Nanostructured Silicon Particles for Medical Applications

Abstract

Porous silicon (PS) which has different properties from the bulk material due to the quantum confinement effects is beside other physical properties (e.g., light emitting) bioactive or even bioresorbable. The aim of this paper is to optimise the experimental conditions for the fabrication of nanostructured Si particles and to find the best methods for attaching on its surface molecules of therapeutic interest. The selective porosification has been performed using (i) a dielectric/metallic masking layer micropatterned with corresponding etching windows; (ii) a controlled diffusion process leading to n-type islands into p-type Si substrate. The PS particles were detached from the Si substrate by switching the electrochemical etching conditions from porosification towards the electropolishing regime. Also, similar results were obtained by fabrication of PS multilayer structures subjected to an additional ultrasonation process. Different organic molecules with antitumoral effect, such as chondroitin sulphate (a sulphated glycosaminoglycan), lactoferrin (globular protein with antimicrobial activity) and N-butyldeoxynojirimycin (an imino sugar that inhibits the growth of the CT-2A brain tumour) were covalently attached on the PS particle surface using 3-aminopropyltriethoxysilane (APTS) molecule as linker. Furthermore, to complete the administration/therapy of drugs, for microparticle targeting and imaging, Fe3O4 nanoparticles were integrated in PS matrix by co-precipitation from a solution of iron salts (Fe3+/Fe2+) in alkaline medium. Microscopic and spectroscopic analyses have been used to characterize the Si microparticles. Tumoral cells were cultivated on the nanostructured PS particles and a significant decrease of the cells density was observed on all investigated samples comparatively with the blank substrate without antitumoral molecules.

Cytotoxicity and intracellular fate of PLGA and chitosan‐coated PLGA nanoparticles in Madin–Darby bovine kidney (MDBK) and human colorectal adenocarcinoma (Colo 205) cells

“…14 It has been shown that the interaction between NPs and mammalian cells (internalization and subcellular localization) varied depending on both particles properties and cell type. [15][16][17][18][19][20][21][22] Therefore, NP-cell interaction must be studied on an individual basis to establish NPs bioreactivity and cytotoxicity profiles for a desired drug delivery application.…”

Emerging nanoproteomics approaches for disease biomarker detection: A current perspective

“…The authors successfully obtained sensitivity of 3-10 μg/mL level with a linear relationship between SiNW FET signals and serum CRP level, which suggested the potential of such electrochemical biosensors for an early diagnosis of gastric cancer. In addition to the semiconductor SiNWs, nanostructured silicon particles have also been used in cancer diagnosis and treatment [95,96]. Detection of multiple biomarkers simultaneously with high sensitivity and selectivity under clinically relevant conditions is important for cancer diagnosis.…”

Fabrication and in vitro testing of porous silicon microcarriers

“…Freestanding films were lifted-off from the substrate by increasing ten times the current density to 200 mA/cm 2 . At this point, the freestanding PS layers are fractured into small microparticles by ultrasonication in ethanol for about 20 minutes [5]. The obtained silicon microparticles morphology were morphologically analyzed using field emission gun scanning electron microscopy (FEG-SEM) -Nova NanoSEM 630 -and their image is shown in figure 1.…”