Development of biodegradable Nano-NdFeB composite materials to surgical anastomosis

doi:10.3969/j.issn.2095-4344.2015.16.009

Abstract

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 will 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 performance in vitro.
METHODS: NdFeB nanoparticles were prepared with high-energy ball milling 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 followed by phugoid oscillation. 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.

中国组织工程研究杂志出版内容重点：生物材料；骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性；组织工程

全文链接：

Key words: Anastomosis, Surgical, Magnetite Nanoparticles, Nanostructures

CLC Number:

R318

Wang Shan-pei, Li Jian-hui, Qian Jun-min, Yan Xiao-peng, Yao Wei-jie, Dong Ding-hui, Ma Feng, Lv Yi . Development of biodegradable Nano-NdFeB composite materials to surgical anastomosis[J]. Chinese Journal of Tissue Engineering Research, 2015, 19(16): 2505-2510.

Figures/Tables 3

2.1 生物可降解PLGA-纳米钕铁硼磁性复合材料大体形态观察温压成型能够成功制备出生物可降解大分子材料PLGA与纳米钕铁硼磁性微粒复合的新型可降解磁性材料。在一定成型温度、压力、PLGA含量范围内所压制出的生物可降解磁性复合材料形态完整、表面光滑、色泽光亮，具有足够的机械强度及良好的最大磁能积，能够进一步加工制作适用于外科吻合重建的磁性吻合器械，见图1。 2.2 磁性复合材料最大磁能积与温压成型压力的关系当PLGA含量一定(10%)，成型温度一定(80 ℃)，磁体最大磁能积与成型压力在一定范围(≤12 MPa)内呈正比，磁性随着成型压力的增大而增大，且在由较小压力值增大到较大压力值(6 MPa→10 MPa)时，最大磁能积大幅度增加；当压力值增大到较高值(10 MPa→12 MPa)时，再增大压力，最大磁能积增大幅度变缓。而当成型压力超过特定范围(> 12 MPa)时，磁体磁性下降；当成型压力超过特定范围(≥14 MPa)时磁体表面出现裂纹，形态不再完整，因此能够取得最佳最大磁能积的成型压力值为12 MPa，见图2。 2.3 磁性复合材料最大磁能积与温压成型温度的关系当PLGA含量一定(10%)，最佳成型压力(12 MPa)，磁体最大磁能积与成型温度在一定范围(≤120 ℃)内呈正比，最大磁能积随着成型温度的升高而增大；而当成型压力超过特定范围(> 120 ℃)时最大磁能积下降，且当成型温度超过持续升高(≥140 ℃)时磁体磁性能急剧下降，能够取得最佳最大磁能积的成型温度值为120 ℃，见图3。 2.4 磁性复合材料最大磁能积与PLGA含量的关系生物可降解PLGA-纳米钕铁硼磁性复合材料的最大磁能积主要取决于纳米钕铁硼与PLGA的含量。在最佳成型温度(120 ℃)、压力(12 MPa)情况下压制磁体，磁体最大磁能积随着纳米钕铁硼含量的增大而明显增大，两者呈正比关系，特别是当磁粉含量由较小增加到较大(50%→90%)时，最大磁能积大幅度增加；当磁粉含量在≥90%后，最大磁能积随纳米钕铁硼含量增加依然增大，但增大幅度变缓；当磁粉含量在≥95%后，再增大纳米钕铁硼含量，磁性能下降；当磁粉含量在≥97.5%后，磁体机械强度降低，无法成型，脱模后磁体破碎；反之，最大磁能积和PLGA含量呈反比关系。由此，能够取得最好最大磁能积=45 kJ/m3的纳米钕铁硼含量为95%、PLGA含量为5%，见图4。"

References

[1] Jamshidi R,Stephenson JT,Clay JG,et al.Magnamosis: magnetic compression anastomosis with comparison to suture and staple techniques.J Pediatr Surg.2009;44(1):222-228.
[2] Obora Y,Tamaki N,Matsumoto S.Nonsuture microvascular anastomosis using magnet rings: preliminary report. Surg Neurol.1978;9(2):117-120.
[3] Yan X, Fan C, Ma J, et al. Portacaval shunt established in six dogs using magnetic compression technique.PLoS One.2013; 8(9):e76873.
[4] Liu SQ, Lei P, Cui XH, et al. Sutureless anastomoses using magnetic rings in canine liver transplantation model.J Surg Res.2013;185(2):923-933.
[5] Liu SQ,Lei P,Cao ZP,et al.Nonsuture anastomosis of arteries and veins using the magnetic pinned-ring device: a histologic and scanning electron microscopic study[Z]. 2012:26,985-995.
[6] Heitmann C,Khan FN, Erdmann D,et al. Vein graft anastomoses with magnets. J Plast Reconstr Aesthet Surg. 2007;60(12): 1296-1301.
[7] Erdmann D, Sweis R, Heitmann C, et al. Side-to-side sutureless vascular anastomosis with magnets.J Vasc Surg. 2004;40(3):院505-511.
[8] Falk V, Walther T, Stein H, et al. Facilitated endoscopic beating heart coronary artery bypass grafting using a magnetic coupling device.J Thorac Cardiovasc Surg.2003;126(5):1575-1579.
[9] Ganz RA,Peters JH,Horgan S,et al. Esophageal sphincter device for gastroesophageal reflux disease.N Engl J Med. 2013;368(8):719-727.
[10] Zaritzky M,Ben R,Zylberg GI,et al.Magnetic compression anastomosis as a nonsurgical treatment for esophageal atresia. Pediatr Radiol.2009;39(9):945-949.
[11] Takamizawa S,Yamanouchi E,Muraji T,et al.MCRA of an anastomotic stenosis after esophagoesophagostomy for long gap esophageal atresia: a case report.J Pediatr Surg.2007; 42(5): 769-772.
[12] Pichakron KO,Jelin EB,Hirose S,et al.Magnamosis II: Magnetic compression anastomosis for minimally invasive gastrojejunostomy and jejunojejunostomy. J Am Coll Surg. 2011; 212(1):42-49.
[13] Wall J, Diana M, Leroy J, et al. MAGNAMOSIS IV: magnetic compression anastomosis for minimally invasive colorectal surgery.Endoscopy.2013;45(8):643-648.
[14] Gonzales KD,Douglas G,Pichakron KO,et al.Magnamosis III: delivery of a magnetic compression anastomosis device using minimally invasive endoscopic techniques. J Pediatr Surg. 2012;47(6):1291-1295.
[15] Russell KW,Rollins MD,Feola GP,et al.Magnamosis: a novel technique for the management of rectal atresia. BMJ Case Rep.2014;2014.pii: bcr2013201330.
[16] An GS,Huai ZQ,Sheng Z,et al.Innovative magnetic rings for circumferential mucosectomy: preliminary research.Surg Today. 2015;45(1):78-82.
[17] Uygun I, Okur M H, Cimen H, et al. Magnetic compression gastrostomy in the rat. Pediatr Surg Int.2012;28(5): 529-532.
[18] Itoi T,Kasuya K,Sofuni A,et al.Magnetic compression anastomosis for biliary obstruction: review and experience at Tokyo Medical University Hospital.J Hepatobiliary Pancreat Sci.2011;18(3):357-365.
[19] Jang SI, Kim JH, Won JY, et al. Magnetic compression anastomosis is useful in biliary anastomotic strictures after living donor liver transplantation.Gastrointest Endosc.2011; 74(5):1040-1048.
[20] Uygun I,Okur MH,Cimen H,et al.Magnetic compression ostomy as new cystostomy technique in the rat: magnacystostomy. Urology.2012;79(3):738-742.
[21] 谢占涛,李建辉,钱军民,等.外科吻合用壳核结构磁性纳米钕铁硼的制备及其细胞毒性[J].中国组织工程研究与临床康复,2010, 14(42):7829-7834.
[22] Capus J,Pickering S,Weaver A.Hoeganaes offers higher density at lower cost. Metal Powder Report.1994;49(7/8): 22-24.
[23] 陈刚,杨小玲,徐晖,等.温压钕铁硼粘结磁体制备技术的研究[J].稀有金属材料与工程,2008,37(2):308-311.
[24] 张修海. 粘结Nd-Fe-B永磁体制备工艺及其性能研究[D].华中科技大学,2008.