Encapsulated Zosteric Acid Embedded in Poly[3-hydroxyalkanoate] Coatings?Protection against Biofouling

Abstract

The natural, non-toxic antifouling compound zosteric acid (ZA, p-coumaric acid sulfate) was encapsulated in polystyrene (PS) microcapsules (30 mg ZAil g PS) with an efficiency of 30 % via an in-liquid drying process. Electron micrographs showed microcapsules with smooth surfaces and a mean diameter of 200 µm. The FIB method was used to cross-section a microcapsule in order to visualize the inner capsule structure and to localize ZA via element analysis. Coatings of a biocompatible polyester, poly[3-hydroxyalkanoate-co-3-hydroxyalkenoate] (PHAE), were prepared on microscopic slides. These coatings contained dispersed ZA (PHAE/ZA) or ZAloaded PS microcapsules (PHAE/PS(ZA)). The release of ZA was monitored vi'a conductivy measurements in water and was 4 µgcm-2 d-1 for PHAE/ZA and 0.9 µgcm-2 d-1 for PHAE/PS(ZA) coatings. To follow the initial steps ofbiofilm formation, coated slides were exposed to activated sludge arid analyzed for cell adhesion with ESEM. ZA was effective during the burst release time of the PHAE/ZA coating, but no significant differences in biofouling were observed after 48 h. This was attributed to the minimal effective release rate of ZA, which is approximately IO µgcm• 2 d-1 •

Zosteric acid and salicylic acid bound to a low density polyethylene surface successfully control bacterial biofilm formation

“…In the past, ZA and SA were incorporated in different polymeric materials able to gradually release the anti-biofilm molecules into the surrounding area (Geiger et al 2004;Barrios et al 2005;Rosenberg et al 2008;Nowatzki et al 2012). However, in most cases these systems showed several problems such as the non-uniform distribution of the anti-biofilm compounds inside the material and the formation of aggregates due to the incomplete miscibility of the molecules in the polymers.…”

Antimacrofouling Efficacy of Innovative Inorganic Nanomaterials Loaded with Booster Biocides

“…Similarly, the technology of nano-containers for antifouling purposes has been explored in order to assess antifouling applications. For example, Geiger et al [16] encapsulated the antifouling biocide zosteric acid (ZA, p-coumaric acid sulfate), extracted from the seagrass Zostera marina, into polystyrene microcapsules and tested it on early stages of biofilm formation. Later, Hart et al [17] encapsulated the broad-spectrum antifungal biocide 4,5-dichloro-2-n-octyl-3(2H)-isothiazolone (DCOIT) into polyvinyl alcohol and into phenolic resin due to the compound's low solubility in seawater.…”

Low density polyethylene functionalized with antibiofilm compounds inhibits Escherichia coli cell adhesion

“…It was previously demonstrated that zosteric acid possesses the remarkable ability to counteract microbial adhesion and subsequent biofilm formation, to shape fungal biofilm architecture, to potentiate the performance of conventional antimicrobial agents and to show cytocompatibility toward soft and hard mammalian tissue cell based models . In the past years, few attempts have been made to incorporate zosteric acid into silicone coatings in order to achieve its slow release in the surrounding area . However, to the best of our knowledge, nobody investigated the possibility to design a non‐leaching, long lasting, anti‐biofilm material to prevent colonization of polymeric materials, by using biocide‐free compounds able to hinder biofilm formation.…”

“…[17][18][19] In the past years, few attempts have been made to incorporate zosteric acid into silicone coatings in order to achieve its slow release in the surrounding area. 10,20 However, to the best of our knowledge, nobody investigated the possibility to design a non-leaching, long lasting, antibiofilm material to prevent colonization of polymeric materials, by using biocide-free compounds able to hinder biofilm formation. In our previous study, 16 we designed and screened against Escherichia coli a 43-member library of small molecules based on zosteric acid scaffold diversity to understand the structural requirements necessary for biofilm inhibition, and to identify functional groups that could be exploited for the covalent linkage to an abiotic surface.…”