Nanoscale coordination polymers: synthesis, characterization, and emerging biomedical applications

Nanoscale coordination polymers (NCPs) encompassing both crystalline nanoscale metal-organic frameworks (nanoMOFs) and amorphous coordination polymer nanoparticles have emerged as adaptable hybrid materials. They have adjustable composition, porosity, and surface functionality. These characteristics allow for precise control over drug loading, release timing, and biological interactions. NCPs are therefore promising choices for theranostics, imaging, and therapy. This review points out recent advancements in the synthesis and nanoscale engineering of NCPs. It highlights relevant structure-property relationships that affect biomedical performance. Quantitative benchmarks from recent literature are incorporated to illustrate the advantages of NCP platforms (e.g. ZIF-8 drug loading up to ∼70-80 wt% versus <30% for amorphous NCPs; Gd-based NCPs exhibiting T₁ relaxivities of ∼25-30 mM^-1 s^-1 compared with 4-5 mM^-1 s^-1 for clinical Gd chelates). We also discuss methods for characterization that link physical and chemical properties to biological function. The growing applications of NCPs in drug delivery, biosensing, enzyme activity, imaging, and antimicrobial or antiviral therapy are examined. Finally, we outline current challenges such as biodegradation, toxicity, scalability, and the lack of clinical application. We also identify opportunities for future progress, including computational design and AI-assisted material discovery.