Development of biodegradable Nano-NdFeB composite materials to surgical anastomosis

doi:10.3969/j.issn.2095-4344.2015.16.009

Abstract：BACKGROUND:Magnamosis is regarded as a fast, convenient, and safe approach of surgical anastomosis in general surgery. Biodegradable Nano-magnetic composite materials with good biocompatibility and degradation of adjustability wil solve the potential problems of magnets left in the body.OBJECTIVE:To develop biodegradable Nano-NdFeB composite materials and to evaluate the magnetic energy product and degradation performancein vitro. METHODS: NdFeB nanoparticles were prepared with high-energy bal miling and Nano-NdFeB magnetic particles bonded biodegradable polymer material poly-L-lactide-co-glycolide (PLGA content 2.5%, 5%, 7.5%, 10%, 20%, 30%, 40%, 50%) by the means of solvent evaporation method. The fabrication procedures of biodegradable PLGA-Nano-NdFeB composite materials by warm compaction process under certain pressure (6, 8, 10, 12, 14 MPa) and temperature (60, 80, 100, 120, 140℃) were investigated to reveal their effects on the maximum magnetic energy product. The vitro degradation experiment of PLGA-Nano-NdFeB composite materials (PLGA molar ratio 90/10, 70/20, 50/50) was done with the magnets soaked in 10% PBS at 37℃constant temperature folowed by phugoid oscilation. Microstructure changes were observed by scanning electron microscopy before and after degradation. The relationship between PLGA molar ratio and degradation time was also investigated. RESULTS AND CONCLUSION: The magnetic energy product of biodegradable PLGA-Nano-NdFeB composite materials was in direct proportion with the content of PLGA-Nano-NdFeB magnetic particles, temperature and pressure during warm compaction process, but in inverse proportion with PLGA content within a certain range. The best energy product of biodegradable PLGA-Nano-NdFeB composite materials was 45 kJ/m3 at 120℃, 12 MPa and PLGA content 5%. The degradation time of biodegradable PLGA-Nano-NdFeB composite materials was closely related to molar ratios of PLGA, directly proportional to PLA content and inversely proportional to PGA content. The degradation peak of molar ratios of PLGA (90/10), (70/20), (50/50) occurred at weeks 8, 6, 4, respectively.