Polyelectrolyte multilayers (PEMs) consisting of hyaluronic acid (HA) and chitosan (Ch) are extensively studied for biomedical applications and suppress bacterial and protein attachment. Here we prepared and tested HA/Ch PEMs as marine fouling-release coatings. PEMs were constructed by layer-by-layer assembly using spin coating.The multilayers were crosslinked for enhanced stability in the sea water environment by chemical and thermal treatment. Protein-repelling properties of the crosslinked multilayers were investigated by surface plasmon resonance spectroscopy (SPR). The marine antifouling and fouling-release properties were tested against the settlement of zoospores of the green alga Ulva linza and the subsequent development and removal of sporelings.With spin coating and thermal crosslinking, a thick yet homogeneous coating was obtained with antifouling properties against marine algal zoospores indicating the potential of these compounds for application in protective coatings.

Layer-by-layer (LbL) assembly is a versatile platform for applying coatings and studying the properties of promising compounds for antifouling applications. Here, alginate-based LbL coatings were fabricated by alternating the deposition of alginic acid and chitosan or polyethylenimine to form multilayer coatings. Films were prepared with either odd or even bilayer numbers to investigate if the termination of the LbL coatings affects the physicochemical properties, resistance against the nonspecific adsorption (NSA) of proteins, and antifouling efficacy. The hydrophilic films, which were characterized using spectroscopic ellipsometry, water contact angle goniometry, ATR-FTIR spectroscopy, AFM, XPS, and SPR spectroscopy, revealed high swelling in water and strongly reduced the NSA of proteins compared to the hydrophobic reference. While the choice of the polycation was important for the protein resistance of the LbL coatings, the termination mattered less. The attachment of diatoms and settling of barnacle cypris larvae revealed good antifouling properties that were controlled by the termination and the charge density of the LbL films.

Polysaccharide multilayers consisting of hyaluronic acid and chitosan were prepared by layer-by-layer assembly. To be used in seawater, the multilayers were crosslinked to a different degree using thermal or chemical methods. ATR-FTIR revealed different amide densities as result of the crosslinking conditions. AFM showed that crosslinking affected the roughness and swelling behavior of the coatings. Stability and degradability of the multilayers in aqueous environments was monitored with spectroscopic ellipsometry. Resistance of the coatings against non-specific protein adsorption was characterized by SPR spectroscopy. Settlement assays using Ulva linza zoospores and removal assays using the diatom Navicula incerta showed that the slowly degradable coatings were less prone to fouling than the strongly crosslinked ones. Thus, the coatings were a suitable model system to show that crosslinking the multilayers under mild condition and equipping the coatings with controlled degradation rates enhances their antifouling and fouling-release properties against marine fouling organisms.

Polyelectrolyte multilayer (PEM) assembly is a versatile tool to construct low-fouling coatings. For application in the marine environment, their structure needs to be stabilized by covalent linkage. Here, we introduce an approach for spin coating of silane-based sol–gel chemistries using layer-by-layer assembly of polysaccharide-based hybrid polymer coatings (LBLHPs). The silane sol–gel chemistry allows the films to be cross-linked under water-based and mild reaction conditions. Two different silanes were used for this purpose, a conventional triethoxymethyl silane and a de novo synthesized zwitterionic silane. The polysaccharide–silane hybrid polymer coatings were thoroughly characterized with spectroscopic ellipsometry, water contact angle (WCA) goniometry, attenuated total reflection–Fourier transform infrared spectroscopy, and atomic force microscopy. The coatings showed good stability in seawater, smooth surfaces, a high degree of hydration, and WCAs below or close to the Berg limit. LBLHPs showed low-fouling properties in biological assays against nonspecific protein adsorption, attachment of the diatom Navicula perminuta, and settlement of zoospores of the macroalga Ulva linza.

Pacharra et al. Cytocompatible PLCL-PEG Copolymers for Cardiovascular Applications best endothelial cell adhesion. PLLA-PEG550 and PLCL-PEG550 70:30 presented as best candidates for cardiovascular implant use from a cytocompatibility perspective across the spectrum of testing completed. Altogether, these polymers are excellent innovative materials suited for an application in stent manufacture due to the ease in translation of this one-step synthesis strategy to device production and their excellent in vitro cyto-and hemocompatibility.