Preparation and characterization of apatite deposited on silk fabric using an alternate soaking process

Abstract

Apatite-deposited silk fabric composite materials were developed using a new alternate soaking process. The characteristics of deposited apatite were studied using scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectrophotometry (FTIR), and X-ray photoelectron spectroscopy (XPS). Apatite weight increased with alternating soaking in a calcium solution [200 mM aqueous calcium chloride solution buffered with tris(hydroxymethyl) aminomethane and HCl (pH 7.4)] and a phosphate solution (120 mM aqueous disodium hydrogenphosphate) changed every hour. SEM showed that apatite deposited after 21 or more repeated soakings was over 20 microm thick. XRD showed that with alternate soakings, the apatite crystals deposited on silk fabric elongated along the c axis. FTIR and XPS indicated the existence of carbonate, HPO(4)(2-), and Na(+) ions in addition to constituent ions of hydroxyapatite. A loss of HPO(4)(2-) and Na(+) ions in the deposit upon further soaking might be associated with an increasing apatite crystallinity. Apatite deposited on silk by the alternate soaking process was a deficient apatite containing carbonate, HPO(4)(2-), and Na(+) ions as in a natural bone tissue. Thus, this apatite-silk composite material might be potentially bioactive.

Self‐Expansion Behavior of Silk Fibroin Film

“…Such soft silk fibroin film will be applicable as a functional dressing material for medical use in the future since many groups have already started to investigate silk fibroin as a potential material for biomedical applications. [17][18][19] …”

Preparation of Poly(γ-glutamic acid) Hydrogel / Apatite Composites and Their Application for Scaffold of Cell Proliferation

“…6 shows the FT-IR spectra of the hydrogel before and after the soaking in 1.5 × SBF. New peaks appeared at 565, 604, 1038, and 1100 cm −1 for the sample after the soaking, which are ascribed to vibration of PO4 3− ions of crystalline apatite [43,44]. On the other hand, no peaks due to PO4 3− ions were found in the similarly treated PGA hydrogel obtained from the sodium form.…”

Nematic ordered cellulose templates mediating order-patterned deposition accompanied with synthesis of calcium phosphates

“…Here, it is noted that the HAp thus formed contains still highly amorphous phases (Roberts et al 1991;Roberts et al 1992). Studies on formation processes of organic-inorganic composites have been extensively conducted according to the concept of biomimicry; for example, mimicking the structure of scaffolds (Jie et al 2005), the composition of ions (Kokubo 1990;Kokubo 2005) and the procedure of mineralization (Taguchi et al 1998;Furuzono et al 2000). None of such studies, however, have been focused on a pair of the functions of both ordered scaffolds and ion suppliers simultaneously.…”