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.

Structural characterization and cell response evaluation of electrospun PCL membranes: Micrometric versus submicrometric fibers

“…3 Several bioresorbable synthetic polymers are currently investigated for scaffold fabrication, such as poly(glycolide), poly(lactide), 4,5 poly(lactide-co-glycolide), 6,7 poly(e-caprolactone) (PCL), 8,9 and polydioxanone. 10 In the last years, PCL-engineered scaffolds has been proposed for skin, 11 bone, 12 cartilage, 8 liver, 13 and vascular grafts.…”

Enhanced vascular-related cellular affinity on surface modified copolyesters of 3-hydroxybutyrate and 3-hydroxyhexanoate (PHBHHx)

“…Plasma treatment is a convenient method for modifying surface properties or introducing desired groups onto the surface of a material [15][16][17]. However, the disadvantage of plasma treatment is the declining property with elapsing time [18].…”

Non-Thermal Plasma Surface Modification of Biodegradable Polymers

“…Allylamine is one of the most frequently used monomers to plasma polymerize on biodegradable polymers such as PLLA, PCL and PHBV (Barry et al, 2005, Guerrouani et al, 2007, Carlisle et al, 2000. Plasma polymerized allylamine films on biodegradable polymers resulted in highly hydrophilic surfaces with contact angles of 20° or lower due to the amine groups on the surface.…”