In vitro study of nano-hydroxyapatite/chitosan-gelatin composites for bio-applications

Abstract

The present work aims to study the in vitro properties of nano-hydroxyapatite/chitosan-gelatin composite materials. In vitro behavior was performed in simulated body fluid (SBF) to verify the formation of apatite layer onto the composite surfaces. The in vitro data proved the deposition of calcium and phosphorus ions onto hydroxyapatite /polymeric composite surfaces especially those containing high concentrations of polymer content. The degradation of the composites decreased with increase in the polymeric matrix content and highly decreased in the presence of citric acid (CA), especially these composites which contain 30% polymeric content. The water absorption of the composites increased with increase in the polymeric content and highly increased with CA addition. The Fourier transformed infrared reflectance (FT-IR) and scanning electron microscope (SEM) for the composites confirmed the formation of bone-like apatite layer on the composite surfaces, especially those containing high content of polymers (30%) with 0.2 M of CA. These promising composites have suitable properties for bio-applications such as bone grafting and bone tissue engineering applications in the future.

Keywords: Chitosan; Composites; Hydroxyapatite; In vitro; SEM.

Fig. 1

Concentration of calcium ions in SBF post-immersion of the HACG composites compared to control and HA sample. Standard error ± 0.384 (n = 3).

Fig. 2

Concentration of calcium ions in SBF post-immersion of the HACGCA composites compared to control and HA sample. Standard error ± 0.336 (n = 3).

Fig. 3

Concentration of phosphorus ions in SBF post-immersion of the HACG composites compared to control and HA sample. Standard error ± 0.214 (n = 3).

Fig. 4

Concentration of phosphorus ions in SBF post-immersion of the HACGCA composites compared to control and HA sample. Standard error ± 0.199 (n = 3).

Fig. 5a

The weight loss% of the HACG composites compared to HA sample. Standard error ± 0.370 (n = 3).

Fig. 5b

The weight loss% of the HACGCA composites compared to HA sample. Standard error ± 0.370 (n = 3).

Fig. 6

Water absorption ability % of the HACG and the HACGCA composites in distilled water. Standard error ± 0.391 (n = 3).

Fig. 7a

The FT-IR of HA sample post-immersion in SBF.

Fig. 7b

The FT-IR of HA70CG30 composite post-immersion in SBF.

Fig. 7c

The FT-IR for HA70CG30CA composite post-immersion in SBF.

Fig. 8

The SEM images of HA sample (a) pre- and (b) post-immersion for 7 days and (c) 28 days in SBF.

Fig. 9

The SEM images of the HA70CG30 composite (a) pre- and post-immersion for 7 days (b), 28 days (c), and its EDX analysis (d).

Fig. 10

The SEM images of HA70CG30CA composite (a) pre- and (b) post-immersion for 7 days, (c) 28 days in SBF, and (d) its EDX analysis.