Collagen Scaffolds Treated by Hydrogen Peroxide for Cell Cultivation.

Collagen in the body is exposed to a range of influences, including free radicals, which can lead to a significant change in its structure. Modeling such an effect on collagen fibrils will allow one to get a native structure in vitro, which is important for modern tissue engineering. The aim of this work is to study the effect of free radicals on a solution of hydrogen peroxide with a concentration of 0.006-0.15% on the structure of collagen fibrils in vitro, and the response of cells to such treatment. SEM measurements show a decrease in the diameter of the collagen fibrils with an increase in the concentration of hydrogen peroxide. Such treatment also leads to an increase in the wetting angle of the collagen surface. Fourier transform infrared spectroscopy demonstrates a decrease in the signal with wave number 1084 cm-1 due to the detachment of glucose and galactose linked to hydroxylysine, connected to the collagen molecule through the -C-O-C- group. During the first day of cultivating ASCs, MG-63, and A-431 cells, an increase in cell adhesion on collagen fibrils treated with H2O2 (0.015, 0.03%) was observed. Thus the effect of H2O2 on biologically relevant extracellular matrices for the formation of collagen scaffolds was shown.

Antitumor and antimigration effects of Salvia clandestina L. extract on osteosarcoma cells.

Salvia clandestina L. is a wild perennial species present in the Salento area of Italy. Here, we examined the in vitro effects of an aqueous extract of S. clandestina L. on the MG-63 osteosarcoma cell line. The extract reduced osteosarcoma cell viability mainly by way of apoptosis, as we observed (1) upregulation of gene and protein expression of p53, cyclin-dependent kinase inhibitors p21WAF1 and p27Kip1 , and proapoptotic BAX; (2) activation of caspases; and (3) induction of a sub-G1 peak in the cell cycle. The mitogen-activated protein kinases (MAPKs) JNK1/2 and p38 are activated and involved in the intracellular effects of the S. clandestina extract, as preincubation with the JNK1/2 inhibitor SP600125 or the p38 inhibitor SB203580 significantly decreased S. clandestina extract-induced cytotoxicity and inhibited increase in p53, p21WAF1 , p27Kip1 , and BAX. SP600125 also inhibited mRNA levels for all the aforementioned proteins, while SB203580 only affected p53 mRNA. Furthermore, S. clandestina extract treatment counteracted epithelial-to-mesenchymal transition, inhibited cell migration, and decreased the expression and activity of matrix metalloproteinase MMP2. In addition, S. clandestina extract enhanced the cytotoxic activity of cisplatin on MG-63 cells through downregulation of the Akt/PKB protein kinase. We conclude that S. clandestina extract may be a novel agent for osteosarcoma treatment.

Enhanced Internalization of Nanoparticles Following Ionizing Radiation Leads to Mitotic Catastrophe in MG-63 Human Osteosarcoma Cells.

This study aims to investigate whether ionizing radiation combined with doxorubicin-conjugated iron oxide nanoparticles (NP-DOX) improves the internalization and cytotoxic effects of the nano-carrier-mediated drug delivery in MG-63 human osteosarcoma cells. NP-DOX was designed and synthesized using the co-precipitation method. Highly stable and crystalline nanoparticles conjugated with DOX were internalized in MG-63 cells through macropinocytosis and located in the perinuclear area. Higher nanoparticles internalization in MG-63 cells previously exposed to 1 Gy X-rays was correlated with an early accumulation of cells in G2/M, starting at 12 h after treatment. After 48 h, the application of the combined treatment led to higher cytotoxic effects compared to the individual treatment, with a reduction in the metabolic capacity and unrepaired DNA breaks, whilst a low percent of arrested cells, contributing to the commitment of mitotic catastrophe. NP-DOX showed hemocompatibility and no systemic cytotoxicity, nor histopathological alteration of the main organs.

Tanshinone IIA inhibits osteosarcoma growth through modulation of AMPK-Nrf2 signaling pathway.

Tanshinone IIA (Tan IIA) is a member of the major lipophilic components extracted from the root of Salvia miltiorrhiza Bunge. Osteosarcomas are primary malignant tumors of bone. The aim of our study is to explore the role of Tan IIA in osteosarcomas survival, migration, and proliferation. MG63 osteosarcoma cell line was cultured in vitro and treated with different concentrations of Tan IIA. Then, ELISA, immunofluorescence, qPCR, western blots, and pathway analysis were conducted to verify whether Tan II modulated osteosarcoma survival, migration, and proliferation through the AMPK/Nrf2 signaling pathway. Our results indicated that Tan IIA dose-dependently inhibited MG63 osteosarcoma cell survival, migration, and proliferation. Mechanistically, Tan IIA reduced cell viability and inhibited the transcriptions of migratory factors. In addition, the number of proliferative MG63 osteosarcoma cell was also reduced by Tan IIA. Molecular investigations demonstrated that Tan IIA treatment caused a drop in the transcriptions and activities of AMPK and Nrf2. Interestingly, knockdown of AMPK and Nrf2 markedly attenuated MG63 osteosarcoma cell survival, migration, and proliferation. Altogether, our results indicate that Tan IIA could be used as an effective anticancer drug to control osteosarcoma proliferation through affecting its survival, migration, and proliferation.

Effect of Calcium Precursor on the Bioactivity and Biocompatibility of Sol-Gel-Derived Glasses.

This study investigated the impact of different calcium reagents on the morphology, composition, bioactivity and biocompatibility of two-component (CaO-SiO2) glasses produced by the Stöber process with respect to their potential application in guided tissue regeneration (GTR) membranes for periodontal repair. The properties of the binary glasses were compared with those of pure silica Stöber particles. The direct addition of calcium chloride (CC), calcium nitrate (CN), calcium methoxide (CM) or calcium ethoxide (CE) at 5 mol % with respect to tetraethyl orthosilicate in the reagent mixture gave rise to textured, micron-sized aggregates rather than monodispersed ~500 nm spheres obtained from the pure silica Stöber synthesis. The broadening of the Si-O-Si band at ~1100 cm-1 in the infrared spectra of the calcium-doped glasses indicated that the silicate network was depolymerised by the incorporation of Ca2+ ions and energy dispersive X-ray analysis revealed that, in all cases, the Ca:Si ratios were significantly lower than the nominal value of 0.05. The distribution of Ca2+ ions was also found to be highly inhomogeneous in the methoxide-derived glass. All samples released soluble silica species on exposure to simulated body fluid, although only calcium-doped glasses exhibited in vitro bioactivity via the formation of hydroxyapatite. The biocompatibilities of model chitosan-glass GTR membranes were assessed using human MG63 osteosarcoma cells and were found to be of the order: CN < pure silica ≈ CC << CM ≈ CE. Calcium nitrate is the most commonly reported precursor for the sol-gel synthesis of bioactive glasses; however, the incomplete removal of nitrate ions during washing compromised the cytocompatibility of the resulting glass. The superior bioactivity and biocompatibility of the alkoxide-derived glasses is attributed to their ease of dissolution and lack of residual toxic anions. Overall, calcium ethoxide was found to be the preferred precursor with respect to extent of calcium-incorporation, homogeneity, bioactivity and biocompatibility.

Influence of CuO/MgO ratio on the gene expression, cytocompatibilty, and antibacterial/anticancerous/analgesic drug loading kinetics for (15-x) CuO-xMgO-10P2 O5 -60SiO2 -10CaO-5ZnO (2.5 ≤ x ≤ 12.5) mesoporous bioactive glasses.

In the present study, novel mesoporous bioactive glasses (MBGs) (15-x)CuO-xMgO-10P2 O5 -60SiO2 -10CaO-5ZnO (2.5 ≤ x ≤ 12.5, varying in steps of 2) are synthesized using the sol-gel technique. The structural phases of the glasses/glass ceramics were studied by XRD. The pH variation and simulated body fluids (SBF) studies demonstrated the in-vitro bioactivity of all the MBGs. MBGs possess surface area variation between 98.22 and 442.41 cm2 /g. The pore size of MBGs lies in the range of 5.8-8.8 nm. The cytotoxicity assays were conducted for MG63 human osteosarcoma cell line depicting non-toxic behavior of all MBGs at 7.8125 µg/ml. In addition to this, the effect of the magnesium on the gene expression was also investigated using reverse transcription-polymerase chain reaction (RT-qPCR). The MBGs were loaded with the antibacterial (vancomycin/amoxicillin), anticancerous (doxorubicin), and analgesic (Iburofen) drugs. Ibuprofen and amoxicillin drugs were almost fully loaded in all the MBGs, whereas doxorubicin and vancomycin drugs illustrated variation in loading with decreasing copper content. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 2116-2130, 2018.

The growth-inhibition of osteosarcoma xenografts by adenovirus-mediated ING4 gene in nude mice / 中国免疫学杂志

Objective:To study the inhibitory effect and anti-cancer mechanisms of adenovirus-mediated ING4 gene on the MG-63 osteosarcoma xenografts in nude mice.Methods:Ad-ING4 was transfected into QBI-293 cells and harvested.15 nude mice of the subcutaneous tumor models were established with MG-63 osteosarcoma cells and were randomly divided into PBS,Ad-GFP and Ad-ING4 groups.Then PBS(100 μl),Ad-GFP(100 μl,10~9pfu/ml) and Ad-ING4 (100 μl,10~9pfu/ml) for each one were given respectively QOD for 5 times,with intratumor injections.Tumor volume changes were monitored;and the 15 mice were sacrificed 2 weeks after treatment,the tumors were removed,weighed and ratios of tumor-suppression were calculated.The morphological changes of apoptotic tumor cells were observed under microscope.Bcl-2,Bax,Caspase-3,VEGF,CD34 expression was tested by immumohistochemistry.Results:High titer(10~9pfu/ml)adenoviral vector of ING4 gene were obtained.In nude mice bearing MG-63 osteosarcoma xenografts,the growth of MG-63 tumors treated by intratumoral injecting of Ad-ING4 was significantly suppressed,compared with PBS group and Ad-GFP group.The ratios of tumor weight-suppression of Ad-ING4 group was 59.3%(P＜0.05).Immumohistochemistry displayed that the expression of Bax,Caspase-3 was up-regulated and the expression of Bcl-2,VEGF,CD34 was down-regulated by Ad-ING4.Conclusion:Ad-ING4 can inhibit the growth of MG-63 osteosarcoma xenografts in nude mice,which may be via activating the apoptosis pathway and inhibiting tumor angiogenesis.