• Journal of Microbiology and Biotechnology
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• 제29권11호
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• pp.1799-1805
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• 2019

Doxorubicin (DOX) is one of the most effective anticancer agents used for the treatment of multiple cancers; however, its use is limited by its short half-life and adverse drug reactions, especially cardiotoxicity. In this study, we found that the conjugate of DOX with APTA12 (Gemcitabine incorporated G-quadruplex aptamer) was significantly more cancer selective and cytotoxic than DOX. The conjugate had an affinity for nucleolin, with higher uptake and retention into the cancer cells than those of DOX. Further, it was localized to the nucleus, which is the target site of DOX. Owing to its mechanism of action, DOX has the ability to intercalate into the nucleotides thus making it a suitable drug to form a conjugate with cancer selective aptamers such as APTA12. The conjugation can lead to selectively accumulate in the cancer cells thus decreasing its potential nonspecific as well as cardiotoxic side effects. The aim of this study was to prepare a conjugate of DOX with APTA12 and assess the chemotherapeutic properties of the conjugate specific to cancer cells. The DOX-APTA12 conjugate was prepared by incubation and its cytotoxicity in MCF-10A (non-cancerous mammary cells) and MDA-MB-231 (breast cancer cells) was assessed. The results indicate that DOX-APTA12 conjugate is a potential option for chemotherapy especially for nucleolin expressing breast cancer with reduced doxorubicin associated side effects.

• 한국전자통신학회논문지
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• 제6권6호
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• pp.965-971
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• 2011

우리나라 암 발생빈도 중 간암은 위암에 이어 두 번째로 흔한 암으로서 조기에 발견될 경우는 치료성적이 우수하여 조기 발견이 대단히 중요시된다. 본 시스템은 간암의 조기발견을 위한 생체 정보 예측 시스템으로, 간암으로 확진된 환자 와 간암이외의 대조군의 혈청을 바이오칩에 반응시켜 압타머 단백질 바이오칩 프로파일을 기계학습을 통해 분류하는 시스템이다. 본 논문에서는 총 85샘플로 구성된 간암 확진환자와 310샘플로 구성된 간암이외의 대조군의 혈액시료를 1149의 서로 다른 올리고로 구성된 압타머 단백질 바이오칩에 반응시켜 획득한 데이터를 인공신경망을 통해 분석한 결과 95.38~97.95%의 분류 성능을 보였다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.126-126
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• 2014

Label-free biomolecular assay based localized surface plasmon resonance (LSPR) of noble metal nanoparticles enables simple and rapid detection with the use of simple equipment. Nanosized metal nanoparticles exhibit a strong absorption band when the incident light frequency is resonant with the collective oscillation of the electrons, which is known as the LSPR. Here we demonstrate localized surface plasmon resonance (LSPR) substrates such as plasmonic Au nanodisks fabricated by a nanoimprinting process and gold nanorod-immobilized surfaces and their applications to highly sensitive and/or label-free biosensing. To increase detection sensitivity various bioreceptors weree designed. A single chain variable fragment (scFv) was used as a receptor to bind C-reactive protein (CRP). The results of this effort showed that CRP in human serum could be quantitatively detected lower than 1 ng/ml. Aptamers, which were immobilized on gold nanorods, were used to detect mycotoxins. The specific binding of ochratoxin A (OTA) to the aptamer was monitored by the longitudinal wavelength shift of LSPR peak in the UV-Vis spectra resulting from the changes of local refractive index near the GNR surface induced by accumulation of OTA and G-quadruplex structure formation of the aptamer. According to our results, OTA could be quantitatively detected lower than 1 nM level. Additionally, aptamer-functionalized GNR substrate was quite robust and can be regenerated many times by rinsing at 70 OC to remove bound target. During seven times of washing steps, the developed OTA sensing system could be reusable. Moreover, the proposed biosensor exhibited selectivity over other mycotoxins with an excellent recovery for detection in grinded corn samples, suggesting that the proposed LSPR based aptasensor plays an important role in label-free detection of mycotoxins.

• BMB Reports
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• 제41권7호
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• pp.511-515
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• 2008

The nucleocapsid (NC) protein of the Human Immunodeficiency Virus-1 plays a key role in viral genomic packaging by specifically recognizing the Psi($\Psi$) RNA sequence within the HIV-1 genome RNA. Recently, a novel cell-based assay was developed to probe the specific interactions in vivo between the NC and $\Psi$-RNA using E.coli cells (J. Virol. 81: 6151-55, 2007). In order to examine the extendibility of this cell-based assay to RNAs other than $\Psi$-RNA, this study tested the RNA aptamers isolated in vitro using the SELEX method, but whose specific binding ability to NC in a living cellular environment has not been established. The results demonstrate for the first time that each of those aptamer RNAs can bind specifically to NC in a NC zinc finger motif dependent manner within the cell. This confirms that the cell-based assay developed for NC-$\Psi$interaction can be further extended and applied to NC-binding RNAs other than $\Psi$-RNA.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 C
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• pp.1629-1630
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• 2006

This paper describes a micro total analysis system ($\mu$ TAS) for detecting and digesting the target protein which includes a bead based temperature controllable microchip and computer based controllers for temperature and valve actuation. We firstly combined the temperature control function with a bead based microchip and realized the on-chip sequential reactions using two kinds of beads. The PEG-grafted bead, on which RNA aptamer was immobilized, was used for capturing and releasing the target protein. The target protein can be chosen by the type of RNA aptamer. In this paper, we used the RNA aptamer of HCV replicase. The trypsin coated bead was used for digesting the released protein prior to the matrix assisted laser desorption ionization time of flight mass spectrometer (MALDI TOF MS). Heat is applied for release of the captured protein binding on the bead, thermal denaturation and trypsin digestion. PDMS microchannel and PDMS micro pneumatic valves were also combined for the small volume liquid handling. The entire procedures for the detection and the digestion of the target protein were successfully carried out on a microchip without any other chemical treatment or off-chip handling using $20\;{\mu}l$ protein mixture within 20 min. We could acquire six matched peaks (7% sequence coverage) of HCV replicase.

• Journal of Korean Biological Nursing Science
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• 제23권3호
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• pp.199-207
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• 2021

Purpose: The purpose of this study was to investigate effects of NXP031, an inhibitor of oxidation by specifically binding to the complex of DNA aptamer/vitamin C, on dopaminergic neurons loss and the reaction of microglia in an animal model of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced subchronic Parkinson's disease (PD). Methods: A subchronic PD mouse model was induced via an intraperitoneal (IP) injection of MPTP 30 mg/kg per day for five days. NXP031 (vitamin C/aptamer at 200 mg/4 mg/kg) and vitamin C at 200 mg/kg were administered via IP injections at one hour after performing MPTP injection. This process was performed for five days. Motor function was then evaluated with pole and rotarod tests, after which an immunohistochemical analysis was performed. Results: NXP031 administration after MPTP injection significantly improved motor functions (via both pole and rotarod tests) compared to the control (MPTP injection only) (p<.001). NXP031 alleviated the loss of dopaminergic neurons in the substantia nigra (SN) and striatum caused by MPTP injection. It was found to have a neuroprotective effect by reducing microglia activity. Conclusion: NXP031 can improve impaired motor function, showing neuroprotective effects on dopaminergic neurons in the SN and striatum of MPTP-induced subchronic Parkinson's disease mouse model. Results of this study suggest that NXP031 has potential in future treatments for PD and interventions for nerve recovery.

• 한국콘텐츠학회논문지
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• 제21권4호
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• pp.825-832
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• 2021

본 연구는 치주질환의 주 원인균인 P. gingivalis에 선택적으로 작용하는 특이적 앱타머를 선별하고 선별된 앱타머와 결합하는 단백질 분자를 정제 및 동정함으로써 P. gingivalis에 관한 작용기전을 규명하고자 하였다. 이를 위하여 39개의 random sequence를 갖는 DNA library를 제조하여 SELEX 방법을 이용하여 P. gingivalis에 특이성을 가진 앱타머를 선별하였으며 PCR2.1 cloning vector를 활용한 cloning을 시행하여 염기서열을 분석했다. 8종의 각기 다른 염기서열을 가진 앱타머를 선별하였고 직접적으로 작용하는 단백질을 밝혀내고자 선별된 앱타머 중 APG-3를 이용하여 modified weston blot을 시행하고 단백질을 분석한 결과 P. gingivalis에 선택적으로 결합하는 11종의 단백질을 분리, 동정하였다. 이와 같은 결과로 앱타머가 치주질환의 원인균인 P. gingivalis의 당 대사 및 세포활성억제와 관련된 단백질에 선택적으로 결합하여 부착함으로써 치주질환의 진단을 위한 센서로 가능성을 제시했다.

• 한국미생물·생명공학회지
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• 제50권3호
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• pp.328-336
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• 2022

Aptamers are short, chemically synthesized, single-stranded DNA or RNA oligonucleotides that fold into unique three-dimensional structures. In this study, we aim to determine the antibiofilm activity and binding specificity of the six polyclonal DNA aptamers (S15K3, S15K4, S15K6, S15K13, S15K15, and S15K20) on Staphylococcus aureus BPA-12 and Escherichia coli EPEC 4. Aptamer S15K6 showed the highest percentage of antibiofilm activity against S. aureus BPA-12 (37.4%) as shown by the lowest OD570 value of 0.313. Aptamer S15K20 showed the highest percentage of antibiofilm activity against E. coli EPEC 4 (15.4%) as shown by the lowest OD570 value of 0.515. Aptamers S15K13 and S15K20 showed antibiofilm activities against both S. aureus BPA-12 and E. coli EPEC4, and thus potentially have broad reactivity. Furthermore, based on the binding capacity and Kd values from our previous study, the binding specificity assay of selected polyclonal DNA aptamers (S15K3 and S15K15) against S. aureus BPA-12, E. coli EPEC 4, S. aureus BPA-6, S. agalactiae, E. coli MHA-6, and Listeria monocytogenes were performed using qPCR. Aptamers S15K3 and S15K15 showed specific binding to S. aureus BPA-12, E. coli EPEC 4, S. aureus BPA-6, and S. agalactiae, but could not bind to E. coli MHA-6 and L. monocytogenes. Therefore, this study showed that the polyclonal DNA aptamers have antibiofilm activity and were able to bind to S. aureus BPA-12 and E. coli EPEC 4 bacteria.

• Journal of Radiation Protection and Research
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• 제48권1호
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• pp.44-51
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• 2023

Background: Aptamers are currently being used in various fields including medical treatments due to their characteristics of selectively binding to specific molecules. Due to their special characteristics, the aptamers are expected to be used to remove radionuclides from a large amount of liquid radioactive waste generated during the decommissioning of nuclear power plants. The radiological effects on the aptamers should be evaluated to ensure their integrity for the application of a radionuclide removal technique. Materials and Methods: In this study, Monte Carlo N-Particle transport code version 6 (MCNP6) and Monte Carlo damage simulation (MCDS) codes were employed to evaluate the radiological effects on the aptamers. MCNP6 was used to evaluate the secondary electron spectrum and the absorbed dose in a medium. MCDS was used to calculate the DNA damage by using the secondary electron spectrum and the absorbed dose. Binding experiments were conducted to indirectly verify the results derived by MCNP6 and MCDS calculations. Results and Discussion: Damage yields of about 5.00×10^-4 were calculated for 100 bp aptamer due to the radiation dose of 1 Gy. In experiments with radioactive materials, the results that the removal rate of the radioactive ⁶⁰Co by the aptamer is the same with the non-radioactive ⁵⁹Co prove the accuracy of the previous DNA damage calculation. Conclusion: The evaluation results suggest that only very small fraction of significant number of the aptamers will be damaged by the radioactive materials in the liquid radioactive waste.

• Advances in nano research
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• 제14권4호
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• pp.313-327
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• 2023

Zinc metal organic framework (MOF_Zn)-loaded goad nanoparticles (AuNPs) sol (Au@MOF_Zn), which was characterized by TEM, Mapping, FTIR, XRD, and molecular spectrum, was prepared conveniently by solvothermal method. The results indicated that Au@MOF_Zn had a very strong catalytic effect with the nanoreaction of AuNPs formation between sodium oxalate (SO) and HAuCl4. AuNPs in the new indicator reaction had a strong resonance Rayleigh scattering (RRS) signal at 370 nm. The indicator AuNPs generated by this reaction, which had the most intense surface enhanced Raman scattering (SERS) peak at 1621 cm -1. The new SERS/RRS indicator reaction in combination with specific aptamer (Apt) to fabricate a sensitive and selective Au@MOF_Zn catalytic amplification-aptamer SERS/RRS assay platform for carbendazim (CBZ), with SERS/RRS linear range of 0.025-0.5 ng/mL. The detection limit was 0.02 ng/mL. Similarly, this assay platform has been also utilized to detect oxytetracycline (OTC) and profenofos (PF).