Growth Of MG-63 Cells Research Articles

IInduction of G2/M Phase Block and Apoptosis by Kaempferol in Human Sarcoma Cells

malignant cells has interested us to seek new strategies for the treatment of sarcoma. Flavonoids have been recently claimed to exert anti-cancer effects. We focused on the flavonoid kaempferol, to determine whether it induces apoptosis of sarcoma cells in vitro. Methods: We examined cell growth using a CCK-8 assay, morphology, cell cycle analysis, and the apoptosis or differentiation effects of kaempferol on cultured human osteosarcoma MG-63 cells. All experiments were performed at least three times in duplicates. The ANOVA and independent sample t-test were used for the comparison of the continuous variables Results: Kaempferol (50 μM), adversely affected the proliferation of MG-63 cells. Anti-proliferative action of kaempferol appeared to be linked to apoptotic cell death based on the morphological changes depicting nuclear fragmentation. Cell cycle analysis demonstrated the induction of G2/M phase arrest and an enhanced sub-G1 population. However, the intracellular alkaline phosphatase (ALP) activity was observed to have been stimulated. This apoptosis might be associated with cell differentiation of the cells in the early stage. Conclusions: This study demonstrates that kaempferol inhibited the growth of MG-63 cells in vitro. G2/M phase arrest and induction of intracellular ALP activities in the early phase are observed. These findings indicate that kaempferol may present as an additional pharmacological tool for the treatment of human sarcoma cells.

Characterization and In Vitro Evaluation of Porous Polymer-Blended Scaffolds Functionalized with Tricalcium Phosphate.

Bone tissue is one of the most transplanted tissues. The ageing population and bone diseases are the main causes of the growing need for novel treatments offered by bone tissue engineering. Three-dimensional (3D) scaffolds, as artificial structures that fulfil certain characteristics, can be used as a temporary matrix for bone regeneration. In this study, we aimed to fabricate 3D porous polymer scaffolds functionalized with tricalcium phosphate (TCP) particles for applications in bone tissue regeneration. Different combinations of poly(lactic acid) (PLA), poly(ethylene glycol) (PEG with molecular weight of 600 or 2000 Da) and poly(ε-caprolactone) (PCL) with TCP were blended by a gel-casting method combined with rapid heating. Porous composite scaffolds with pore sizes from 100 to 1500 µm were obtained. ATR-FTIR, DSC, and wettability tests were performed to study scaffold composition, thermal properties, and hydrophilicity, respectively. The samples were observed with the use of optical and scanning electron microscopes. The addition of PCL to PLA increased the hydrophobicity of the composite scaffolds and reduced their susceptibility to degradation, whereas the addition of PEG increased the hydrophilicity and degradation rates but concomitantly resulted in enhanced creation of rounded mineral deposits. The scaffolds were not cytotoxic according to an indirect test in L929 fibroblasts, and they supported adhesion and growth of MG-63 cells when cultured in direct contact.

Ultrathin TiO2 Coatings via Atomic Layer Deposition Strongly Improve Cellular Interactions on Planar and Nanotubular Biomedical Ti Substrates.

This work aims to investigate the chemical and/or structural modification of Ti and Ti-6Al-4V (TiAlV) alloy surfaces to possess even more favorable properties toward cell growth. These modifications were achieved by (i) growing TiO2 nanotube layers on these substrates by anodization, (ii) surface coating by ultrathin TiO2 atomic layer deposition (ALD), or (iii) by the combination of both. In particular, an ultrathin TiO2 coating, achieved by 1 cycle of TiO2 ALD, was intended to shade the impurities of F- and V-based species in tested materials while preserving the original structure and morphology. The cell growth on TiO2-coated and uncoated TiO2 nanotube layers, Ti foils, and TiAlV alloy foils were compared after incubation for up to 72 h. For evaluation of the biocompatibility of tested materials, cell lines of different tissue origin, including predominantly MG-63 osteoblastic cells, were used. For all tested nanomaterials, adding an ultrathin TiO2 coating improved the growth of MG-63 cells and other cell lines compared with the non-TiO2-coated counterparts. Here, the presented approach of ultrathin TiO2 coating could be used potentially for improving implants, especially in terms of shading problematic F- and V-based species in TiO2 nanotube layers.

Morphological and fractal features of cancer cells anchored on composite layers based on magnesium-doped hydroxyapatite loaded in chitosan matrix

In the present study, we report the development and characterization of composite layers (by spin coating) based on magnesium-doped hydroxyapatite in a chitosan matrix, containing human osteosarcoma MG63 cells anchored. Studies regarding the biocompatibility of the composite layers were performed with the aid of a MTT (3–4,5-Dimethylthiazol 2,5-diphenyltetrazolium bromide) assay. The data determined that the composite layers did not inhibit the growth and adhesion of MG63 cells to their surfaces exhibiting good biocompatibility properties. Furthermore, the attachment and development of MG63 cells on the surface of MgHApCh composite layers were investigated using atomic force microscopy (AFM). AFM topographical maps emphasized that the HApCh and 8MgHApCh composite layers surface promoted the attachment and proliferation of MG63 cells on their surface. Meanwhile, in the case of 30MgHApCh layers incubated for 48 h, a slight modification of the morphological features of the MG63 cells. In addition, the effects of the composite layers against Candida albicans ATCC 10231 were also evaluated. The data results from the in vitro antifungal assay depicted that the composite layers successfully inhibited the growth of the fungal cells onto their surface. Morphological and fractal analyses unveil cancer cell surfaces on Mg-containing composite layers with intricate 3D patterns, driven by high-frequency components. Their remarkable complexity and roughness arises from a strong multifractal nature, supporting more effective vertical growth compared to Si and HApCh surfaces. The cell viability reduced of uncoated Si surface is highlighted by its less intense 3D pattern growth. Our results show that the uncoated Si surface promotes lower viability of MG63 cancer cells, with less rough and complex 3D spatial patterns.

CB65 and novel CB65 liposomal system suppress MG63 and Saos-2 osteosarcoma cell growth in vitro

Curable approaches for primary osteosarcoma are inadequate and urge investigation of novel therapeutic formulations. Cannabinoid ligands exert antiproliferative and apoptotic effect on osteosarcoma cells via cannabinoid 2 (CB2) or transient receptor potential vanilloid type (TRPV1) receptors. In this study, we confirmed CB2 receptor expression in MG63 and Saos-2 osteosarcoma cells by qRT-PCR and flow cytometry (FCM), then reported the reduction effect of synthetic specific CB2 receptor agonist CB65 on the proliferation of osteosarcoma cells by WST-1 (water-soluble tetrazolium-1) and RTCA (real-time impedance-based proliferation). CB65 revealed an IC50 (inhibitory concentration) for MG63 and Saos-2 cells as 1.11 × 10−11 and 4.95 × 10−11 M, respectively. The specific antiproliferative effect of CB65 on osteosarcoma cells was inhibited by CB2 antagonist AM630. CB65 induced late apoptosis of MG63 and Saos-2 cells at 24 and 48 h, respectively by FCM when applied submaximal concentration. A novel CB65 liposomal system was generated by a thin film hydration method with optimal particle size (141.7 ± 0.6 nm), polydispersity index (0.451 ± 0.026), and zeta potential (−10.9 ± 0.3 mV) values. The encapsulation efficiency (EE%) of the CB65-loaded liposomal formulation was 51.12%. The CB65 and CB65-loaded liposomal formulation releasing IC50 of CB65 reduced proliferation by RTCA and invasion by scratch assay and induced late apoptosis of MG63 and Saos-2 cells, by FCM. Our results demonstrate the CB2 receptor-mediated antiproliferative and apoptotic effect of a new liposomal CB65 delivery system on osteosarcoma cells that can be used as a targeted and intelligent tool for bone tumors to ameliorate pediatric bone cancers following in vivo validation.

3D-printed polycaprolactone scaffolds coated with beta tricalcium phosphate for bone regeneration

3D-printing technology is an important tool for the bone tissue engineering (BTE). The aim of this study was to investigate the interaction of polycaprolactone (PCL) scaffolds and modified mesh PCL coated with beta TCP (PCL/β-TCP) scaffolds with MG-63. This study used the fused deposition modeling (FDM) technique with the 3D printing technique to fabricate the thermoplastic polymer and composite scaffolds. Scaffold structure and coating quality were observed under a scanning electron microscope (SEM). MG-63 cells were injected and attached to the mesh-manufactured PCL scaffolds. The biocompatibility of mesh structured PCL and PCL/β-TCP scaffolds could be examined by measuring the viability of MG-63 cells of MTT assay. Bone cell differentiation was evaluated ALP activity by mineralization assay. The results showed that both mesh PCL scaffolds and PCL/β-TCP scaffolds were non-toxic to the cells. The ALP activities of cells in PCL/β-TCP scaffolds groups were significant differences and better than PCL groups in all groups at all experimental dates. The mineralization process was time-dependent, and significantly higher mineralization of osteosarcoma cells was observed on PCL/β-TCP scaffolds at experimental dates. We concluded that both meshes structured PCL and PCL/β-TCP scaffolds could promote the MG-63 cell growth, and PCL/β-TCP was better than the PCL scaffolds for the outcome of MG63 cell differentiation and mineralization.

Corrosion behavior, mechanical properties, and in-vitro biocompatibility of cast Mg–3Zn–xSi biodegradable alloys for bone regeneration

In this research, Mg–3Zn–xSi (x = 0, 0.1, 0.3, and 0.6 wt%) biodegradable alloys were produced by simple stir casting method, their microstructure and phase changes were evaluated using X-ray diffraction (XRD), optical microscope (OM) and scanning electron microscope coupled with energy dispersive x-ray analysis (SEM–EDS). Potentiodynamic polarization was conducted to measure the alloys’ corrosion behavior in simulated body fluid (SBF). Tensile strength test and in-vitro biocompatibility evaluation regarding MTT cytotoxicity, ALP osseointegration assay and MG-63 cell growth pattern were conducted. Electrochemical investigations showed that Mg–3Zn alloys enclosing Si attained degradation rates suitable for structural support until bone healing, while the Mg–3Zn alloy without Si had a corrosion rate of 0.128 mm/year which is much lower than the required value. None of the inspected alloys exhibited a significant cytotoxic effect, meanwhile, Mg–Zn base alloy and the alloy with 0.3 wt% Si demonstrated the highest ALP level. The optimum cell growth pattern was demonstrated for Mg–Zn base alloy and the alloy with 0.1 wt% Si. Evidence of calcium phosphate precipitation was observed in the four investigated Mg–3Zn alloys. Therefore, based on the fore mentioned results, Mg–3Zn–xSi alloys were suggested as viable biodegradable materials due to their compatible degradation rates, proved cytocompatibility, high cell viability and excellent osseointegration potential.

Electrophoretic Deposition, Microstructure, and Selected Properties of Poly(lactic-co-glycolic) Acid-Based Antibacterial Coatings on Mg Substrate.

There is an urgent need to develop biodegradable implants that can degrade once they have fulfilled their function. Commercially pure magnesium (Mg) and its alloys have the potential to surpass traditional orthopedic implants due to their good biocompatibility and mechanical properties, and most critically, biodegradability. The present work focuses on the synthesis and characterization (microstructural, antibacterial, surface, and biological properties) of poly(lactic-co-glycolic) acid (PLGA)/henna (Lawsonia inermis)/Cu-doped mesoporous bioactive glass nanoparticles (Cu-MBGNs) composite coatings deposited via electrophoretic deposition (EPD) on Mg substrates. PLGA/henna/Cu-MBGNs composite coatings were robustly deposited on Mg substrates using EPD, and their adhesive strength, bioactivity, antibacterial activity, corrosion resistance, and biodegradability were thoroughly investigated. Scanning electron microscopy and Fourier transform infrared spectroscopy studies confirmed the uniformity of the coatings' morphology and the presence of functional groups that were attributable to PLGA, henna, and Cu-MBGNs, respectively. The composites exhibited good hydrophilicity with an average roughness of 2.6 μm, indicating desirable properties for bone forming cell attachment, proliferation, and growth. Crosshatch and bend tests confirmed that the adhesion of the coatings to Mg substrates and their deformability were adequate. Electrochemical Tafel polarization tests revealed that the composite coating adjusted the degradation rate of Mg substrate in a human physiological environment. Incorporating henna into PLGA/Cu-MBGNs composite coatings resulted in antibacterial activity against Escherichia coli and Staphylococcus aureus. The coatings stimulated the proliferation and growth of osteosarcoma MG-63 cells during the initial incubation period of 48 h (determined by the WST-8 assay).

3D printed Sr‐HA/PCL scaffolds: Fabrication via liquid solvent technique

AbstractIn this research, the Sr‐HA/poly(ɛ‐caprolactone) (PCL) composite scaffold was fabricated using a solvent‐based extrusion method. First, the coprecipitation method was used to synthesize the Sr‐HA powders. For this purpose, strontium was doped into hydroxyapatite (HA) with molar ratios of 0%, 2%, 4%, and 6%. Then, the solvent‐based extrusion method was used to manufacture the 3D printed Sr‐HA/PCL scaffolds. X‐ray diffraction analysis, Fourier transform infrared spectrum, and field emission scanning electron microscope of all samples calcined at 900°C for 1 h indicated the formation of a single‐phase HA structure. The composition of the synthesized powders was confirmed using an inductively coupled plasma test and energy‐dispersive X‐ray spectroscopy. The compressive strength of Sr‐HA/PCL scaffolds compared with pure HA increased from 3.8 to 5.9 MPa. Results of the MTT test showed that Sr‐HA/PCL scaffolds were biocompatible and the growth and proliferation of MG63 cells on the surface of scaffolds increased with the presence of strontium.

In vitro bioactivity and biocompatibility of magnesium implants coated with poly(methyl methacrylate) - bioactive glass composite

Magnesium (Mg) and its alloys have proved promising as biodegradable candidates for the repair of bone tissue. Despite the encouraging bio-related properties of Mg, its high corrosion rate in contact with body fluids still presents a major challenge. An efficient approach to address this issue is to provide a protective coating on Mg. The present research evaluates, for the first time, in vitro bioactivity and biocompatibility of a novel multifunctional composite coating based on poly(methyl methacrylate) (PMMA) biopolymer and bioactive glass (BG) particles on Mg-based implant. Electrophoretic deposition (EPD) was utilized to obtain this coating from a bi-component suspension. Coatings’ morphological analyses by scanning electron microscopy established that EPD provides a facile route for simultaneous deposition of the biopolymeric matrix and BG in the form of a dense and homogeneous coating on the surface of Mg. Chemical characterizations of the coatings performed by energy-dispersive spectroscopy and FT-IR spectroscopy confirmed the presence of both PMMA and BG components in the composite film. In vitro acellular bioactivity test in simulated body fluid (SBF) verified bone-like apatite formation on coatings due to the presence of BG particles. Additionally, in vitro cellular cytotoxicity using MTT assay demonstrated cellular viability in contact with the composite coatings. Moreover, the corrosion behavior of the pure Mg vs coated Mg samples in SBF was assessed electrochemically using linear polarization and impedance spectroscopy techniques. A significant increase in the polarization resistance from 65.89 Ω.cm 2 for uncoated Mg to 1365.1 Ω.cm 2 for Mg coated with a composite film (obtained from 45 g/L PMMA and 3.5 g/L BG suspension) was observed. This indicated a reduction of 95.17% in the corrosion rate of Mg substrate by application of a composite coating. The dramatic reduction in Mg substrate corrosion rate accompanied by in vitro bioactivity and cytocompatibility of the developed composite, reflect the high potential of the present strategy in the modification of Mg-based implants for successful bone tissue engineering applications. • Novel bioactive and corrosion-resistant composite coating on Mg biomedical implant • PMMA facilitates bioactive glass deposition via a facile electrophoretic method • Composite coatings were bioactive due to apatite formation in simulated body fluid • 95.17% reduction in corrosion rate in composite-coated Mg vs bare Mg • Coatings supported the growth of MG63 cells and were non-cytotoxic

Surface characteristics and in vitro biocompatibility of surface-modified titanium foils as a regenerative barrier membrane for guided bone regeneration.

This study evaluated surface characteristics and biocompatibility of surface-modified thin titanium (Ti) foils as a regenerative barrier membrane for future application in guided bone regeneration (GBR) surgery to augment atrophic alveolar bone. Anodic oxidation and post-heat treatment were performed to prepare various Ti foil samples. Then, the in vitro soft and hard tissue compatibility of the samples was evaluated by examining the cell responses using primary human gingival fibroblasts (HGFs) and MG63 human osteoblast-like cells. Investigated Ti foil samples showed marked differences in physicochemical surface properties. Additional 400°C heat treatment applied to the anodized Ti surface led to formation of an anatase titanium dioxide structure and well-organized nanoscale protrusions, and significantly increased surface wettability. Anodization and heat treatment enhanced the growth of HGFs and MG63 cells in Ti foil samples. Additional heat treatment for 10 and 30min further significantly improved the response of HGFs including spreading and proliferation, and upregulated the mRNA expression of cell adhesion- and maturation-related genes as well as the osteoblast differentiation of MG63 cells. Ti foil sample with thin oxide coating obtained by a 30min heat treatment exhibited poor clinical plasticity as a regenerative barrier membrane, which showed complete coating failure in the bending test. Our results indicate that anatase Ti oxide coating of a specific film thickness with nanoscale surface protrusion morphology and hydrophilic characteristics obtained by anodization and post-heat treatment would be an effective approach as a biocompatible Ti regenerative membrane for inducing better regeneration of both gingival tissue and bone.

Distinct degradation behaviors of semi-crystalline poly (4-hydroxybutyrate) containing a nucleating agent under enzymatic or alkaline conditions

Poly(4-hydroxybutyrate) (P4HB) is an absorbable thermoplastic polyester with excellent mechanical properties, good biodegradability and biocompatibility, and has great application prospects in the biomedical field. Therefore, it is of great significance to adjust the degradation rate of P4HB to meet the needs of different application scenarios. In this work, the effects of multimethyl-benzilidene sorbitol (TM6) on the crystallization and degradation behaviors of P4HB were studied. The differential scanning calorimetry, polarized optical microscopy and atomic force microscopy results indicated that TM6 increased the crystallization rate of P4HB as heterogeneous nuclei. The results of weight loss and gel permeation chromatography measurements indicated that both enzymatic and alkaline degradation proceeded via a surface erosion, while the effects of TM6 on the respective degradation rates were quite different. When TM6 content reached 0.5 wt%, the enzymatic degradation rate of P4HB was significantly reduced, and the degraded surface showed a network structure, indicating that TM6-induced crystals were difficult to be degraded, which may be attributed to the high local crystallinity around linear TM6 and/or the different spatial arrangements of TM6-induced crystals. However, the alkaline degradation rate of P4HB was slightly increased because the introduction of TM6 decreased the overall crystallinity. The scanning electron microscope results of P4HB composites after degradation suggested that the enzymatic degradation had higher selectivity to the local physical structure. Based on the degradation results, microspheres with holes or loose nanofibrous structures on the surface were prepared. The cell culture results on the microspheres indicated that nanofibrous structure were more conducive to the adhesion and growth of MG-63 cells. This method for regulating the surface structure of scaffolds is simple and easy to implement, so it has great application potential in the field of tissue engineering.

Injectable, Anti-Cancer Drug-Eluted Chitosan Microspheres against Osteosarcoma.

The purpose of this study is to fabricate different anti-cancer drug-eluted chitosan microspheres for combination therapy of osteosarcoma. In this study, electrospray in combination with ground liquid nitrogen was utilized to manufacture the microspheres. The size of obtained chitosan microspheres was uniform, and the average diameter was 532 μm. The model drug release rate and biodegradation rate of chitosan microspheres could be controlled by the glutaraldehyde vapor crosslinking time. Then the 5-fluorouracil (5-FU), paclitaxel (PTX), and Cis-dichlorodiammine-platinum (CDDP) eluted chitosan microspheres were prepared, and two osteosarcoma cell lines, namely, HOS and MG-63, were selected as cell models for in vitro demonstration. We found the 5-FU microspheres, PTX microspheres, and CDDP microspheres could significantly inhibit the growth and migration of both HOS and MG-63 cells. The apoptosis of both cells treated with 5-FU microspheres, PTX microspheres, and CDDP microspheres was significantly increased compared to the counterparts of control and blank groups. The anti-cancer drug-eluted chitosan microspheres show great potential for the treatment of osteosarcoma.

Bioinspired fabrication of EDC-crosslinked gelatin/nanohydroxyapatite injectable microspheres for bone repair

The present study focuses on the synthesis and evaluation of the gelatin/nanohydroxyapatite (Gel/n-HA) composite microspheres fabricated by the water-in-oil (W/O) emulsification process as potential substrates for bone repair applications. Herein, 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC)-crosslinked Gel/n-HA (10 wt%) composite microspheres were synthesized. The morphology, physicochemical properties, and cellular behavior of the EDC-crosslinked Gel-HA microspheres (ECM) were characterized. In vitro cell culture assays demonstrated that the ECM could effectively promote the adhesion and growth of MG63 cells and in vivo bone repair experiments suggested that ECM possessed sustainable regenerative effects. This study provided a simple strategy to prepare functionalized microspheres that showed great potential in promoting bone regeneration as injectable microscaffolds.

Optimization of the Rheological Properties of Self-Assembled Tripeptide/Alginate/Cellulose Hydrogels for 3D Printing.

3D printing is an emerging and powerful technique to create shape-defined three-dimensional structures for tissue engineering applications. Herein, different alginate–cellulose formulations were optimized to be used as printable inks. Alginate (Alg) was chosen as the main component of the scaffold due to its tunable mechanical properties, rapid gelation, and non-toxicity, whereas microcrystalline cellulose (MCC) was added to the hydrogel to modulate its mechanical properties for printing. Additionally, Fmoc-FFY (Fmoc: 9-fluorenylmethoxycarbonyl; F: phenylalanine; Y: tyrosine), a self-assembled peptide that promotes cell adhesion was incorporated into the ink without modifying its rheological properties and shear-thinning behavior. Then, 3D-printed scaffolds made of Alg, 40% of MCC inks and Fmoc-FFY peptide were characterized by scanning electron microscopy and infrared spectroscopy, confirming the morphological microstructure of the hydrogel scaffolds with edged particles of MCC homogeneously distributed within the alginate matrix and the self-assembly of the peptide in a β-sheet conformation. Finally, the cytocompatibility of the scaffolds was tested in contact with the MG63 osteosarcoma cells, confirming the absence of cytotoxic components that may compromise their viability. Interestingly, MG63 cell growth was retarded in the scaffolds containing the peptide, but cells were more likely to promote adhesive interactions with the material rather than with the other cells, indicating the benefits of the peptide in promoting biological functionality to alginate-based biomaterials.

Tailoring Additively Manufactured Titanium Implants for Short‐Time Pediatric Implantations with Enhanced Bactericidal Activity

Paediatric titanium (Ti) implants are used for the short-term fixation of fractures, after which they are removed. However, bone overgrowth on the implant surface can complicate their removal. The current Ti implants research focuses on improving their osseointegration and antibacterial properties for long-term use while overlooking the requirements of temporary implants. This paper presents the engineering of additively manufactured Ti implants with antibacterial properties and prevention of bone cell overgrowth. 3D-printed implants were fabricated followed by electrochemical anodization to generate vertically aligned titania nanotubes (TNTs) on the surface with specific diameters (∼100 nm) to reduce cell attachment and proliferation. To achieve enhanced antibacterial performance, TNTs were coated with gallium nitrate as antibacterial agent. The physicochemical characteristics of these implants assessed by the attachment, growth and viability of osteoblastic MG-63 cells showed significantly reduced cell attachment and proliferation, confirming the ability of TNTs surface to avoid cell overgrowth. Gallium coated TNTs showed strong antibacterial activity against S. aureus and P. aeruginosa with reduced bacterial attachment and high rates of bacterial death. Thus a new approach for the engineering of temporary Ti implants with enhanced bactericidal properties with reduced bone cell attachment is demonstrated as a new strategy toward a new generation of short-term implants in paediatrics.

Bioactivity and biocompatibility of porous gradient bioceramic coating prepared via laser cladding process

In this work, porous gradient bioceramic coating was fabricated via laser cladding process, and its bioactivity and biocompatibility were evaluated by various tests such as simulated body fluid (SBF) soaking, cell proliferation, cell fixation, osteoblast staining, osteoblast alkaline phosphatase (ALP) activity, and hydroxyproline (HYP) activity. Various porous bioceramic coatings were prepared with 0, 2.5, 5, 7.5, and 10wt% forming agents, and they were denoted as 0 wt% PFA, 2.5 wt% PFA, 5 wt% PFA, 7.5 wt% PFA, and 10 wt% PFA coating, respectively. Among these coatings, 2.5 wt% PFA and 5 wt% PFA coatings after immersing in SBF showed good ability towards mineralization and deposition of bioactive phase components, i.e., HA and β-TCP. In contrast to other coatings prepared in this work, the presence of pore structure on the surfaces of 2.5 wt% PFA and 5 wt% PFA coatings favored the deposition of bone-like apatite. The results obtained from the cell proliferation experiment revealed that 2.5–5 wt% PFA porous coatings possessed superior cell proliferation ability when compared to the other coatings. After investigating the cell fixation morphology, the pore structures of 2.5–5 wt% PFA coatings were shown to be more beneficial for the attachment and growth of MG63 cells on the surface or within the pore structure. Furthermore, the osteoblast staining test proved an extensive wide-ranged MG63 cell growth on the surfaces of 2.5–5 wt% PFA porous coatings. The ALP activity result revealed the increase in ALP contents for 2.5–10 wt% PFA porous coatings. This was especially noticeable for 2.5 wt% PFA coating as it presented the highest ALP content after 6 days. The HYP activity result indicated a continuous HYP content increment for 0–10 wt% PFA porous coatings, with only a slight difference observed between 2 days and 6 days. Therefore, a porous gradient coating with a certain pore structure, i.e., large pore size, even pore distribution, and high pore number, could significantly influence its bioactivity and biocompatibility. Based on the collective results, 2.5 wt% PFA coating with a uniform pore distribution and numerous large-sized pores exhibited the best comprehensive bioactivity and biocompatibility.

Pre-oxidation induced in situ interface strengthening in biodegradable Zn/nano-SiC composites prepared by selective laser melting

IntroductionNano-SiC has attracted great attention as ceramic reinforcement in metal matrix composites, but the weak interface bonding between them remains a bottleneck for efficient strengthening. ObjectiveIn this study, pre-oxidation treatments and selective laser melting (SLM) were employed to prepare Zn/nano-SiC biocomposites with strengthened interface bonding via in situ reaction. MethodsNano-SiC and Zn powders were pre-oxidized respectively, and then used to prepare Zn/nano-SiC biocomposites via SLM. The powder microstructure, and the interface characteristics and mechanical properties of the biocomposites were investigated. The degradation properties and cell response were analyzed to evaluate their feasibility for orthopedic applications. ResultsThe results indicated that the pre-oxidation treatments generated a uniform oxide layer on the surface of both nano-SiC and Zn particles and the thickness of the oxide layer increased with pre-oxidation temperature. During the SLM process, the oxide layers not only improved the metal-ceramic wettability by reducing interface energy, but also induced in situ reaction to form chemical bonding between the Zn matrix and nano-SiC, thereby improving the interface bonding. Consequently, the Zn biocomposite reinforced by nano-SiC with a pre-oxidation temperature of 1000 °C (ZS1000 biocomposite) exhibited more transgranular fracture and significantly enhanced compressive yield strength of 171.5 MPa, which was 31.6% higher than that of the Zn biocomposite reinforced by nano-SiC without pre-oxidation. Moreover, the ZS1000 biocomposite presented slightly accelerated degradation which might be ascribed to the facilitated electron transfer by the interface product (Zn2SiO4). In addition, the ZS1000 biocomposite also showed appropriate biocompatibility for MG-63 cell adhesion, growth, and proliferation. ConclusionThis study shows the potential practical applicability for the preparation of Zn-based biocomposites with strong interface bonding and mechanical properties for orthopedic applications.

Long-non-coding RNA RUSC1-AS1 accelerates osteosarcoma development by miR-101-3p-mediated Notch1 signalling pathway

BackgroundLong non-coding RNA (lncRNA) RUSC1-AS1 has been found to modulate several cancers development. In this study, we explored the role of RUSC1-AS1 on osteosarcoma (OS) progression. MethodsQuantitative Real-time PCR (qRT-PCR) was conducted to test the relative expression of RUSC1-AS1, Notch1 mRNA and miR-101-3p in OS tissues and adjacent normal tissues. Gain- or loss- of functional assays were carried out to determine the roles of RUSC1-AS1 and miR-101-3p in OS progression both in vitro and in vivo. The expression of E-cadherin, N-cadherin, Vimentin, Snail, Notch1, Ras and ERK was determined by Western blot. Furthermore, the relationships between RUSC1-AS1 and miR-101-3p, Notch1 and miR-101-3p were confirmed through RNA immunoprecipitation (RIP) and dual luciferase reporter gene assay. ResultsRUSC1-AS1 and Notch1 were up-regulated in OS cells and tissues. Down-regulating RUSC1-AS1 significantly attenuated the proliferative, epithelial-mesenchymal transition (EMT), growth, lung metastasis, migrative and invasive abilities of MG-63 and Saos-2 cells, and aggravated apoptosis, accompanied with down-regulated Notch1-Ras-ERK1/2 in those cells both in vitro and in vivo, while overexpression of RUSC1-AS1 exerted opposite effects. Overexpressing miR-101-3p in OS cells had similar effects as RUSC1-AS1 inhibition. In addition, RUSC1-AS1 functioned as a competing endogenous RNA (ceRNA) to competitively sponge miR-101-3p, thus upregulating Notch1 expression and mediating the malignant behaviors of OS cells. ConclusionRUSC1-AS1 is a novel oncogenic lncRNA in OS through the miR-101-3p-Notch1-Ras-ERK pathway, which might be a potential therapeutic target for OS.

Rhaponticin suppresses osteosarcoma through the inhibition of PI3K-Akt-mTOR pathway.

Osteosarcoma is the frequent pediatric bone cancer where pediatric osteosarcoma incidences are more than 10% within the population. Most of the patients with osteosarcoma fall within the age of 15–30 years. Therefore, in this research, we examined the anticancer effect of Rhaponticin against the human osteosarcoma (MG-63) cells. The cytotoxicity of Rhaponticin on the MC3T3-E1 and MG-63 cells was examined through the MTT assay. The intracellular ROS accumulation, cell nuclear morphological alterations, apoptotic cell death and nuclear damages, and MMP status of Rhaponticin administered MG-63 cells were inspected by fluorescent staining techniques. The cell migration was assessed through scratch assay. The mRNA expressions of PI3K-Akt-mTOR signaling proteins were studied by RT-PCR analysis. Rhaponticin showed potent cytotoxicity, substantially inhibited the MG-63 cell growth, and displayed morphological alterations. However, rhaponticin did not affect the MC3T3-E1 cell viability. Rhaponticin administered MG-63 cells demonstrated augmented intracellular ROS accretion, weakened MMP, increased nuclear damages, and increased apoptosis. Rhaponticin effectively down-regulated the PI3K-Akt-mTOR signaling cascade in the MG-63 cells. These outcomes proved that the Rhaponticin can be a hopeful chemotherapeutic agent in the future to treat human osteosarcoma.