Bioresponsive carbon nano-gated multifunctional mesoporous silica for cancer theranostics

Abstract

Designing bioresponsive nanocarriers for controlled and efficient intracellular drug release for cancer therapy is a major thrust area in nanomedicine. With recent recognition by the US FDA as a safe material for human trials, mesoporous silica nanoparticles (MSNPs) are being extensively explored as promising theranostic agents. Green fluorescent carbon quantum dots (CQDs), though known as possible alternatives for their more toxic and relatively less efficient predecessors, are less known as gate keepers for drug release control. We report for the first time an efficient bioresponse of CQDs when judiciously designed using glutathione cleavable (redox responsive) disulphide bonds. When the anticancer drug doxorubicin loaded MSNPs are capped with these CQDs, they display promising drug release control on exposure to a mimicked intracellular cancer environment. Their dual functionality is well established with good control on preventing the premature release and exceptional bio-imaging of HeLa cancer cells. Fluorescence images prove selective targeting of HeLa cells by overexpression of folate receptors from the surface functionalised folic acid ligand. Extensive characterisation using XRD, TEM, BET analysis, drug loading tests, drug release kinetics, MTT assay and fluoroscence cell imaging helps in understanding the multifunctionalities of the successful design, extending its scope with exciting prospects towards non-invasive targeted drug delivery and bio-imaging for effective cancer diagnosis and treatment.

Recent advance of carbon dots in bio-related applications

“…The heat generated by laser light by the complexes easily damage the cells which triggered the release of DOX from complexes. Prasad et al [162,163] used mesoporous silica nanoparticles as a carrier. DOX and CDs were loaded into the mesoporous silica nanoparticles and conjugated FA on the surface of nanoparticles.…”

Promising Nanocarriers for PEDF Gene Targeting Delivery to Cervical Cancer Cells Mediated by the Over-expressing FRα

“…Cervical tumor tissues over-express folate receptor α (FRα) especially in metastatic focus and recurrent tumors19, which could provide conditions for folate-mediated targeting delivery for PEDF gene. Folate-decorated nanoparticles have been reported to successfully targeting deliver low molecular weight chemotherapeutic agents20 or theranostic agents21 to cervix cancer tissues in vivo. Our group formerly constructed a novel non-viral gene vector, folate-modified nano-liposomes (FLP) which could specifically deliver therapeutic gene CLDN3 shRNA to ovarian cancer cells and thereby achieve high in vivo anti-tumor efficacy by recognizing the up-regulated FRα22.…”

Anticancer drug delivery systems based on inorganic nanocarriers with fluorescent tracers

“…Selvaraj et al reported carbon quantum dots (CQDs) functionalized mesoporous silica nanoparticle based nanotheronastic agent . Green fluorescent CQDs as gate keepers were capped onto the openings of the DOX loaded pores of MSNPs using GSH sensitive disulphide bonds.…”