While polymers are widely utilized materials in the biomedical industry, they are rarely used in an unmodified state. Some kind of a surface treatment is often necessary to achieve properties suitable for specific applications. There are multiple methods of surface treatment, each with their own pros and cons, such as plasma and laser treatment, UV lamp modification, etching, grafting, metallization, ion sputtering and others. An appropriate treatment can change the physico-chemical properties of the surface of a polymer in a way that makes it attractive for a variety of biological compounds, or, on the contrary, makes the polymer exhibit antibacterial or cytotoxic properties, thus making the polymer usable in a variety of biomedical applications. This review examines four popular methods of polymer surface modification: laser treatment, ion implantation, plasma treatment and nanoparticle grafting. Surface treatment-induced changes of the physico-chemical properties, morphology, chemical composition and biocompatibility of a variety of polymer substrates are studied. Relevant biological methods are used to determine the influence of various surface treatments and grafting processes on the biocompatibility of the new surfaces-mammalian cell adhesion and proliferation is studied as well as other potential applications of the surface-treated polymer substrates in the biomedical industry.

• Keywords
• antimicrobial properties, laser treatment, nanoparticles, nanoscale design, plasma exposure, surface modification, tissue engineering,
• Publication type
• Journal Article MeSH
• Review MeSH

The attractiveness of synthetic polymers for cell colonization can be affected by physical, chemical, and biological modification of the polymer surface. In this study, low-density polyethylene (LDPE) was treated by an Ar(+) plasma discharge and then grafted with biologically active substances, namely, glycine (Gly), polyethylene glycol (PEG), bovine serum albumin (BSA), colloidal carbon particles (C), or BSA+C. All modifications increased the oxygen content, the wettability, and the surface free energy of the materials compared to the pristine LDPE, but these changes were most pronounced in LDPE with Gly or PEG, where all the three values were higher than in the only plasma-treated samples. When seeded with vascular smooth muscle cells (VSMCs), the Gly- or PEG-grafted samples increased mainly the spreading and concentration of focal adhesion proteins talin and vinculin in these cells. LDPE grafted with BSA or BSA+C showed a similar oxygen content and similar wettability, as the samples only treated with plasma, but the nano- and submicron-scale irregularities on their surface were more pronounced and of a different shape. These samples promoted predominantly the growth, the formation of a confluent layer, and phenotypic maturation of VSMC, demonstrated by higher concentrations of contractile proteins alpha-actin and SM1 and SM2 myosins. Thus, the behavior of VSMC on LDPE can be regulated by the type of bioactive substances that are grafted.

• MeSH
• Aorta cytology   drug effects   MeSH
• Biocompatible Materials chemistry   pharmacology   MeSH
• Cell Adhesion drug effects   MeSH
• Glycine chemistry   pharmacology   MeSH
• Rats MeSH
• Cells, Cultured MeSH
• Myocytes, Smooth Muscle cytology   drug effects   MeSH
• Polyethylene chemistry   pharmacology   MeSH
• Polyethylene Glycols chemistry   pharmacology   MeSH
• Surface Properties MeSH
• Cell Proliferation drug effects   MeSH
• Serum Albumin, Bovine chemistry   pharmacology   MeSH
• Muscle, Smooth, Vascular cytology   drug effects   MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Biocompatible Materials MeSH
• Glycine MeSH
• Polyethylene MeSH
• Polyethylene Glycols MeSH
• Serum Albumin, Bovine MeSH

High-density polyethylene (PE) foils were modified by an Ar(+) plasma discharge and subsequent grafting with biomolecules, namely glycine (Gly), polyethylene glycol (PEG), bovine serum albumin (BSA), colloidal carbon particles (C) or BSA and C (BSA + C). As revealed by atomic force microscopy (AFM), goniometry and Rutherford Backscattering Spectroscopy (RBS), the surface chemical structure and surface morphology of PE changed dramatically after plasma treatment. The contact angle decreased for the samples treated by plasma, mainly in relation to the formation of oxygen structures during plasma irradiation. A further decrease in the contact angle was obvious after glycine and PEG grafting. The increase in oxygen concentration after glycine and PEG grafting proved that the two molecules were chemically linked to the plasma-activated surface. Plasma treatment led to ablation of the PE surface layer, thus the surface morphology was changed and the surface roughness was increased. The materials were then seeded with vascular smooth muscle cells (VSMC) derived from rat aorta and incubated in a DMEM medium with fetal bovine serum. Generally, the cells adhered and grew better on modified rather than on unmodified PE samples. Immunofluorescence showed that focal adhesion plaques containing talin, vinculin and paxillin were most apparent in cells on PE grafted with PEG or BSA + C, and the fibres containing alpha-actin, beta-actin or SM1 and SM2 myosins were thicker, more numerous and more brightly stained in the cells on all modified PE samples than on pristine PE. An enzyme-linked immunosorbent assay (ELISA) revealed increased concentrations of focal adhesion proteins talin and vinculin and also a cytoskeletal protein beta-actin in cells on PE modified with BSA + C. A contractile protein alpha-actin was increased in cells on PE grafted with PEG or Gly. These results showed that PE activated with plasma and subsequently grafted with bioactive molecules and colloidal C particles, especially with PEG and BSA + C, promotes the adhesion, proliferation and phenotypic maturation of VSMC.

• Keywords
• bioactivity, biocompatibility, plasma irradiation, tissue engineering and reconstruction,
• MeSH
• Actins metabolism   MeSH
• Aorta cytology   MeSH
• Cell Adhesion drug effects   MeSH
• Glycine pharmacology   MeSH
• Rats MeSH
• Cells, Cultured MeSH
• Oxygen metabolism   MeSH
• Microscopy, Atomic Force MeSH
• Polyethylene chemistry   pharmacology   MeSH
• Polyethylene Glycols chemistry   pharmacology   MeSH
• Cell Proliferation drug effects   MeSH
• Serum Albumin, Bovine pharmacology   MeSH
• Cattle MeSH
• Muscle, Smooth, Vascular cytology   drug effects   metabolism   MeSH
• Carbon chemistry   MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Cattle MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Actins MeSH
• Glycine MeSH
• Oxygen MeSH
• Polyethylene MeSH
• Polyethylene Glycols MeSH
• Serum Albumin, Bovine MeSH
• Carbon MeSH