Evaluate the growth and adhesion of osteoblast cells on nanocomposite scaffold of hydroxyapatite/titania coated with poly hydroxybutyrate

Abstract

Background: The generation of bioartificial bone tissues may help to overcome the problems related to donor site morbidity and size limitations.

Materials and methods: In this paper, hydroxyapatite (HA) powder was made out of bovine bone by thermal analysis at 900°C and first, and then, porous HA (50 weight percentage) was produced by polyurethane sponge replication method. In order to improve the scaffold mechanical properties, they have been coated with poly hydroxybutyrate. In terms of phase studies, morphology, and specifying agent groups, the specific characterization devices such as X-ray diffraction and Fourier transform infrared, were employed. To compare the behavior of cellular scaffolds, they were divided into four groups of scaffolds. The osteoblast cells were cultured. To perform phase studies, analysis of Methylthiazole tetrazolium (MTT) and Trypan blue were carried out for the viability and attachment on the surface of the scaffold, and the specification of Scanning electron microscopy was employed for the morphology of the cells.

Results: The results of MTT analysis performed on four groups of scaffolds have shown that Titanium oxide (Tio₂) had no effect on cell growth alone and HA was the main factor of growth and cell osteoblast adhesion on the scaffold. Moreover, the results showed that the use of coating with poly-3-hydroxybutyrate saved the factors and placed the osteoblasts within the pore. Since the main part of bone consists of HA, the TiO₂ accelerates the formation of apatite crystals at the scaffold surface which is the evidence for bone tissue regeneration.

Conclusions: It is likely that the relation between HA and TiO₂ leads to an increase in osteoblast adhesion and growth of cells on the scaffold surface.

Keywords: Osteoblast; poly- hydroxybutyrate; scaffold; tissue Engineering; titania.

Figure 1

X-ray diffraction pattern of the powder hydroxyapatite (according to standard of JCPDS: 9-432)

Figure 2

Fourier transform infrared absorption spectrum hydroxyapatite powder

Figure 3

Fourier transform infrared pattern of scaffolds

Figure 4

Scanning electron microscopy of scaffolds (a) polyurethane sponge (b) hydroxyapatite (c) hydroxyapatite/titanium dioxide (d) hydroxyapatite/titanium dioxide coated poly-3-hydroxybutyrate (e) hydroxyapatite coated poly-3-hydroxybutyrate

Figure 5

Thermal gravimetric analysis graph of polyurethane sponge and drawing temperature 200–300°C

Figure 6

Cell proliferation assay using methylthiazole tetrazolium assay of three days growth of osteoblast on scaffolds made of hydroxyapatite/titanium dioxide + poly-3-hydroxybutyrate (a), hydroxyapatite/polyhydroxybutyrate (b), titanium dioxide + poly-3-hydroxybutyrate (c), hydroxyapatite (d) and control. (a) After 3 days and (b) after 7 days cell culture on Scaffolds) (n = 5, mean ± standard deviation, P < 0.05)

Figure 7

Study of cell attachment on the hydroxyapatite/titanium dioxide + poly-3-hydroxybutyrate, hydroxyapatite/polyhydroxybutyrate, titanium dioxide + poly-3-hydroxybutyrate, hydroxyapatite, and control, respectively. About 2 × 10⁴ cells/well of Saos-II was seeded on each scaffold (n = 5). Saos-II cells adhered on the plate as 100% control. (a) After 3 days and (b) after 7 days cell culture on Scaffolds)