title: Evaluation of anti-inflammatory drug-conjugated silicon quantum dots: their cytotoxicity and biological effect.
abstract: Silicon quantum dots (Si-QDs) have great potential for biomedical applications, including their use as biological fluorescent markers and carriers for drug delivery systems. Biologically inert Si-QDs are less toxic than conventional cadmium-based QDs,  and can modify the surface of the Si-QD with covalent bond. We synthesized  water-soluble alminoprofen-conjugated Si-QDs (Ap-Si). Alminoprofen is a non-steroid anti-inflammatory drug (NSAID) used as an analgesic for rheumatism. Our results showed that the "silicon drug" is less toxic than the control Si-QD and the original drug. These phenomena indicate that the condensed surface integration of ligand/receptor-type drugs might reduce the adverse interaction between the cells and drug molecules. In addition, the medicinal effect of the Si-QDs (i.e., the inhibition of COX-2 enzyme) was maintained compared to that of the original drug. The same drug effect is related to the integration ratio of original drugs, which might control the binding interaction between COX-2 and the silicon drug. We conclude that drug conjugation with biocompatible Si-QDs is a potential method for functional pharmaceutical drug development.
authors.affiliation: Vice Director-General's Lab, Research Institute, National Center for Global Health and Medicine, Tokyo 162-8655, Japan. hanada@ri.ncgm.go.jp.
authors.forename: Sanshiro
authors.initials: S
authors.lastname: Hanada
authors.forename: Kouki
authors.initials: K
authors.lastname: Fujioka
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Futamura
authors.forename: Noriyoshi
authors.initials: N
authors.lastname: Manabe
authors.forename: Akiyoshi
authors.initials: A
authors.lastname: Hoshino
authors.forename: Kenji
authors.initials: K
authors.lastname: Yamamoto
mesh_terms: D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000737:chemistry* / Q000494:pharmacology; D016718:Arachidonic Acid / Q000378:metabolism; D055162:Biocatalysis / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D051546:Cyclooxygenase 2 / Q000378:metabolism; D052246:Cyclooxygenase 2 Inhibitors / Q000737:chemistry / Q000494:pharmacology; D015237:Dinoprost / Q000378:metabolism; D004353:Drug Evaluation, Preclinical; D004797:Enzyme-Linked Immunosorbent Assay; D056945:Hep G2 Cells; D006801:Humans; D007700:Kinetics; D046529:Microscopy, Electron, Transmission; D011422:Propionates / Q000737:chemistry* / Q000494:pharmacology; D066244:Proton Magnetic Resonance Spectroscopy; D045663:Quantum Dots; D012825:Silicon / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D052246:Cyclooxygenase 2 Inhibitors; D011422:Propionates; C027953:alminoprofen; D016718:Arachidonic Acid; D015237:Dinoprost; D051546:Cyclooxygenase 2; D012825:Silicon