Lakshmi S, Jayakrishnan A
Polymer Chemistry Division, Biomedical Technology Wing, Sree Chitra Tirunal Institute for Medical Sciences & Technology, Satelmond Palace Campus, Trivandrum 695 012, India.
J Biomed Mater Res B Appl Biomater. 2003 Apr 15;65(1):204-10. doi: 10.1002/jbm.b.10562.
Plasticized poly(vinyl chloride) (PVC) was surface modified by nucleophilic substitution of the chlorine atoms of PVC by sulfide ions in aqueous media in the presence of a phase-transfer catalyst (PTC) to make it migration resistant. The modified PVC was sterilized by steam autoclaving and gamma radiation and subjected to plasticizer extraction in an extraction medium such as hexane. Virtually no plasticizer migrated out of modified PVC into the medium even after prolonged incubation for 30 d. The properties of the modified surface were evaluated by contact angle measurements, scanning electron microscopy (SEM), cell-culture studies, hemolysis assay, and whole-blood clotting time measurements. The mechanical properties of modified sheets were evaluated by measurements of tensile strength and strain at break after subjecting the specimens to different modes of sterilization. The modified PVC surface showed enhanced wettability and was found to be non-hemolytic and non-cytotoxic. Whole-blood clotting profiles of unmodified and modified PVC were virtually the same. Modification imparted slight yellow color to the material. Surface modification resulted in an 8% decrease in the ultimate stress and 28% decrease in the strain at break values. The sulfide-substituted PVC was found to be blood compatible and would be useful in applications such as tubing for transfusion, dialysis etc., where migration resistance is important.
在相转移催化剂（PTC）存在的情况下，通过在水介质中用硫离子对聚氯乙烯（PVC）的氯原子进行亲核取代，对增塑聚氯乙烯（PVC）进行表面改性，以使其具有抗迁移性。改性后的PVC通过蒸汽高压灭菌和伽马射线辐射进行灭菌，并在己烷等萃取介质中进行增塑剂萃取。即使经过30天的长时间孵育，实际上也没有增塑剂从改性PVC中迁移到介质中。通过接触角测量、扫描电子显微镜（SEM）、细胞培养研究、溶血试验和全血凝固时间测量来评估改性表面的性能。通过对经过不同灭菌方式处理的试样进行拉伸强度和断裂应变测量，来评估改性片材的机械性能。改性后的PVC表面显示出增强的润湿性，并且被发现是非溶血和无细胞毒性的。未改性和改性PVC的全血凝固曲线几乎相同。改性使材料呈现轻微的黄色。表面改性导致极限应力降低8%，断裂应变值降低28%。发现硫化取代的PVC具有血液相容性，在诸如输血、透析等管材应用中，抗迁移性很重要，它将会很有用。
