This study evaluated the cytotoxicity of a new type silicone rubber for maxillofacial prosthesis, which was developed by the present authors. According to the GB/T16886.5-2003, the samples were prepared and tested with cell counting kit-8 (CCK-8) assay, the relative growth rate (RGR) was calculated, and morphology of L929 cells were observed by scanning electron microscope and phase contrast microscope. The results showed that RGR of L929 cells were 91.65% (24 h), 87.03% (48 h), 87.30% (72 h), respectively, and the level of cytotoxicity was grade 1. The L929 cells showed typical fusiform shape and their morphology did not changed significantly after 24 h, 48 h and 72 h. These data indicated that the newly-developed silicone rubber material, as a maxillofacial prosthesis material, should be a safe biomaterial.
This paper is to evaluate the biocompatibility and cytotoxicity of a new Ni-free Zr-based bulk metallic glass (BMG), Zr60.14Cu22.31Fe4.85Al9.7Ag3, by comparing it with conventional Ti6Al4V alloy. According to ISO 10993-5:1999 and GB/T 16886.5-1997 standards, Zr60.14Cu22.31Fe4.85Al9.7Ag3, pure Zr and Ti6Al4V materials were extracted with surface area of sample/volume of medium ratio being 1 cm2/mL and 0.5 cm2/mL, respectively. The viabilities of MG-63 cells (Human osteosarcoma cell line) cultured in the BMG medium extracts for 1, 3 and 5 days were determined by CCK-8 assay. The cellular morphology of MG-63 cells cultured on the surface of samples for 3 days was tested through laser scanning confocal microscopy (LSCM) and scanning electron microscopy (SEM). The relative growth rate (RGR) of MG-63 cells cultured in Zr60.14Cu22.31 Fe4.85 Al9.7Ag3 and pure Zr were both more than 85%, indicating that the cytotoxicity of BMG was relatively low and met the national biomedical material eligibility standard. There was insignificant difference in the morphology of MG-63 cells cultured in the BMG medium extracts and the control group through LSCM and SEM, which showed the BMG had excellent biological compatibility. The Zr-based bulk metallic glass Zr60.14Cu22.31Fe4.85Al9.7Ag3 and the conventional Ti6Al4V alloy both had no obvious cytotoxicity to MG-63 cells. These results provided evidence that the new Zr-based bulk metallic glass could be potential replacement material for the orthopedic surgical implant.
The objective of the study is to analyze the biological characteristics and stability of the linear derivative Bac2a from bactenecin, compared with the control peptide melittin. The secondary structure, antibacterial activity, hemolytic activity, cell toxicity and stability of the Bac2a were determined by circular dichroism spectroscopy, broth micro-dilution method and MTT assay. The results showed that Bac2a was a nonregular curl in aqueous solution, however, it was an α-helix structure in the hydrophobic environment. The minimal inhibitory concentration (MIC) of Bac2a ranged from 2 to 32 μmol/L, so the bacteriostatic activity of Bac2a was strong. The hemolytic rate was only 14.81% when the concentration of Bac2a was 64 μmol/L, which showed that the hemolytic rate of Bac2a was low. The therapy index of Bac2a was 3.26, and the cytotoxicity was relatively low, thus the cell selectivity was relatively high. In addition, with the heating treatment of 100℃ for 1 h, Bac2a still possessed rather a high antibacterial activity and showed a good heating stability. In a word, Bac2a has good application prospects in food, medicine and other fields, and is expected as a substitute for traditional antibiotics.
Objective To investigate the biocompatibility of true bone ceramic (TBC) and provide experimental basis for clinic application. Methods TBC was prepared from healthy adult bovine cancellous bone by deproteinization and high temperature calcinations. Mouse fibroblast cell line (L929 cells) were cultured with the leaching liquor of TBC in vitro, and the cytotoxicity was evaluated at 2nd, 4th, and 7th days. L929 cells were inoculated into the TBC and cultured for 4 days. The cell adhesion and proliferation on the surface of the TBC were observed by scanning electron microscopy, and evaluated the cell compatibility of TBC. Ten New Zealand white rabbits were divided into 2 groups, and drilled holes at the tibia of both hind limbs. TBC and hydroxyapatite (HA) were implanted into the left side (experimental group) and the right side (control group), respectively. And the biocompatibility of TBC was evaluated by general observation and histological observation at 4 and 26 weeks after implantation. Results Cytotoxicity test showed that the cytotoxicity level of leaching liquor of TBC was grade 0-1. Cell compatibility experiments showed that the L929 cells adhered well on the surface of TBC and migrated into the pores. The implantation test in vivo showed that experimental group and control group both had mild or moderate inflammatory response at 4 weeks, and new bone formation occurred. At 26 weeks, there was no inflammatory reaction observed in both groups, and new bone formation was observed in varying degrees. Conclusion TBC have good biocompatibility and can be used to repair bone defect in clinic.
ObjectiveTo study the effect of three-dimensional (3D) printed β-tricalcium phosphate (β-TCP) scaffold loaded poly (lactide-co-glycolide) (PLGA) anti-tuberculosis drug sustained release microspheres on osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) and its cytotoxicity.MethodsIsoniazid and rifampicin/PLGA sustained release microspheres were prepared by W/O/W multiple emulsion method. The β-TCP scaffolds were prepared by 3D printing technique. The microspheres were loaded on the scaffolds by centrifugal oscillation method to prepare composite materials. The BMSCs of Sprague Dawley rat were isolated and cultured by whole bone marrow adherent method, and the third generation cells were used for the following experiments. BMSCs were co-cultured with osteogenic induction medium (group A), PLGA anti-tuberculosis drug sustained release microsphere extract (group B), 3D printed β-TCP scaffold extract (group C), and 3D printed β-TCP scaffold loaded PLGA anti-tuberculosis drug sustained release microsphere composite extract (group D), respectively. Cytotoxicity was detected by cell counting kit 8 (CCK-8) method; the calcium deposition was observed by alizarin red staining; and the mRNA expressions of alkaline phosphatase (ALP), osteocalcin (OCN), and bone sialoprotein (BSP) were detected by real-time fluorescence quantitative PCR (RT-qPCR).ResultsCCK-8 assay showed that the absorbance (A) value of groups A, B, C, and D increased gradually with the culture time prolonging. After cultured for 24, 48, and 72 hours, the A value decreased in the order of groups A, C, B, and D. There was no significant difference between groups B and D (P>0.05), but there were significant differences between other groups (P<0.05). The cytotoxicity was evaluated as grade 0-2, and the toxicity test was qualified. Alizarin red staining showed that red mineralized nodules were formed in all groups at 21 days after osteogenic induction, but the number of mineralized nodules decreased sequentially in groups C, D, A, and B. RT-qPCR test results showed that the relative expressions of OCN and BSP genes in groups A, B, C, and D increased gradually with the culture time prolonging. The relative expression of ALP gene increased at 7 and 14 days, and decreased at 21 days. After cultured for 7, 14, and 21 days, the relative expressions of ALP, OCN, and BSP genes decreased sequentially in groups C, D, A, and B; the differences were significant between groups at different time points (P<0.05).Conclusion3D printed β-TCP loaded PLGA anti-tuberculosis drug sustained release microsphere composites have no obvious cytotoxicity to BMSCs, and can promote BMSCs to differentiate into osteoblasts to a certain extent.
Objective To investigate the effect of human tooth bone graft materials on the proliferation, differentiation, and morphology of macrophages, and to understand the biocompatibility and cytotoxicity of human tooth bone graft materials. Methods Fresh human teeth were collected to prepare human tooth bone graft materials, the adhesion of mouse mononuclear macrophages RAW264.7 to human bone graft materials was observed under confocal microscopy. Scanning electron microscopy was used to observe the morphology of human tooth bone graft materials, OSTEONⅡ synthetic highly resorbable bone grafting materials, and untreated tooth powder (dental particles without preparation reagents). Different components of the extract were prepared in 4 groups: group A (DMEM medium containing 10% fetal bovine serum), group B (human tooth bone graft materials), group C (OSTEONⅡ synthetic highly resorbable bone grafting materials), group D (untreated tooth powder without preparation reagents). The 4 groups of extracts were co-cultured with the cells, and the cytotoxicity was qualitatively determined by observing the cell morphological changes by inverted microscope. The cell proliferation and differentiation results and cell relative proliferation rate were determined by MTT method to quantitatively determine cytotoxicity. The cell viability was detected by trypanosoma blue staining, and tumor necrosis factor α (TNF-α ) and interleukin 6 (IL-6) expressions were detected by ELISA. Results Scanning electron microscopy showed that the surface of the human tooth bone graft material and the OSTEONⅡ synthetic highly resorbable bone grafting materials had a uniform pore structure, while the untreated tooth particle collagen fiber structure and the demineralized dentin layer collapsed without specific structure. Confocal microscopy showed that the cells grew well on human tooth bone graft materials. After co-culture with the extract, the morphology and quantity of cells in groups A, B, and C were normal, and the toxic reaction grades were all grade 0, while group D was grade 3 reaction. MTT test showed that the cytotoxicity of groups B and C was grade 0 or 1 at each time point, indicating that the materials were qualified. The cytotoxicity was grade 2 in group D at 1 day after culture, and was grade 4 at 3, 5, and 7 days. Combined with cell morphology analysis, the materials were unqualified. The trypanosoma blue staining showed that the number of cells in groups A, B, and C was significantly higher than that in group D at each time point (P<0.05), but no significant difference was found among groups A, B, and C (P<0.05). ELISA test showed that the levels of TNF-α and IL-6 in groups A, B, and C were significantly lower than those in group D (P<0.05), but no significant difference was found among groups A, B, and C (P<0.05). Conclusion The human tooth bone graft materials is co-cultured with mice mononuclear macrophages without cytotoxicity. The extract has no significant effect on cell proliferation and differentiation, does not increase the expression of inflammatory factors, has good biocompatibility, and is expected to be used for clinical bone defect repair.