Silica-based nanoparticles as drug delivery systems: Chances and challenges

Silica-based nanoparticles are used as excipients in pharmaceutical technology. Recently, mesoporous silica nanoparticles have emerged as drug delivery systems. Their porous structure enables the high drug-loading of drugs with poor water solubility. The silica matrix protects entrapped drugs against enzymatic degradation. Furthermore, the premature release of drugs is hindered by pore-gating strategies. Adding a targeting ligand to the silica-based nanoparticles directs them to diseased cells and can diminish side-effects in healthy cells. Silica-based nanoparticles are preferably injected intravenously, since this administration route lacks the disadvantages of oral, dermal, and pulmonary delivery. Once injected, silica-based nanoparticles encounter blood cells and complement proteins. Complement protein binding, hemolysis, and coagulation are challenges for drug delivery systems, because this reduces their efficacy and also challenges their safety. Consequently, hemocompatibility testing is a must for nano drug carriers. This chapter provides an overview of the chances and challenges for silica-based nanoparticles in intravenous drug delivery.