Hyeon Mo Cho

Antiallergic Activity Profile in Vitro RBL-2H3 and in Vivo Passive Cutaneous Anaphylaxis Mouse Model of New Sila-Substituted 1,3,4-Oxadiazoles

A new class of sila-substituted 1,3,4-oxadiazoles was synthesized and evaluated for antiallergic activity using RBL-2H3 as the in vitro model and the in vivo anaphylactic mouse model. We observed that compound 5c effectively suppressed DNP-HSA-induced mast cell degranulation, compared to carbon analogue 9, and also suppressed the expression of TNF-α mRNA and Akt phosphorylation in antigen-stimulated RBL-2H3 cells. We also studied the effect of 5c in an in vivo passive cutaneous anaphylaxis (PCA) mouse model. The suppression by 5c was more effective than that by diphenylhydramine (DPH), a typical anti-histamine drug.

Syntheses and NMR study of [(2-dimethylaminomethyl)phenyl]vinylsilane derivatives and [(2-dimethylaminomethyl)phenyl]ethylsilane derivatives

Abstract Various vinylsilanes, SiX(CHCH2)(CH3)[2-(CH3)2NCH2C6H4], and ethylsilanes, SiX(CH2CH3)(CH3)[2-(CH3)2NCH2C6H4] [X=Cl (1); OMe (2); H (3); F (4); OSiMe3 (5); NMe2 (6); Me (7)], were synthesized in order to investigate the electronic effect of vinyl group on silicon atom having an intramolecular coordination arm. The magnitude of Δδ (ethyl→vinyl for 29Si-NMR) of chlorosilane, 1, was the biggest one among 1–7. The differences of 29Si chemical shifts between vinylsilanes and ethylsilanes increased in the following order: X=Me, NMe2

Soluble polycyclosilane–polysiloxane hybrid material and silicon thin film with optical properties at 193 nm and etch selectivity

A polycyclosilane precursor was synthesized to develop soluble silicon materials and silicon thin films with optical properties at 193 nm, high silicon content, and etch selectivity for O2 and CFx plasmas. A new class of polycyclosilane–polysiloxane hybrid materials and their thin films exhibited good etch selectivity and good optical properties at 193 nm without organic absorbents.

Controlled drug release in silicone adhesive utilizing particulate additives

Polydimethylsiloxane (PDMS) based adhesives were prepared by cross-linking tetraethoxyorthosilicate (TEOS) while controlling stoichiometry with PDMS, acid catalyst, and water. Particulate additives, alginate and bentonite, were added during the cross-linking process. Cationic drug lidocaine was incorporated into the adhesive with or without additive, and the time-dependent drug release profile was evaluated in phosphate buffered saline and ethanol, respectively. According to kinetic fitting to power function and parabolic diffusion, both solvent and additive type influenced drug release. In particular, particulate additives were found to suppress or facilitate drug release in water or ethanol, respectively.