Mechanism of erosion of nanostructured porous silicon drug carriers in neoplastic tissues

Abstract

Nanostructured porous silicon (PSi) is emerging as a promising platform for drug delivery owing to its biocompatibility, degradability and high surface area available for drug loading. The ability to control PSi structure, size and porosity enables programming its in vivo retention, providing tight control over embedded drug release kinetics. In this work, the relationship between the in vitro and in vivo degradation of PSi under (pre)clinically relevant conditions, using breast cancer mouse model, is defined. We show that PSi undergoes enhanced degradation in diseased environment compared with healthy state, owing to the upregulation of reactive oxygen species (ROS) in the tumour vicinity that oxidize the silicon scaffold and catalyse its degradation. We further show that PSi degradation in vitro and in vivo correlates in healthy and diseased states when ROS-free or ROS-containing media are used, respectively. Our work demonstrates that understanding the governing mechanisms associated with specific tissue microenvironment permits predictive material performance.

PLGA-Mesoporous Silicon Microspheres for the in Vivo Controlled Temporospatial Delivery of Proteins

“…However, it has been extensively demonstrated that MSV degradation in biological conditions occurs faster in cancer therapy 35,36 than what is needed for tissue engineering applications, inciting the need for the inclusion of MSV in polymer shells or scaffolds. Panels in Figure 8 show the histological evaluation of the tissue surrounding the injection site up to 14 days after injection, compared to the control.…”

Functional role of inorganic trace elements in angiogenesis—Part II: Cr, Si, Zn, Cu, and S

“…Using the same experimental model, Nandi et al [35] described by angiography that there is well-organized transimplant angiogenesis and establishment of vascular supply across the bone defects treated with bioactive glass porous struts of 35-40 vol% porosity, prepared from a bioactive glass powder of composition (in wt%) 58.60% SiO 2 , 23.66% CaO, 3.38% P 2 O 5 , 3.78% B 2 O 3 , 1.26% TiO 2 , 9.32% Na 2 O. Nanostructured porous silicon (PSi) also undergoes enhanced degradation in diseased environment compared to healthy state, owing to up-regulation of ROS in the tumor vicinity that oxidize the silicon scaffold and catalyze its degradation [27]. The authors further showed that PSi degradation in vitro and in vivo correlated with healthy and diseased states when ROS-free or ROS-containing medium were used, respectively.…”

Perspective on Nanoparticle Technology for Biomedical Use

“…Meso-porous silica is used widely for delivery of active drug molecules based on physical or chemical adsorption. The small pores greatly enhance the capacity of drug loading [106]. In contrast, non-porous particles deliver molecules through encapsulation or conjugation.…”