Influence of Polymer Composition and Substrate on the Performance of Bioinspired Coatings with Antibacterial Activity

Abstract

A series of methacrylic copolymers bearing thiazolium cationic groups and catechol moieties were evaluated as antibacterial coatings on a variety of materials including aluminum and plastics such as polycarbonate, poly(methyl methacrylate), and silicone rubber. The thermal properties of the copolymers were first studied by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The cationic copolymers were thermally stable up to 200 °C and presented glass transition temperatures values well above 100 °C; thus, an acceptable thermal behavior for typical biomedical applications. The cationic copolymers with variable content of the adhesive anchoring N-(3,4-dihydroxyphenethyl) methacrylamide (DOMA) units were coated onto the metal and polymeric substrates by drop casting and the adhesive properties of the obtained coatings were further evaluated as a function of DOMA content and substrate. Optical profilometry, attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectra, and antimicrobial studies reveal that the coatings adhere stronger to metal substrates than to the polymeric substrates. The copolymers with higher content of DOMA, 24 mol.%, resist solvent erosion treatment when coated onto all substrates and exhibit antimicrobial activity against Gram-positive S. aureus bacteria after this erosion treatment. In contrast, copolymers with low content, 9 mol.% of DOMA, only remain attached onto the aluminum metal substrate after solvent treatment, while on polymeric substrates the coatings are almost removed and do not show any efficacy against S. aureus bacteria.

Antibacterial Character of Cationic Polymers Attached to Carbon-Based Nanomaterials

“…Figure 5 a shows thermal stabilities of the hybrid sample GO_MD10, compared to GO and MD10 polymer. The degradation of the cationic polymer occurs in three stages [ 41 ], whereas the GO degrades in two steps, in addition to the loss of adsorbed/absorbed water. The first process at 235 °C is ascribed to the removal of most of functional groups containing oxygen such as labile epoxy, hydroxyl, and carboxylic groups (~36% weight loss) from the GO structure, whereas the second decrease in weight, at around 483 °C, is abrupt and can be associated to the complete thermal decomposition of GO [ 42 ].…”

Bioinspired Polymers: Bridging Nature’s Ingenuity with Synthetic Innovation

“…Surface treatments that boost cell viability and functionality in organ-on-a-chip systems represent a significant leap forward in pathophysiological research and drug screening [22]. Novel antibacterial coatings that offer tunable adhesion and antimicrobial properties open new paths for medical applications [64]. Enhanced methods for dopamine delivery for Parkinson's disease treatment, featuring high encapsulation efficiency and lower toxicity, are promising [23].…”

“…Eduok et al's evaluation of the coatings' barrier efficacy and corrosion resistance through electrochemical and surface analyses demonstrates their applicability in metal surface treatments and anticorrosion paints [47] (Figure 1). [64]. Enhanced methods for dopamine delivery for Parkinson's disease treatment, featuring high encapsulation efficiency and lower toxicity, are promising [23].…”

Polydopamine as a Materials Platform to Promote Strong and Durable Interfaces in Thermoplastic Polymer‐Titanium Joints

“…[139] Similar degradation patterns are also observed when dopamine is attached to aliphatic backbones. [140,141] Consequently, the application of dopamine in its pristine form cannot be applied to thermally joined interfaces due to the elevated processing tem-peratures required by the process. A dopamine derivative with a higher degree of aromaticity than dopamine, such as PDA, [14] could pose a more thermally stable alternative.…”