Surface engineering of PHBV by covalent collagen immobilization to improve cell compatibility

Abstract

Covalent immobilization of collagen onto poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) film was achieved to improve its cell compatibility. Amide groups photografted on PHBV films were initially converted into amine groups through Hofmann degradation and collagen was then chemically bonded to amine groups, consequently forming the amide, amine, and collagen-modified PHBV. The structures of these modified PHBV films were confirmed by ATR-FTIR, XPS, and SEM analyses. Compared with that of PHBV film, surface wettability of the modified PHBV films enhanced remarkably. In particular, water contact angle of the collagen-modified PHBV film decreased from 65.0 degrees to 2.1 degrees within 130 s. Sheep chondrocytes cultured on PHBV and modified PHBV films were evaluated by cell adhesion test, MTT assay, and morphological observation under SEM. Results showed that the collagen-modified PHBV film had better cell adhesion and proliferation than other modified PHBV films and PHBV film. Chondrocytes on the collagen-modified PHBV film adhered through filopodia, spread by cytoplasmic webbing, and formed cells layer earlier than other modified ones, indicating that the collagen-modified PHBV is a promising biomaterial for cartilage tissue engineering.

Amide‐linkage formed between ammonia plasma treated poly(D,L‐lactide acid) scaffolds and bio‐peptides: Enhancement of cell adhesion and osteogenic differentiation in vitro

“…14 The covalent couple promotes effective and stable conjugation and has been recommended by several researchers. [15][16][17][18] However, excess use of chemical reagents might lead to complicated reaction, over side reaction, and difficulty to dispose excess reagents. Low-temperature plasma technique was found to be an efficient method for modifying the surface of biomaterials without changing the bulk properties.…”

CHAPTER 11. Grafting of Functional Monomers on Biomaterials

“…A limitation of XPS is that it cannot be used directly to assess for example, carboxylate groups on a polyester substrate due to the similar binding energies of COOH and COOR (289.2-289.2 eV and 288.6-289.2, respectively 90 ) and FTIR cannot easily be used to e.g., quantify different nitrogen-containing groups due to overlap in band positions. 33 Some of these shortcomings can be overcome using derivatisation methods, most commonly in conjunction with XPS although it has also successfully been used with Raman spectroscopy. 88 Examples of commonly used probes and the functional groups with which they react are given in Table 11.5.…”

Surface modification of biomaterials by photochemical immobilization and photograft polymerization to improve hemocompatibility

“…This method has been widely used to functionalize biomaterials by the immobilization of biomacromolecules. Also, the unsaturated monomers have often been photografted on biomaterial surfaces as functional spacers to immobilize collagen, galactose ligands, succinic anhydride, and urease for indirect improvement of hemocompatibility or promotion of human endothelial cell adhesion and growth to realize endothelializated surface of biomaterials [20][21][22].…”