Zwitterionic Polyhydroxybutyrate Electrospun Fibrous Membranes with a Compromise of Bioinert Control and Tissue-Cell Growth

Abstract

We present a method for surface modification by thermal-evaporation self-assembling of poly(3-hydroxybutyrate) (PHB) fibrous membranes with a copolymer of hydrophobic octadecyl acrylate repeat units and hydrophilic zwitterionic 4-vinylpyridine blocks, zP(4VP-r-ODA), in view of controlling biofoulant-fiber interactions. PHB is of interest as a material for bioscaffolding, but its disadvantage is its hydrophobicity, which leads to unwanted interactions with proteins, blood cells, or bacteria. Surface modification of electrospun PHB fibers addresses this issue because the hydrophilicity of the membranes is improved, leading to a significant reduction in bovine serum albumin (92%), lysozyme (73%), and fibrinogen (50%) adsorption. From a coating density of 0.78 mg/cm, no bacteria interacted with the fibers, and from 1.13 mg/cm, excellent hemocompatibility of membranes was measured from thrombocytes, erythrocytes, leukocytes, and whole blood attachment tests. Additionally, HT-1080 fibroblasts were observed to develop in contact with the fibers after 3-7 days of incubation (cell density up to 329 ± 16 cells/mm), suggesting that zP(4VP-r-ODA) provides an adequate humid environment for their growth. Providing an effective control of the surface chemistry and of the coating density, the association of PHB and zP(4VP-r-ODA) can promote the growth of fibroblasts, still maintaining resistance to unwanted biofoulants, and appears to be a promising composite material for tissue engineering.

Self-disinfecting surfaces and infection control

“…This fact gives these polymers ultra-hydrophilicity and consequently great hydration ability [70,71]. Studies concerning surface modification with zwitterionic polymers have proved to be a promising strategy to reduce microorganisms' adhesion [72,73]. Very recently, a study using a tyramine-conjugated sulfobetaine polymer, grafted on polyurethane showed a great reduction in S. aureus adhesion to the surface [74].…”

Poly(3-hydroxybutyrate): Promising biomaterial for bone tissue engineering

“…Chitosan reduced crystallinity and improved surface proper ties and biological activity of scaffolds (3,20,39). Most recent studies report modifications of PHB with poly(ε-caprolactone) (PCL) and sol-gel silica (42), PCL and bioglass (43), cellulose acetate (44), zwitterionic poly(4-vinylpiridine) hydrophilic groups on poly(octadecylacrylate) blocks (45) and natural anionic polysaccharides (46). Sol-gel silica enhanced the stiffness and strength of PHB/PCL fibers (42), while PHB/cellulose acetate scaffolds had three times higher degradation rates compared to PHB scaffolds (44).…”

A Uniform and Robust Bioinspired Zwitterion Coating for Use in Blood‐Contacting Catheters with Improved Anti‐Inflammatory and Antithrombotic Properties

“…[30,31] By contrast, coating processes are mainly dependent on the hydrophobic interactions between the modified surface and the hydrophobic units of the zwitterionic polymers and they have distinct advantages such as simplicity and uniformity, compared to grafting. [32,33] Nevertheless, existing polar interactions between the zwitterionic moieties and the surrounding aqueous medium, such as blood flow, is one major weakness of this coating strategy, as they can destabilize the coating and cause a loss in coating functionality. [34] Thus, a stable, uniform surface modification strategy is needed for zwitterionic polymers for use in blood-contacting devices.…”