Nanotheranostics in Zebrafish Cancer Models: Insights into Targeting, Biodistribution, and Systemic Drug Delivery

Nanotheranostics have brought a new era in cancer treatment. However, obstacles to their wider use persist in the areas of biodistribution, safety profiling, and clinical translation. Consequently, for nanotechnology to work properly, it is crucial to assess its safety and potential therapeutic applications. However, the traditional mammalian models face constraints due to their high cost, ethical concerns, and low throughput. An effective substitute to overcome these restrictions in nanotheranostics research are the xenotransplant, genetic, and chemically induced zebrafish (<i><i>Danio rerio</i></i>) models. The zebrafish offers several benefits as a model organism for research into cancer treatments. Due to their short life cycle, high degree of genetic resemblance to humans, and well-studied organ systems, they are an excellent candidate for pharmacokinetic and toxicological studies. Factors including complicated pharmacokinetics, organ-specific toxicity, and unexpected <i>in vivo</i> behavior frequently impede the progress of nanotheranostics for biomedical uses, especially in cancer treatment and drug delivery. To overcome the aforementioned limitations, various nanotheranostics such as liposomes, mesoporous silica nanoparticles (NPs), magnetic NPs, exosomes, micelles, polymerosomes, etc., showed a promising outcome in enhancing drug delivery, improving therapeutic efficacy, and reducing systemic toxicity. This review discusses the utility of zebrafish larvae cancer models in evaluating nanotheranostics, with emphasis on factors influencing nanoparticle biodistribution and the potential of targeted drug delivery within these models.