Clinical translation of silica nanoparticles
Silica nanoparticles have entered clinical trials for a variety of biomedical applications, including oral drug delivery, diagnostics, plasmonic resonance and photothermal ablation therapy. Preliminary results indicate the safety, efficacy and viability of silica nanoparticles under these clinical scenarios.
Nanoparticle-based therapies have found their way into various clinical applications, with more than 30 nanoformulations approved and over 100 in clinical trials1. Furthermore, the expeditious development of two lipid nanoparticle-based COVID-19 mRNA vaccines (BNT162b2 and mRNA-1273)1 has demonstrated the potential clinical impact of nanoparticle-based therapeutics and initiated a new wave of preclinical and clinical research activities for nanoparticle-based systems. Other examples of approved nanoparticle-based formulations in the clinic include anti-cancer medications (Doxil, Abraxane, Myocet and MEPACT), contrast agents (Resovist), anaesthetics (Diprivan), antifungal drugs (AmBisome), RNAi drugs (ONPATTRO) and other vaccines (Epaxal and Inflexal V).
In addition to lipid nanoparticles, the number of approved inorganic nanoparticles has also substantially increased, making them one of the major classes of clinically used nanoparticles1. In particular, silica nanoparticles are being explored as multifunctional delivery carriers in a variety of biomedical applications, including diagnosis, sensing and drug delivery2. Mesoporous silica nanoparticles with pore sizes of 2–50 nm have beneficial properties, such as a large surface area (>1,000 m2 g−1), and tunable shapes and sizes, making them an ideal platform for diagnosis and as vehicles for drug or gene delivery2. Compared with organic nanoparticles, silica nanoparticles have a higher loading capacity, particularly for biologics, good mechanical stability, and they can be tuned to control drug release in response to internal (for example, pH, enzyme and bacteria) and/or external (for example, pH, light, heat and magnetic field) stimuli2. As a material, colloidal silica has been used in tablet manufacturing as a glidant for decades and is generally recognized as safe by the US Food and Drug Administration (FDA). In addition, the commonly used food additive E551 is composed of 100 nm silica nanoparticles. Consequently, various silica nanoparticle-based formulations are now in phase I and phase II clinical trials.
Article information: Janjua, T.I., Cao, Y., Yu, C. et al. Clinical translation of silica nanoparticles. Nat Rev Mater (2021). https://doi.org/10.1038/s41578-021-00385-x