Poly(dimethyl siloxane)(PDMS)is suitable for the fabrication of space cell culture chips.It is necessary to perform highly stable hydrophilic modification to promote cell adhesion on PDMS surface.We modified PDMS surface by oxygen plasma treatment combining with physical adsorption in this article.PDMS,which was treated with oxygen plasma and sequentially coated with Poly-L-lysine or collagen(PLL-ox-PDMS,COL-ox-PDMS)with various solution concentration and kept in different environmental conditions,were characterized by contact angle and surface energy measurements,and atomic force microscopy(AFM).Cell growth conditions on bare PDMS and modified PDMS were compared,and the numbers of live cells cultured for 1-3 days were evaluated.Experimental results indicate that higher solution concentration and low storage temperature benefit the hydrophilicity stability.The contact angles of PLL-ox-PDMS stored in 4℃and COL-ox-PDMS were close to 60°and 65°on day 25 and 14,respectively.Both modified PDMS surfaces are suitable for cell adhesion and proliferation,and no cell layer falls offin 10 days.The modification method is especially suitable for applications such as medium and long term space cell culture.

Objective To evaluate the safety and efficacy of bipolar plasmakinetic system in exfoliative tran-surethral resection of bladder tumors .Methods Clinical data of 72 patients with non muscle invasive bladder cancer (NMIBC) were retrospectively analyzed.Transurethral bipolar plasmakinetic system was used ,30°viewer,F27 outer sheath was pushed off and bladder tumor was cut .When the bladder filling state ,pushed off bladder mucosa distance from tumor basal 2cm,then electricity cut the exfoliative bladder tumor .When bladder half filling state electricity cut the base of the bladder muscle layer of bladder tumor .Results This group of 72 cases were successfully completed surgery,surgery time 37~93 min,without intraoperative bladder perforation ,slight obturator nerve reflex in 5 cases. The keeping intact pathologic specimens was good for pathological staging .Conclusion Exfoliative transurethral resection of bladder tumors with bipolar plasma is a safe , practical and effective way of operation , which can avoid severe obturator reflex occurred in the operation , and greatly reduce the occurrence of bladder perforation , without TURS,surgical removal of the pathological specimens is specification .