Loading and Release of Drugs from Oxygen‐rich Plasma Polymer Coatings

Abstract

Low‐pressure plasma‐polymerized ethylene film coatings rich in bonded oxygen groups (L‐PPE:O) were deposited on poly(ethylene terephthalate; PET) in order to act as hosts for antimicrobial drugs. Increasing O2 content in the ethylene (C2H4)/Ar–diluted oxygen (O2) gas mixture reduced the deposition rate, but increased the concentration of bonded oxygen, [O], including that of carboxylic acid groups, [COOH], as determined by X‐ray photoelectron‐ (XPS) and Fourier transform infrared (FTIR) spectroscopies, and by toluidine blue O (TBO) assays. L‐PPE:O coatings took up and sustained the release of ciprofloxacin for several hours. Steric hindrance impeded vancomycin penetration into the cross‐linked L‐PPE:O coatings. Ciprofloxacin‐loaded L‐PPE:O coatings inhibited in vitro the growth of Staphylococcus aureus. Deposition of L‐PPE:O on medical devices may endow them with ability to prevent nosocomial infections.

Tuning the Surface Properties of Oxygen-Rich and Nitrogen-Rich Plasma Polymers: Functional Groups and Surface Charge

“…5c, d. As expected, plots of C1 to C4 show higher oxidation states in the deposits with rising R, i.e. the probability of forming alcohols, ketones, and carboxyls increased by increasing the proportion of oxygen in the gas mixture [16]. Moreover, the trend of the C4 component which include carboxyl group support the results obtained by derivatization by TBO assay (Fig.…”

“…The broad bands indicate overlaps of various infra-red active molecular motions; the peaks in the range of 3200-3600 cm -1 are designated to -OH stretch in carboxylic acids or alcohols while the peaks between 1700 and 1725 cm -1 correspond to -C=O stretch in ketones and carboxylic acids and 1000-1300 cm -1 peaks relate to -C-O alcohol, ether and ester. The bands in 3200-3600 cm -1 and 1700-1725 cm -1 regions correspond to the overlaps of different OH and C=O functionalities from ketone, carboxyl and alcohol groups [16]. The peak assignments in FTIR of different plasma polymers are shown in Table 3.…”

“…The surface concentration of carboxylic acid groups, [-COOH], were determined by surface derivatization with toluidine blue (TBO, Bioshop Canada Inc.) [16]. The samples were immersed in 5 ml of TBO solution (15 mg/l) in freshly diluted 0.1 mM sodium hydroxide (NaOH, 30 %w/w, 10 N, Fischer Scientific) and then incubated at 40°C for 1 h. The samples were then washed with 0.1 mM NaOH to remove free TBO and were immersed in 5 ml of a 50 %v/v aqueous acetic acid solution (99.7 %, Fischer Scientific) and incubated at 40°C for 0.5 h to release bounded TBO.…”

“…In this regard, modifying surfaces with plasma is considered as one of the most efficient methods through which surface adhesion can be enhanced either through functional group grafting or deposition of a new functional layer [13][14][15]. One frequently proposed plasma base strategy is the coating of a surface with organic macromolecules (plasma polymers) containing a desirable chemical composition and morphology which allows some control over the interactions of the surfaces with surrounding biomolecules and living cells while the bulk properties of the substrate remain largely intact [16][17][18].…”

Enhancing sensitivity of SPR sensors by using nanostructured Au chips coated with functional plasma polymer nanofilms

“…On the one hand, such thin layers should not disturb the SPR formation, and on the other hand, they should provide a substantial number of -COOH, -NH 2 , anhydride or other reactive groups. Functional plasma polymer films, mainly comprising oxygen-or nitrogen-containing groups, are of increasing importance for biomedical applications, but also as adhesion-promoting layers [19][20][21]. These methods have already been successfully applied for deposition of amine-rich thin films on the surface of the gold electrode for quartz crystal microbalance biosensors [22,23].…”