Understanding Electrodeposition of Chitosan-Hydroxyapatite Structures for Regeneration of Tubular-Shaped Tissues and Organs

Abstract

Tubular-shaped hydrogel structures were obtained in the process of cathodic electrodeposition from a chitosan-hydroxyapatite solution carried out in a cylindrical geometry. The impact of the initial concentration of solution components (i.e., chitosan, hydroxyapatite, and lactic acid) and process parameters (i.e., time and voltage) on the mass and structural properties of deposit was examined. Commercially available chitosan differs in average molecular weight and deacetylation degree; therefore, these parameters were also studied. The application of Fourier-transform infrared spectroscopy, scanning electron microscopy, and time-of-flight secondary ion mass spectrometry allowed obtaining fundamental information about the type of bonds and interactions created in electrodeposited structures. Biocompatible tubular implants are highly desired in the field of regeneration or replacement of tubular-shaped tissues and organs; therefore, the possibility of obtaining deposits with the desired structural properties is highly anticipated.

Keywords: biomaterials; chitosan; electrodeposition; hydrogel; implants; tissue regeneration.

Figure 1

The influence of (a) chitosan concentration, (b) lactic acid concentration, (c) hydroxyapatite concentration, (d) voltage, and (e) time on (A) characteristics, (B) dry mass, (C) water content, and (D) Fourier-transform infrared (FTIR) spectra of tubular-shaped chitosan–hydroxyapatite deposits. The solution concentrations are listed in Table 2.

Figure 2

SEM photographs of deposits obtained from solutions containing (A) 0.4 wt./vol.% CH, 0.05 wt./vol.% HAp, 3 wt./vol.% LA (10 min), (B) 0.6 wt./vol.% CH, 0.05 wt./vol.% HAp, 3 wt./vol.% LA (10 min), (C) 0.6 wt./vol.% CH, 0.1 wt./vol.% HAp, 3 wt./vol.% LA (10 min), and (D) 0.4 wt./vol.% CH, 0.1 wt./vol.% HAp, 3 wt./vol.% LA (30 min). (a) Transverse cross-section, (b) longitudinal view, (c) 200× magnification of inner surface, and (d) 200× magnification of outer surface.