Silica nanoparticles on the oral delivery of insulin

Abstract

When intravenous or subcutaneous administration of insulin, various side effects or possible risks have been reported. Oral administration of insulin has significant advantages of convenience, painless and mimetic endogenous insulin pathway, and thus it presents patients compliance, protects pancreatic β cells and lessens adverse effects caused by long-term injection. This challenging oral delivery of insulin can be achieved by promising silica nanoparticles (SNs), especially mesoporous silica nanoparticles (MSNs), with controllable morphology and high loading efficiency. This review presents the synthesis and physiological behaviors of SNs such as in vivo and in vitro degradation, absorption, distribution, and excretion, as well as preparations of oral insulin based on SNs. As well, this review will provide insights for innovative oral delivery of SNs and insulin. Areas covered: Promising SNs and MSNs have gained interests for application in oral drug delivery of insulin. Expert opinion: After synthesis under proper conditions and methods, promising SNs with controllable structure and suitable stability can be synthesized. By improving permeability and penetration, achieving controlled release and adjusting physiological processes, functionalization on SNs by active groups, molecules, or polymers is necessary for oral delivery of insulin.

Role of nanostructures in improvising oral medicine

“…Recently, oral vaccination with Omp31 loaded N -trimethyl chitosan nanoparticles has been found to induce immunity against Brucella melitensis [56]. Oral administration of acid resistant Helicobacter pylori vaccine encapsulated (HP55/PLGA) nanoparticles has been reported to promote immune protection [58].…”

“…The nanoparticles, not only protect these proteins from the harsh intestinal microenvironment (from the varying pH range and digestive enzymes) and facilitate the uptake and transport of them across the gastrointestinal barriers but also improve their bioavailability [60]. An applicative example is that the risks of intravenous or subcutaneous administration of insulin can be overcome by the oral delivery of insulin via the mesoporous silica nanoparticles (MSNs) owing to their controllable morphology and high loading efficiency [58].…”

Toxicologic Evaluation for Amorphous Silica Nanoparticles: Genotoxic and Non-Genotoxic Tumor-Promoting Potential

“…Although the nanoparticles can be introduced into the biological systems through different routes (oral, inhalation, intravenous, etc. ), the oral route was chosen as the most likely route of exposure to SiO 2 NPs in this in vivo genotoxicity assay since SiO 2 NPs have been recently reported as an oral drug delivery system [ 18 ]. Throughout the study period, no mortality, clinical signs, or abnormalities in body weight ( Table S3 ) were observed following exposure to SiO 2 NPs up to 2000 mg/kg based on the maximum limit dose recommended in OECD.…”

“…The growth of nanotechnology in many fields has raised the risk of unexpected adverse effects associated with nanoparticle exposures. Especially, amorphous silicas have generated substantial interest in nanomedicine [ 14 , 15 , 17 , 18 , 44 ], but some amorphous samples were found to induce cellular damage [ 45 ] and proinflammatory responses [ 46 ]. Size-dependent pulmonary injury and neutrophilic infiltration were observed in mice that received silica particles via oropharyngeal aspiration [ 47 ].…”

“…Fused silica particles are reported to induce interleukin-1β (IL-1β) release from lipopolysaccharide (LPS)-primed mouse macrophage-like cell line RAW264.7 [ 13 ]. As another form of silica, amorphous silica has a wide range of applications including food and cosmetic industries as well as in medicine via targeted drug/DNA delivery, cancer therapy, enzyme immobilization, and in dentistry as an abrasive agent [ 14 , 15 , 16 , 17 , 18 ]. Although amorphous silica has been considered to be a less toxic form, its toxicity is still highly disputed.…”