title: Minimalism in fabrication of self-organized nanogels holding both anti-cancer drug and targeting moiety.
abstract: Recent researches to develop nano-carrier systems in anti-cancer drug delivery have focused on more complicated design to improve therapeutic efficacy and to reduce side effects. Although such efforts have great impact to biomedical science and engineering, the complexity has been a huddle because of clinical and economic problems. In order to overcome the problems, a simplest strategy to fabricate nano-carriers to deliver doxorubicin (DOX) was proposed in the present study. Two significant subjects (i) formation of nanoparticles loading and releasing DOX and (ii) binding specificity of them to cells, were examined. Folic acid (FA) was directly coupled with pullulan (Pul) backbone by ester linkage (FA/Pul conjugate) and the degree of substitution (DS) was varied, which were confirmed by 1H NMR and UV spectrophotometry. Light scattering results revealed that the nanogels possessed two major size distributions around 70 and 270 nm in an aqueous solution. Their critical aggregation concentrations (CACs) were less than 10 microg/mL, which are lower than general critical micelle concentrations (CMCs) of low-molecular-weight surfactants. Transmission electron microscopy (TEM) images showed well-dispersed nanogel morphology in a dried state. Depending on the DS, the nanogels showed different DOX-loading and releasing profiles. The DOX release rate from FA8/Pul (with the highest DS) for 24h was slower than that from FA4/or FA6/Pul, indicating that the FA worked as a hydrophobic moiety for drug holding. Cellular uptake of the nanogels (KB cells) was also monitored by confocal microscopy. All nanogels were internalized regardless of the DS of FA. Based on the results, the objectives of this study, to suggest a new method overcoming the complications in the drug carrier design, were successfully verified.
authors.affiliation: Biomedical Research Center, Korea Institute of Science and Technology, 39-1 Hawolgok-dong, Seongbuk-gu, Seoul 136-791, Republic of Korea.
authors.forename: Sungwon
authors.initials: S
authors.lastname: Kim
authors.forename: Kyong Mi
authors.initials: KM
authors.lastname: Park
authors.forename: Jin Young
authors.initials: JY
authors.lastname: Ko
authors.forename: Ick Chan
authors.initials: IC
authors.lastname: Kwon
authors.forename: Hyeon Geun
authors.initials: HG
authors.lastname: Cho
authors.forename: Dongmin
authors.initials: D
authors.lastname: Kang
authors.forename: In Tag
authors.initials: IT
authors.lastname: Yu
authors.forename: Kwangmeyung
authors.initials: K
authors.lastname: Kim
authors.forename: Kun
authors.initials: K
authors.lastname: Na
mesh_terms: D000970:Antineoplastic Agents / Q000008:administration & dosage* / Q000737:chemistry / Q000633:toxicity; D002240:Carbohydrate Sequence; D002470:Cell Survival / Q000187:drug effects; D004317:Doxorubicin / Q000008:administration & dosage / Q000737:chemistry / Q000633:toxicity; D016503:Drug Delivery Systems; D005079:Excipients; D005492:Folic Acid; D005936:Glucans / Q000737:chemistry; D006801:Humans; D007624:KB Cells; D008027:Light; D009682:Magnetic Resonance Spectroscopy; D018613:Microscopy, Confocal; D008969:Molecular Sequence Data; D053758:Nanoparticles; D012542:Scattering, Radiation; D013056:Spectrophotometry, Ultraviolet; D013778:Tetrazolium Salts; D013844:Thiazoles
chemical_list: D000970:Antineoplastic Agents; D005079:Excipients; D005936:Glucans; D013778:Tetrazolium Salts; D013844:Thiazoles; D004317:Doxorubicin; C009109:pullulan; D005492:Folic Acid; C022616:thiazolyl blue