• Journal of Adhesion and Interface
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• v.24 no.4
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• pp.113-119
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• 2023

Since it was reported that the unusual amino acid DOPA in synergy with lysine and histidine residues found in mussel adhesive proteins plays a pivotal role in mussel adhesion in underwater environments, there has been a burgeoning development of various catecholamines-based adhesives for biomedical applications. Among these, catechol-conjugated chitosan, containing catecholamine, featuring multiple catechol groups within its aminerich chitosan backbone, has found versatile utility in fields, such as tissue adhesion, wound dressing, tissue healing, hemostats, drug delivery systems, and tissue engineering scaffolds. Significantly, chitosan-catechol is a mussel-inspired material approved by both US Food and Drug Administration (FDA) and KR Ministry of Food and Drug Safety (MFDS) for its effectiveness in hemostasis. This review focuses on 1) general aspects of catechol-conjugated chitosan, highlighting catechol group integration into chitosan backbones, 2) examination of proposed mechanisms of hemostasis, and 3) exploration of diverse physical forms, including solution, hydrogels, patches, and thin films with practical applications inapplicable to hemostasis.

• The Korean Journal of Pharmacology
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• v.29 no.2
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• pp.183-188
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• 1993

Effects of glucose on the catecholamine release from the hypothalamic fragments in vitro were studied. Basal release of catecholamines was inversely related to the concentrations $(5{\sim}30\;mM)$ of glucose in the incubation medium. Glucose did not affect the 30 mM $K{^+}-stimulated$ release of catecholamine. In the presence of tetrodotoxin $(10\;{\mu}M)$, the inhibitory effect of glucose on the basal release of catecholamines was largely persisted, but the inhibitory effect of 30 mM glucose on dopamine release was largerly blocked. In the presence of both tetrodotoxin $(10\;{\mu}M)$ and desipramine $(3\;{\mu}M)$, glucose failed to affect the basal catecholamine release. The results suggest that glucose modulates the catecholamine release through a direct action on the catecholaminergic nerve terminals, as well as through a trans-synaptical action. The glucose-modulation of the catecholamine release may explain, at least in part, the diabetes-induced changes in the hypothalamic catecholamine metabolism.

• Journal of Adhesion and Interface
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• v.19 no.3
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• pp.123-128
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• 2018

As a mussel-inspired surface independent modification chemistry using catecholamine family molecule was suggested on 2007, there are tremendous efforts being done by researchers from around the world to adjust and develop diverse applications using catecholamine family. Accordingly, we will discuss about the novel method to extend catecholamine applications, which is through the functional group substitution of catecholamine molecules.

• Applied Chemistry for Engineering
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• v.33 no.2
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• pp.216-221
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• 2022

Biocompatible polysaccharide coating technology can be a promising solution to overcome unexpected diseases caused by inflammatory reactions of metallic biomaterials (e.g., stent restenosis, etc.). However, due to their inherent hydrophilicity, it is difficult to maintain the coating layer for a long time in the physiological wet-environment. Herein, catechol functionalized hyaluronic acid was synthesized and introduced to the polymeric stent (polylactic acid) as the adhesive biocoating material. Surprisingly, even with the low degree of substitution of catechol (1.26%), a significant improvement in the underwater stability was observed, confirmed by capillary experiments and spectroscopic analysis. Our results may provide an insight into the positive role of catechol molecular adhesive group in the in-vivo stability of biocoating materials.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.11a
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• pp.249-250
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• 2022

In this study, two types of chitosan-catechol polymers (a-CP and b-CP) were synthesized and mixed with polyvinyl alcohol (PVA) and sodium tetraborate decahydrate (Na₂B4O₇·10H₂O) to form hydrogels. The characteristics of these polymers were tuned by varying the pH during their syntheses, and their structures were characterized using nuclear magnetic resonance spectroscopy and ultraviolet-visible spectroscopy. Rheological and self-healing properties of hydrogels were evaluated. As a result, the viscoelastic modulus was improved due to the increased functional group content, and the self-healing property was excellent regardless of the functional group content.

• Korean Chemical Engineering Research
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• v.44 no.4
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• pp.387-392
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• 2006

(Fe, Co)/zeolite catalysts such as (Fe, Co)/NaY, (Fe, Co)/NaBeta and (Fe, Co)/HUSY were prepared by ion-exchange method and their catalytic performance was examined in the hydroxylation of phenol with $H_2O_2$ for the production of catechol. The (Fe, Co)/NaBeta catalyst showed its best performance at reaction temperature=$70^{\circ}C$, molar ratio of phenol/$H_2O_2=3$, weight ratio of phenol/catalyst=50 and weight ratio of solvent (water)/phenol=6 as 20％ of phenol conversion, 77％ of the selectivity for the hydroxylation, 70％ of the selectivity for catechol, and 2.5 of the formation ratio of catechol/hydroquinone. The (Fe, Co)/zeolite catalysts showed the reproducible activities without deactivation after repeated regeneration. The fresh and used(Fe, Co)/zeolites were characterized by XRD, UV-VIS DRS, and XPS and their catalytic performance was discussed based on these characterization results.

• Journal of Plant Biology
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• v.37 no.1
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• pp.69-76
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• 1994

The present work was conducted to examine the effect of tobacco smoke solution, and its components such as nicotine and catechol treated separately on the root tip cells of Allium cepa L The mitotic abnormalities in root tip cells treated with those three components were increased linearly, while the mitotic index was decreased following concentrations of the components. Chromosomal abnormalities showed 29.7%, 15.8% and 13.0% in the treatment of tobacco smoke solution, nicotine, and catechol, respectively. The abonormalities were included polyploid, c-mitosis, stickness at metaphase, laggard, bridge formation at anaphase or telophase, and micronucleus, abnormal nucleus at interphase, after the treatment of the components for 24 hours. hours.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1992.05a
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• pp.26-26
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• 1992

신경계의 수용체 중에서 카테콜아민 신경계의 작용을 매개하는 수용체에는 $\alpha$-, $\beta$-, D-수용채 등이 있으며 카테콜아민 신경계의 활성변화를 유발시켜 인위적으로 생리현상 변화를 초래할 목적으로 사용되는 각종 의약품 등의 효능도 결국 체내에서 이들 수용체를 경유하여 발현된다는 사실들이 밝혀지고 있다. 신약대상물질의 신속한 효능검색 이외에 수용체를 활용해야 하는 중요한 신약개발 연구는 수용체의 구조 파악과 수용체와의 결합력을 근간으로 하여 신약의 기본구조에 접근하는 방식이다. 이러한 연구에서 소기의 성과를 얻기 위해서는 수용체의 추출, 정제, 특성파악, 수용체-신호전달 체계의 상관성, 수용체 관련 질병의 분류, 수용채의 클로닝 및 대량생산 등이 동반 수행되어야 한다.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1992.05a
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• pp.38-38
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• 1992

횐쥐 적출 완류부신을 이용하여 neuronal nicotinic(NN) agonist인 DMPP와 M1-muscarinic agonist인 McN-A-343의 카테콜아민(CA) 분비 작용의 차이와 특성에 대해서 연구한 결과는 다음과 같다. DMPP (100 $\mu$M)와 McN-A-343(100 $\mu$M)은 부신정맥내로 투여시 유의한 카테콜아민 분비작용을 나타내었다. Mol농도로 비교시 McN-A-343의 CA분비작용은 DMPP의 약 1/5정도였다. DMPP의 CA분비작용은 chlorisondamine이나 desipramine 또는 $Ca_2$$^{2}$-free Krebs ＋ EGTA 관류등의 전처치로 의의있게 억제되었으나, pirenzepine, ouabain 및 physostigmine등 전처치에 의해서는 영향을 받지않았다. 그러나 atropine 전처치시 DMPP의 분비작용은 오히려 증강되었다.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.11a
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• pp.251-252
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• 2022

Chemical crosslinking is the most widely used method for hydrogel preparations. We prepared a hydrogel using chitosan catechol/polyvinyl alcohol and sodium tetraborate decahydrate (Na₂B₄O₇·10H₂O). The formation of hydrogels often presents inconsistent results and issues according to the reaction scale. Therefore, we measured and analyzed the self-healing property and viscoelasticity of hydrogels attributed to scale-up synthesis using a rheometer.