Towards multifunctional, targeted drug delivery systems using mesoporous silica nanoparticles – opportunities & challenges

Abstract

One of the big challenges of medicine today is to deliver drugs specifically to defected cells. Nanoparticulate drug carriers have the potential to answer to this call, as nanoparticles can cross physiological barriers and access different tissues, and also be provided in a targetable form aimed at enhancing cell specificity of the carrier. Recent developments within material science and strong collaborative efforts crossing disciplinary borders have highlighted the potential of mesoporous silica nanoparticles (MSNs) for such targeted drug delivery. Here we outline recent advances which in this sense push MSNs to the forefront of drug delivery development. Relatively straightforward inside-out tuning of the vehicles, high flexibility, and potential for sophisticated release mechanisms make these nanostructures promising candidates for targeted drug delivery such as 'smart' cancer therapies. Moreover, due to the large surface area and the controllable surface functionality of MSNs, they can be controllably loaded with large amounts of drugs and coupled to homing molecules to facilitate active targeting, simultaneously carrying traceable (fluorescent or magnetically active) modalities, also making them highly interesting as theragnostic agents. However, the increased relative surface area and small size, and flexible surface functionalization which is beneficially exploited in nanomedicine, consequently also includes potential risks in their interactions with biological systems. Therefore, we also discuss some safety issues regarding MSNs and highlight how different features of the drug delivery platform influence their behaviour in a biological setting. Addressing these burning questions will facilitate the application of MSNs in nanomedicine.

pH-controlled Release System for Curcumin based on Functionalized Dendritic Mesoporous Silica Nanoparticles

“…DDSs can improve the bioavailability of poorly water-soluble drugs via preventing premature degradation and enhancing uptake, leading to maintain the desirable controlled drug release and reducing side effects by targeting medicine to specified places [1]. Since mesoporous silica nanoparticles (MSNs) have been reported as a drug delivery systems for the first time [2], they became widely popular inorganic nano-carriers in DDSs [3][4][5][6][7][8][9][10][11][12]. MSNs have several attractive properties including their straightforward synthesis, large surface area, porous structure, silanol-containing surface that lead to facile functionalization chemistry, chemical and mechanical stability, biocompatibility and low-toxicity [13][14][15].…”

Glutathione-sensitive nanoplatform for monitored intracellular delivery and controlled release of Camptothecin

“…[4][5][6][7] Here, redox-sensitive, disulfide-based mechanisms have shown significant efficiency for selective intracellular release, based mainly in glutathione-driven cleavage. 8,9 Otherwise, mesoporous silica nanoparticles (MSN) have been proposed for the delivery and controlled release of small therapeutic molecules and for theranostic systems, due to their large surface area, tunable pore size, multifunctionality and good biocompatibility, [10][11][12][13] and they look like good candidates as vehicles for the delivery of covalently linked anticancer compounds such as camptothecin and paclitaxel. 14,15 Unfortunately, the direct coupling of these molecules to an inorganic nanoparticle is circumvented by the reduced therapeutic activity of the structure-modified derivatives.…”

Molecular characterization of drug´s nanocarriers based on plasmon-enhanced spectroscopy: Fluorescence (SEF) and Raman (SERS)

“…Al igual que el dióxido de silicio [11,12] es biocompatible, pero presenta una mayor biodegradabilidad, requisitos ambos imprescindibles cuando se trata de fabricar sistemas de liberación controlada de fármacos para uso in vivo. El PSi presenta otra ventaja adicional y es que su fotoluminiscencia en la región visible del espectro electromagnético descubierta por Canham en 1990 [13] puede servir como señal indicadora de la presencia del fármaco transportado, siempre y cuando éste se encuentre debidamente inmovilizado en la superficie del PSi, lo que habitualmente requiere una adecuada funcionalización de la misma [14].…”