금속 증착에 의한 전도성 고분자 멤브레인 제작 및 대전된 나노 입자의 여과

박지효,강도현,윤재성,유영은,한흥남,김관오 한국소성·가공학회 2023 한국소성가공학회 학술대회 논문집 Vol.2023 No.5

원전 안전성 향상을 위한 리스크정보활용체계 도입 필요성에 대한 고찰

박지효,김자경,이재중 한국에너지학회 2024 한국에너지공학회 학술발표회 Vol.2024 No.5

개정향풀 추출물의 향장학적 활성 평가

박지효,이지안 중소기업융합학회 2021 융합정보논문지 Vol.11 No.1

본 연구에서는 개정향풀 열수추출물 (AW)과 메탄올추출물 (AM)의 기능성 화장품 활성을 조사하였다. DPPH 항산화 활성 결과에서 열수추출물은 90.5%의 높은 라디컬 소거 활성 (IC50 37.717±8.209 ㎍/mL)을 나타 냈으며, ABTS 항산화 활성은 96.2%로 매우 높았으며, 이때 IC50은 185.244 ± 12.602 ㎍/mL이었다. 대식세포 RAW264.7에서 두 추출물은 LPS에 의한 NO, TNF-α, IL-6의 생성 및 iNOS 발현을 유의하게 억제하였다. 모든 추출물의 농도에서 세포독성은 거의 없었다. 수렴활성 결과 열수추출물이 74.33±2.48 mg/mL로 높은 수렴효능 을 보였다. 따라서 이러한 결과들을 통하여 개정향풀 추출물은 항산화제, 항염 및 수렴제와 같은 미용 목적을 위한 천연제품, 식품첨가제 등 건강 증진에 기여할 것으로 기대된다. In this study, the functional cosmetic activity of hot-water (AW) and methanol(AM) extracts from Apocynum lancifolium Russanov are examined. In the DPPH antioxidant activity test, the AW extract showed the highest inhibition rate of 90.5% (IC50 37.717 ± 8.209 ㎍/mL) and the antioxidative activity of ABTS showed a high activity in the AW extract with an IC50 of 185.244 ± 12.602 ㎍/mL and 96.2%, respectively. In RAW264.7 macrophages, the two extracts significantly suppressed the LPS-induced nitric oxide (NO), TNF-α, IL-6 production and iNOS expression level. The MTT assay measured by the cell survival rate showed that AW and AM extracts have no toxicity. The astringent activity of the AW extract exhibited the highest astringent activity with 74.336±2.487 mg/mL. Therefore, these results suggest that A. lancifolium extracts have a health promotion potential which can be further developed as food additive, natural products for cosmetic purpose.

Bioinspired surface engineering of plastic devices for rapid and convenient detection of antibiotics-resistant pathogens

박지효,홍선기 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.0

Though antibiotics are used for therapeutic purposes in humans, the use of inadequate antibiotics is accelerating the resistance. It is a public health threat that has threatens health security and increases the burden on socio-economics. Therefore, such pathogens detection is of great importance in many different areas including clinical research, food safety and so on. So far, various techniques for the pathogens diagnosis in point-of-care setting have been studied using microfluidic devices. Herein, we report a rapid, convenient, and accurate pathogen detection platform using a disposable plastic-based device. To fabricate the plastic-based device, we tuned the hydrophobic nature of plastics via nature-inspired, material-independent surface functionalization. This technique enables the selective on-surface enrichment of bacterial RNA from the lysate so that further colorimetric amplification/detection occur on the same chamber subsequently without complicated fluid transfer steps.

Recent advances in melanin-like nanomaterials in biomedical applications: a mini review

박지효,Haeram Moon,홍선기 한국생체재료학회 2019 생체재료학회지 Vol.23 No.4

Background: Melanins are a group of biopigments in microorganisms that generate a wide range of colorants. Due to their multifunctionality, including ultraviolet protection, radical scavenging, and photothermal conversion, in addition to their intrinsic biocompatibility, natural melanins and synthetic melanin-like nanomaterials have been suggested as novel nano-bio platforms in biomedical applications. Main body: Recent approaches in the synthesis of melanin-like nanomaterials and their biomedical applications have briefly been reviewed. Melanin-like nanomaterials have been suggested as endogenous chromophores for photoacoustic imaging and radical scavengers for the treatment of inflammatory diseases. The photothermal conversion ability of these materials under near-infrared irradiation allows hyperthermia-mediated cancer treatments, and their intrinsic fluorescence can be an indicator in biosensing applications. Furthermore, catecholrich melanin and melanin-like nanomaterials possess a versatile affinity for various functional organic and inorganic additives, allowing the design of multifunctional hybrid nanomaterials that expand their range of applications in bioimaging, therapy, theranostics, and biosensing. Conclusion: Melanin-like natural and synthetic nanomaterials have emerged; however, the under-elucidated chemical structures of these materials are still a major obstacle to the construction of novel nanomaterials through bottom-up approaches and tuning the material properties at the molecular level. Further advancements in melaninbased medical applications can be achieved with the incorporation of next-generation chemical and molecular analytical tools.

Feasibility of decaffeinated green tea extract as a building block for animicrobial coating

박지효,김승휘,홍선기 한국공업화학회 2020 한국공업화학회 연구논문 초록집 Vol.2020 No.-

The gallol-rich components of plant tea extracts have emerged as biocompatible antioxidants and therapeutics, but their purification methods have underdeveloped. This study aims to investigate the feasibility of decaffeinated green tea extract as a molecular building block for antimicrobial surface coating. It was measured that caffeine content was more than 50% of total mass of the green tea extract, which might interfere the metal-phenolic network formation with incorporated iron ions. We confirmed that decaffeinated green tea extract was successfully coated on titanium oxide and engineered to possesses superior antimicrobial activity, which can be further applied to various medical devices such as dental implant and cardiovascular catheter.

Bio-inspired Surface Engineering of Plastic Chips for Simple and Rapid Pathogen Detection

박지효,홍선기 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.1

With the development of simple and rapid point-of-care testing (POCT) diagnostic platform, various types of microfluidic-based chips have been designed intensively. If plastics which can be mass-produced at low cost applied to these applications, the cost of the disease diagnosis will be much reduced, thus consequently bring massive economic benefits to patients. However, the surface of plastics is known to be hydrophobic, making it difficult to use on platform for bioassays. Hence, we aim to adopt a nature-inspired surface engineering using polydopamine to modify plastic surface, which enables incorporation of a silica coating to extract nucleic acids, specifically RNA. As a demonstration, we applied surface-modified plastic chips for enrichment and in situ amplification of RNA to determine antibioticresistance of bacteria.

Biomimetic Surface Functionalization of Plastics for Bioassays

박지효,홍선기 한국공업화학회 2018 한국공업화학회 연구논문 초록집 Vol.2018 No.0

The ability of nucleic acid extraction is an essential technique in molecular biology for many downstream applications such as diagnosis of genetic diseases. Plastics can be great substrate for bioassays because it is cheap and easy to produce and have great optic property since it is transparent. However, plastics have hydrophobicity which cannot be used easily without surface functionalization. Functionalized plastic surface serves as a good platform for bioassays, but it is not that easy to achieve. In this study, transformation of hydrophobic surface of plastics to hydrophilic surface with bio-inspired coating will be shown. In addition, nucleic acid extractions using variety types of functionalized plastic substrates will be addressed.

방석나물 추출물과 그 분획물의 항산화, 항염 및 피부 보호 효능

박지효,이지안 국제보건미용학회 2023 국제보건미용학회지 Vol.17 No.2

This study aims to assess the anti-oxidant, anti-inflammatory, and anti-microbial effects of Suaeda australis, which is known as halophytes. Methanol extracts of S. australis were fractioned according to the polarity with n-hexane, chloroform, ethyl acetate, n-butanol, and H2O. The anti-oxide activity of the fractions was evaluated using DPPH radical scavenging activity and total polyphenol content. All solvent fractions showed potent anti-oxidative effects, as assessed using radical scavenging activity, with IC50 values ranging from 109.782 to 754.691 ㎍/mL. In agreement with this pattern, the total phenolic contents were widely distributed in solvent fractions, and ranged from 10.746 to 50.672 mg/g GAE of dry weight. In the evaluation of anti-inflammatory effects, LPS-activated RAW264.7 macrophages suppressed the expression of iNOS and COX-2, as well as the production of TNF-α and IL-6. Skin barrier protective effects were investigated in HaCaT cells measuring the mRNA expression of skin barrier integrity and hydration genes, namely, HBD (human β-defensin), LL-37(cathelicidin), and HAS (hyaluronic acid synthase). The ethyl acetate fraction showed the strongest skin barrier integrity. Based on the current results, S. australis was suggested to posses natural anti-oxidant and anti-inflammatory agents, and skin protective materials, indicating that it could be a valuable source of multi-functional cosmetic ingredients.

Plant-derived Surface Engineering for Antimicrobial Activity

박지효,홍선기 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.1

The humidifier disinfectant incident caused Korea to panic in 2011 was the death of many people due to the disinfectant caused pulmonary disease. Humidifier disinfectants are chemicals for the purpose of preventing microbial growth in a humidifier. As these issues emerge, a number of researches have been conducted on antimicrobials derived from nature that are non-toxic and biocompatible but have an effective bactericidal effect. Herein, we report a polyphenolic nano-thin surface coating using tannins which effectively inhibit the growth of different types of bacteria. In addition to showing the effect on its own, tannin has ability to reduce silver ions which enables a surface where tannin and reduced silver particles are co-existed for synergistic action. ** This work was carried out with the support of Cooperative Research Program for Agriculture Science and Technology Development (Project No. PJ01323201) Rural Development Administration, Republic of Korea.