner mitochondrial membrane (IMM), permitting the exchange of molecules of up to 1.5 kDa in and out of the IMM. Recent studies have highlighted the critical role of the mPTP in bone tissue, but there is currently a lack of reviews concerning this topic. This review discusses the structure and function of the mPTP and its impact on bone-related cells and bone-related pathological states. The mPTP activity is reduced during the osteogenic differentiation of mesenchymal stem cells (MSCs), while its desensitisation may underlie the mechanism of enhanced resistance to apoptosis in neoplastic osteoblastic cells. mPTP over-opening triggers mitochondrial swelling, regulated cell death, and inflammatory response. In particular, mPTP over-opening is involved in dexamethasone-induced osteoblast dysfunction and bisphosphonate-induced osteoclast apoptosis. In vivo, the mPTP plays a significant role in maintaining bone homeostasis, with many bone disorders linked to its excessive opening. Genetic deletion or pharmacological inhibition of the over-opening of mPTP has shown potential in enhancing bone injury recovery and alleviating bone diseases. Here, we review the findings on the relationship of the mPTP and bone at both the cellular and disease levels, highlighting novel avenues for pharmacological approaches targeting mitochondrial function to promote bone healing and manage bone-related disorders.

Effect of Hydroxyapatite Nanowires on Formation and Bioactivity of Osteoblastic Cell Spheroid.

Compared with traditional high-density cell spheroids, which are more prone to core necrosis, nanowires effectively improve the biological activity of core cells in spheroids, emanating more innovations for optimizing the internal cell survival environment and providing differentiation signals. In this study, hydroxyapatite nanowires (HAW), which provide numerous material exchange channels for internal cells by interpenetrating into cell spheroids, were added to osteoblast precursor (MC3T3-E1) cell spheroids. HAW, synthesized using the hydrothermal method, was used as a regulatory material to prepare uniformly sized 3D composite spheroids with good biological activity. Subsequently, material characterization and biocompatibility tests were performed on HAW, and the biological activity and osteogenic differentiation ability of the cell spheroids were tested. Notably, in 2D coculture, HAW displayed a certain attraction to MC3T3-E1 cells and promoted cell aggregation toward it. The content of HAW determined whether composite cell spheroids can form aggregated spherical structures, and incorporation of HAW alleviated core necrosis and enhanced the osteogenic phenotype. In summary, these findings indicate that the prepared HAW-bone cell composite spheroids can potentially be used as building blocks for the construction of large high-density biomimetic tissues and organoids using 3D bioprinting technology.

Orthosilicic acid inhibits human osteoclast differentiation and bone resorption.

Silicon (Si), which is present in the diet in the bioavailable form of orthosilicic acid (OSA) and is detected as a dissolution product of certain bone-substitute materials, is suggested to promote bone health, and enhance bone healing, respectively. Silicon has been shown to stimulate osteoblastic cell differentiation and function, although the effect of Si on human osteoclasts is unclear. The present study investigated the direct effects of Si on human osteoclast differentiation, gene expression, and bone resorption. Human CD14+ monocytes were isolated from buffy coats and cultured with M-CSF and RANKL in medium without or with Si (50 μg/ml; constituting 75% OSA). The effects of Si on osteoclast differentiation were evaluated by TRAP-staining and the expression levels of CtsK, CalcR, TRAP, and DC-STAMP measured by RT-qPCR. The effect of Si on the expression level of AQP9, which encodes a potential Si transporter, was also analyzed. Bone resorption was determined based on the number of resorption pits formed when the RANKL-stimulated monocytes were cultured on bone slices, and by the levels of type I collagen fragments released into the cell culture medium. Silicon significantly inhibited the number of TRAP+ multinucleated cells and the expression of osteoclast related genes but increased the late expression of AQP9. Furthermore, Si significantly inhibited the number of resorption pits and the amount of collagen fragments in the medium when cells were cultured on bone slices. Our results demonstrate that OSA inhibits RANKL-stimulated human osteoclast differentiation, gene expression of osteoclast phenotypic markers, and bone resorption.

O-GlcNAcylation regulates osteoblast differentiation through the morphological changes in mitochondria, cytoskeleton, and endoplasmic reticulum.

To explore the potential mechanisms which O-linked-N-acetylglucosaminylation (O-GlcNAcylation) regulates osteogenesis, a publicly RNA-seq dataset was re-analyzed with literature-mining and showed the primary targets of O-GlcNAcylation in osteoblasts are mitochondria/cytoskeleton. Although the O-GlcNAcylation-regulated mitochondria/cytoskeleton has been extensively studied, its specific role during osteogenesis remains unclear. To address this, we knocked out Ogt (Ogt-KO) in MC3T3-E1 osteoblastic cells. Then, significantly reduced osteoblast differentiation, motility, proliferation, mitochondria-endoplasmic reticulum (Mito-ER) coupling, volume of ER, nuclear tubulins, and oxygen metabolism were observed in Ogt-KO cells. Through artificial intelligence (AI)-predicted cellular structures, the time-lapse live cells imaging with reactive-oxygen-species/hypoxia staining showed that lower cell proliferation and altered oxygen metabolism in the Ogt-KO cells were correlated with the Mito-ER coupling. Bioinformatics analysis, combined with correlated mRNA and protein expression, suggested that Ezh2 and its downstream targets (Opa1, Gsk3a, Wnt3a, Hif1a, and Hspa9) may be involved in O-GlcNAcylation-regulated Mito-ER coupling, ultimately impacting osteoblast differentiation. In conclusion, our findings indicate that O-GlcNAcylation-regulated osteoblast differentiation is linked to morphological changes in mitochondria, cytoskeleton, and ER, with Ezh2 potentially playing a crucial role.

Insights into the Various Cellular Antimicrobial Responses, Biocompatibility, Osteogenesis, Wound Healing, and Angiogenesis of Copper-Doped Nano-Hydroxyapatite Composite Calcium Phosphate Bone Cement In Vitro

Calcium phosphate bone cement (CPC) is a popular material for bone remodeling, and nanohydroxyapatite (nHA) represents a breakthrough that has a wide range of clinical applications. During the early stages of bone repair, antibacterial and angiogenesis effects are essential to remodel new bone tissues. In this study, an antibacterial effect was achieved by incorporating Cu2+-doped nano-hydroxyapatite (Cu–nHA) synthesized through hydrothermal methods into CPC, and the impact of various amounts of Cu–nHA addition on the antibacterial and mechanical properties of CPC hybridization was evaluated. Moreover, the effects of Cu–nHA/CPC composites on the proliferation and mineralization of mouse progenitor osteoblastic cells (D1 cells) were characterized; the cell migration and angiogenesis ability of vascular endothelial cells (HUVECs) were also studied. Results indicated that incorporating 5 wt.% and 10 wt.% Cu–nHA into CPC led to a practical short-term antibacterial effect on S. aureus but not on E. coli. These Cu–nHA/CPC slurries remained injectable, anti-disintegrative, and non-toxic. Furthermore, compared with pure CPC, these Cu–nHA/CPC slurries demonstrated positive effects on D1 cells, resulting in better proliferation and mineralization. In addition, these Cu–nHA/CPC slurries were more effective in promoting the migration and angiogenesis of HUVECs. These findings indicate that 10 wt.% Cu–nHA/CPC has great application potential in bone regeneration.

Development of Novel Biocomposites with Antimicrobial-Activity-Based Magnesium-Doped Hydroxyapatite with Amoxicillin.

Background/Objectives: A biocomposite based on magnesium-doped hydroxyapatite and enriched with amoxicillin (MgHApOx) was synthesized using the coprecipitation method and is presented here for the first time. Methods: The stability of MgHAp and MgHApOx suspensions was evaluated by ultrasound measurements. The structure of the synthesized MgHAp and MgHApOx was examined with X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy and X-ray photoelectron spectroscopy (XPS). The crystalline structure was determined by X-ray diffraction. The FTIR data were collected in the range of 4000-400 cm-1. The morphology of the nanoparticles was evaluated by scanning electron microscopy (SEM). Furthermore, the biocompatible properties of MgHAp, MgHApOx and amoxicillin (Ox) suspensions were assessed using human fetal osteoblastic cells (hFOB 1.19 cell line). The antimicrobial properties of the MgHAp, MgHApOx and Ox suspension nanoparticles were assessed using the standard reference microbial strains Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922 and Candida albicans ATCC 10231. Results: X-ray studies have shown that the biocomposite retains the characteristics of HAp and amoxicillin. The SEM assessment exhibited that the apatite contains particles at nanometric scale with acicular flakes morphology. The XRD and SEM results exhibited crystalline nanoparticles. The average crystallite size calculated from XRD analysis increased from 15.31 nm for MgHAp to 17.79 nm in the case of the MgHApOx sample. The energy-dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS) analysis highlighted the presence of the constituent elements of MgHAp and amoxicillin. Moreover, XPS confirmed the substitution of Ca2+ ions with Mg2+ and the presence of amoxicillin constituents in the MgHAp lattice. The results of the in vitro antimicrobial assay demonstrated that MgHAp, MgHApOx and Ox suspensions exhibited good antimicrobial activity against the tested microbial strains. The results showed that the antimicrobial activity of the samples was influenced by the presence of the antibiotic and also by the incubation time. Conclusions: The findings from the biological assays indicate that MgHAp and MgHApOx are promising candidates for the development of new biocompatible and antimicrobial agents for biomedical applications.

Customized bioresin formulation for stereolithography in tissue engineering

Recently, advancements in fabrication technology have brought a new aspect to the field of tissue engineering. By utilizing advanced techniques in 3D manufacturing and biomaterials, scientists have successfully created tissue engineering scaffolds with complex three-dimensional structures and customized chemical compositions that closely mimic the natural environment of living tissues. These methodologies show potential not only for developing therapies that restore lost tissue function but also for creating in vitro models that replicate living tissue. The current investigation involved the synthesis of methacrylated polycaprolactone (PCLMA) by incorporating methacryloyl chloride (Meth-Cl) into polycaprolactone (PCL) with a molecular weight of 80,000 Da. Afterwards, PCLMA was subjected to crosslinking with glycerol acrylate (GA) and, by utilizing Diphenyl(2,4,6-trimethylbenzoyl) phosphine oxide (TPO) as a photoinitiator, achieved the three-dimensional (3D) printing of tissue materials using Stereolithography (SLA). Analytical techniques included nuclear magnetic resonance (NMR), Fourier-transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). Cell viability was investigated using Human Osteoblast (HOB) cells. The biocompatibility of glycerol acrylate (GA) crosslinked polymethacrylated polycaprolactone (PCLMA) was confirmed using cell viability experiments. Overall, the GA-crosslinked PCLMA bioresin, particularly PCLMA-8, shows promise for further use in tissue engineering applications.

Role of in-situ electrical stimulation on early-stage mineralization and in-vitro osteogenesis of electroactive bioactive glass composites

Bioactive glass (BAG) has emerged as an effective bone graft substitute due to its diverse qualities of biocompatibility, bioactivity, osteoblast adhesion and enhanced revascularization. However, inferior osteogenic capacity of BAG compared to autologous bone grafts continues to limiting it's wide-spread clinical applications towards repairing of bone fractures and healing. In this study, we have fabricated BAG composites with 0.5 to 2 wt% bismuth ferrite (BF, a multiferroic material) with an aim to generate in-situ electrical charges pertinent to early-stage bone regeneration thus mimicking nature bone, which is a piezoelectric material. The fabricated BAG composites were characterised in terms of microstructures, phase analysis, remanent polarization, wettability and subsequently evaluated for in vitro cell proliferation and osteogenesis with and without magnetic field exposure (200 mT, 30 min./day). Pre-osteoblast cells from mice (MC3T3-E1) seeded on these composites exhibited excellent cell growth without any cytotoxicity, which is further supported by FITC/DAPI staining and a live/dead assay. The results of Alizarin Red S assay and increased levels of Alkaline Phosphatase (ALP) activity, at 21 days of culture, suggest that the BAG-BF composites promote in vitro osteogenic differentiation of pre-osteoblast cells. The enhanced osteogenesis of BAG-BF composites was also confirmed through qRT-PCR analysis, which showed rapid upregulation of osteoblastogenic specific genes namely RunX-2, Collagen-1, Bone Sialo Protein, and ALP after 21 days. Additionally, the osteogenic differentiation was assessed by the Western Blot technique, which revealed significantly higher band intensity of osteogenic markers in BAG-1.5 BF and BAG-2 BF composites than pure BAG. These findings clearly demonstrate that in-situ electrical stimulation and osteoconductive capacity of BF reinforced BAG composites have positive impact on osteoblast cell development, bone formation, and healing.

Phage-Loaded Biomimetic Apatite Powder With Antibiofilm Activity to Treat Bone-Associated Infections.

For decades, calcium phosphate (CaP)-based ceramics have been used for coating of bone and joint substitutes after arthroplasty due to their biocompatible properties. Infections following orthopedic replacement occur in 1%-5% of cases, causing serious complications. Biofilm formation either on the biomaterial's surface or on patient's tissues greatly enhances the resistance against antibiotic treatments and can induce a chronic infection, emphasizing the need for novel antimicrobial delivery systems. In this study, we established a protocol enabling bacteriophage loading during the synthesis of a CaP-based powder. The resulting biomaterial proved to be noncytotoxic against human osteoblastic cells and able to significantly inhibit 24-h matured S. aureus biofilm cultures or even completely eradicate it after 5 days of contact. Additional S. aureus biofilm assays with a freeze-dried material using two different excipients showed that sucrose had a protective role against Remus bacteriophage treatment of S. aureus biofilms, whereas lactose-freeze-dried powder maintained the antibiofilm activity.

Electrospun polyvinyl alcohol nanofiber scaffolds incorporated strontium-substituted hydroxyapatite from sand lobster shells: synthesis, characterization, and in vitro biological properties

The paper describes the synthesis of hydroxyapatite (HAp) and strontium-substituted hydroxyapatite (SrHAp) from sand lobster shells by a hydrothermal method. The HAp and SrHAp were incorporated into the polyvinyl alcohol (PVA) nanofiber scaffold through the eletrospinning method. The scaffolds were incorporated with 5wt% of hydroxyapatite (HAp), 5wt%, 10wt%, and 15% of SrHAp. The physicochemical, mechanical, and in vitro biological properties of the scaffold were evaluated. The incorporation of HAp or SrHAp was evidenced by the diffraction patterns and the phosphate functional groups related to HAp. The morphological results showed the decrement of fiber diameter in line with the increased SrHAp concentration. A tensile test was conducted to investigate the mechanical properties of the scaffolds, and the results showed that the scaffolds perform poorly at a higher SrHAp concentration because of exceeding agglomeration levels. The PVA/SrHAp15 performed the best antibacterial activity against E. coli and S. aureus with an inhibition zone of (15.2 ± 0.2) and (14.5 ± 0.8), respectively. The apatite formation was more abundant in PVA/SrHAp10 after immersion in a simulated body fluid (SBF). Cell viability results showed that the scaffold enabled the osteoblast cells to grow and proliferate. The biocompatibility of HAp and SrHAp resulted in the enhancement of cell adhesion. Based on all tests, the PVA/SrHAp 10 scaffold shows a strong candidate for further in vivo studies.