MG-63 Cells Research Articles

Biocompatible nanocomposite scaffolds based on carrageenan incorporating hydroxyapatite and hesperidin loaded nanoparticles for bone tissue regeneration

AbstractIn this study, injectable and osteoinductive carrageenan (CGN)‐based composite hydrogel integrated with 1% wt/vol hydroxyapatite (HA) and hesperidin (HPN) loaded poly (3‐hydroxybutyrate‐co‐3‐hydroxyvalerate acid) nanoparticles (PHBV NPs) were developed as a scaffold for bone tissue engineering. Accordingly, HPN was encapsulated into PHBV NPs by the oil in water emulsion‐solvent evaporation technique and optimized using the fractional factorial design. Then, the effects of the amount of drug, polymer, surfactant concentration, sonication time, and the water/organic phase volume ratio on the characteristics of NPs, including particle size (PS), polydispersity index (PdI), zeta potential (ZP), drug loading (DL) % and encapsulation efficiency (EE) % were investigated. The crystalline state of HPN and the interaction between the drug and the polymer were also investigated using the x‐ray powder diffraction method and the Fourier transform infrared method, respectively. Further, CGN hydrogel was developed and loaded with optimized NPs and HA (HPN‐PHBV NPs‐CGN/HA hydrogel). The prepared hydrogel was then characterized for drug release, swelling and degradation behavior, mechanical properties, and injectability. In addition, the potential of the composite hydrogel as bone tissue scaffolds was assessed by the MTT assay, alkaline phosphatase (ALP) activity, and alizarin red S staining. The optimized formulation had the size of 353.5 nm, PdI of 0.43, EE% of 88.47%, DL% of 29.58% and the ZP of −17.4. HPN‐PHBV NPs‐CGN/HA hydrogel also showed sustained drug release, as compared to the HPN‐CGN/HA hydrogel. Further, the hydrogel containing HA showed improved mechanical properties, as compared with the HA free one. In addition, HPN‐PHBV NPs‐CGN/HA hydrogel significantly enhanced MG63 cell proliferation, ALP activity and matrix mineralization, as compared with other groups. Overall, the use of this hydrogel with enhanced osteogenic capacity could be considered as an effective approach for bone tissue engineering.

Iron oxide nanoparticle-stabilized Pickering emulsion-templated porous scaffolds loaded with polyunsaturated fatty acids (PUFAs) for bone tissue engineering.

Dietary intake of ω-3-polyunsaturated fatty acids (PUFAs) can significantly improve the expression levels of alkaline phosphatase (ALP) and osteocalcin. However, PUFAs are hydrophobic and highly sensitive to temperature, oxygen concentration, pH, and ionic strength. Hence, it is challenging to use PUFAs as bioactive compounds for bone tissue engineering. Here, we encapsulated PUFAs in liposomes to improve their stability. The hydrodynamic size of the PUFA-loaded liposomes was found to be 121.3 ± 35 nm. GC-MS analysis showed that the encapsulation efficiency of the PUFAs was 19.9 ± 3.4%. These PUFA-loaded liposomes were loaded into porous scaffolds that were prepared by polymerizing glycidyl methacrylate and trimethylolpropane triacrylate monomers using the Pickering emulsion polymerization technique. Oleic acid-coated iron oxide nanoparticles were used as the stabilizing agent to prepare these acrylate-based scaffolds containing PUFA-loaded liposomes (P-Lipo-IO(GMA-TMPTA)). SEM micrographs confirmed the porous nature of the scaffolds and the presence of well-adhered liposomes. An in vitro cytotoxicity study conducted using MG63 cells confirmed that these scaffolds showed desirable cytocompatibility. Cell adhesion study showed a well-spread morphology, indicating firm adhesion of the cells. The alizarin red staining of P-Lipo-IO(GMA-TMPTA) scaffolds showed 3- and 2-fold higher calcium deposition compared to the control on days 7 and 14, respectively. ALP activity was also 2-fold higher than that of the control on day 14. RT-PCR analysis of cells exposed to P-Lipo-IO(GMA-TMPTA) scaffolds showed significantly higher expression of osteogenic markers compared to the control. An antibacterial study conducted on Staphylococcus aureus showed a higher percentage inhibition and reactive oxygen species generation in samples treated with P-Lipo-IO(GMA-TMPTA) scaffolds. These desirable biological properties indicate that the developed scaffolds are suitable for bone tissue engineering.

Investigating the interplay between environmental conditioning and nanotopographical cueing on the response of human MG63 osteoblastic cells to titanium nanotubes.

Titanium nanotubular surfaces have been extensively studied for their potential use in biomedical implants due to their ability to promote relevant phenomena associated with osseointegration, among other functions. However, despite the large body of literature on the subject, potential synergistic/antagonistic effects resulting from the combined influence of environmental variables and nanotopographical cues remain poorly investigated. Specifically, it is still unclear whether the nanotube-induced variations in cellular activity are preserved across different biochemical contexts. To bridge this gap, this study systematically evaluates the combined influence of nanotopographical cues and environmental factors on human MG63 osteoblastic cells. To this end, we capitalized on a triphasic anodization protocol to create nanostructured surfaces characterized by an average nanotube inner diameter of 25 nm (NT1) and 82 nm (NT2), as well as a two-tiered honeycomb (HC) architecture. A variable glucose content was chosen as the environmental modifier due to its well-known ability to affect specific functions of MG63 cells. Alkaline phosphatase (ALP), viability/metabolic activity and proliferation were quantified to identify the suitable preconditioning window required for dictating a change in behaviour without significantly damaging cells. Successively, a combination of immunofluorescence, colorimetric assays, live cell imaging and western blots quantified viability/metabolic activity and cell proliferation, migration and differentiation as a function of the combined effects exerted by the nanostructured substrates and the glucose content. To achieve a thorough understanding of MG63 cell adaptation and response, a comparative analysis table that includes and systematically cross-analyzes all variables from this study was used for interpretation and discussion of the results. Taken together, we have demonstrated that all surfaces mitigate the negative effects of high glucose. However, nanotubular topographies, particularly NT2, elicit a more beneficial outcome in high glucose in respect to untreated titanium. In addition, while NT1 surfaces are associated with the most stable cellular response across varying glucose levels, the NT2 and HC substrates exhibit the strongest enhancement of cell migration, viability/metabolism and differentiation. Moreover, shorter-term processes such as adhesion and proliferation are favored on untreated titanium, while anodized samples support later-term events. Lastly, the role of anodized surfaces is dominant over the effects of environmental glucose, underscoring the importance of carefully considering nanoscale surface features in the design and development of cell-instructive titanium surfaces.

Comparison of properties of HAp and CaTiO3-HAp ceramic composite fabricated by different sintering conditions

A hydroxyapatite (HAp) ceramic and a 20% wt CaTiO3-HAp ceramic composite for potential application as biomaterials were produced using single-step sintering (SS) and two-step sintering (TSS) in air. The sample pellets were SS sintered at 1250 ?C with a holding time of 1 h. For TSS, the pellets were heated at 10?C/min to 1250?C (T1) and held at this temperature for 20 min (t1). The temperature was then rapidly lowered at 20?C/min to 1150?C (T2), and held at this temperature for 10 min (t2). The 20% wt CaTiO3-HAp ceramic composite obtained from TSS had a fine grain of 0.56 ? 0.04 mm due to the restraint of grain growth caused by the fast cooling from T1 to T2 and the hard CaTiO3 particles dispersed in the HAp matrix. The microstructure refinement of the 20% wt CaTiO3-HAp ceramic composite fabricated by TSS produced suitable sintered density due to increased locking at triple junctions. This ceramic composite exhibited fracture toughness of 2.10 MPa.m1/2 with a brittleness of 1.97 mm-1/2, indicating that crack propagation was suppressed. MG-63 osteoblast cells were able to adhere to the surface of both HAp and the 20% wt CaTiO3-HAp ceramic composite produced by TSS and were no different between 3 and 7 days of culture. The alkaline phosphatase activity of MG-63 cells was higher on both ceramics cultured in osteogenic differentiation medium than in complete growth medium, which indicated more efficient osteoinductivity.

Bio-response of copper-magnesium co-substituted mesoporous bioactive glass for bone tissue regeneration.

Mesoporous bioactive glass (MBG) is widely acknowledged in bone tissue engineering due to its mesoporous structure, large surface area, and bioactivity. Recent research indicates that introduction of metallic ions has beneficial impacts on bone metabolism and angiogenesis. Thus, the features of MBG can be modified by incorporating combinations of ions, such as magnesium (Mg) and copper (Cu), which can play a considerable role in bone formation, influencing angiogenesis, osteogenesis, as well as antibacterial properties. In this study, Mg and Cu were co-doped for the first time (in a ratio of 1 : 1) in 80SiO2-5P2O5-(15 - 2x)CaO-xMgO-xCuO glass composition with x = 0, 0.5, 1, and 2 mol%, synthesized using the sol-gel and evaporation-induced self-assembly method. X-ray diffraction analysis confirmed the amorphous nature of the powders, while inductively coupled plasma-optical emission spectrometry verified the existence of dopant ions in the respective amounts. The nitrogen sorption method indicated the formation of uniform cylindrical mesopores which are open at both ends and a high surface area of the powders. TEM images show fringes, indicating an ordered mesoporous structure in all MgCu co-doped systems. In vitro bioactivity was observed in all MBG powders, confirmed by the formation of an apatite phase when placed in simulated body fluid (SBF). Flake-like microstructure characteristics of HAp crystals found on the surface of MBG powders were visualized using FESEM. Cytotoxicity tests at lower concentrations (0.1 and 1 wt/vol%) of co-doped 2MC MBG (co-doping up to 2 mol%) showed cell proliferation and viability of osteoblast-like MG-63 cells and normal human dermal fibroblast (NHDF) cells similar to the basic glass 80S. Antibacterial study of MBG pellets showed an increment in the zone of inhibition with the sequential addition of doping ions. The turbidity measurement of bacterial cultures revealed that the optimal concentration for effectively inhibiting bacterial growth was 1 wt/vol% (i.e., 10 mg mL-1) concentration of MBG extracts. The result suggested that the incorporation of Mg and Cu ions in MBG in lower concentrations of up to 2 mol% can be useful in bone regeneration owing to bioactivity, cell proliferation, and antibacterial characteristics.

Silver-deposited titanium as a prophylactic 'nano coat' for peri-implantitis.

Dental implant failures caused by bacterial infections are a significant concern for dental implantologists. We modified the titanium surface by depositing silver (Ti-Ag) using direct current (DC) sputtering and confirmed the formation of a 'nano coat' by X-ray photoelectron spectroscopy (XPS), surface profilometry and energy dispersive spectroscopy (EDS). Scanning electron microscopy (SEM) and atomic force microscopy (AFM) revealed the deposition of a uniform nano Ag thin film. A gradual increase in thickness was observed, and the film thickness (530 nm) at 5 min deposition time (Ti-Ag5) resulted in a reduction of the water contact angle (WCA, 15%) and an increase in surface energy (SFE, 22%) in comparison to the uncoated Ti surface. Using inductively coupled plasma-atomic emission spectroscopy (ICP-AES), the slow, steady release of Ag from the coating was observed over 21 days. The Ti-Ag5 surface exhibited excellent antibacterial activity against Streptococcus oralis, Streptococcus sanguinis, Aggregatibacter actinomycetemcomitans, and Porphyromonas gingivalis, which belonged to the yellow, purple, and red complexes, representing specific periodontal pathogens. Furthermore, we observed excellent cytocompatibility of Ag-deposited Ti towards MG-63 osteoblasts with no inhibitory effect on their proliferative potential. Quantitation of alkaline phosphatase (ALP) activity, mineralization efficiency, and osteogenesis-related gene expression of MG-63 cells over 21 days was suggestive of rapid osseointegration. Overall, the 'nano coat' of Ag on Ti is indeed a prophylactic against peri-implantitis, ensuring increased implant success.

Lenvatinib Suppresses Protein Kinase B Signaling and Induces Apoptosis in Osteosarcoma Cells.

Lenvatinib, an oral multikinase inhibitor, has demonstrated promising activity in patients with osteosarcoma (OS). Therefore, it is worth exploring the inhibitory efficacy and mechanism of action of lenvatinib in osteosarcoma. The primary goal of this study was to examine the inhibitory effectiveness and mechanism of lenvatinib on the growth and invasion of OS cells. The effects of lenvatinib on cell viability, apoptosis, protein kinase B (AKT) activation, its downstream effector proteins involved in tumor progression, and invasion capability were assessed using MTT assay, flow cytometry, western blotting, and invasion/migration assay on U-2 OS and MG63 cells. Lenvatinib effectively induced cytotoxicity, apoptosis, as well as extrinsic and intrinsic apoptotic signaling in OS cells. Lenvatinib also significantly decreased the invasion/migration capability, AKT activation, and downstream effector proteins. The anti-OS effect of lenvatinib may be associated with the induction of apoptosis and the inactivation of AKT.

Anticancer and antimicrobial potential of zinc/sodium alginate/polyethylene glycol/d-pinitol nanocomposites against osteosarcoma MG-63 cells

Abstract Background The field of nanomedicine has attracted much interest and is now serving as the impetus for many revolutionary advances in the pharmaceutical industry. Objectives In the current exploration, we intended to fabricate the zinc/sodium alginate/polyethylene glycol/d-pinitol nanocomposites (ZSP/D-Pin/NCs) and evaluate their antimicrobial and anticancer properties against MG-63 cells. Methods ZSP/D-Pin/NCs were synthesized and characterized using several techniques and their cytotoxicity was examined against osteosarcoma MG-63 cells and normal 3T3 cells using the MTT assay. The levels of oxidative stress and apoptotic protein were examined using assay kits and fluorescence staining. Results and Conclusion The findings of several characterization studies revealed the development of agglomerated and crystalline ZSP/D-Pin/NCs. The antimicrobial assay demonstrated that ZSP/D-Pin/NCs substantially inhibited the growth of pathogens. Additionally, the MG-63 cell viability, which was exposed to several doses (1–20 µg) of ZSP/D-Pin/NCs, showed a remarkable decrease at various time periods, i.e., 24, 48, and 72 h without showing toxicity in 3T3 cells. The results of the fluorescence staining assay demonstrated that ZSP/D-Pin/NCs considerably increased apoptosis in the MG-63 cells by triggering oxidative stress. The antioxidants were reduced and upregulated the Bax and caspase expressions in ZSP/D-Pin/NC-treated MG-63 cells.

Assessing the Antioxidant Properties, In Vitro Cytotoxicity and Antitumoral Effects of Polyphenol-Rich Perilla leaves Extracts.

(1) Background: This study aimed to outline the antioxidant, antitumoral, and cytotoxic proprieties of various types of Perilla frutescens extracts obtained from the leaves of the species. (2) Methods: We determined total polyphenols, flavonoids and anthocyanins contents, as well as the in vitro antioxidant, antitumoral, and cytotoxic actions in three types of ethanolic extracts (E1, E2, E3) and in three types of acetone: ethanol extracts (A1, A2, A3) of Perilla frutescens according to standardized procedures. (3) Results: We found that Perilla frutescens ethanolic extracts had the highest total phenol and anthocyanins concentrations. The flavonoids concentration was not statistically different between the extracts. The iron chelating capacity, hydroxyl radical scavenging capacity, superoxide anion radical scavenging capacity, and lipoxygenase inhibition capacity showed a significant increase with higher concentrations of Perilla frutescens extracts, particularly the ethanolic extracts. Perillyl alcohol had greater cytotoxic capacity in the MG-63 cell line and E1 extract showed similar significant cytotoxic effects in the A431 cell line. (4) Conclusions: Both ethanolic and acetone-ethanol extracts from Perilla frutescens exhibited important antioxidant and antitumoral actions in vitro, which proportionally increased with concentration. The cytotoxic threshold determined in this study for various types of extracts could help determine the best dosage with the maximum antioxidant and antitumoral potential. Our results could serve as a basis for further studies that will investigate the cytotoxic effects of Perilla frutescens variants on various types of cancer cell lines.

Biomimetic Collagen Membranes as Drug Carriers of Geranylgeraniol to Counteract the Effect of Zoledronate.

To counteract the effect of zoledronate and decrease the risk of osteonecrosis of the jaw (BRONJ) development in patients undergoing guided bone regeneration surgery, the use of geranylgeraniol (GGOH) has been proposed. Collagen membranes may act as biomimetical drug carriers. The objective of this study was to determine the capacity of collagen-based membranes doped with GGOH to revert the negative impact of zoledronate on the growth and differentiation of human osteoblasts. MG-63 cells were cultured on collagen membranes. Two groups were established: (1) undoped membranes and (2) membranes doped with geranylgeraniol. Osteoblasts were cultured with or without zoledronate (50 μM). Cell proliferation was evaluated at 48 h using the MTT colorimetric method. Differentiation was tested by staining mineralization nodules with alizarin red and by gene expression analysis of bone morphogenetic proteins 2 and 7, alkaline phosphatase (ALP), bone morphogenetic proteins 2 and 7 (BMP-2 and BMP-7), type I collagen (Col-I), osterix (OSX), osteocalcin (OSC), osteoprotegerin (OPG), receptor for RANK (RANKL), runt-related transcription factor 2 (Runx-2), TGF-β1 and TGF-β receptors (TGF-βR1, TGF-βR2, and TGF-βR3), and vascular endothelial growth factor (VEGF) with real-time PCR. One-way ANOVA or Kruskal-Wallis and post hoc Bonferroni tests were applied (p < 0.05). Scanning electron microscopy (SEM) observations were also performed. Treatment of osteoblasts with 50 μM zoledronate produced a significant decrease in cell proliferation, mineralization capacity, and gene expression of several differentiation markers if compared to the control (p < 0.001). When osteoblasts were treated with zoledronate and cultured on GGOH-doped membranes, these variables were, in general, similar to the control group (p > 0.05). GGOH applied on collagen membranes is able to reverse the negative impact of zoledronate on the proliferation, differentiation, and gene expression of different osteoblasts' markers.

3D printed polylactic acid-based nanocomposite scaffold stuffed with microporous simvastatin-loaded polyelectrolyte for craniofacial reconstruction

Critical sized craniofacial defects are among the most challenging bone defects to repair, due to the anatomical complexity and aesthetic importance. In this study, a polylactic acid/hardystonite-graphene oxide (PLA/HTGO) scaffold was fabricated through 3D printing. In order to upgrade the 3D printed scaffold to a highly porous scaffold, its channels were filled with pectin-quaternized chitosan (Pec-QCs) polyelectrolyte solution containing 0 or 20 mg/mL of simvastatin (Sim) and then freeze-dried. These scaffolds were named FD and FD-Sim, respectively. Also, similar PLA/HTGO scaffolds were prepared and dip coated with Pec-QCs solution containing 0 or 20 mg/mL of Sim and were named DC and DC-Sim, respectively. The formation of macro/microporous structure was confirmed by morphological investigations. The release of Sim from DC-Sim and FD-Sim scaffolds after 28 days was measured as 77.40 ± 5.25 and 86.02 ± 3.63 %, respectively. Cytocompatibility assessments showed that MG-63 cells had the highest proliferation, attachment and spread on the Sim containing scaffolds, especially FD-Sim. In vivo studies on a rat calvarial defect model revealed that an almost complete recovery occurred in the group treated with FD-Sim scaffold after 8 weeks and the defect was filled with newly formed bone. The results of this study acknowledge that the FD-Sim scaffold can be a perfect candidate for calvarial defect repair.

Role of MAPKs in TGF-β1-induced maturation and mineralization in human osteoblast-like cells

Objectives: Our study aimed to clarify the role of mitogen-activated protein kinases (MAPKs) in transforming growth factor (TGF)-β1-stimulated mineralization in the human osteoblast-like MG63 cells. MethodsThe viability of MG63 cells under TGF-β1 stimulation was assessed by MTS assay. Western blotting determined TGF-β1-mediated activation of extracellular signal-related protein kinase (ERK), p38, and c-Jun amino-terminal kinase (JNK). Mineralization-related gene expression was examined by quantitative real-time PCR, and mineral deposition levels were evaluated by alizarin red S staining. ResultsTGF-β1 had no effect on MG63 cell proliferation. Activation of p38 was observed at 3 h post TGF-β1 stimulation. Moreover, JNK phosphorylation was upregulated by TGF-β1 from 1 to 6 h post stimulation, but had no activation on ERK phosphorylation throughout the experimental period. Treatment with JNK inhibitor diminished the alizarin red S-stained area in a dose-dependent manner. Mineral deposition was unaffected by MEK inhibitor, whereas p38 inhibitor increased the red-stained area. Gene expression levels of ALP and BSP were significantly decreased under treatment with JNK inhibitor and p38 inhibitor. The MEK inhibitor had no effect on the TGF-β1–mediated upregulation of ALP and BSP. Although all three inhibitors suppressed expression of COL I, none were found to stimulate expression of OCN. ConclusionsHuman osteoblast-like MG63 cells maturation and mineralization are induced through JNK activation of MAPK signaling in response to TGF-β1.

Biogenic synthesis of dopamine/carboxymethyl cellulose/TiO2 nanoparticles using Psidium guajavaleaf extract with enhanced antimicrobial and anticancer activities.

The green synthesis of metal oxide nanoparticles (NPs) has garnered considerable attention from researchers due to its utilization of eco-friendly solvents during synthesis and cost-effective approaches. This study focuses on the synthesis of titanium oxide (TiO2) and dopamine (DA) carboxymethyl cellulose (CMC)-doped TiO2 (DA/CMC/TiO2) NP using Psidium guajava leaf extract, while also investigating the structural, optical, and morphological and biocidal potential of the prepared NPs. Significantly larger zones of inhibition were observed for DA/CMC/TiO2 NPs compared to TiO2 against various pathogens. Moreover, the MTT assay was carried out to evaluate the anticancer activity of the prepared samples against MG-63 cells, and the results revealed that DA/CMC/TiO2 NPs exhibited significantly higher level of anticancer activity compared to TiO2. The experimental results demonstrated that DA/CMC/TiO2 NPs exhibited enhanced anticancer activity in a dose-dependent manner when compared to TiO2 NPs.

Impact of Conventional and Potential New Metal-Based Drugs on Lipid Metabolism in Osteosarcoma MG-63 Cells.

This work investigated the mechanisms of action of conventional drugs, cisplatin and oxaliplatin, and the potentially less deleterious drug Pd2Spermine (Spm) and its Pt(II) analog, against osteosarcoma MG-63 cells, using nuclear-magnetic-resonance metabolomics of the cellular lipidome. The Pt(II) chelates induced different responses, namely regarding polyunsaturated-fatty-acids (increased upon cisplatin), suggesting that cisplatin-treated cells have higher membrane fluidity/permeability, thus facilitating cell entry and justifying higher cytotoxicity. Both conventional drugs significantly increased triglyceride levels, while Pt2Spm maintained control levels; this may reflect enhanced apoptotic behavior for conventional drugs, but not for Pt2Spm. Compared to Pt2Spm, the more cytotoxic Pd2Spm (IC50 comparable to cisplatin) induced a distinct phospholipids profile, possibly reflecting enhanced de novo biosynthesis to modulate membrane fluidity and drug-accessibility to cells, similarly to cisplatin. However, Pd2Spm differed from cisplatin in that cells had equivalent (low) levels of triglycerides as Pt2Spm, suggesting the absence/low extent of apoptosis. Our results suggest that Pd2Spm acts on MG-63 cells mainly through adaptation of cell membrane fluidity, whereas cisplatin seems to couple a similar effect with typical signs of apoptosis. These results were discussed in articulation with reported polar metabolome adaptations, building on the insight of these drugs' mechanisms, and particularly of Pd2Spm as a possible cisplatin substitute.

Microgravity triggers ferroptosis and accelerates senescence in the MG-63 cell model of osteoblastic cells

In space, cells sustain strong modifications of their mechanical environment. Mechanosensitive molecules at the cell membrane regulate mechanotransduction pathways that induce adaptive responses through the regulation of gene expression, post-translational modifications, protein interactions or intracellular trafficking, among others. In the current study, human osteoblastic cells were cultured on the ISS in microgravity and at 1 g in a centrifuge, as onboard controls. RNAseq analyses showed that microgravity inhibits cell proliferation and DNA repair, stimulates inflammatory pathways and induces ferroptosis and senescence, two pathways related to ageing. Morphological hallmarks of senescence, such as reduced nuclear size and changes in chromatin architecture, proliferation marker distribution, tubulin acetylation and lysosomal transport were identified by immunofluorescence microscopy, reinforcing the hypothesis of induction of cell senescence in microgravity during space flight. These processes could be attributed, at least in part, to the regulation of YAP1 and its downstream effectors NUPR1 and CKAP2L.

Characterization and in vitro bioactivity evaluation of polyvinyl alcohol incorporated electro spun chitosan/ fluor apatite nanofibrous scaffold for bone tissue engineering

In this study, polyvinyl alcohol/chitosan/fluor apatite scaffolds with different concentrations of polyvinyl alcohol of 0.075 g ml−1 and 0.1 g ml−1, respectively named A and B fabricated by electrospinning method to use in tissue engineering. By examining the scaffolds by FE-SEM, an appetite layer formation which was on the scaffold surface was clearly observable. Increasing the concentration of polyvinyl alcohol from 0.075 g ml−1 to 0.1 g ml−1 in the nanofibrous scaffolds improved degradation characteristic with an optimized value of 26 ± 2 and 42 ± 1 % after 28 days, respectively. The mean diameter of fibers both scaffolds was 405 nm and 212 nm, respectively. Furthermore, the percentage of porosity in both scaffolds was calculated as 84% and 91%, separately. The level of hydrophilicity of the scaffolds was measured by the dynamic contact angle method. Moreover, the increase in the percentage of polyvinyl alcohol led to the decrease in the average contact angle in scaffold A and scaffold B from 90° to 70°, respectively. The results of bone marrow culture test with MG-63 (NCBI C555) cell on the surface of scaffolds demonstrated not cytotoxicity in the resulting scaffolds as well as a suitable substrate for the adhesion and growth of the cells. According to our findings, the electrospun fluorapatite-incorporated-chitosan/polyvinyl alcohol scaffold could provide a new nanocomposite for biomedical applications.

Engineering alginate-based injectable hydrogels combined with bioactive polymers for targeted plasma-derived oxidative stress delivery in osteosarcoma therapy

Reactive Oxygen and Nitrogen Species (RONS) in biological systems display hormetic effects, capable of either promoting cell regenerative effects or inducing cell death. Recently, hydrogels have emerged as a promising delivery platform for RONS generated from Cold Atmospheric Plasmas (CAP), known as Plasma-Treated Hydrogels (PTH). PTH have been proposed as an alternative therapy to conventional cancer treatments, offering reduced side effects through the controlled and localized delivery of plasma-derived RONS. In this work, we have developed alginate-based PTH with dual therapeutic action provided by plasma-derived RONS acting as selective anticancer agents for osteosarcoma treatment, and biomolecules (hyaluronic acid and gelatin) to promote stem cell-mediated bone regeneration. For this purpose, we designed a novel manufacturing process to maximize the load of plasma-derived RONS within the PTH. Then, we assessed the PTH bioactivity on osteosarcoma MG-63 cells, and human mesenchymal stem cells (hMSCs). The results showed that the PTH composed of 0.25 % alginate +1 % hyaluronic acid is the most promising formulation in osteosarcoma treatment, showing a dual-action bioactivity as a selective cytotoxic anticancer agent, and as promoter of the proliferation and osteogenic differentiation of hMSCs. These findings provide strong evidence of the significant potential of PTH in the oncological field.

Degradable Zn–5Ce alloys with high strength, suitable degradability, good cytocompatibility, and osteogenic differentiation fabricated via hot-rolling, hot-extrusion, and high-pressure torsion for potential load-bearing bone-implant application

Zinc (Zn)-based alloys are considered the next-generation biodegradable material for promising bone-implant devices due to their good degradability, formability, and functionality. Nevertheless, the as-cast Zn alloys showed a low strength-toughness, making it challenging to meet the mechanical properties requirements for high-load-bearing bone implants due to their hexagonal close-packed structure, coarse grain size, and less sliding system. Herein, we have developed biodegradable Zn–5Ce alloys by cerium (Ce) alloying followed by hot-rolling, hot-extrusion, and high-pressure torsion (HPT), respectively, for potential bone-implant application. Mechanical testing revealed that the HPT sample exhibited the best mechanical performance matching among the Zn–5Ce samples with a high ultimate tensile strength of ∼345 MPa, yield strength of ∼230 MPa, a moderate elongation of ∼11.4%, and macro-hardness of ∼96.6 HB. Electrochemical corrosion and static immersion testing revealed that the HPT sample showed the highest electrochemical corrosion rate of ∼416 μm/y and degradation rate of ∼43.8 μm/y in Hanks' solution among the Zn–5Ce samples, which is suitable for degradation rate requirements for bone-implant application. Bio-tribological testing revealed that the HPT sample showed high bio-tribological properties matching in Hanks’ solution with the lowest friction coefficients of ∼0.530 and moderate wear loss of ∼2.2 mg. Cytocompatibility and osteogenic differentiation assessment revealed that the diluted extract of the HPT sample showed the highest cytocompatibility towards 3T3 and MG-63 cells and osteogenic differentiation performance towards 3T3 cells among the most diluted extracts. Accordingly, the HPT Zn–5Ce sample is expected to be used for high-load-bearing degradable bone-implant devices, including bone fixation and guided bone regeneration systems.

In vitro bioactivity and biocompatibility behaviour of atmospheric plasma sprayed Indian clam seashell derived hydroxyapatite coating on Ti-alloy

Initially, various hydroxyapatite (HA) powders were derived from the Indian clam seashell by the hydrothermal reaction method with varying heating temperatures (700–1000 ℃). Further, the synthesized and agglomerated pure HA powders were sprayed on Ti-6Al-4 V (ELI) alloy to deposit different HA coatings through the atmospheric plasma spraying (APS) technique. In the current work, the in vitro bioactivity and biocompatibility properties of the fabricated HA coatings are examined to find the usefulness of such coated samples for biomedical applications. In the first test, the coatings are exposed to the simulated body fluid (SBF) for 1, 3, and 5 days of duration. The XRD (X-ray diffractometry) and FESEM (Field Emission Scanning Electron Microscopy) analyses of the treated HA coatings reveal the formation of apatite structure, which has grown with immersion time. The biocompatibility of the HA coatings is examined through MTT (3-(4,5-dimethylthiazol-2-yl)− 2,5-diphenyltetrazolium bromide) assay analysis by using human osteosarcoma cell line (MG-63 cell). All the HA coatings are found to show improvement in cell density with an increase in incubation time from 1 to 5 days. From these tests, the seashell-derived HA coatings are found to be both bioactive and biocompatible in nature. The variation in biological properties observed among the HA coatings is due to their different microstructural features resulting from the melting and solidification behavior of the HA feedstocks. As the deposition parameters are kept constant, the synthesis condition of HA powders, such as the reaction temperature, has played a key role in varying the phases and stoichiometry of the resulting coating. With the highest amount of metastable and near stoichiometric HA phase content, the HA-1000 coating has shown the maximum amount of cell proliferation and apatite growth among all. However, from the alkaline phosphatase (ALP) activity test, the HA-800 coating is found to show the maximum ALP expression level. This is attributed to the highest thickness of such coating resulting from the high deposition rate of HA-800 powder. Possibly, the high porosity of HA-800 coating has allowed a good amount of HA material to participate in the reaction process.

Drug kinetics and antimicrobial properties of quaternary bioactive glasses 81S(81SiO2-(16-x)CaO-2P2O5-1Na2O-xMgO); an in-vitro study

Bioactive glasses have recently been attracted to meet the challenge in bone tissue regeneration, repair, healing, dental implants, etc. Among the conventional bio-glasses, a novel quaternary mesoporous nano bio-glass with composition 81S(81SiO2-(16-x)CaO-2P2O5-1Na2O-xMgO) (x = 0, 1.6, 2.4, 4 and 8 mol%) employing Stober's method has been explored for examining the above potential application through in-vitro SBF assay, MTT assay, antimicrobial activity and drug loading and release ability. With increasing the MgO concentration up to 4 mol%, from in-vitro SBF assay, we observe that HAp layer develops on the surface of the nBGs confirmed from XRD, FTIR and FESEM. MTT assay using MG-63 cells confirms the biocompatibility of the nBGs having cell viability >225 % for MGO_4 after 72 h which is more than the clinically used 45S5 bio-glass. We have observed cell viability of >125 % even after 168 h. Moreover, MGO_4 is found to restrict the growth of E. coli by 65 % while S. aureus by 75 %, confirming the antimicrobial activity. Despite an increase in the concentration of magnesium, nBGs are found to be non-toxic towards the RBCs up to 4 mol% of MgO while for 8 %, the hemolysis percentage is >6 % which is toxic. Being confirmed MGO_4 nBG as a bioactive material, various concentrations of drug (Dexamethasone (DEX)) loading and release kinetics are examined. We show that 80 % of loading in case of 10 mg-ml−1 and 70 % of cumulative release in 100 h. The mesoporous structure of MGO_4 having an average pore diameter of 5 nm and surface area of 216 m2 g−1 confirmed from BET supports the loading and release kinetics. We conclude that the quaternary MGO_4 nBG may be employed effectively for bone tissue regeneration due to its high biocompatibility, excellent in-vitro cell viability, antimicrobial response and protracted drug release.