Identification of major dietary patterns in Korean adults and their association with cancer risk in the Cancer Screening Examination Cohort.

BACKGROUND/OBJECTIVES: Cancer is the primary cause of disease-related death in Korea. The purposes of this study were to confirm the major dietary patterns and to evaluate whether there were associations between these identified dietary patterns and the risk of cancer based on data from the Cancer Screening Examination Cohort (CSEC) 2004-2008 of the National Cancer Center (NCC) of Korea. SUBJECTS/METHODS: This study included 8 024 subjects who completed a written survey on demographics and lifestyles, as well as a 3-day dietary record. Dietary patterns were identified by factor analysis using the principal component analysis method. The associations between the identified dietary patterns and cancer risk were examined using Cox proportional hazards regression models. RESULTS: During a median follow-up period of 9.0 years, 425 cancer cases were newly diagnosed. We identified 4 major dietary patterns ('rice and kimchi', 'vegetables and fish', 'fruits and dairy', and 'meats and sweets'). There was a negative relation between 'rice and kimchi' pattern and the risk of non-gastrointestinal cancers only (highest vs. lowest tertile; multivariate-adjusted hazard ratio=0.60, 95% confidence interval=0.41, 0.88). The 'fruits and dairy' pattern tended to decrease the risk of cancer, and the preventive effect was noted only for gastrointestinal cancer risk. However, there was no association after adjusting for covariates. CONCLUSIONS: The traditional dietary pattern with high consumption of rice, kimchi, soybean paste and vegetables may decrease the cancer risk among Koreans, and strategies based on the dietary pattern may effectively reduce the cancer risk.

Evaluation of semi-interpenetrating polymer networks composed of chitosan and poloxamer for wound dressing application.

We have elsewhere reported the work on the preparation of semi-interpenetrating polymer networks (SIPNs) composed of chitosan (CS) and poloxamer to improve the mechanical strength of CS sponge. This study focuses on evaluation of the CS/poloxamer SIPNs to intend for wound dressing application and the efficacy of dehydroepiandrosterone (DHEA)-loaded CS/poloxamer SIPNs in the wound model studies. The properties required for ideal wound dressing, such as equilibrium water content (EWC), water absorption (A(w)), water vapor transmission rate (WVTR), and evaporative water loss, were examined. The CS/poloxamer SIPNs were found to have a water content of 90% of their weight which could prevent the wound bed from accumulation of exudates and also have excellent water adsorption. The WVTR of CS/poloxamer SIPNs was found to be 2,508.2+/-65.7gm(-2)day(-1), indicating that the SIPNs can maintain a moist environment over wound bed in moderate to heavily exuding wound which enhances epithelial cell migration during the healing process. Also, the CS/poloxamer SIPNs in vitro assessment showed proper biodegradation and low cytotoxicity for wound dressing application. The wound healing efficacy of CS/poloxamer SIPNs as a wound dressing was evaluated on experimental full thickness wounds in a mouse model. It was found that the wounds covered with CS/poloxamer SIPNs or DHEA-loaded CS/poloxamer SIPNs were completely filled with new epithelium without any significant adverse reactions after 3 weeks. The results thus indicate that CS/poloxamer SIPNs could be employed in the future as potential wound dressing materials.

Release of ciprofloxacin from chondroitin 6-sulfate-graft-poloxamer hydrogel in vitro for ophthalmic drug delivery.

The system was designed to use Poloxamer as a vehicle for ophthalmic drug delivery using in situ gel formation property. To enhance the wound healing and cell adhesion as well as transparency of Poloxamer hydrogel, chondroitin 6-sulfate (C6S) was introduced into Poloxamer. For this purpose, mono amine-terminated Poloxamer (MATP), which was end-capped with ethylene amine group only in one side of terminal hydroxyl groups of Poloxamer, was synthesized. Subsequently, C6S-graft-Poloxamer copolymer (C6S-g-Poloxamer) was prepared by reaction between the amine groups of MATP and carboxyl groups of C6S in the presence of 1-ethyl-3-(3-dimethylaminopropyl)-carboimide (EDC). The coupling of MATP with C6S was clarified by 1H-NMR and FT-IR spectroscopy. The gelation temperature of graft copolymers was determined by measuring the temperature at which immobility of the meniscus in each solution was first noted. Release behavior of ciprofloxacin from C6S-g-Poloxamer hydrogel in vitro was investigated as a function of C6S content in the graft copolymer by a spectrophotometric assay at 287 nm using an UV spectrophotometer. Differences in the adhesion and morphology of human lens cell between Poloxamer- and C6S-g-Poloxamer-coated surfaces were also investigated. The gelation temperatures of C6S-g-Poloxamer copolymers were lowered with increasing of the concentration of the copolymer and decreasing of C6S content. The release of ciprofloxacin from the graft copolymer was sustained compared with Poloxamer itself and decreased with increasing the content of C6S in the copolymer due to the in situ gel formation of the copolymer and viscous properties of C6S. Human lens cells (B3) adhered to C6S-g-Poloxamer-coated surface were observed as transformed shapes after 2 days. The bioadhesive and thermally gelling of these graft copolymers will be expected to be an excellent drug carrier for the prolonged delivery to surface of the eye.