Biomimetic nanoparticles (NPs) have been actively studied for their biological compatibility due to its distinguished abilities viz. long-term circulation, low toxicity, ease for surface modification, and its ability to avoid phagocytosis of NPs by macrophages. Coating the NPs with a variety of cell membranes bearing the immune control proteins increases drug efficacy while complementing the intrinsic advantages of the NPs. In this study, efforts were made to introduce oxophilic radiometal ⁸⁹Zr with hollow mesoporous silica nanospheres (HMSNs) having abundant silanol groups and were bioengineered with red blood cell membrane (Rm) having cluster of differentiation 47 (CD47) protein to evaluate its long-term in vivo behavior. We were successful in demonstrating the increased in vivo stability of synthesized Rm-camouflaged, ⁸⁹Zr-labelled HMSNs with the markedly reduced ⁸⁹Zr release. Rm camouflaged ⁸⁹Zr-HMSNs effectively accumulated in the tumor by avoiding phagocytosis of macrophages. In addition, re-injecting the Rm isolated using the blood of the same animal helped to overcome the immune barrier. This novel strategy can be applied extensively to identify the long-term in vivo behavior of nano-drugs while enhancing their biocompatibility.

Radioisotope Co-57 was stably incorporated into a framework of layered double hydroxide nanoparticles through isomorphous substitution. An in vitro cellular uptake test resulted in ∼45 ID% high radioactivity delivering efficiency. In vivo biodistribution demonstrated time-dependent tumor accumulation of Co-57 by LDH showing high tumor-to-organ ratios.

⁶⁴Cu and ⁶⁷Cu are theragnostic pair radionuclides with promising application in the nuclear medicine. ⁶⁴Cu is PET nuclide for the non-invasive diagnosis and ⁶⁷Cu is beta emitter for therapy of various cancers. This study discusses optimization efforts in the production of these radioactive coppers carried out with 30 MeV cyclotron. Optimized conditions include target preparation, chemical separation, and quality control. The production routes of ⁶⁴Cu and ⁶⁷Cu were studied based on the nuclear reactions of ⁶⁴Ni(p,n)⁶⁴Cu and ⁷⁰Zn(p,α)⁶⁷Cu. The produced ⁶⁴Cu and ⁶⁷Cu have >99.9% of the radionuclidic purity. The yield at the end of bombardment (EOB) of ⁶⁴Cu and ⁶⁷Cu is 28.5 MBq/μAh and ⁶⁷Cu is 0.58 MBq/μAh, respectively.

Nano-sized materials with properties that enable their internalization into target cells using passive targeting systems have been utilized with radioisotopes to track their pharmacokinetics in the body. Here, we report the incorporation of novel chelator-free Zr-89 using a hierarchical iron oxide nanocomposite (⁸⁹Zr-IONC). Characterization revealed that it had a rice-shape with a mean width of 160 nm. The surface of the ⁸⁹Zr-IONCs was coated by polyethyleneimine (PEI) and polyvinylpyrrolidone (PVP) to improve the cancer target efficacy. The biological behavior of the nanoparticles coated with the polymers differed significantly by the surface composition. Positron emission tomography measurements by the labeled Zr-89 effectively confirmed the cancer target capability and the fate of distribution in the body. We found that only PVP coated ⁸⁹Zr-IONC reached the tumor region while non-coated and PEI coated ⁸⁹Zr-IONC tended to be undesirably entirely cleared in the liver and spleen. The ⁸⁹Zr-incorporated iron oxide nanocomposite is significantly stable for radiolabeling despite various surface modifications, allowing the potential carrier to specifically target cancer cells. The strategy of utilizing the biocompatible PEI and PVP surface coating system for negative charged nanoparticles such as iron oxide will afford enhanced biological application.