Comparative study of nanohydroxyapatite microspheres for medical applications

Abstract

This study concerns the preparation, physical, and in vitro characterization of two different types of hydroxyapatite (HA) microspheres, which are intended to be used as drug-delivery systems and bone-regeneration matrices. Hydroxyapatite nanoparticles (HA-1 and HA-2) were prepared using the chemical precipitation synthesis with H 3 PO 4 , Ca(OH) 2 , and a surfactant, SDS (sodium dodecyl sulfate), as starting reagents. The HA powders were dispersed in a sodium alginate solution, and spherical particles were obtained by droplet extrusion coupled with ionotropic gelation in the presence of Ca 2þ . These were subsequently sintered to produce HA-1 and HA-2 microspheres with a uniform size and interconnected microporosity. Both powders and microspheres were characterized using FTIR and X-ray diffraction. Moreover, SEM and mercury intrusion porosimetry were used to analyze the microspheres, and TEM was used to analyze the powders. Results showed that pure HA and mixtures of HA/b-TCP in the nanometer range and needlelike shape were obtained for HA-1 and HA-2 powders, respectively. Neutral Red, scanning electron microscopy and confocal microscopy were used to evaluate the behavior of osteoblastic-like MG-63 cells cultured on HA microspheres surfaces for 7 days. Results showed that good adhesion and proliferation of osteoblasts on the HA microspheres surface. Cells built bridges between adjacent microspheres, forming microspheres-cells clusters in both types of materials.

Innovative macroporous granules of nanostructured‐hydroxyapatite agglomerates: Bioactivity and osteoblast‐like cell behaviour

“…The starting material (nanostructured-HA agglomerates) was prepared through a wet chemical route, which is the most extensively used method to synthesize HA. 26 The XRD results suggested that wet chemical reaction used for nano-HA synthesis has produced phase pure and homogeneous HA. They also revealed that ''as prepared'' nanostructured-HA seems to exhibits considerable amount of amorphous phase, even if the apatite phase is clearly presented and HA crystalline phase increased with heat-treatment temperature, as expected.…”

“…3) showed that CO 2À 3 groups disappeared after sintering; so, these groups might come from the atmospheric CO 2 during HA processing, and they might be only adsorbed to the surface or weekly bonded in the HA lattice. 26 FTIR analysis indicated characteristic spectra bands for all the studied materials. [28][29][30] The spaces between these nanoparticles agglomerates may contribute to a very high microporosity in nanostructured-HA granules.…”

Bioactive SrO–SiO2 glass with well-ordered mesopores: Characterization, physiochemistry and biological properties

“…Certain figures in this article, particularly Figures 1,5,6,9, 10 and 11, are difficult to interpret in black and white. The full colour images can be found in the on-line version, at doi: 10.1016/ j.actbio.2010.12.018).…”

“…To this end, a number of different materials, such as inorganic bioglass [2,4,5], calcium phosphate ceramics [6] and polymers [7], have been studied for their suitability in bone tissue repair. Over the past several years, mesoporous SiO 2 has received a significant amount of attention.…”

Influence of nanohydroxyapatite surface properties on Staphylococcus epidermidis biofilm formation

“…5 Additionally, the capacity of nanoHA to be a vehicle for the transport of biochemical factors or drugs, respectively, for tissue engineering or cancer treatment has been assessed. 6,7 Bacterial infections associated to prosthetic implants and medical devices present strong clinical challenges. The micro-organisms are able to attach to biomaterials used in prosthetic implants and medical devices, consequently causing biomaterials-related infections in humans.…”