Biomedical subjects

Peter Frey

Publications and source records attributed to Peter Frey.

21 records · Page 2Linked to original sources

PubMed2002

Plasma-induced graft polymerization of acrylic acid onto poly(ethylene terephthalate) films: characterization and human smooth muscle cell growth on grafted films.

Graft polymerization of acrylic acid onto plasma treated poly(ethylene terephthalate) (PET) films was carried out to develop surfaces for protein immobilization and smooth muscle cell seeding. Films with various graft densities were characterized by contact angle measurements, attenuated total reflectance infrared spectroscopy, X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). The contact angle was observed to decrease from 72.9 degrees for the virgin PET films to between 26 degrees and 33 degrees depending on the graft density. Storage of grafted films led to an increase in the contact angle, suggesting molecular rearrangement at the surface. However, films with the lowest graft levels showed maximum enhancement in the contact angle up on storage. XPS confirmed the presence of the polyacrylic acid grafts at the film surface and AFM showed a marked increase in the wavelength of the surface roughness as the graft density increased. The amount of collagen immobilized at the surface of the grafted films also increased as the graft density increased. The collagen immobilized films provided an excellent substrate for the growth of human smooth muscle cells.

Acrylates↗

PubMed2002

Acrylic acid grafting and collagen immobilization on poly(ethylene terephthalate) surfaces for adherence and growth of human bladder smooth muscle cells.

In tissue engineering, degradable or non-degradable polymer matrices can act as cell-carrier-scaffolds. Cell adhesion and growth on these scaffolds can be promoted by immobilizing extracellular matrix proteins. Therefore, in this study, polymer poly(ethylene terephthalate) (PET) films were surface modified by graft polymerization of acrylic acid, to subsequently allow collagen (types I and III) immobilization and human smooth muscle cell expansion. The surfaces of PET were activated by plasma, followed by acrylic acid graft polymerization, resulting in covalently bound brushes, containing an average of either 0.22+/-0.1 or 5.93+/-0.87 microg/cm2 of poly(acrylic acid) (PAA). Subsequent electrostatic adsorption of collagen gave a surface concentration of 4.96 and 17.2 microg/cm2, respectively, as determined using radiolabelled 125I collagen. Both PET films grafted with 0.22 microg/cm2 of PAA with or without adsorbed collagen were apt for smooth muscle cell adhesion and proliferation. However, films grafted with 5.93 microg/cm2 were not. PAA-grafted PET films, onto which serum proteins of the culture medium adsorbed spontaneously, proved to be better matrices than films on which collagen has been immobilized. It, therefore, can be speculated that other serum proteins are more important than collagen for the human smooth muscle cell adhesion and growth on surface-modified polymer matrices.

Acrylic Resins↗

PubMedDate not supplied

In vitro growth of human urinary tract smooth muscle cells on laminin and collagen type I-coated membranes under static and dynamic conditions.

This study investigates in vitro growth of human urinary tract smooth muscle cells under static conditions and mechanical stimulation. The cells were cultured on collagen type I- and laminin-coated silicon membranes. Using a Flexcell device for mechanical stimulation, a cyclic strain of 0-20% was applied in a strain-stress-time model (stretch, 104 min relaxation, 15 s), imitating physiological bladder filling and voiding. Cell proliferation and alpha-actin, calponin, and caldesmon phenotype marker expression were analyzed. Nonstretched cells showed significant better growth on laminin during the first 8 days, thereafter becoming comparable to cells grown on collagen type I. Cyclic strain significantly reduced cell growth on both surfaces; however, better growth was observed on laminin. Neither the type of surface nor mechanical stimulation influenced the expression pattern of phenotype markers; alpha-actin was predominantly expressed. Coating with the extracellular matrix protein laminin improved in vitro growth of human urinary tract smooth muscle cells.

Biomarkers↗