Battraw G A, Szivek J A, Anderson P L
Department of Surgery, University of Arizona, Tucson 85724, USA.
J Biomed Mater Res. 1998 Winter;43(4):462-8. doi: 10.1002/(sici)1097-4636(199824)43:4<462::aid-jbm14>3.0.co;2-j.
In vivo strain gauging has been used to understand physiological loading and bone remodeling. In early studies, a cyanoacrylate adhesive was used to bond gauges to bone, even though this adhesive is susceptible to biodegradation that results in rapid debonding. Calcium phosphate ceramic (CPC) coated gauges have been successfully bonded to bone for long periods. However, earlier studies noted occasional debonding of coatings from gauges. The goals of this project were to develop a technique to securely bond particles to gauge backings and develop an in vitro test and assess its accuracy in simulating in vivo degradation of this interface. Gauges were heated for different time intervals, roughened with carbide papers, and prepared using layered coatings of polysulfone and CPC particles that varied in size, shape, and crystallinity. They were soaked in solution or placed in muscle pouches of rats for up to 16 weeks. They were then epoxied to fixtures, mounted on an MTS machine, and loaded to failure. Heating and roughening gauge surfaces increased the interface strengths by up to 2000%. In vivo and in vitro testing showed an initial drop in the interface strength, which leveled off to approximately 7.0+/-2.0 MPa.
体内应变测量已被用于了解生理负荷和骨重塑。在早期研究中，使用氰基丙烯酸酯粘合剂将应变片粘结到骨上，尽管这种粘合剂易受生物降解影响，会导致快速脱粘。磷酸钙陶瓷（CPC）涂层应变片已成功长期粘结到骨上。然而，早期研究指出涂层偶尔会从应变片上脱粘。本项目的目标是开发一种将颗粒牢固粘结到应变片背衬的技术，并开发一种体外试验，评估其在模拟该界面体内降解方面的准确性。应变片在不同时间间隔加热，用碳化砂纸粗糙化，并使用尺寸、形状和结晶度不同的聚砜和CPC颗粒分层涂层制备。将它们浸泡在溶液中或置于大鼠的肌肉袋中长达16周。然后用环氧树脂将它们粘结到固定装置上，安装在MTS机器上，并加载至破坏。加热和粗糙化应变片表面可使界面强度提高多达2000%。体内和体外试验显示界面强度最初下降，之后稳定在约7.0±2.0 MPa。
