In vitro/In vivo Evaluations of Hydroxyapatite Nanoparticles with Different Geometry.

Area of Science:

• Biomaterials Science
• Nanotechnology
• Cell Biology

Background:

• Hydroxyapatite nanoparticles (HANPs) are widely used in biomedical applications due to their targeting capabilities.
• Limited understanding exists regarding the adverse effects and molecular mechanisms of HANPs with varying geometries in the bloodstream.

Purpose of the Study:

• To investigate the impact of different hydroxyapatite nanoparticle geometries on endothelial cell behavior and in vivo biocompatibility.
• To elucidate the molecular mechanisms underlying the observed effects of HANPs.

Main Methods:

• Characterization of HANP size, Zeta potential, and morphology.
• In vitro evaluation of HANP effects on human umbilical vein endothelial cell (HUVEC) proliferation, migration, cell cycle, and apoptosis.
• Transcriptome sequencing to analyze gene expression changes induced by HANPs.
• In vivo biocompatibility assessment in mice via gavage administration.

Main Results:

• Sphere-shaped HANPs induced significant toxicity, apoptosis, and S-phase cell cycle arrest in HUVECs at 200 μM.
• Rod-shaped HANPs promoted HUVEC proliferation at 200 μM.
• Sphere-shaped HANPs increased SULT1A3 levels, potentially facilitating chemical carcinogenesis-DNA adduct pathways.
• In vivo studies showed HANPs influenced blood cell counts and metabolic indicators but without significant toxicity.

Conclusions:

• HANP geometry and surface area critically influence vascular endothelial cell survival and proliferation.
• These findings are crucial for optimizing HANPs in cell engineering and biomaterial design.