• 대한의용생체공학회:의공학회지
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• 제43권2호
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• pp.94-101
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• 2022

Recent advancement of micro/nano technology enables the development of diverse micro/nano particle-based delivery systems. Due to the multi-functionality and engineerability, particle-based delivery system are expected to be a promising method for delivery to the target cell. Since the particle-based delivery system should be delivered to the various kinds of target cell, including the cardiovascular system, cancer cell etc., it is frequently decorated with multiple kinds of targeting molecule(s) to induce specific interaction to the target cell. The surface decorated molecules interact with the cell surface expressed molecule(s) to specifically form a firm adhesion. Thus, in this study, the probability of adhesion is estimated to predict the possibility to form a firm adhesion for the multi-ligand decorated particle-based delivery system.

• 대한의용생체공학회:의공학회지
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• 제43권1호
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• pp.61-70
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• 2022

Natural and synthetic forms of calcium phosphate cement (CPC) have been widely used in bone repair and augmentation. The major challenge of injectable CPC is to deliver the cells without cell death in order to regenerate new bone. The study objective was to investigate for the potential of stem cell-laden gelatin fibers containing injectable, nanocrystalline CPC to function as a delivery system. Gelatin noddle fiber method was developed to delivered cells into nCPC. Experimental groups were prepared by mixing cells with nCPC, mixing cell-laden gelatin fibers with nCPC and mixing cell-laden gelatin fibers containing BMP-2 with nCPC. Media diffusion test was conducted after dissolving the gelatin fibers. SEM examined the generated channels and delivered cell morphology. Fibers mixed with nCPC showed physical setting and hardening within 20 min after injection and showed good shape maintenances. The gelatin fibers mixed nCPC group had several vacant channels generated from the dissolved gelatin. Particularly, proliferation and attachment of the cells were observed inside of the channels. While live cells were not observed in the cell mixed nCPC group, cells delivered with the gelatin fibers into the nCPC showed good viability and increased DNA content with culture. Cell-laden gelatin fiber was a novel method for cell delivery into nCPC without cell damages. Results also indicated the osteogenic differentiation of gelatin fiber delivered cells. We suggest that the cell-laden gelatin fibers mixed with nCPC can be used as an injectable cell delivery vehicle and the addition of BMP-2 to enhances osteogenesis.

• Journal of Pharmaceutical Investigation
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• 제35권5호
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• pp.343-348
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• 2005

Recently, siRNA has been emerging as new therapeutic agents for various diseases such as cancers and infectious diseases. However, the evaluation for delivery systems for siRNA has not been fully done. In this study, we designed and delivered siRNA of oncogenic E6 and E7 proteins to several cell lines and tested the delivery efficiencies of various cationic nonviral delivery vectors. Of cationic delivery systems tested in this study, lipid-based Lipofectamine revealed higher delivery efficiency of siRNA to cervical cancer cell line, SiHa, compared to other delivery systems. Notably, the polyethylenimine, which showed the comparable delivery efficiencies in plasmid DNA, did not show significant delivery of siRNA in cervical cancer cells. These results indicate that the mechanisms involved in siRNA delivery might be different from those in plasmid DNA delivery, and that cationic lipid-based delivery vehicles deliver siRNA with higher efficiency to intracellular target sites.

• Korean Chemical Engineering Research
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• 제47권5호
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• pp.538-545
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• 2009

본 총설에서는 주사형프로브현미경의 원리와 응용에 관하여 간략히 설명하고 최근 본 그룹에 의하여 활발하게 연구되고 있는 나노탐침과 AFM(원자간력현미경 atomic force microscopy)을 이용한 저침습성(low-invasive) 단일세포 조작기술과 고효율 유전자 도입기술을 소개하고자 한다. 시판 AFM 탐침을 침상구조로 가공한 나노탐침과 AFM을 이용하였을 경우, 탐침의 세포삽입의 성공여부를 force-distance curve 상의 척력소실의 유무로 판단할 수 있다. 침상 나노탐침을 사용하면 대부분의 세포에서 80~90%의 고효율 세포삽입이 가능하여 마이크로인젝션용 미세관을 이용하는 경우보다 세포삽입효율이 높았다. 또한 나노탐침의 직경이 400 nm 이하의 경우에는 세포 종류에 관계없이 장시간 나노탐침의 삽입에도 세포활성에 큰 영향이 없었다. 침상나노탐침을 이용하여 DNA를 도입하였을 경우에도 기존의 DNA 도입방법과 비교하여 높은 도입효율과 유전자 발현율로 DNA를 도입할 수 있는 가능성을 확인하였다.

• BMB Reports
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• 제52권5호
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• pp.324-329
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• 2019

Recent progress in cellular reprogramming technology and lineage-specific cell differentiation has provided great opportunities for translational research. Because virus-based gene delivery is not a practical reprogramming protocol, protein-based reprogramming has been receiving attention as a safe way to generate reprogrammed cells. However, the poor efficiency of the cellular uptake of reprogramming proteins is still a major obstacle. Here, we reported key factors which improve the cellular uptake of these proteins. Purified red fluorescent proteins fused with 9xLysine (dsRED-9K) as a cell penetrating peptide were efficiently delivered into the diverse primary cells. Protein delivery was improved by the addition of amodiaquine. Furthermore, purified dsRED-9K was able to penetrate all cell lineages derived from mouse embryonic stem cells efficiently. Our data may provide important insights into the design of protein-based reprogramming or differentiation protocols.

• Journal of Microbiology and Biotechnology
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• 제15권2호
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• pp.451-454
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• 2005

Introduction of foreign genes into brain cells, such as neurons and astrocytes, is a powerful approach to study the gene function and regulation in the neuroscience field. Calcium phosphate precipitates have been shown to cause cytotoxicity in some mammalian cells and brain cells, thus leading to low transfection efficiency. Here, we describe a retrovirus-mediated gene delivery method to transduce foreign genes into brain cells. In an attempt to achieve higher gene delivery efficiency in these cells, we made several changes to the original method, including (1) use of a new packaging cell line, Phoenix ampho cells, (2) transfection of pMX retroviral DNA, (3) inclusion of 25 mM chloroquine in the transduction, and (4) 3- 5 h incubation of retroviruses with target cells. The results showed that the modified protocol resulted in a range of 40- 60% gene delivery efficiency in neurons and astrocytes. Furthermore, these results suggest the potential of the retrovirus-mediated gene delivery protocol being modified and adapted for other transfection-refractory cell lines and primary cells.

• International Journal of Oral Biology
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• 제32권1호
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• pp.7-11
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• 2007

It is difficult to introduce DNA in non-invasive manner into oral cancer cells as well as primary cells for gene manipulation and expression in vivo. So far, several methods for a gene delivery have been performed to solve this problem. Magnetofection is one of the recent methods for gene transfer, and nanoparticles are applied under a magnetic field for DNA delivery. We investigated whether the magnetofection increases the efficiency of a gene delivery into several oral cell lines. By using a plasmid coding the green fluorescent protein (GFP), the efficiency of gene transfer by magnetofection was compared with those by using the calcium phosphate and the commercial transfection agent. Indeed, the magnetofection increased the green fluorescent signal in cells, suggested that this method apparently enhance the efficiency of gene delivery without any defects in various oral cancer cell lines. Finally, we have shown that magnetofection can be a useful technique for gene delivery to difficult-to-transfect cells to perform a functional study of genes in vivo.

• Archives of Plastic Surgery
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• 제48권4호
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• pp.448-456
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• 2021

Background Locoregional stem cell delivery is very important for increasing the efficiency of cell therapy. Amnisite BA (Amnisite) is a freeze-dried amniotic membrane harvested from bovine placenta. The objective of this study was to investigate the retention of cells of the stromal vascular fraction (SVF) on Amnisite and to determine the effects of cell-loaded Amnisite in a porcine radiation-induced chronic wound model. Methods Initially, experiments were conducted to find the most suitable hydration and incubation conditions for the attachment of SVF cells extracted from pig fat to Amnisite. Before seeding, SVFs were labeled with PKH67. The SVF cell-loaded Amnisite (group S), Amnisite only (group A), and polyurethane foam (group C) were applied to treat radiation-induced chronic wounds in a porcine model. Biopsy was performed at 10, 14, and 21 days post-operation for histological analysis. Results Retaining the SVF on Amnisite required 30 minutes for hydration and 1 hour for incubation. A PKH67 fluorescence study showed that Amnisite successfully delivered the SVF to the wounds. In histological analysis, group S showed increased re-epithelialization and revascularization with decreased inflammation at 10 days post-operation. Conclusions SVFs had acceptable adherence on hydrated Amnisite, with successful cell delivery to a radiation-induced chronic wound model.

• KSBB Journal
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• 제25권6호
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• pp.497-506
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• 2010

Vaccine is a protective clinical measure capable of persuading immune system against infectious agents. Vaccine can be categorized as live attenuated and inactivated. Live attenuated vaccines activate immunity similar to natural infection by replicating living organisms whereas inactivated vaccines are either whole cell vaccines, eliciting immune response by killed organisms,or subunit vaccines, stimulating immunity by non-replicating sub cellular parts. The components of vaccine play a critical role in deciding the immune response mediated by the vaccine. The innate immune responds against the antigen component. Adjuvants represent an importantcomponent of vaccine for enhancing the immunogenicity of the antigens. Subunit vaccines with isolated fractions of killed and recombinant antigens are mostly co-administered with adjuvants. The delivery system of the vaccine is another essential component to ensurethat vaccine is delivered to the right target with right dosage form. Furthermore, vaccine delivery system ensures that the desired immune response is achieved by manipulating the optimal interaction of vaccine and adjuvantwith the immune cell. The aforementioned components along with routes of administration of vaccine are the key elements of a successful vaccination procedure. Vaccines can be administered either orally or by parenteral routes. Many groups had made remarkable efforts for the development of new vaccine and delivery system. The emergence of new vaccine delivery system may lead to pursue the immunization goals with better clinical practices.

• Korean Chemical Engineering Research
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• 제57권6호
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• pp.898-906
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• 2019

본 연구에서는 전기천공시스템에서 형광 염료를 사용한 세포 생존율 평가와 형광 염료를 전달 물질로 하여 세포 내부로의 전달 효율 평가를 통해 세포의 생존율과 전달 물질의 전달 효율 평가에 사용하기 적합한 형광 염료의 선정 및 사용에 적절한 농도에 대한 가이드라인을 제시 할 수 있는 기초 연구를 수행하였다. 형광 염료로는 Propidium Iodide와 Yo-Pro-1을 사용하였다. Propidium Iodide과 Yo-Pro-1을 사용한 세포 생존율 평가와 전달 효율의 평가에서 각 형광염료의 유세포 분석 히스토그램의 모양은 형광 염료의 종류와 사용한 농도에 따라 다른 것을 확인하였다. 이는 사용하는 형광 염료의 특성과 연관이 있는 것으로 이 결과를 통해 세포 분석에 사용하는 형광 염료의 특성에 따라 분석 결과가 달라지는 것을 알 수 있었다. 형광 염료 자체가 세포 생존률에 미치는 영향은 크지 않음을 확인하였다. 또한 두 종류 이상의 형광 염료를 사용하여 분석을 하는 경우 발생할 수 있는 형광 신호 간의 간섭 영향을 확인하였다. 간섭의 영향은 Yo-Pro-1의 농도가 높을수록 큰 것으로 확인되었으며 Propidium Iodide의 농도는 형광 신호의 간섭에 큰 영향을 미치지 않음을 확인하였다. 본 연구를 통해 형광 염료의 종류와 농도에 따라 세포 생존율 평가와 전달 효율의 평가 결과가 영향을 받는 것을 확인했으며 이는 형광 염료의 특성과 연관이 있는 것으로 판단된다. 또한, 본 연구 결과를 토대로 세포 생존율 평가와 전달 효율 평가에 적절한 형광 염료의 선정과 사용에 적절한 농도를 제시하였다.