Yu Seok Youn

Together with the development of nanoscience,lanthanide (Ln)-doped upconversion nanoparticles(UCNPs), which can emit UV/VIS light upon irradiation bynear-infrared laser sources, is emerging as one of the mostfavorable materials in the fi eld of nanomedicines. Lightresponsivedrug delivery is known as an effi cient strategy toachieve temporal and spatial controlled drug release. Comparedto conventional light-sensitive drug delivery systems,UCNPs are endowed with many advantages, such as deepertiss

We fabricated single-wall carbon nanotubes (SWNTs) modified with chlorine e6 (as a photosensitizing drug: Ce6) and poly(ethylene glycol) (PEG, as a polymeric stabilizer) were fabricated to develop a light-sensitive nanovehicle for tumor treatment. The carboxyl group of Ce6 and poly(ethylene glycol) (PEG) was coupled with aminated SWNT via N,N'-dicyclohexyl carbodiimide (DCC)- and N-hydroxysuccinimide (NHS)-mediated amide formation. During light irradiation, singlet oxygen generation from Ce6 cou

Biocompatible polymers have been of considerable interest in developing drug delivery systems (DDSs). However, physicochemical characterizations of the polymers and DDSs had been limited because of the difficulty in obtaining the same synthesized copolymers and achieving a similar drug loading ability with the differing properties of the drugs. Therefore, a correlational study of the relationships between copolymers and DDSs was required to estimate the properties of the DDSs and to develop opti

Nanotechnology has been applied to the oral drug delivery for enhancing bioavailability after oral administration. Numerous forms of reported nanomedicines are classified as lipid based nanomedicine (LBNM), polymer based nanomedicine (PBNM), and nanosuspension. LBNM includes self nano-emulsifying drug delivery systems, liposomes and solid lipid nanoparticle (SLN). PBNM includes polymeric nanoparticles and polymeric micelles. Unlike intravenous administration, oral administration has more complic

In this study, a poly(L-lactic acid)-b-poly(ethylene glycol) (PLLA-b-PEG) diblock copolymer modified with a sialic acid derivative (methyl-b-neuraminic acid: mNA) was prepared for the development and application of a therapeutic nanosystem with multifunctionality. The terminal carboxyl group of PEG was coupled with mNA via N,N’-dicyclohexyl carbodiimide (DCC)-and N-hydroxysuccinimide (NHS)-mediated amide formation. Polymeric micelles were formed using the diafilteration method at pH 7.4, which r

While the number and diversity of lead compoundshas increased with the development of sciencetechnologies, ca. 90 % of new chemical entities underdevelopment have shown low aqueous solubility, classifiedas class II or IV of the biopharmaceutics classificationsystem (BCS). The low aqueous solubility hinders theirclinical translations due to low bioavailability and dissolution-limited absorption of orally-administered drugs. Several technologies have been employed to improve thesolubility of poorl

In this study, we report water-soluble globular poly(ethylene glycol) (gPEG) nanoparticles for targeting mitochondria and for improved photodynamic tumor therapy. Here, gPEG (prepared after all of the π-π carbon bonds in fullerene (as a hollow core structure) were chemically combined with poly(ethylene glycol) (PEG)) was chemically linked with chlorin e6 (Ce6, as a photosensitizing anticancer drug) and iodomethyltriphenylphosphonium (IMTP). In particular, IMTP acted as a mitochondria-targeting m

Albumin has been viewed as one of the most useful and versatile carrier proteins in pharmaceutical and clinical fields. Albumin is biocompatible and non-toxic, and so can be used as a pharmaceutical carrier more safely versus many synthetic polymers. Importantly, albumin has great ability to extend circulating half-lives of short-lived peptides and protein drugs when they are properly linked because albumin is hardly filtered in the glomerulus due to its large size (*66.4 kDa). Albumin is also a

Nanocarriers with pH-sensitive functionality are of great interest in the development of pH-dependent drug release compounds in acidic tumor microenvironments. A new polyelectrolyte block copolymer, poly[(benzyl-L-aspartate)-co-(N- (3-aminopropyl) imidazole-L-aspartamide)]-poly(ethylene glycol) (PABI-PEG), was prepared by one-step modulation to produce pH-sensitive nanocarriers. PABI-PEG formed a stable nanocarrier at pH values above 7.4 and was destabilized in acidic conditions (pH 6.5) through

Albumin nanoparticles have become an attractivecancer nanomedicine platform due to their pharmaceuticaladvantages. Recently, photothermal therapy has beenextensively applied to cancer treatment due to heat-inducedtumor ablation. Herein, we fabricated albumin nanoparticles(HSA-NPs) loaded with paclitaxel (PTX), indocyanine green(ICG; a hyperthermal agent) and hyaluronidase (HAase) thatbreaks down hyaluronan, a major component of the extracellularmatrix (ECM) in tumors. Synthesis was based on asli

We developed novel poly(L-lysine) [poly(Lys)]derivative nanogels with smart drug release properties. Poly(Lys) derivative was prepared after the chemicalreaction of poly(Lys) and 3-diethylaminopropyl isothiocyanate(DEAP), and was coupled with poly(ethyleneglycol) (PEG). The obtained poly(Lys-DEAP)-b-PEG wascrosslinked by genipin (crosslinking agent) in an oil/wateremulsion condition, producing poly(Lys) derivative nanogels. These nanogels (*95 nm in diameter, pH 7.4)showed volume expansion (*200

Purpose Our goal was to increase the targetability of our nanoparticles to specific targets to increase their penetration into the tumor and to enhance immunotherapy with ketoconazole (KTZ), BMS-202, and indocyanine green (ICG)-induced photothermal therapy (PTT) for anticancer effects. Methods We prepared liposomes through a thin film formation process in which hydrophobic drugs BMS-202 and KTZ were embedded in a lipid bilayer, and ICG was embedded inside the liposomes as a hydrophilic drug. In

There is an increasing demand for the development of functional photosensitizing nano-sized drugs. Fullerene, one of the new carbon molecules, has been considered to be a useful and versatile material for this purpose. Notably, fullerenes are water-insoluble, and they readily aggregate in aqueous solution. Therefore, fullerenes usually have been coupled with water-soluble, biocompatible, biodegradable polymers (e.g., polysaccharides, proteins, and other functional polymers), achieving their impr

We developed a novel pH-sensitive microparticleusing poly(lactide-co-glycolide) (PLGA) and 3-diethylaminopropylatedpoly(L-lysine) [poly(Lys-DEAP)](pKb of DEAP ~6.5). Here, the design of the microparticletakes advantage of the unique pH-sensitive feature ofpoly(Lys-DEAP) as either a non-ionic characteristic ofDEAP moieties at pH 7.4 or an ionic characteristic ofDEAP moieties at acidic pH. In particular, the ionizedDEAP in PLGA microparticles modulated acidic pH-activatedmicroparticle-destruction

Cui, Honggang; Beloqui, Ana; Brambilla, Davide; Caliceti, Paolo; Chen, Yunching Becky; Ensign, Laura M; Kim, Jong Oh; Lammers, Twan; Miyata, Kanjiro; Oh, Yu-Kyoung; Peer, Dan; Popat, Amirali; Schiffelers, Raymond; Shi, Yang; Sun, Xun; Vader, Pieter; Yeo, Yoon; Yin, Lichen; Youn, Yu Seok; Zhong, Zhiyuan; De Smedt, Stefaan C