Targeted Delivery of Chemotherapeutic Agents Using Improved Radiosensitive Liquid Core Microcapsules and Assessment of Their Antitumor Effect

Delivery and Effectiveness of Carboplatin via Targeted Delivery Compared to Passive Accumulation of Intravenously Injected Particles Releasing Carboplatin upon Irradiation

In this study, nanoparticles that release anticancer drugs upon irradiation were developed. Here, MM46 and MM48 tumors in C3He/N mice were irradiated. Furthermore, the intravenously (i.v.) injected nanoparticles were tested for their ability to deliver the anticancer drug, increase the antitumor effect via a synergistic effect of combining targeted anticancer drugs with radiation and decrease adverse effects by localizing the anticancer drug. The nanoparticles were prepared by spraying a mixture of hyaluronic acid and alginate, supplemented with carboplatin, into a solution of CaCl₂ and FeCl₂ through a 0.8-lm-pore stainless mesh filter. Nanoparticles (1 × 10¹⁰) were i.v. injected and irradiated (100-KeV soft X rays, 10-40 Gy) when the accumulation of particles peaked. The nanoparticles were 547 ± 43 nm in diameter. The i.v.-injected nanoparticles accumulated around tumors. Maximum accumulations were observed 9 h post-injection. Subsequently, 10-40 Gy of radiation was administered. The accumulated nanoparticles released the carboplatin and gelatinized their outer shells, which prolonged the intra-tumor concentration of carboplatin and increased the radiation-induced synergistic antitumor effect. The localization of carboplatin by nanoparticles significantly reduced the adverse effects of the anticancer drug.

Hyaluronic acid for anticancer drug and nucleic acid delivery

Hyaluronic acid (HA) is widely used in anticancer drug delivery, since it is biocompatible, biodegradable, non-toxic, and non-immunogenic; moreover, HA receptors are overexpressed on many tumor cells. Exploiting this ligand-receptor interaction, the use of HA is now a rapidly-growing platform for targeting CD44-overexpressing cells, to improve anticancer therapies. The rationale underlying approaches, chemical strategies, and recent advances in the use of HA to design drug carriers for delivering anticancer agents, are reviewed. Comprehensive descriptions are given of HA-based drug conjugates, particulate carriers (micelles, liposomes, nanoparticles, microparticles), inorganic nanostructures, and hydrogels, with particular emphasis on reports of preclinical/clinical results.

NanoSIMS multi-element imaging reveals internalisation and nucleolar targeting for a highly-charged polynuclear platinum compound

Simultaneous multi-element imaging using NanoSIMS (nano-scale secondary ion mass spectrometry), exploiting the novel combination of (195)Pt and (15)N in platinum-am(m)ine antitumour drugs, provides information on the internalisation and subcellular localisation of both metal and ligands, and allows identification of ligand exchange.