Plasma polymerized C:H:N:O thin films for controlled release of antibiotic substances

Abstract

Thin films, which are able to deliver antibiotics in a controlled way, are considered as a promising approach to combat bacterial infections. A novel drug delivery method based on reservoir/diffusion barrier is introduced in this paper. As reservoir serves a film of sputtered nylon 6,6 impregnated with ampicillin, which is then covered by a diffusion barrier from the same material. It is demonstrated that the impregnation process does not affect either the morphology or the surface chemical structure. The amount of immobilized antibiotics can be tailored by changing the reservoir film thickness, while the release kinetics can be controlled by the thickness of the diffusion barrier. Finally, it is shown that the ampicillin impregnated films have an antibacterial effect against Staphylococcus epidermidis.

Physicochemical and Mechanical Performance of Freestanding Boron-Doped Diamond Nanosheets Coated with C:H:N:O Plasma Polymer

“…Another important parameter is the stability of C:H:N:O in water-based environments. As reported in [36], we found that C:H:N:O films swell by about 17% after 2 h of water immersion, but after full drying of the film, the thickness returns to its original value, which points to the good stability of such a polymer network in water. In other words, C:H:N:O films do not dissolve in water, which is important for applications in water-based environments.…”

“…Such a low value of surface roughness highlights the very smooth characteristic of the C:H:N:O film, and since the sputtering process was performed under a relatively high pressure of 3 Pa and low power, it was assumed that such a film would probably copy the surface topography of the underlying diamond foil and not destroy it. The adhesion of the carbon-containing C:H:N:O film to the diamond as a carbon structure can be expected to be high, because of both (i) the possible activation of the nanodiamond surface by the plasma [37], which may lead to the creation of covalent bonds between the nanodiamond and the C:H:N:O film, and (ii) the relatively high surface energy of the C:H:N:O material, i.e., 46 mJ/m 2 , composed of a polar part of 24 mJ/m 2 and a dispersive part of 21 mJ/m 2 , as measured in our previous study [36], which can lead to electrostatic and dispersive interaction between both materials. Another important parameter is the stability of C:H:N:O in water-based environments.…”

“…After 15 min of discharge stabilization, the samples were inserted by the load-lock system into the chamber at a distance 6 cm from the magnetron, which was given by chamber geometry, so that the temperature of the substrate did not exceed 50 • C. The deposition was stopped by taking the samples out and placing them back in the load-lock chamber, where they were left for 15 min under a vacuum in order to let the plasma polymer relax, which improves the film stability. These deposition conditions were selected based on our previous studies [34] and [36]. The deposition speed was estimated using spectroscopic ellipsometry as (8.4 ± 0.8) nm·min −1 .…”

State-of-the-Art, and Perspectives of, Silver/Plasma Polymer Antibacterial Nanocomposites

“…Regardless of the antibacterial agent used, its local delivery at a specific site ensures a high local dose without exceeding the systemic toxicity. Because of this, various techniques for the production of such antibacterial coatings were developed, including plasma-based ones that utilized organic antibiotics [ 42 , 43 ].…”

Tailored wettability of plasma polymers made of C–F, C–H, and N–H

“…[33,34] It can be realized simply by introducing a precursor gas feed directly in the deposition chamber as the polymerization occurs directly in the magnetron discharge. As we applied C:F hydrophobic coatings as a stabilization hydrophobic biocompatible barrier for nanoparticles [35] and hydrophilic amino-rich C:H:N:O films for antibiotics immobilization and diffusion barriers, [36,37] we looked at methods to control material properties, mainly tailor wettability of plasma polymers as a dependence of a single parameter.…”