title: Surface characteristics of acrylic modified polysulfone membranes improves renal proximal tubule cell adhesion and spreading.
abstract: Current polyvinylpyrrolidone-modified polysulfone (PVP-PSU) membranes in haemodialysers do not facilitate the attachment and proliferation of renal proximal tubule cells (RPTCs). For bioartificial kidney (BAK) development expensive extracellular matrices are employed to ensure the PVP-PSU membranes can serve as a substrate for RPTCs. In this study we modified PSU using an acrylic monomer (am-PSU) and polymerization using ultraviolet irradiation. We demonstrated that on adjusting the PSU or acrylic content of the membranes the wettability and surface chemistry were altered, and this affected the amount of fibronectin (Fn) that was adsorbed onto the membranes. Using an integrin blocking assay we ascertained that Fn is an important extracellular matrix component that mediates RPTC attachment. The amount of Fn adsorbed also led to different bioresponses of RPTCs, which were evaluated using attachment and proliferation assays and qualitative quantification of vinculin, focal adhesion kinase, zonula occludens and Na(+)/K(+) ATPase. Our optimized membrane, am-PSU1 (21.4% C-O groups, 19.1% PVP-PSU; contact angle 71.5-80.80, PVP-PSU: 52.4-67.50), supports a confluent monolayer of RPTCs and prevents creatinine and inulin diffusion from the apical to the basal side, meeting the requirements for application in BAKs. However, further in vivo evaluation to assess the full functionality of RPTCs on am-PSU1 is required.
authors.affiliation: Institute of Bioengineering and Nanotechnology, The Nanos, Singapore, Singapore. jem.teo@gmail.com
authors.forename: Jeremy Choon Meng
authors.initials: JC
authors.lastname: Teo
authors.forename: Roderica Rui Ge
authors.initials: RR
authors.lastname: Ng
authors.forename: Chee Ping
authors.initials: CP
authors.lastname: Ng
authors.forename: Alex Wei Haw
authors.initials: AW
authors.lastname: Lin
mesh_terms: D000179:Acrylates / Q000737:chemistry*; D000327:Adsorption / Q000187:drug effects; D001681:Biological Assay; D001692:Biological Transport / Q000187:drug effects; D002448:Cell Adhesion / Q000187:drug effects; D002465:Cell Movement / Q000187:drug effects*; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D004847:Epithelial Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D005353:Fibronectins / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D006801:Humans; D016023:Integrins / Q000378:metabolism; D007687:Kidney Tubules, Proximal / Q000166:cytology*; D008567:Membranes, Artificial; D056951:Photoelectron Spectroscopy; D011108:Polymers / Q000494:pharmacology*; D011205:Povidone / Q000494:pharmacology; D013194:Staining and Labeling; D013450:Sulfones / Q000494:pharmacology*; D017155:Wettability / Q000187:drug effects
chemical_list: D000179:Acrylates; D005353:Fibronectins; D016023:Integrins; D008567:Membranes, Artificial; D011108:Polymers; D013450:Sulfones; C017662:polysulfone P 1700; D011205:Povidone; C036658:acrylic acid