Schuetz et al. (2012). Colloids and Surfaces B Biointerfaces. doi: 10.1016/j.colsurfb.2012.06.006
…]. 2.2. Preparation of collagen gels Collagen was extracted from rat-tail tendons (Pel-Freeze Bio- logicals) according to the procedure of Ho et al. [20] lyophilized and stored at 4 ◦C until used. The yield was 29–31%. The collagen was then dissolved in 0.01 M HCl and the purity of the product was examined by SDS–PAGE (Bio-Rad, Mini-Protean TGX). TPAu were coupled to the collagen via EDC (N-(3-
Abstract
Scanning electron microscopy, transmission electron microscopy, rheometry, and electrochemistry were used to provide insight into the microstructure of collagen type I gel (1%, w/v) modified with the tiopronin-protected (N-(2-mercaptopropionyl)glycine) gold nanoparticles (TPAu), a multivalent crosslinker. The cross-linking reaction, performed via EDC (1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide) coupling, results in compliant, mechanically stable and continuous gels. The gels contain unusual interconnected collagen-TPAu particles. Electrochemical measurements of 4-hydroxy-(2,2,6,6-tetramethylpiperidine-1-oxyl) (4HT) diffusion within the gel reveal that the gel hindrance is nearly independent of the TPAu concentration. The properties of the collagen-TPAu gel make it suitable for potential biomedical applications, such as delivery of small molecule drugs.