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

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/cm2 , no bacteria interacted with the fibers, and from 1.13 mg/cm2 , 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/mm2 ), 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.