Henry Marie, Ulrichs Karin, Moskalenko Vasily, Bonneau Michel, Kang Chantal, Belcourt Alain, Bertrand Patrick
Université Catholique de Louvain, PCPM, Croix du Sud 1, B1348 Louvain-La-Neuve, Belgium.
Biomed Mater. 2007 Mar;2(1):S78-89. doi: 10.1088/1748-6041/2/1/S12. Epub 2007 Mar 2.
The biocompatibility of membranes aiming at being a part of a bioartificial pancreas has been tested. For that purpose, we have studied a polycarbonate membrane surface after its implantation in mini-pigs. The membranes were made hydrophilic by an argon plasma surface treatment followed by a dipping in a hydrophilic polymer solution. Two polymers were tested: polyvinylpyrrolidone (PVP) and hydroxypropylmethylcellulose (HPMC). To test their biocompatibility, an encapsulation device for pig Langerhans islets, with external membranes treated as described above, was implanted in different mini-pigs. The pigs received no further treatment. The devices were explanted after in vivo exposure and the membranes were analysed by XPS (x-ray photoelectron spectroscopy) and ToF-SIMS (time-of-flight secondary ion mass spectrometry). After this time, the substrate with the PVP or HPMC treatment was still detected on the different samples. The surface treatment signal, however, was attenuated. This is explained by the detection of other components partly covering the surface. XPS and ToF-SIMS analyses revealed the presence of biological molecules on the two faces of the membrane: the outside face in contact with the biological environment and the inside face in contact with the device. ToF-SIMS images show the inhomogeneity of the biological molecules on the membrane surface. In conclusion, biological molecules adhered to the encapsulation membrane surface after implantation but the surface treatments remained unaltered.
针对作为生物人工胰腺一部分的膜的生物相容性进行了测试。为此，我们研究了聚碳酸酯膜在小型猪体内植入后的表面情况。通过氩等离子体表面处理并随后浸入亲水性聚合物溶液，使膜具有亲水性。测试了两种聚合物：聚乙烯吡咯烷酮（PVP）和羟丙基甲基纤维素（HPMC）。为了测试它们的生物相容性，将用于猪胰岛的封装装置（其外部膜按上述方法处理）植入不同的小型猪体内。这些猪未接受进一步治疗。在体内暴露后取出装置，并通过X射线光电子能谱（XPS）和飞行时间二次离子质谱（ToF-SIMS）对膜进行分析。此时，在不同样品上仍检测到经过PVP或HPMC处理的底物。然而，表面处理信号减弱了。这是由于检测到部分覆盖表面的其他成分所致。XPS和ToF-SIMS分析表明，在膜的两面都存在生物分子：与生物环境接触的外表面和与装置接触的内表面。ToF-SIMS图像显示了膜表面生物分子的不均匀性。总之，植入后生物分子附着在封装膜表面，但表面处理保持不变。
