Corona discharge treatment of the plastified PVC films obtained by chemical grafting

ABSTRACT:In the field of biomaterials and biomedical devices, surface activation has been focused on creating functional groups capable of preferential adsorption of biologically active species (proteins, enzymes, cells, drugs, etc.). In this way an interface can be created between the synthetic material and the biological medium, with the aim of increasing the compatibility of the implant with the human organism. In our experiments a dielectric barrier discharge (DBD), in helium at atmospheric pressure, was used as the source of energy capable of creating active centers that render the functionalized surface favorable to immobilization of biological molecules. Retention of immunoglobulin (IgG) and heparin biomolecules on polyamide-6 (PA-6) surfaces after treatment by the DBD was analyzed by atomic force microscopy, adhesion evaluation, and measurement of the contact angle titration in order to assess this incorporation on the treated surfaces. The marked adsorption of the biomolecules on the active sites created by DBD on the exposed surfaces also was related to a complex set of processes, such as enhanced roughness, increased surface wettability, and modified distribution of cationic and anionic groups on the treated surfaces. All these factors could promote interfacial interactions between the specific groups of the biomolecules existing in the biological medium and the type of cationic and/or anionic groups present on the surface. The efficiency of the DBD treatment showed that the DBD technique is useful for preactivation of the polymer surface for immobilization of other biologically active species (such as drugs and enzymes).

“…We mention also that marked adsorption of IgG and heparin has been obtained on PVC samples treated by DBD, these surfaces being more wettable after plasma treatment 10, 25…”

Section: Resultsmentioning

confidence: 95%

Immobilization of biologically active species on PA‐6 foils treated by a dielectric barrier discharge

Dumitrascu

Borcia

Apetroaei

et al. 2003

“…PVC has no functional groups in its structure, so chemical modification was carried out to introduce the proper functional groups. Grafting technique, with different types of polymers possess different functional groups, was intensively presented as the main solution using either chemical or radiation initiation system 20–23. On the other hand, another simple technique using the aminoalkylation reaction with diamine has been presented 24.…”

Section: Introductionmentioning

confidence: 99%

Covalent immobilization of penicillin G acylase onto amine‐functionalized PVC membranes for 6‐APA production from penicillin hydrolysis process. II. Enzyme immobilization and characterization

Eldin

El‐Enshasy

Hassan

et al. 2012

This article describes the covalent immobilization of penicillin G acylase (PGA) onto glutaraldehydeactivated NH 2 -PVC membranes. The immobilized enzyme was used for 6-aminopenicillanic acid production from penicillin hydrolysis. Parameters affecting the immobilization process, which affecting the catalytic activity of the immobilized enzyme, such as enzyme concentration, immobilization's time and temperature were investigated. Enzyme concentration and immobilization's time were found of determine effect. Higher activity was obtained through performing enzyme immobilization at room temperature. Both optimum temperature (35 C) and pH (8.0) of immobilized enzyme have not been altered upon immobilization. However, immobilized enzyme acquires stability against changes in the substrate's pH and temperature values especially in the higher temperature region and lower pH region. The residual relative activities after incubation at 60 C were more than 75% compared to 45% for free enzyme and above 50% compared to 20% for free enzyme after incubation at pH 4.5. The apparent kinetic parameters K M and V M were determined. K M of the immobilized PGA (125.8 mM) was higher than that of the free enzyme (5.4 mM), indicating a lower substrate affinity of the immobilized PGA. Operational stability for immobilized PGA was monitored over 21 repeated cycles. The catalytic membranes were retained up to 40% of its initial activity after 10.5 working h. V C 2012 Wiley Periodicals, Inc. J Appl Polym Sci 125: [3820][3821][3822][3823][3824][3825][3826][3827][3828] 2012

“…PVC has no functional groups in its structure, so chemical modification was carried out to introduce the proper functional groups. The grafting technique, with different types of polymers possessing different functional groups, has been presented extensively as the main solution, with either a chemical or radiation initiation system 20–23. On the other hand, another simple technique using the aminoalkylation reaction with diamine was presented 24.…”

Section: Introductionmentioning

confidence: 99%

Covalent immobilization of penicillin G acylase onto chemically activated surface of poly(vinyl chloride) membranes for 6‐penicillic acid production from penicillin hydrolysis process I. Optimization of surface modification and its characterization

Eldin

El‐Enshasy

Sayed

et al. 2011

The covalent immobilization of penicillin G acylase (PGA) onto the surface of NH 2 -poly(vinyl chloride) (PVC) membranes was studied. PGA was chosen because it plays a relevant role in the pharmaceutical industry, catalyzing the production of an important intermediate for the industrial production of semisynthetic penicillin and cephalosporine. Because PVC has no functional groups in its structure, in this work, we focused on the functionalization of PVC with primary amine functional groups for the covalent immobilization of PGA. This goal was achieved through an aminoalkylation process of the surface of the PVC membranes with ethylene diamine followed by activation with glutaraldehyde to finally immobilize the enzyme. Different factors affecting the modification and activation processes were studied, and their impacts on the catalytic activity of the immobilized PGA were followed. The functionalized membranes were characterized with Fourier transform infrared spectroscopy, thermogravimetric analysis, and scanning electron microscopy to verify the modification process. In addition, the changes resulting from the modification in physical characteristics, such as surface roughness, water uptake, and mechanical properties, were monitored. V C 2011Wiley Periodicals, Inc. J Appl Polym Sci 124: E27-E36, 2012