Polydimethylsiloxane (PDMS) and hydroxyapatite (HA) were combined in our laboratory to fabricate an elastic porous cell scaffold with pore-forming agent, and then the scaffold was used as culture media for rat bone marrow derived mesenchymal stem cells (rBMSCs). Different porous materials (square and circular in shape) were prepared by different pore-forming agents (NaCl or paraffin spheres) with adjustable porosity (62%-76%). The HA crystals grew on the wall of hole when the material was exposed to SBF solutions, showing its biocompatibility and ability to support the cells to attach on the materials.
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.
In order to improve the interfacial bonding strength of hydroxyapatite/polyurethane implanted material and dispersion of hydroxyapatite in the polyurethane matrix, we in the present study synthesized nano-hydroxyapatite/polyurethane composites by in situ polymerization. We then characterized and analyzed the fracture morphology, thermal stability, glass transition temperature and mechanical properties. We seeded MG63 cells on composites to evaluate the cytocompatibility of the composites. In situ polymerization could improve the interfacial bonding strength, ameliorate dispersion of hydroxyapatite in the properties of the composites. After adding 20 wt% hydroxyapatite into the polyurethane, the thermal stability was improved and the glass transition temperatures were increased. The tensile strength and maximum elongation were 6.83 MPa and 861.17%, respectively. Compared with those of pure polyurethane the tensile strength and maximum elongation increased by 236.45% and 143.30%, respectively. The composites were helpful for cell adhesion and proliferation in cultivation.
This study aims to compare two kinds of modified poly (lactic acid) (PLA) materials:PLA-chitosan (PLA-CTS) and PLA-poly (glycolic acid) (PLA-PGA). PLA-CTS and PLA-PGA scaffolds were prepared and observed under electron microscope. The scaffold porosity was calculated and the pH of the degradation solution was measured. Then rat olfactory ensheathing cells (OECs) were cultivated, and mixed cultured respectively with two scaffolds as two groups. The proliferation, adhesion rate and growth condition of the OECs were observed and compared between the two groups. Results showed that both the prepared PLA-CTS and PLA-PGA scaffolds were three-dimensional porous structure and the porosity of PLA-CTS was 91%, while that of PLA-PGA was 87%. The pH of degradation solution decreased gradually, of which PLA-PGA fell faster than PLA-CTS. After added to the two scaffolds, most OECs could grow well, and there were no significant differences between the two groups on MTT test and nuclei number determined by fluorescent microscope. However, the cell adhesion rate of PLA-CTS group was significantly higher than that of PLA-PGA. It can be concluded that compared with PLA-PGA, PLA-CTS might be a better choice as OECs scaffold.
Objective To investigate the biocompatibility of type I collagen scaffold with rat bone marrow mesenchymal stem cell (BMSCs) and its role on proliferation and differentiation of BMSCs so as to explore the feasibility of collagen scaffold as neural tissue engineering scaffold. Methods Type I collagen was used fabricate collagen scaffold. BMSCs were isolated by density gradient centrifugation. The 5th passage cells were used to prepare the collagen scaffold-BMSCs complex. The morphology of collagen scaffold and BMSCs was observed by scanning electron microscope (SEM) and HE staining. The cell proliferation was measured by MTT assay at 1, 3, 5, and 7 days after culturein vitro. After cultured on collagen scaffold for 24 hours, the growth and adhesion of green fluorescent protein positive (GFP+) BMSCs were observed by confocal microscopy and live cell imaging. Results The confocal microscopy and live cell imaging results showed that GFP+ BMSCs uniformly distributed in the collagen scaffold; cells were fusiform shaped, and cell process or junctions between the cells formed in some cells, indicating good cell growth in the collagen scaffold. Collagen scoffold had porous fiber structure under SEM; BMSCs could adhered to the scaffold, with good cell morphology. The absorbance (A) value of BMSCs on collagen scaffold at 5 and 7 days after culture was significantly higher than that of purely-cultured BMSCs (t=4.472,P=0.011;t=4.819,P=0.009). HE staining showed that collagen scaffold presented a homogeneous, light-pink filament like structure under light microscope. BMSCs on the collagen scaffold distributed uniformly at 24 hours; cell displayed various forms, and some cells extended multiple processes at 7 days, showing neuron-like cell morphology. Conclusion Gelatinous collagen scaffold is easy to prepare and has superior biocompatibility. It is a promising scaffold for neural tissue engineering.
Three-dimensional (3D) bio-printing is a novel engineering technique by which the cells and support materials can be manufactured to a complex 3D structure. Compared with other 3D printing methods, 3D bio-printing should pay more attention to the biocompatible environment of the printing methods and the materials. Aimed at studying the feature of the 3D bio-printing, this paper mainly focuses on the current research state of 3D bio-printing, with the techniques and materials of the bio-printing especially emphasized. To introduce current printing methods, the inkjet method, extrusion method, stereolithography skill and laser-assisted technique are described. The printing precision, process, requirements and influence of all the techniques on cell status are compared. For introduction of the printing materials, the cross-link, biocompatibility and applications of common bio-printing materials are reviewed and compared. Most of the 3D bio-printing studies are being remained at the experimental stage up to now, so the review of 3D bio-printing could improve this technique for practical use, and it could also contribute to the further development of 3D bio-printing.
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 investigate the biocompatibility and immunogenicity of the tracheal matrix decellularized by sodium perchlorate (NaClO4).MethodsBone marrow mesenchymal stem cells (BMSCs) were divided from 2-month-old New Zealand white rabbits. The trachea of 6-month-old New Zealand white rabbits were trimmed to a length of 1.5 cm and randomly divided into control group (group A1, n=5, just stripped the loose connective tissue outside the trachea) and experimental group (group B1, n=5, decellularized by improved NaClO4 immersion method). The cytotoxicity of the scaffold leaching solution was detected by MTT assay, and the major histocompatibility complex (MHC) expression was detected by immunohistochemical method. The 4th generation of BMSCs were seeded onto the scaffold of 2 groups, and the cell activity around the material was observed by inverted microscope after Giemsa staining at 48 hours, while the cells states on the scaffold were observed at 7 and 14 days after culturing by scanning electron microscope. Another 10 6-month-old New Zealand white rabbits were randomly divided into control group (group A2, n=5) and experimental group (group B2, n=5), which implanted the native trachea and decellularized tracheal matrix into the subcutaneous sac of the back neck, respectively. The serum immunoglobulin IgM and IgG contents were analysed at 5, 10, 15, 20, 25, and 30 days after operation, and HE staining observation was performed at 30 days after operation.ResultsMTT assay showed that the proliferation activity of BMSCs cultured in the leach liquor of group B1 was well, showing no significant difference when compared with group A1 and negative control group with pure culture medium (P>0.05). The immunohistochemical staining showed that the decellularized process could significantly reducing the antigenicity of matrix materials. Giemsa staining showed that BMSCs grew well around the two tracheal matrixs (groups A1 and B1) in vitro. Scanning electron microscope observation showed that the cells were attached to the outer wall of the tracheal material in group A1, which present a flat, round, oval shaped, tightly arranged cells and cluster distribution; and in group B1, the cells formed a single lamellar sheet cover the outer wall of the tracheal material, whose morphology was similar to that in group A1, and the growth trend was better. In vivo experimental results showed that the rejection of group B2 was lower than that of group A2. The contens of IgM and IgG in group A2 were significantly higher than those in group B2 at each time point after operation (P<0.05). HE staining showed no signs of rejection, macrophagocyte, or lymphocyte infiltration occurred, and the collagen fibers maintained their integrity in group B2.ConclusionThe decellularized matrix treated by NaClO4 has a fine biocompatibility, while its immunogenicity decreased, and it is suitable for the scaffold material for constructing of tissue engineered trachea.
In view of the excellent biocompatibility as well as the low cost, nanoscale ZnO shows great potential for drug delivery application. Moreover, The charming character enable nanoscale ZnO some excellent features (e.g. dissolution in acid, ultrasonic permeability, microwave absorbing, hydrophobic/hydrophilic transition). All of that make nanoscale ZnO reasonable choices for smart drug delivery. In the recent decade, more and more studies have focused on controlling the drug release behavior via smart drug delivery systems based on nanoscale ZnO responsive to some certain stimuli. Herein, we review the recent exciting progress on the pH-responsive, ultrasound-responsive, microwave-responsive and UV-responsive nanoscale ZnO-based drug delivery systems. A brief introduction of the drug controlled release behavior and its effect of the drug delivery systems is presented. The biocompatibility of nanoscale ZnO is also discussed. Moreover, its development prospect is looked forward.
ObjectiveTo evaluate the effect of a novel micro-arc oxidation (MAO) coated magnesium-zinc-calcium (Mg-Zn-Ca) alloy scaffold/autologous bone particles to repair critical size bone defect (CSD) in rabbit and explore the novel scaffold in vivo corrosion resistance and biocompatibility.MethodsSeventy-two New Zealand white rabbits were randomly divided into 3 groups (n=24), group A was uncoated Mg-Zn-Ca alloy scaffold group, group B was 10 μm MAO coated Mg-Zn-Ca alloy scaffold group, and group C was control group with only autologous bone graft. The animals were operated to obtain bilateral ulnar CSD (15 mm in length) models. The bone fragment was removed and minced into small particles and were filled into the scaffolds of groups A and B. Then, the scaffolds or autologous bone particles were replanted into the defects. The animals were sacrificed at 2, 4, 8, and 12 weeks after surgery (6 rabbits each group). The local subcutaneous pneumatosis was observed and recorded. The ulna defect healing was evaluated by X-ray image and Van Gieson staining. The X-ray images were assessed and scored by Lane-Sandhu criteria. The percentage of the lost volume of the scaffold (ΔV) and corrosion rate (CR) were calculated by the Micro-CT. The Mg2+ and Ca2+ concentrations were monitored during experiment and the rabbit liver, brain, kidney, and spleen were obtained to process HE staining at 12 weeks after surgery.ResultsThe local subcutaneous pneumatosis in group B was less than that in group A at 2, 4, and 8 weeks after surgery, showing significant differences between 2 groups at 2 and 4 weeks after surgery (P<0.05); and the local subcutaneous pneumatosis was significantly higher in group B than that in group A at 12 weeks after surgery (P<0.05). The X-ray result showed that the score of group C was significantly higher than those of groups A and B at 4 and 8 weeks after surgery (P<0.05), and the score of group B was significantly higher than that of group A at 8 weeks (P<0.05). At 12 weeks after surgery, the scores of groups B and C were significantly higher than that of group A (P<0.05). Meanwhile, the renew bone moulding of group B was better than that in group A at 12 weeks after surgery. Micro-CT showed that ΔV and CR in group B were significantly lower than those in group A (P<0.05). Van Gieson staining showed that group B had better biocompatibility and osteanagenesis than group A. The Mg2+ and Ca2+ concentrations in serum showed no significant difference between groups during experiments (P>0.05). And there was no obvious pathological changes in the liver, brain, kidney, and spleen of the 3 groups with HE staining at 12 weeks.ConclusionThe MAO coated Mg-Zn-Ca alloy scaffold/autologous bone particles could be used to repair CSD effectively. At the same time, 10 μm MAO coating can effectively improve the osteanagenesis, corrosion resistance, and biocompatibility of Mg-Zn-Ca alloy scaffold.