Size-dependent interactions between calciprotein particles and vascular endothelium.

Area of Science:

• Nanomedicine and Vascular Biology
• Biomaterials Science
• Cellular and Molecular Physiology

Background:

• Mechanisms of nanoparticle-endothelial cell interactions are poorly understood, hindering optimal nanoparticle design for clinical use.
• Vascular endothelial barrier integrity is critical for systemic health, and its disruption can lead to pathological conditions like medial calcification.
• Calciprotein particles (CPPs) are implicated in vascular calcification, but their specific interactions with endothelial cells require elucidation.

Purpose of the Study:

• To investigate the size-dependent interactions between calciprotein particles (CPPs) and endothelial cells (ECs).
• To elucidate the impact of CPP size on endothelial barrier function and integrity.
• To inform the design of nanoparticles for therapeutic applications by understanding their vascular interactions.

Main Methods:

• Synthesized small (S-CPP1, <50 nm) and large (L-CPP1, 50-100 nm) calciprotein particles (CPPs) with distinct morphologies.
• Utilized a rat model of chronic kidney disease (CKD) induced by 5/6 nephrectomy.
• Assessed endothelial permeability and cell morphology using immunofluorescence microscopy and quantified intercellular gap changes.

Main Results:

• Small CPP1 (S-CPP1) significantly increased endothelial permeability at tested concentrations, disrupting the endothelial barrier integrity.
• S-CPP1 induced irregular endothelial cell morphology and widened intercellular gaps, suggesting disruption of VE-cadherin junctions.
• Large CPP1 (L-CPP1) was internalized by endothelial cells via endocytosis, showing size-specific uptake mechanisms.

Conclusions:

• The interaction between CPPs and the vascular endothelium is critically dependent on particle size.
• Small CPPs pose a greater risk to endothelial barrier integrity, potentially contributing to medial calcification.
• Understanding these size-dependent interactions is crucial for developing safer and more effective nanoparticle-based therapies.