title: Enhancing hepatocyte adhesion by pulsed plasma deposition and polyethylene glycol coupling.
abstract: Decreased hepatocyte adhesion to polymeric constructs limits the function of tissue engineered hepatic assist devices. We grafted adhesion peptides (RGD and YIGSR) to polycaprolactone (PCL) and poly-L-lactic acid (PLLA) in order to mimic the in vivo extracellular matrix and thus enhance hepatocyte adhesion. Peptide grafting was done by a novel technique in which polyethylene glycol (PEG)-adhesion peptide was linked to allyl-amine coated on the surface of PCL and PLLA by pulsed plasma deposition (PPD). Peptide grafting density, quantified by radio-iodinated tyrosine in YIGSR, was 158 fmol/cm(2) on PLLA and 425 fmol/cm(2) on PCL surfaces. The adhesion of hepatocytes was determined by plating 250,000 hepatocytes/well (test substrates were coated on 12 well plates) and quantifying the percentage of adhered cells after 6 h by MTT assay. Adhesion on PCL surfaces was significantly enhanced (p < 0.05) by both YIGSR (percentage of adhered cells = 53 +/- 7%) and RGD (53 +/- 12%) when compared to control surfaces (31 +/- 8%). Hepatocyte adhesion on PLLA was significantly (p < 0.05) enhanced on PLLA-PEG-RGD surfaces (76 +/- 14%) compared to control surfaces (42 +/- 19%) and more (68 +/- 25%) but not statistically significant (p = 0.15) on PLLA-PEG-YIGSR surfaces compared to control surfaces. These results indicate that hepatocyte adhesion to PCL and PLLA based polymeric surfaces can be enhanced by a novel adhesion peptide grafting technique using pulsed plasma deposition and PEG cross-linking.
authors.affiliation: Joint Program in Biomedical Engineering, University of Texas Southwestern Medical Center, Dallas, Texas 75235, USA.
authors.forename: E S
authors.initials: ES
authors.lastname: Carlisle
authors.forename: M R
authors.initials: MR
authors.lastname: Mariappan
authors.forename: K D
authors.initials: KD
authors.lastname: Nelson
authors.forename: B E
authors.initials: BE
authors.lastname: Thomes
authors.forename: R B
authors.initials: RB
authors.lastname: Timmons
authors.forename: A
authors.initials: A
authors.lastname: Constantinescu
authors.forename: R C
authors.initials: RC
authors.lastname: Eberhart
authors.forename: P E
authors.initials: PE
authors.lastname: Bankey
mesh_terms: D000818:Animals; D001672:Biocompatible Materials; D001698:Biomedical Engineering; D002448:Cell Adhesion; D002460:Cell Line; D019344:Lactic Acid; D008099:Liver / Q000166:cytology*; D008422:Materials Testing; D051379:Mice; D009842:Oligopeptides; D011091:Polyesters; D011092:Polyethylene Glycols; D011108:Polymers; D013499:Surface Properties
chemical_list: D001672:Biocompatible Materials; D009842:Oligopeptides; D011091:Polyesters; D011108:Polymers; C081571:tyrosyl-isoleucyl-glycyl-seryl-arginine; C016240:polycaprolactone; D019344:Lactic Acid; D011092:Polyethylene Glycols; C033616:poly(lactide); C047981:arginyl-glycyl-aspartic acid