RESUMO
BACKGROUND: Polyvinyl alcohol hydrogel (PVA) has been generally considered as a good substitute material of articular cartilage. Polyamide 66 (PA66) polymer has achieved an extensive application in the fields of engineering and medicine owing to its high intensity, strong tenacity and good stability. Polyurethanes exhibit good histocompatibility and blood compatibility and show distinct advantages in repairing cartilage.OBJECTIVE: To compare the outcomes of repairing articular cartilage defects in rabbit knee joints with three materials and to find the best material.METHODS: Thirty-six healthy adult New Zealand rabbits were prepared for the models of articular cartilage defects by perforating on the patellofemoral joint and randomly divided into 4 groups, with 9 animals in each group. PVA, polyurethane, and PA66 were implanted into the into articular cartilage defects in rabbits of corresponding groups. There was no treatment in the control group.The macroscopic and histological evaluations of rabbit knee joints were performed at 4, 8 and 12 weeks postoperatively. The score of histology was used to evaluate the repairs of articular cartilage defects at 12 weeks postoperatively.RESULTS AND CONCLUSION: No infection was observed in all animals with good motion of joints. At 12 weeks postoperatively, the materials got well with surrounding cartilage, which did not degenerate obviously. The defects in the control group were filled with fibrous scar-like tissues that arranged in disorder. The histological score of the in the group implanted by PVA, as well as polyurethane, was higher than that in PA66 and the control groups (P < 0.05), but the difference between the two groups had no significance (P>0.05).The porous materials PVA and polyurathane have good function for replacing articular cartilage, with good biocompatibility.
RESUMO
BACKGROUND: Cartilage stent materials were abundant. With the development of preparation technique, structure, and surface modification technique, performance of materials were improved remarkably; thus, Integrated-repaidng defects of articular cartilage and subchondral bone required high stability of cartilage replacement materials.OBJECTIVE: To evaluate the effect of polyurethane/nano-hydroxyapatite+polyamide66 (PU/n-HA+PA66) biological composite material on repairing articular cartilage and subchondral bone.METHODS: Twenty dog models were randomly divided into 4 groups: porous PU/n-HA+PA66 implant group, compact PU/n-HA+PA66 implant group, n-HA+PA66 implant group and blank control group. The macroscopic and histological evaluations were performed at 4, 12, and 24 weeks postoperatively. The interfaces of biomaterial implants with articular cartilage were observed by scanning electron microscope.RESULTS AND CONCLUSION: After 12 and 24 weeks, bone tissue grew into lower layer materials. Porous PU was well fused with peripheral cartilage. At 24 weeks postoperatively, the porous PU was closely connected with surrounding articular cartilage than the compact PU, and the articular cartilage surrounding the compact PU degenerated obviously. PU/n-HA+PA66 had a similar structure with normal cartilage and subchondral bone and had remarkable effects on repairing defects of articular cartilage and subchondral bone.
RESUMO
BACKGROUND: An ideal repairing material characterizes by both great biocompatibility and osteogenesis ability. Any biomaterials should meet excellent biological security and biocompatibility prior to clinical application.OBJECTIVE: To evaluate the biocompatibility and the biological security of the TiO_2-Ag-nano-hydroxyapatite/polyamide66 (TiO_2-Ag-nHA/PA66) composite.DESIGN, TIME AND SETTING: A randomized controlled duplicated design was performed in Chongqing Medical University from July 2008 to July 2009.MATERIALS: A total of 40 Kunming mice aged 3 weeks and of clean grade and 32 healthy adult New Zealand rabbits were provided by Experimental Animal Center of Chongqing Medical University. TiO_2-Ag-nHA/PA66 composite powder (10 g),TiO_2-Ag-nHA/PA66 composites (n=32, 5 mm ×25 mm), and TiO_2-Ag-nHA/PA66 composites (n=32, 3 mm × 5 mm) were provided by Research Center of Nano-Biomaterials of Sichuan University.METHODS: General toxicity test: Forty mice were randomly divided into experimental and control groups. Composite powder was used to prepare leaching liquor which was treated on experimental mice by an intraperitoneal injection. While, an equal amount saline was inserted into the control mice. Intramuscular implanting test: The 16 rabbits were randomly divided into experimental and control groups. Two TiO_2-Ag-nHA/PA66 composite (5 mm × 25 mm) were implanted into left and right erector spinae, respectively. A similar surgery with the exception of implantation was performed on the control rabbits. Intrabony implanting test: The resting 16 rabbits were implanted one TiO_2-Ag-nHA/PA66 composite (3 mm × 5 mm) into left and right lateral epicondyle, respectively. Hemolytic test: A 8-mL anti-coagulation blood was obtained and added with composite powder (0.1,0.15, and 0.2 g).MAIN OUTCOME MEASURES: Biocompatibility and biological security of TiO_2-Ag-nHA/PA66 composite.RESULTS: General toxicity test demonstrated that mice in the two groups had good activity and eating, normal breathing, stable body mass, no paralysis, convulsion, and death. Intramuscular implanting test and intrabony implanting test showed that there was no significant difference in levels of alanine aminotransferase, aspartate transaminase, urea nitrogen, and creatinine and leukocyte numbers between the two groups before implantation and at day 4,1 week, and 2 weeks after implantation (P> 0.05).In particular, there was no significant difference in the experimental group at varying time points (P> 0.05). Intramuscular implanting test indicated that tissue sections in the experimental group displayed coated tissue of materials. The inflammatory variation in the experimental group was generally similar to that in the control group. Intrabony implanting test indicated that tissue sections in the experimental group displayed new bone formation. Hemolytic test suggested that hemolytic ratio of three varying concentrations of TiOrAg-nHA/PA66 composites was less than 5%, which met the normal criterion.CONCLUSION: TiO_2-Ag-nHA/PA66 composite has a good biocompatibility and biological security.
RESUMO
It is limited for cartilage tissue to repair its injury. The biological substitution of articular cartilage, namely artificial cartilage, has a good prospect due to the tissue engineering. Biological scaffold material is an important part of tissue engineering cartilage, and therefore, it is significant to explore the progress in biological scaffold materials for the construction of articular cartilage. The main research tendency of recent biological scaffold materials for artificial cartilage is to develop composite, bionic and intelligent materials with good biocompatibility and mechanical functions, through integrated application of surface modification, new construction technology and respective advantages of natural and synthetic materials.