Sol-Gel Silica Nanoparticles in Medicine: A Natural Choice. Design, Synthesis and Products

Abstract

Silica is one of the most abundant minerals in the Earth’s crust, and over time it has been introduced first into human life and later into engineering. Silica is present in the food chain and in the human body. As a biomaterial, silica is widely used in dentistry, orthopedics, and dermatology. Recently amorphous sol-gel SiO2 nanoparticles (NPs) have appeared as nanocarriers in a wide range of medical applications, namely in drug/gene target delivery and imaging diagnosis, where they stand out for their high biocompatibility, hydrophilicity, enormous flexibility for surface modification with a high payload capacity, and prolonged blood circulation time. The sol-gel process is an extremely versatile bottom-up methodology used in the synthesis of silica NPs, offering a great variety of chemical possibilities, such as high homogeneity and purity, along with full scale pH processing. By introducing organic functional groups or surfactants during the sol-gel process, ORMOSIL NPs or mesoporous NPs are produced. Colloidal route, biomimetic synthesis, solution route and template synthesis (the main sol-gel methods to produce monosized silica nanoparticles) are compared and discussed. This short review goes over some of the emerging approaches in the field of non-porous sol-gel silica NPs aiming at medical applications, centered on the syntheses processes used.

Gold‐Speckled SPION@SiO2 Nanoparticles Decorated with Thiocarbohydrates for ASGPR1 Targeting: Towards HCC Dual Mode Imaging Potential Applications

“…The silica shell coating the OLEAM‐capped SPIONs was grown by exploiting a water‐in‐oil microemulsion approach, to obtain superparamagnetic nanostructures with a good degree of biocompatibility and colloidal stability in aqueous media . In particular, appropriate amounts of Igepal CA‐630, ammonia aqueous solution and TEOS were added, at 28 °C, in a cyclohexane dispersion of OLEAM capped SPIONs.…”

Approaches to promoting bone marrow mesenchymal stem cell osteogenesis on orthopedic implant surface

“…Sol–gel process first described 150 years ago is still receiving great attention as one of the easiest ways to develop modified materials which possess required properties and are characterized by durability and stability[ 32 ]. Hence, sol-gel process is another method for preparing bioactive ceramic coatings.…”

Trends in Degradable Mesoporous Organosilica-Based Nanomaterials for Controlling Drug Delivery: A Mini Review

“…The drug carrying possibilities of these compact silica-based nanomaterials rely on: (i) the functionalization of the drug molecules to the −OH groups from the silica surface with an extra inconvenient modification according to the chemical structure of the drugs [ 23 , 35 ]; (ii) drugs to be physisorbed on the silica nanoparticle’s surface, which will also depend on the available active surface area correlated to the nanoparticle’s diameter; or (iii) the incorporation of the payload or drug doping within the matrix during the nanoparticle’s preparation [ 36 ]. Therefore, the challenge of preparing degradable nanoparticles that can control the degradation profile in order to obtain an effective drug delivery all-in-all in an aqueous bioenvironment and in the absence of additional stimuli or reagents is still in development.…”