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By: Atul Khajuria.
Dean, Department of Allied & Health Care Sciences, Rayat Bahra Professional University, Hoshiarpur–Chandigarh Rd, VPO, Bohan, Hoshiarpur, Punjab, India.
Nanoparticle-based contrast agents for X-ray computed tomography (CT) seek to overcome limitations of conventional iodinated small-molecule media but raise distinctive safety, toxicology, and regulatory science questions. Nano–bio-interactions specific to CT nanocontrast include reticuloendothelial system (RES) uptake, long-term hepatic and splenic retention, size-dependent renal versus hepatobiliary clearance, and potential immunogenicity and genotoxicity, all strongly influenced by particle composition, size, shape, surface charge, and coating chemistry. Robust preclinical evaluation requires harmonized in vitro assays, small, and large animal models, pharmacokinetic, and biodistribution studies designed according to emerging nanomaterial guidelines, and standardized reporting tailored to CT nano-agents. Regulatory frameworks from major agencies emphasize case-by- case assessment, enhanced physicochemical characterization, adapted toxicology programs, and post- marketing surveillance, while ethical and health-economic analyses must balance innovation against population-level safety, cost, and equity in access to nano-enabled CT. This review summarizes nano– bio-interactions most relevant to CT contrast safety, outlines a structured preclinical evaluation framework, and discusses regulatory, ethical, and economic considerations for deploying nanotechnology-based CT agents in routine diagnostics and screening.
Keywords: Nanoparticle-based contrast agents, X-ray computed tomography (CT), nano–bio-interactions, preclinical toxicology evaluation, regulatory science and safety assessment.
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