Silica Particles: A Novel Drug‐Delivery System

TLDR

Recent advances in drug‑delivery have produced organic carriers such as micelles, liposomes, and polymeric nanoparticles, but these suffer from instability and rapid immune clearance, whereas silica particles—especially those made via sol–gel emulsions—offer biocompatibility, stability, and ambient‑temperature processing with homogeneous drug distribution. Silica particles are fabricated by sol–gel polymerization combined with spray‑drying or emulsion chemistry, enabling easy encapsulation of bioactive molecules and independent tuning of particle size and drug release rate. In vivo studies show that these silica nanoparticles exhibit improved blood stability and sustained release of anti‑tumor agents, indicating promising efficacy for cancer therapy.

Abstract

Abstract In recent decades, significant advances in drug‐delivery systems have enabled more effective drug administration. To deliver drugs to specific organs, a range of organic systems (e.g., micelles, liposomes, and polymeric nanoparticles) have been designed. They suffer from limitations, including poor thermal and chemical stability, and rapid elimination by the immune system. In contrast, silica particles offer a biocompatible, stable, and “stealthy” alternative. Bioactive molecules can be easily encapsulated within silica particles by combining sol–gel polymerization with either spray‐drying or emulsion chemistry. Spray‐drying faces challenges, including low yield, surface segregation, and size limitations. In contrast, sol–gel emulsions enable the production of nanoparticles with homogeneous drug distribution, and permit ambient temperature processing, necessary for handling biologicals. Independent control of the size and release rate can be readily achieved. Preliminary in‐vivo experiments reveal enhanced blood stability of the nanoparticles, which, coupled with sustained release of anti‐tumor agents, show good potential for cancer treatment.