Lee, KY Kwon, IC Kim, YH Jo, WH Jeong, SY 2024-01-21T17:16:08Z 2024-01-21T17:16:08Z 2021-09-05 1998-02-12 0168-3659 https://pubs.kist.re.kr/handle/201004/143237 Hydrophobically modified chitosan containing 5.1 deoxycholic acid groups per 100 anhydroglucose units was synthesized by an EDC-mediated coupling reaction. Formation and characteristics of self-aggregates of hydrophobically modified chitosan were studied by fluorescence spectroscopy and dynamic light scattering method. The critical aggregation concentration (cac) of the self-aggregate was determined by measuring the fluorescence intensity of pyrene as a fluorescent probe. The cac value in PBS solution (pH 7.2) was 1.7 x 10(-2) mg/ml. Mean diameter of self-aggregates in PBS solution (pH 7.2) was 162 +/- 18 nm with an unimodal size distribution. Charge complex formation between self-aggregates and plasmid DNA was confirmed by electrophoresis on an agarose gel. Migration of DNA on an agarose gel was completely retarded above a charge ratio (+/-) of 4/1 at pH 7.2. The free DNA dissociated from the complexes was observed by electrophoresis above pH 8.0 at a fixed charge ratio of 4/1. An efficient transfection of COS-1 cells was achieved by self-aggregates/DNA complexes. (C) 1998 Elsevier Science B.V. English ELSEVIER SCIENCE BV DRUG CARRIERS CELLS THERAPY Preparation of chitosan self-aggregates as a gene delivery system Article 10.1016/S0168-3659(97)00173-9 1 JOURNAL OF CONTROLLED RELEASE, v.51, no.2-3, pp.213 - 220 JOURNAL OF CONTROLLED RELEASE 51 2-3 213 220 scie scopus 000072419400013 2-s2.0-0032509928 Chemistry, Multidisciplinary Pharmacology & Pharmacy Chemistry Pharmacology & Pharmacy Article DRUG CARRIERS CELLS THERAPY hydrophobic modification chitosan self-aggregate plasmid DNA charge complex cell transfection