Department of Basic Medical Sciences, Ghent University, Belgium.
J Biomater Appl. 2013 Feb;27(6):651-60. doi: 10.1177/0885328211422119. Epub 2012 Jan 24.
An electronic sensor system for urinary bladder pressure monitoring requires an imbedding into a biocompatible, flexible, and liquid-impermeable material. Poly(dimethylsiloxane) (PDMS) was selected in the present set-up as packaging material because it fulfills the abovementioned requirements. However, the surface of PDMS is hydrophobic and causes undesired interactions with salts, proteins, and cells present in urine. To reduce possible interactions of urine salts in the urinary bladder, monomers, [2-(methacryloyloxy)ethyl]-dimethyl-3-sulfopropyl-ammonium hydroxide (sulfobetaine) and 2-acrylamido-2-methylpropyl sulfonic acid, were grafted onto the surface through oxygen plasma treatment. A reduction in salt deposition between the pure PDMS and the modified PDMS was observed both in vitro (artificial urine flow over the surface) and in vivo (implants into the urinary bladder of experimental pigs). Additionally, a 10-fold reduction in salt deposition was observed in vitro due to grafting of the monomers onto the surface. These modified PDMS materials proved also to be biocompatible in cell cultures, which was further confirmed by histological screening of the bladder tissue after implantation in an in vivo pig model.
用于膀胱压力监测的电子传感器系统需要嵌入到一种生物相容、柔韧且不透液体的材料中。在本研究中，聚二甲基硅氧烷（PDMS）被选为包装材料，因为它满足上述要求。然而，PDMS 的表面是疏水性的，会导致与尿液中存在的盐、蛋白质和细胞产生不良相互作用。为了减少膀胱中尿液盐的可能相互作用，通过氧等离子体处理将单体[2-（甲基丙烯酰氧基）乙基]-二甲基-3-磺丙基-铵氢氧化物（磺基甜菜碱）和 2-丙烯酰胺基-2-甲基丙磺酸接枝到表面上。在体外（人工尿液流过表面）和体内（植入实验猪的膀胱）都观察到纯 PDMS 和改性 PDMS 之间盐沉积的减少。此外，由于单体接枝到表面上，体外盐沉积减少了 10 倍。这些改性 PDMS 材料在细胞培养中也被证明是生物相容的，这在体内猪模型植入后对膀胱组织进行组织学筛选后得到了进一步证实。
