ObjectiveTo observe the morphological characteristic by implanting domestic porous tantalum in rabbit patellar tendon and to evaluate biocompatibility features so as to provide experimental basis for porous tantalum used as interface fixation between tendon and bone. MethodsA total of 48 adult New Zealand white rabbits, male or female, weighing 2.5-3.0 kg, were selected. Porous tantalum flake (5 mm×5 mm×2 mm) was implanted in the left patellar tendon (experimental group) and the same size porous titanium flake in the right patellar tendon (control group). The animals were sacrificed at 2, 4, 8, and 12 weeks after implantation, then the specimens were harvested for gross observation, HE staining, scanning electron microscope (SEM) observation, and hard slices observation. ResultsNo animal died after operation. Porous tantalum was bonded closely with host tendon and no inflammatory reaction was found. Loose and thick fibrous capsule was observed at the beginning and became density and thinner in the end by microscope, showing significant difference between different time points in 2 groups (P<0.05), but no significant difference was found between 2 groups at different time points (P>0.05). The SEM observation showed that fibrous tissue attached to the surface and inner walls of porous tantalum at early stage, and extended on the material to reach confluence at late period, but the experimental group was more than the control group. Hard slices observation showed that the collagen fibrils were seen on porous tantalum interface with host tendon, and blood vessels grew into the pores. The control group and the experimental group showed no significant difference. ConclusionThe domestic porous tantalum has good biocompatibility. Connection and integration can be established between tendon and porous tantalum, and therefore it could be used in reconstruction of tendon-bone fixation device.
Objective To choose the best procedure on preparation of acellularbovine pericardium (ABP) guided bone regeneration (GBR) material. Methods The BP was decellularized with 0.25% Trypsin+0.5% Triton X-100. The acellular bovine pericardiums (ABPs) were treated with phosphatebuffered saline(PBS) (group A), 95% glycerol (group B), EDAC (group C), and EDAC and 95% glycerol (group D) respectively. The treated ABPs were implanted subcutaneously in the back of SD rats respectively at random and no material was implanted as control. Seven rats were sacrificed at 2 weeks, twelve at 4 weeks, twelve at 8 weeks, seven at 16 weeks. Local reaction was studied grossly. The amount of antigen presenting cell (APC) and the percentage of ABP degeneration were reckoned by images analysis system. Results The ABPs were replaced by fibroblasts completely in group A at 8 weeks， in group C at 16 weeks, but only less than 50% till 16 weeks in groups B and D. In all groups, the depth of surrounding fibres attenuated timedependingly. The APC amount of the groups B and D was higher than that of the control group, and the ABP of the groups B and D degraded partly at 16 weeks. Conclusion The ABP treated with EDAC can be replaced by the surrounding tissues and has good biocompatibility.
ObjectiveTo evaluate the biocompatibility of poly lactic acid/bone matrix gelatin (PLA/BMG) composite biomaterial so as to lay a foundation for bone defect repair. MethodsRats'MC3T3-E1 cells were cultured with leaching solution of PLA/BMG and PLA material respectively for 7 days. The cell proliferation rate was tested by MTT and cell toxicity grading was carried out everyday. The PLA/BMG and MC3T3-E1 cells were co-cultured, the cell shape and proliferation were observed by inverted phase contrast microscope at 1, 3, and 5 days and cell adhesion by scanning electron microscope at 5 days. The PLA and PLA/BMG were implanted subcutaneously in 15 Wistar rats. The histological observation was done, and the thickness of fibrous membrane, the number of inflammatory cells, and the vascularization area were measured at postoperative 2nd, 4th, and 8th week. ResultsThe tests for cytotoxicity in vitro showed that the cell proliferation rates were over 100% and the cell cytotoxic grades were grade 0 at 1-7 days in PLA/BMG group. While in PLA group, the cell proliferation rates were less than 100% and the cell cytotoxic grades were grade 1 at 2, 4, and 7 days. After co-culture of PLA/BMG and MC3T3-E1 cells, cells grew on the surface and in the pores of PLA/BMG, and the cellular morphology was triangle or polygon with abundant microvillus on the surface. After subcutaneous implantation, the rats survived to the end of experiment, and incision healed well. PLA was wrapped by connective tissue where there were a lot of lymphocytes and neutrophilic granulocytes. The cells and tissue grew slowly in PLA. The PLA/BMG materials were wrapped by little connective tissue where there were a few inflammatory cells. The connective tissue ingrowth was observed in the center of PLA/BMG. There was no significant difference in the thickness of fibrous membrane between 2 groups at each time point (P>0.05). The number of inflammatory cells of PLA/BMG group were significantly less than those in PLA group at 2, 4, and 8 weeks (P<0.05); the vascularization area was significantly larger than that in PLA group (P<0.05). ConclusionPLA/BMG composite biomaterials prepared by super critical-CO2 technique are good in cell and tissue biocompatibilty.
Objective To evaluate the biocompatibility of a new bone matrix material (NBM) composed of both organic and inorganic materials for bone tissue engineering. Methods Osteoblasts combined with NBM in vitro were cultured. The morphological characteristics was observed; cell proliferation, protein content and basic alkaline phosphatase(ALP) activity were measured. NBM combined with osteoblasts were implanted into the skeletal muscles of rabbits and the osteogenic potential of NBM was evaluated through contraat microscope, scanning electromicroscope and histological examination. In vitro osteoblasts could attach and proliferate well in the NBM, secreting lots of extracellular matrix; NBM did not cause the inhibition of proliferation and ALP activity of osteoblasts. While in vivo experiment of the NBM with osteoblasts showed that a large number of lymphacytes and phagocytes invading into the inner of the material in the rabbit skeletalmuscle were seen after 4 weeks of implantation and that no new bone formation was observed after 8 weeks. Conclusion This biocompat ibility difference between in vitro and in vivo may be due to the immunogenity of NBM which causes cellular immuno reaction so as to destroy the osteogenic environment. The immunoreaction between the host and the organic-inorganic composite materials in tissue engineering should be paid more attention to.
The poor mechanical property and vulnerability to bacterial infections are the main problems in clinic for dental restoration resins. Based on this problem, the purpose of this study is to synthesize silver-titanium dioxide (Ag-TiO2) nanoparticles with good photocatalytic properties, and add them to the composite resin to improve the mechanical properties and photocatalytic antibacterial capability of the resin. The microstructure and chemical composition of Ag-TiO2 nanoparticles and composite resins were characterized. The results indicated that Ag existed in both metallic and silver oxide state in the Ag-TiO2, and Ag-TiO2 nanoparticles were uniformly dispersed in the resins. The results of mechanical experiments suggested that the mechanical properties of the composite resin were significantly improved due to the incorporation of Ag-TiO2 nanoparticles. The antibacterial results indicated that the Ag-TiO2 nanoparticle-filled composite resins exhibited excellent antibacterial activities under 660 nm light irradiation for 10 min due to the photocatalysis, and the Ag-TiO2 nanoparticle-filled composite resins could also exhibit excellent antibacterial activities after contact with bacteria for 24 h without light irradiation because of the release of Ag ions. In summary, this study provides a new antibacterial idea for the field of dental composite resins.
Objective To study the inflammation response and the biocompatibil ity of valved bovine jugular vein conduit (BJVC) and valved bovine jugular vein patch (VBJV-P) in treating complex congenital heart disease (CHD). Methods From December 2007 to March 2008, 16 patients with complex CHD were treated. Of 16 patients, 6 underwent conjunction right ventricular to pulmonary artery with BJVC and broaden right ventricular outflow tract (RVOT) with VBJV-P (BJVC group), and 10 underwent broaden RVOT with self pericardial patch (control group). In BJVC group, there were 3 males and 3 females, aging (5.6 ± 3.6) years, and including 1 case of type I truncus arteriosus, 1 case of type I truncus arteriosus with ventricular septal defect and patent foramen ovale, 1 case of congenital pulmonary atresia with ventricular septal defect and patent arterial duct, and 3 cases of Fallot’s tetrad. In control group, there were 5 males and 5 females, aging(4.3 ± 3.1) years, all being Fallot’s tetrad. The periphery vein blood of the two groups was collected during operation and after operation, and the levels of cytokine were detected with ELISA method. Meanwhile the cl inical data of the two groups were collected. Results There were no significant differences at levels of TNF-α and IL-6 between BJVC group and control group 1 week after operation (P gt; 0.05), and there was significant difference at level of IL-10 [(25.7 ± 5.0) pg/mL vs (19.5 ± 4.7) pg/ mL, P lt; 0.05]. There were no significant differences at levels of IL-6 and IL-10 within groups both in control group and in BJVC group (P gt; 0.05) between 1 week after operation and the anesthesia inducing period. And there was significant difference at level of TNF-α in BJVC group [(77.0 ± 1.6) pg/mL vs (82.9 ± 1.3) pg/mL, P lt; 0.05] and in control group [(78.6 ± 3.4) pg/mL vs (83.1 ± 1.9) pg/mL, P lt; 0.05] between 1 week after operation and the anesthesia inducing period. There were no statistically significant differences (P gt; 0.05) in leukocyte count and body temperature between BJVC group and control group. The X-ray films showed no abnormal ity in BJVC group and control group before operation and after operation. No hepatic and renal dysfunction occurred in control group; and 2 patients had hepatic dysfunction, which may be caused by antibiotics. Conclusion BJVC has a good biocompatibil ity in treating complexty CHD.
Objective To prepare and study the biocompatibil ity of selectively decellular xenoskin which has the character of the lower antigen, continuous epidermis, and the dermal matrix without any cellular components. Methods The porcine skin was treated with glutaraldehyde solution, trypsin, and detergent solution TritonX-100 to prepare the selectivelydecellular xenoskin. The cytotoxicity was tested according to GB/T16886.5-2003 biological evaluation of medical devices for in vitro cytotoxicity, and the levels of cytotoxicity were evaluated with the United States Pharmacopeia. Subdermal implantation was tested according to GB/T16886.6-1997 biological evaluation of medical devices for local effects after implantation. Seventytwo mature Wistar rats were randomly assigned to groups A, B, and C (n=24). Three kinds of materials were implanted into subcutaneous of rats back. Selectively decellular xenoskin was transplanted into group A, fresh porcine skin was transplanted into group B, and allogeneic skin was transplanted into group C. The samples were collected to make the observation of gross and histology after 1, 2, 4, 8, 12, and 16 weeks. Results The cytotoxicity was proved to be first grade by biocompatibil ity test. The gross and histological observation of subdermal implantation: after implantation, the most severe inflammatory reactions were seen in group B which dispersion was very slow. Inflammatory reactions in groups A and C alleviated gradually. In groups A and C, there was an increased collagen fiber density and angiogenesis at late stage; the transplanted skin was gradually degraded and absorbed. In group B, no obvious degradation and absorption were observed. Conclusion Selectively decellular xenoskin, prepared with glutaraldehyde solution, trypsin, and detergent solution, possesses characteristics of integral skin structure andexcellent biocompatibil ity, so it can be used as a new type substitute to repair the burn wound.
ObjectiveTo explore the influence of three central venous catheter biomedical materials (polyurethane, silicone, and polyvinyl chloride) on the proliferation, apoptosis, and cell cycle of Xuanwei Lung Cancer-05 (XWLC-05) cells so as to provide the basis for clinical choice of central venous catheter. MethodsXWLC-05 cells were cultured and subcultured, and the cells at passage 3 were cultured with polyurethane, silicone, and polyvinyl chloride (1.0 cm × 1.0 cm in size), and only cells served as a control. At 24, 48, and 72 hours after cultured, MTT assay was used to detect the cellular proliferation and flow cytometry to detect the cell cycle and apoptosis. At 72 hours after cultured, inverted microscope was used to observe the cell growth. ResultsInverted microscope showed the cells grew well in control group, polyurethane group, and silicone group. In polyvinyl chloride group, the cells decreased, necrosed, and dissolved; residual adherent cells had morphologic deformity and decreased transmittance. At 24 and 48 hours, no significant difference in proliferation, apoptosis, and cell cycle was found among 4 groups (P gt; 0.05). At 72 hours, the proliferations of XWLC-05 cells in three material groups were significantly inhibited when compared with control group (P lt; 0.05), and the cells in polyvinyl chloride group had more significant proliferation inhibition than polyurethane group and silicone group (P lt; 0.05), but there was no signifcant difference in proliferation inhibition between polyurethane group and silicone group (P gt; 0.05). Compared with the control group, three material groups had significant impact on the rate of apoptosis and cell cycle: polyvinyl chloride group was the most remarkable, followed by silicone group, polyurethane group was minimum (P lt; 0.05). ConclusionPolyvinyl chloride can significantly impact the proliferation, apoptosis, and cell cycle of XWLC-05 cells; polyurethane has better biocompatibility than polyvinyl chloride and silicone
Objective To investigate the feasibility of a new kind of porous β tricalcium phosphate (β-TCP) as a scaffold for the bone tissue engineering Methods The inverted phase contrast microscope was used to observe the growth of the marrow mesenchymal stem cells (MSCs) in the experimentalgroup and the control group at 10 days.In the experimental group, the MSCs were cultured with β-TCP(3 mm×3 mm×3 mm) in the 24-hole cultivation board, and in the control to control group, only MSCs were cultivated. The scanning electron microscope was used to observe growth of MSCs at 6 days. Cultivated with β-TCP at 3, 6, 9, 12 days, the MTT assay was used to judge the biocompatibility. The cytotoxicity was analyzed with the method that used the different density(100%， 50%， 10%， 1%，0%) leaching liquor gained from β-TCP to raise MSCs. MSCs were induced into the osteoblasts and were mixed with β-TCP, and the composite was used to repair a large radius bone defect in the rabbit. The specimens were made at 2,6,12 weeks. The histology imageology, and the radionuclide bone scan were used to analyze the bone formation. Results Some MSCs had a good adherence 4 hours after MSCs were inoculated and had a complete adherence at 12 hours. The cells were shaped like polyangle, spindle or converge monolayer after 8-10 days. The cells in the two groups had no difference. The cell adhesion was good, when observed by the inverted phase contrast microscope and the scanning electron microscope at 6 days. MTT showed that the absorbance (A)was not statistically different between the experimental group and the control group (P＞0.05); the different density leaching liquor had no cytotoxicity at the different time points. Histology, X-ray, and CT tomograph showed that itcould repair the large radius bone defect in the rabbit and its in vivo degradationrate was the same as the bone formation rate. Conclusion The new porous β-TCP has a unique three dimensional (3D) stereochemical structure and superordinary physicochemical property, and so it is a good scaffold for the bone tissue engineering.
ObjectiveTo study the hydrophilicity and the cell biocompatibility of the poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) coated with a fusion protein polyhydroxyalkanoates granule binding protein (PhaP) fused with Arg-Gly-Asp (RGD) peptide (PhaP-RGD). MethodsPHBV and PHBHHx films were fabricated by solvent evaporation.Scanning electronic microscope (SEM) was used to study the morphology of the films.PhaP-RGD fusion proteins were expressed and purified by the technology of protein engineering; PHBV and PHBHHx films were immersed in the PhaP-RGD with an amount of 3.5 mg/mL protein/per sample respectively.The hydrophilicity of the surface were detected by the contact angle measurements.Septal cartilage cells obtained from human septal cartilage were cultured in vitro.The 2nd passage chondrocytes were incubated on PHBV unmodified with PhaP-RGD in group A1,PHBV modified with PhaP-RGD in group A2,PHBHHx unmodified with PhaP-RGD in group B1,PHBHHx modified with PhaP-RGD in group B2,and on the cell culture plates in group C.After cultured for 3 days,the proliferation of cells was detected by the DAPI staining; the proliferation viability of cells was detected by the MTT assay after cultured for 3 and 7 days; after cultured for 7 days,the adhesion and morphology of the cells on the surface of the biomaterial films were observed by SEM and the matrix of the cells was detected through the toluidine blue staining. ResultsSEM observation showed that PHBV and PHBHHx films had porous structures.The contact angle of the surface of the PHBV and PHBHHx films modified with PhaP-RGD fusion proteins were significantly reduced when compared with the films unmodified with PhaP-RGD fusion proteins (P<0.05).Chondrocytes of human nasal septal cartilage incubated on the films could grow in all groups.After 3 days of cultivation in vitro,the cell proliferation and viability of group B2 were the strongest among all groups (P<0.05); the cell proliferation after cultured for 7 days was significantly stronger than that after cultured for 3 days in groups A1,A2,B1,and B2 (P<0.05); and the cell proliferation was significantly stronger in groups B1 and B2 than groups A1,A2 and C,in group B2 than group B1,and in group A1 than group A2 (P<0.05).The results of toluidine blue staining showed that blue metachromasia matrixes were observed in groups A1,A2,B1,and B2; group A1 and group A2 had similar staining degree,and the staining of group B2 was deeper than that of group B1.The adhesion of cells in all groups was good through SEM observation; and the connection of cells formed and stretched into the pores of the materials. ConclusionThe biomaterial films of PHBHHx modified with PhaP-RGD fusion protein can promote its biocompatibility with chondrocytes.