Since hydroxyapatite has excellent biocompatibility and bone bonding ability, porous hydroxyapatite ceramics have been intensively studied. However, porous hydroxyapatite bodies are mechanically weak and brittle, which makes shaping and implantation difficult. One way to solve this problem is to introduce a strong porous network onto which hydroxyapatite coating is applied. In this study, porou...

Collagen-hydroxyapatite interfaces compose an important building block of bone structures. While it is known that the nanoscale structure of this elementary building block can affect the mechanical properties of bone, a systematic understanding of the effect of the geometry on the mechanical properties of this interface between protein and mineral is lacking. Here we study the effect of geometr...

A range of crystalline and nano-sized carbonate- and silicate-substituted hydroxyapatite has been successfully produced by using continuous hydrothermal flow synthesis technology. Ion-substituted calcium phosphates are better candidates for bone replacement applications (due to improved bioactivity) as compared to phase-pure hydroxyapatite. Urea was used as a carbonate source for synthesising p...

OBJECTIVES The purpose of this study was to measure and analyze the mechanical properties of several composite materials designed for dental restoration. METHODS The materials were composed of a visible light-curing monomer mixture (either Bis-GMA+TEGDMA or Bis-GMA+HEMA) as a matrix and hydroxyapatite (either microscopic or nanoscopic particles) as a reinforcing filler. The surface of the hyd...

Recognizing the significance of the life stage of fish for nano-eco-toxicological studies, the acute toxicity of colloidal silver nanoparticles (AgNPs) was tested in three different life stages of rainbow trout. Fishes were exposed to colloidal AgNPs at nominal concentrations of 100, 32, 10, 3.2, 1, 0.32, 0.1, and 0.032 mg/L. The estimated 96 hr LC50 values were 0.25, 0.71, and 2.16 mg/L for th...

Colloidal crystals of polymeric or inorganic microspheres are of extensive interest due to their potential applications in such as sensing, optics, photonic bandgap and surface patterning. The article highlights a set of approaches developed in our group, which are efficient to prepare colloidal crystals with ordered voids, patterned colloidal crystals on non-planar surfaces, heterogeneous coll...

The healing process after implantation of sintered bone in the rat parietal bone was compared with that of synthetic hydroxyapatite using both scanning electron and light microscopy. The results showed that the differences between the sintered natural bone and the synthetic hydroxyapatite implantations were in the states of bone union and the bioresorbability of the implanted materials, even th...

Crab's shells of Portunus pelagicus species were used as raw materials for synthesis of hydroxyapatite were used for protection against demineralization of teeth. Calcination was conducted to crab's shells of Portunus pelagicus at temperature of 1000°C for 5 hours. The results of calcination was reacted with (NH4)2HPO4, then dried at 110°C for 5 hours. Sintering was conducted to results of prec...

Poly (2-hydroxy ethyl) methacrylate (PHEMA) is a polymer that can be carboxymethylated to induce calcification on its surface. This mimics the calcification of bone matrix since the polymer surface induces the deposit of large hydroxyapatite calcospherites. We investigated the effect of Sr on hydroxyapatite crystals developed on PHEMA pellets. Pellets were incubated for 1 week in a synthetic bo...