Design And Synthesis Of Intelligent Drug Delivery System Based On Organic Silica Nanoparticles

In recent years, drug delivery systems (DDSs) have aroused great interestin cancer therapy due to their well performance onenhancing the solubility and stability of anticancer-drug, thus improving the therapy efficacy as well as eliminating the side-effect.Among various drug deliveries, silica nanoparticles are regarded as one of the most prospective carriers, which have been extensively applied in photodynamic/photothermaltherapy, gene therapy, and tissue engineering, owing to their favorable features, such as high surface area, chemical and thermal stability, and benign biocompatibility.With the further study of silica nanoparticles, researchersemphasizetheclinic translation of them,claiming the higher quality on their degradability and multi-function.Primarily, despite thegood histocompatibility and hemocompatibilityof silica nanoparticles, the torpid and incomplete degradation of them restricts their clinic application. In addition, researchers devote themselves into broadening the multi-function of silica nanoparticles, because of the complexity and multi-drug resistance of tumor tissue, which could decrease the efficiency. They endowed silica nanoparticles with the capacity of multi-response, multi-drug, or theranostic, and with these efforts, they could improve the adaptability of silica nanoparticles in clinic translation.To solve the problems above,we present the following strategies: i) we focused on the development of low-residue organosilica nanoparticles, which were obtained by introducing biodegradable group into the monomer. Under acid condition, the imine bonds of nanoparticles cleaved, releasing the loaded DOX. Besides, the nanoparticles would fast degrade into low molecular weight fragments and excreted more easily. As a result, there would be slight amount of residues of NPs in vivo. ?) we developed a kind of dual-responsive, including pH-response and redox-response, silica nanoparticles,based on the above one.These nanoparticles have core-shell structure, which contained pH-responsive core and redox-responsive shell. This special structure made it possible for the nanoparticles to load micromolecular drug in their inner core and macromolecular drug in their shell. Under acid condition, the pH-responsive core could be degraded rapidly and released the pre-loaded micromolecular drug; Under reduction condition, the shell could be slowly decomposed, liberating macromolecular drug. Different drug could be liberated in different condition, realizing the individual and non-interfering release of drug.