Poly(ethylene oxide) functionalized polyimide-based microporous films to prevent bacterial adhesion

Anti-Biofouling Polymers with Special Surface Wettability for Biomedical Applications

The use of anti-biofouling polymers has widespread potential for counteracting marine, medical, and industrial biofouling. The anti-biofouling action is usually related to the degree of surface wettability. This review is focusing on anti-biofouling polymers with special surface wettability, and it will provide a new perspective to promote the development of anti-biofouling polymers for biomedical applications. Firstly, current anti-biofouling strategies are discussed followed by a comprehensive review of anti-biofouling polymers with specific types of surface wettability, including superhydrophilicity, hydrophilicity, and hydrophobicity. We then summarize the applications of anti-biofouling polymers with specific surface wettability in typical biomedical fields both in vivo and in vitro, such as cardiology, ophthalmology, and nephrology. Finally, the challenges and directions of the development of anti-biofouling polymers with special surface wettability are discussed. It is helpful for future researchers to choose suitable anti-biofouling polymers with special surface wettability for specific biomedical applications.

Recent advances on porous interfaces for biomedical applications

Porous structures on solid surfaces prepared artificially through the water droplet template method have the features of easy operation, low cost and self-removal of templates, and thus are widely applied in the fields of medicine, biomedicine, adsorption, catalysis, and separation, optical and electronic materials. Due to their tunable dimensions, abundant selection of materials, mechanical stability, high porosity, and enlarged pore surface, the formed porous interfaces show specific significance in bio-related systems. In this study, recent achievements related to applications of porous interfaces and a focus into biological and medical-related systems are summarized. The discussion involves the preparation of porous interfaces, and porous interface-induced cell behaviors including culture, growth, proliferation, adhesion, and differentiation of cells. The inhibitory effect of bacteria and separated features of microorganisms supported by porous interfaces, the immobilization of biomolecules related to proteins, DNA and enzymes, and the controllable drug delivery are also discussed. The summary of recent advances pointed out in the study, are suggestive of insights for motivating unique potential applications including their extension to porous interfaces in biomedical materials.

Design and fabrication of biocompatible wrinkled hydrogel films with selective antibiofouling properties

In this article, we explored the selective antibiofouling capacity acquired by functional wrinkled hydrogel films via a fine tuning of their chemical structure through the gradual insertion of hydrophobic radical groups in their network. The hydrogel consists of three main components: hydroxyethyl methacrylate (HEMA, amphiphilic monomer), trifluoroethyl methacrylate (TFMA, hydrophobic monomer), and poly(ethylene glycol) diacrylate (PEGDA, hydrophilic crosslinking agent). Interestingly, the manipulation of the chemical composition affects both, surface morphology and physicochemical characteristics of the patterns, inducing transitions between different surface microstructures, i.e. from wrinkles to creases, to folds, and to crumples. Contact angle measurements show that the insertion of TFMA produces a slight decrease in surface wettability, remaining however highly hydrophilic. By using confocal Raman spectroscopy, important information about wrinkle formation mechanism could be obtained. The procedure presented in this article involves two consecutive thermal and photopolymerization steps, generating a "pseudo" two-layer system, which contracts at different extents when is exposed to external stimuli, leading to the formation of wrinkled surfaces. Finally, bacterial and cellular adhesion/proliferation studies were carried out, evidencing that the amount of TFMA included clearly reduce the bacterial adhesion while mammalian cells are able to still proliferate.

Role of poly(ethylene oxide) in copper-containing composite used for intrauterine contraceptive devices

Copper-containing composite is a cupric ions release system to prepare a novel copper intrauterine devices (Cu-IUDs), its biocompatibility and weight of the prepared composite Cu-IUDs are directly relevant to its such side-effects as pain and bleeding. To improve its biocompatibility and reduce its weight of such a composite Cu-IUDs, a copper-containing composite based on polymer alloy of poly(ethylene oxide) (PEO) and low-density polyethylene (LDPE) is developed. Here the role of its PEO in this novel cupric ions release system is reported. The results show that its cupric ions release rate can be adjusted easily by only changing its PEO content, and it increases remarkably with the increase of its PEO content. Our study also show that this influence is caused by the improvement of its hydrophilicity and the formation of its porous structure owing to the introduction of PEO. The improvement of its hydrophilicity make it easier for the surrounding aqueous solution to infiltrate into the composite, and the formation of its porous structure provide more routes for entry of the aqueous solution and diffusion of the released cupric ions. All these results indicate that the Cu/PEO/LDPE composite is a potential material that can be used to prepare such cupric ions release micro-devices as Cu-IUDs with slighter side-effects through its smaller weight.

Surface segregation of a branched polymer with hydrophilic poly[2-(2-ethoxy)ethoxyethyl vinyl ether] side chains

A branched polymer with hydrophilic side chains was designed and prepared for anti-biofouling surface construction through its preferential segregation.

Toward Cell Selective Surfaces: Cell Adhesion and Proliferation on Breath Figures with Antifouling Surface Chemistry

We report the preparation of microporous functional polymer surfaces that have been proven to be selective surfaces toward eukaryotic cells while maintaining antifouling properties against bacteria. The fabrication of functional porous films has been carried out by the breath figures approach that allowed us to create porous interfaces with either poly(ethylene glycol) methyl ether methacrylate (PEGMA) or 2,3,4,5,6-pentafluorostyrene (5FS). For this purpose, blends of block copolymers in a polystyrene homopolymer matrix have been employed. In contrast to the case of single functional polymer, using blends enables us to vary the chemical distribution of the functional groups inside and outside the formed pores. In particular, fluorinated groups were positioned at the edges while the hydrophilic PEGMA groups were selectively located inside the pores, as demonstrated by TOF-SIMS. More interestingly, studies of cell adhesion, growth, and proliferation on these surfaces confirmed that PEGMA functionalized interfaces are excellent candidates to selectively allow cell growth and proliferation while maintaining antifouling properties.