Plasma-induced graft-polymerization of polyethylene glycol acrylate on polypropylene films: chemical characterization and evaluation of the protein adsorption.
This work deals with the optimization of argon plasma-induced graft-polymerization of polyethylene glycol acrylate (PEGA) on polypropylene (PP) films in order to obtain surfaces with a reduced protein adsorption for possible biomedical applications. To this end, we examined the protein adsorption on the treated and untreated surfaces. The graft-polymerization process consisted of four steps: (a) plasma pre-activation of the PP substrates; (b) immersion in a PEGA solution; (c) argon plasma-induced graft-polymerization; (d) washing and drying of the samples. The efficiency of these processes was evaluated in terms of the amount of grafted polymer, coverage uniformity and substrates wettability. The process was monitored by contact angle measurements, attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), X-ray Photoelectron Spectroscopy (XPS) and atomic force microscopy (AFM) analyses. The stability of the obtained thin films was evaluated in water and in Phosphate Buffer Saline (PBS) at 37 degrees C. The adsorption of fibrinogen and green fluorescent protein (GFP)--taken as model proteins--on the differently prepared surfaces was evaluated through a fluorescence approach using laser scanning confocal microscopy with photon counting detection. After plasma treatments of short duration, the protein adsorption decreases by about 60-70% with respect to that of the untreated film, while long plasma exposure resulted in a higher protein adsorption, due to damaging of the grafted polymer.
Zanini
Stefano
S
Dipartimento di Fisica G. Occhialini, Università degli Studi di Milano-Bicocca, p.za della Scienza, 3 I-20126 Milano, Italy. stefano.zanini@mib.infn.it
Riccardi
Claudia
C
Grimoldi
Elisa
E
Colombo
Claudia
C
Villa
Anna Maria
AM
Natalello
Antonino
A
Gatti-Lafranconi
Pietro
P
Lotti
Marina
M
Doglia
Silvia Maria
SM
D000179:Acrylates / Q000737:chemistry; D000327:Adsorption; D011092:Polyethylene Glycols / Q000737:chemistry*; D011126:Polypropylenes / Q000737:chemistry*; D011506:Proteins / Q000737:chemistry*; D013499:Surface Properties
D000179:Acrylates; D011126:Polypropylenes; D011506:Proteins; D011092:Polyethylene Glycols; C036658:acrylic acid