Objective To evaluate the effect of nano-hydroxyapatit e collagen (nHAC) bone and marrow mesenchymal stem cells (MSCs) on the treatment of rabbit osteonecrosis of the femoral head (ONFH) defect. Methods From June to October 2004, animal models of ONFH defect were established i n 45 New Zealand rabbits. They were divided into 3 groups randomly:In group A, as the control group, defect was not filled with any implants; In group B with nHAC; In group C with nHAC+MSC. Imaging and histological observation were made 4, 8, 12 weeks after operation. Results group C had a better o steogenesis ability than group B and group A. group B had a better osteogenesis ability than group A. Obvious new bones and osteogenesis were observed in group C 4 weeks after operation. The defect areas in group C were almost repaired 12 weeks after operation. Conclusion nHAC has a better effect of o steoconduction and it is a superior material for repairing bone defect of ONFH a nd of great value in treating ONFH when compounded with MSCs.
We prepared silver nanoparticles/polyethyleneimine-reduction graphene oxide (AgNP/rGO-PEI) composite materials, and evaluated their quality performance in our center. Firstly, we prepared AgNP/rGO-PEI, and then analysed its stability, antibacterial activity, and cellular toxicity by comparing the AgNP/rGO-PEI with the silver nanoparticles (PVP/AgNP) modified by polyvinylpyrrolidone. We found in the study that silver nanoparticles (AgNP) distributed relatively uniformly in AgNP/rGO-PEI surface, silver nanoparticles mass fraction was 4.5%, and particle size was 6-13 nm. In dark or in low illumination light intensity of 3 000 lx meter environment (lux) for 10 days, PVP/AgNP aggregation was more obvious, but the AgNP/rGO-PEI had good dispersibility and its aggregation was not obvious; AgNP/rGO-PEI had a more excellent antibacterial activity, biological compatibility and relatively low biological toxicity. It was concluded that AgNP/rGO-PEI composite materials had reliable quality and good performance, and would have broad application prospects in the future.
This paper provides a brief overview of the current research activities which focused on the bio-application of gold magnetic nanocomposite particles. By combining the magnetic characteristics of the iron oxide core with the unique features of nano-gold particles such as targeting by surface modification and optical properties, such composite nanoparticles have a wide range of applications in cancer hyperthermia, CT and MRI imaging, bio-separation, biosensors, gene diagnosis, drug targeting and many other biomedical fields.
To observe the clinical effect and safety of the nano-hydroxyapatite/polyamide 66 (n-HA/PA66) composite in repairing the bone defects due to benign bone tumors. Methods From January 2003 to May 2005, 38 patients (21 males, 16 females; age, 19-58 years, averaged 38.5 years) with the bone defects due to benign bone tumors were treated with the n-HA/PA66 grains. Among the 37 patients, 11 had fibrous dysplasia, 14 had bone cyst, 10 had giant cell tumor of the bone (Grade Ⅰ), and 2 had enchondroma. The tumors ranged in size from 1.0 cm×0.7 cm×0.4 cm to 10.0 cm×4.0 cm×3.0 cm, with the location of the proximal femur in 12 patients, the distal femur in 7, the proximal tibia in 9, the proximal humerus in 5, the phalanges of the finger in 2, the metacarpal bone in 1,and the calcaneus in 1. Allthe benign bone tumors underwent the curettage treatment, and then the tumor cavities were filled up with the n-HA/PA66 grains. The incision healing, local inflammatory reaction, rejection, toxic reaction, tumor cavity healing, and function recovery of the limbs were all observed after operation. Results All the patients were followed up for 5-33 months, and all the incisions healed by the first intention except 1 incision, which developed infection. The inflammatory reaction was mild, with no reection or general toxic reaction. At 3 to 5.5 months(mean 4 months) after operation, osteogenesis wasfound in the space filled with the n-HA/PA66 grains. Eight months after operation, the patients’ lower limbs could bear weights; 5 months after operation, the upper limbs could complete daily work. Conclusion The n-HA/PA66 grains have great biological safety, good biocompatibility, and good bone conduction, which aregood materials for the bone repair and reconstruction, and can be safely, andeffectively used for repairing the bone defects due to benign bone tumors．
Good results were achieved in Ⅰ8 cases of cranioplasty in which a new meterial of medical polymer had been used. The properties of the material and the operation method are also described in this paper, The advantages of the new matiral become more obvious, in comparison with other methods which are usually used in cranioplasty.
Silicon carbide (SiC) film and silicon dioxide (SiO2) film were deposited on the surface of carbon/carbon composite (C/C) by low pressure chemical vapor deposition (LPCVD). The biocompatibility of the three carbon-based composites, e. g. C/C, C/C-SiC, C/C-SiO2 were investigated by cytotoxicity test, cell direct contact and cell adhesion experiments. Cytotoxicity, cell direct contact and cell adhesion showed that the three materials had no toxic effect on mouse fibroblasts (L929 cells). However, the particles dropped off from the three materials had a great impact on evaluation accuracy of the thiazolyl blue (MTT) test. More the particles were lost, more growth inhibition to L929 cells. The evaluation accuracy of MTT method can be kept with the filtered extract of materials. Furthermore, the results of surface particles shedding experiment showed that the amount of surface particles shed from C/C-SiO2 was the most, followed by C/C and C/C-SiC in 72 hours. Particles shedding curves showed there was a peak reached at eighth hour and then declined to the thirty-sixth hour. The filtrate analysis showed that there was no ion exchange between the three materials and simulated body fluid (SBF) solution. The results of this study on biocompatibility of carbon-based composites have certain guiding significance for their future application in clinical filed.
Objective To develop a biodegradable implantable bone material with compatible mechanics with the bone tissue, providing a new biomaterial for clinical bone repair and regeneration. Methods Silk reinforced polycaprolactone composites (SPC) containing 20%, 40%, and 60% silk were prepared by layer-by-layer assembly and hot-pressing technology. Macroscopic morphology was observed and microstructure were observed by scanning electron microscopy, compressive mechanical properties were detected by compression test, surface wettability was detected by surface contact angle test, degradation of materials was observed after soaking in PBS for 180 days, and proliferation of MC3T3-E1 cells was detected by cell counting kit 8 assay. Six Sprague Dawley rats were subcutaneously implanted with polycaprolactone (PCL) and 20%-SPC, respectively. Masson staining was used to analyze the in vivo degradation behavior and vascularization effect within 180 days. Results The pore defects of the three SPC sections were relatively few. In the range of 20% to 60%, as the silk content increased and the PCL content decreased, the interlayer spacing of silk fabric decreased, and the fibers almost covered the entire cross-section. The compressive modulus and compressive strength of SPC showed an increasing trend, and the compressive modulus of 60%-SPC was slightly lower than that of 40%-SPC. There were significant differences in compressive modulus and compressive strength between the materials (P<0.05). In vitro simulated fluid degradation experiments showed that the mass loss of the three types of SPC after 180 days of degradation was within 5%, with the highest mass loss observed in 60%-SPC. The differences in mass loss between the materials were significant (P<0.05). As the silk content increased, the static water contact angle of each material gradually decreased, and all could promote the proliferation of MC3T3-E1 cells. The subcutaneous degradation experiment in rats showed that 20%-SPC began to degrade at 30 days after implantation, and material degradation and vascularization were significant at 180 days, which was in sharp contrast to PCL. Conclusion SPC has the mechanical and hydrophilic properties that are compatible with bone tissue. It maintains its mechanical strength for a long time in a simulated body fluid environment in vitro, and achieves dynamic synchronization of material degradation, tissue regeneration, and vascularization through the body’s immune regulation mechanism in vivo. It is expected to provide a new type of implant material for clinical bone repair.
Objective To evaluate the biological safety of continuous carbonfiber reinforced polyolefin as hard tissue repair material. Methods Biocompatibility of the material was evaluated through hemolysis test, pyrogen test,skin irritation test, cytotoxicity test, ames test,in vitro chromosome aberration test, and bone marrow cells Micronuclei test. Results No obvious hemolysis, pyrogenic characteristics, sensitivity, cytotoxxicity, and mutagenicity were observed. Conclusion The continuous carbonfiber reinforced polyolefin composite material is of good biological safety. It meets all the demand made by biological safety as hardtissue repair material.
Graphene and its derivatives have good physical and chemical properties and biological properties, which can promote stem cell proliferation and osteogenic differentiation, and it has antibacterial properties and drug release property. Therefore, it has broad application prospects in the field of orthopedic biomaterials. This paper mainly introduces the research progress of graphene nanocomposite materials applied in the aspects of bone tissue engineering scaffold, bone repair, bone graft materials, etc. in order to provide desirable information for the future application basis and clinical research.
Objective To investigate the therapeutic effect of the chitosan/polyethylene glycols-succinate/ mitomycin C (CH/PEG-SA/MMC) film on epidural scarring tissues. Methods According to a specific proportion of respective materials, the film of CH/PEG-SA/MMC was developed under some condition. Thirty SD rats were selected and randomized into 6 groups with 5 rats in each group. A rat model of lumbar laminectomy was used. The amount of 20 mg of the CH film was implanted into the animals in group I, 20 mg of CH/PEG film in group II, 20 mg of CH/PEGSA film in group III, 0.05 mg/mL of the MMC soaking for 5 minutes in group IV, 20 mg of CH/PEG-SA/MMC film in group V, and nothing was done in group VI. Specimens were harvested 4 weeks after the above procedures and were then subjected to immunohistochemical and histological examinations to compare their therapeutic effects on epidural cicatricial tissues. Results All rats were in good conditions after operation, without gait abnormal ity, restlessness, infection and death. There was no significant difference among the 6 groups in the postoperative Rydell score (P lt; 0.05). The content of hydroxyprol ine in groups I, II, III, IV, V and VI was (0.570 8 ± 0.345 0), (0.728 6 ± 0.150 6), (0.553 4 ± 0.122 3), (0.313 3 ± 0.106 4), (0.261 9 ± 0.102 1)and (1.020 1 ± 0.120 6) μg/ mg, respectively. There was a significant difference between groups IV, V and groups I, II, III (P lt; 0.05), and there was significant difference between group VI and the rest 5 groups (P lt; 0.05). According to the histological observation, group V had less collagenous fiber parallel ing the dura mater, with few inflammatory cells infiltration, with few capillary vessels and no reaction of macrophages. Conclusion CH/PEG-SA/MMC films can effectively reduce the amount of Hyp in epidural scarring tissues after lumbar laminectomy and therefore is a good treating method in preventing scarring tissue adhesion.