미국의 식물유래약용물질(Plant-Made Pharmaceuticals, PMPs)의 안전성 규제

김태산,원소윤,이근표,류태훈,진용문,이길복,김현준 한국국제농업개발학회 2005 韓國國際農業開發學會誌 Vol.17 No.1

1. 식물유래 약용물질 (PMP)은 살아있는 식물에서 생산된 치료용 단백질로, 발효조에서 세포계통을 이용하는 것보다 적은 비용으로 높은 순도의 단백질을 생산할 수 있어 이에 대한 연구개발이 확대될 전망이다. 2. 식물유래 약용물질의 재배시험을 감독하는 주관부서는 미농무부(USDA)의 동식물 검역청(APHIS)이다. 3. PMP의 생산에는 알팔파. 옥수수, 벼 잇꽃과 담배 등이 이용되고 있다. 4. 현재 상업화된 PMP는 없으나 ProdiGene, Inc사 등 몇몇 생명공학 회사에서 이들의 연구개발이 진행되고 있다. 5. 2002년에 PMP 재배시험은 130에이커 규모로 34개 시험장에서 20건이 허가 되었으며 주별로는 애리조나, 네브라스카 등 14주에서 시험이 이루어 졌다. 6. 미국 USDA의 PMP 재배 지침에 의하면 PMP의 재배생산에는 안전성확보를 위한 별도의 전용장비를 필요로 하며 파종에서 생산까지 엄격하게 관리된다. 7. 미국 USDA의 APHIS는 2002년 PMP 옥수수를 생산하는 ProdiGene, Inc사에 대하여 2건의 포장시험허가 위반사항을 적발하여 벌금 조치를 한바있다. Plant-made pharmaceuticals(PMPs) are therapeutic agents(pharmaceutical proteins) produced in genetically engineered plants. To yield these valuable products plants offer several advantages that include large-scale production capacity at a reduced cost, equivalent purity/activity to other manufacturing systems, and freedom from contamination with animal pathogens, prions, or disease-causing germs. But there are risks of contamination of the food supply and unintended effects on ecosystems. In the U.S. PMPs are regulated under stringent requirement of the U.S. Department of Agriculture(USDA) and the Food and Drug Administration(FDA). In this article, contamination incident with PMP corn engineered by ProdiGene, Inc will be briefly introduced and regulations of PMPs will be discussed.

Cell-Interactive Polymers for Tissue Engineering

Lee, Kuen Yong,Mooney, David J. The Korean Fiber Society 2001 Fibers and polymers Vol.2 No.2

Tissue engineering is one exciting approach to treat patients who need a new organ or tissue. A critical element in this approach is the polymer scaffold, as it provides a space for new tissue formation and mimics many roles of natural extra-cellular matrices. In this review, we describe several design parameters of polymer matrices that can significantly affect cellular behavior, as well as various polymers which are frequently used to date or potentially useful in many tissue engineering applications. Interactions between cells and polymer scaffolds, including specific receptor-ligand interactions, physical and degradation feature of the scaffolds, and delivery of soluble factors, should be considered in the design and tailoring of appropriate polymer matrices to be used in tissue engineering applications, as these interactions control the function and structure of engineered tissues.

Design Parameters of Polymers for Tissue Engineering Applications

Lee, Kuen-Yong The Polymer Society of Korea 2005 Macromolecular Research Vol.13 No.4

The loss or failure of an organ or tissue can occur because of accident or disease, for which tissue or organ transplantation is a generally accepted treatment. However, this approach is extremely limited due to donor shortage. Tissue engineering is a new and exciting strategy, in which patients who need a new organ or tissue are supplied with a synthetic organ or tissue. In this approach, tissues are engineered using a combination of the patient's own cells and a polymer scaffold. The polymer scaffold potentially mimics many roles of extracellular matrices in the body. Various polymers have been studied and utilized to date in tissue engineering approaches. However, no single polymer has been considered ideal for all types of tissues and approaches. This paper discusses the design parameters of those polymers potentially useful in tissue regeneration.

Controlled delivery of heat shock protein using an injectable microsphere/hydrogel combination system for the treatment of myocardial infarction

Lee, Jangwook,Tan, Cheau Yih,Lee, Sang-Kyung,Kim, Yong-Hee,Lee, Kuen Yong Elsevier 2009 Journal of controlled release Vol.137 No.3

<P><B>Abstract</B></P><P>Myocardial infarction causes a high rate of morbidity and mortality worldwide, and heat shock proteins as molecular chaperones have been attractive targets for protecting cardiomyoblasts under environmental stimuli. In this study, in order to enhance the penetration of heat shock protein 27 (HSP27) across cell membranes, we fused HSP27 with transcriptional activator (TAT) derived from human immunodeficiency virus (HIV) as a protein transduction domain (PTD). We loaded the fusion protein (TAT-HSP27) into microsphere/hydrogel combination delivery systems to control the release behavior for prolonged time periods. We found that the release behavior of TAT-HSP27 was able to be controlled by varying the ratio of PLGA microspheres and alginate hydrogels. Indeed, the released fusion protein maintained its bioactivity and could recover the proliferation of cardiomyoblasts cultured under hypoxic conditions. This approach to controlling the release behavior of TAT-HSP27 using microsphere/hydrogel combination delivery systems may be useful for treating myocardial infarction in a minimally invasive manner.</P> <P><B>Graphical abstract</B></P><P>The release behavior of TAT-HSP27 from microsphere/hydrogel combination systems was controlled over time, and the released protein was useful to recover the proliferation of cardiomyoblasts under hypoxic conditions.<ce:figure></ce:figure></P>

Facile control of porous structures of polymer microspheres using an osmotic agent for pulmonary delivery

Lee, Jangwook,Oh, Yu Jin,Lee, Sang Kyung,Lee, Kuen Yong Elsevier 2010 Journal of controlled release Vol.146 No.1

<P><B>Abstract</B></P><P>It has been challenging to prepare polymeric microspheres with controlled porous structures for many biomedical applications, particularly for pulmonary drug delivery. Here, we report the use of bovine serum albumin (BSA) as an osmotic agent in order to control the porous structure of poly(<SMALL>D</SMALL>,<SMALL>L</SMALL>-lactide-co-glycolide) (PLGA) microspheres prepared by a double emulsion method. BSA was useful to induce osmosis between internal and external water phases during the double emulsion process, resulting in the fabrication of microspheres with controllable, uniform porous structures. The pore size of PLGA microspheres was controlled independently from the particle size by this approach. The use of BSA as an osmotic agent reduced the initial burst of model proteins (e.g., insulin and VEGF) entrapped in the porous microspheres, and the sustained release of VEGF was achieved for two weeks <I>in vitro</I>. This approach to controlling porous structures of polymer microspheres could be useful to develop novel pulmonary drug delivery systems.</P> <P><B>Graphical abstract</B></P><P>Polymer microspheres with uniform porous structures were prepared by the use of an osmotic agent, which can control the particle size and pore size independently.<ce:figure></ce:figure></P>

Characterization of Silk Fibroin/S-carboxymethyl Kerateine Surfaces: Evaluation of Biocompatibility by Contact Angle Measurements

Lee, Kuen-Yong The Korean Fiber Society 2001 Fibers and polymers Vol.2 No.2

Surface characterization of materials has been considered critical in the development of biomaterials, as many unfavorable responses from the body occur at the interface between a material and the body component. The contact angle measurement is one means to characterize the surface properties and to correlate them to the biocompatibility of materials. In this paper, surface characteristics of silk fibroin/S-carboxymethyl kerateine, representative fibrous proteins, were investigated by contact angle measurements of ESCA. The biocompatibility of the blends was evaluated based on minimal interfacial free energy concept, and compared with other potential biomaterials. It was also hypothesized that the enhanced surface polarity of the blends was generated from the conformational transition of proteins. This approach to evaluate the biocompatibility of materials based on surface characteristics may find wide utility in many biomedical applications.

Characterization of the surface immobilized synthetic heparin binding domain derived from human fibroblast growth factor-2 and its effect on osteoblast differentiation

Lee, Jue-Yeon,Choo, Jung-Eun,Choi, Young-Sook,Lee, Kuen-Yong,Min, Do-Sik,Pi, Sung-Hee,Seol, Yang-Jo,Lee, Seung-Jin,Jo, In-Ho,Chung, Chong-Pyoung,Park, Yoon-Jeong Wiley Publishers 2007 JOURNAL OF BIOMEDICAL MATERIALS RESEARCH PART A Vol. No.

<P>Fibroblast growth factor (FGF)-2 regulates a variety of cellular functions, such as proliferation and differentiation, by binding to cell surface FGF receptors (FGFRs) in the presence of heparin proteoglycans. FGF-2 is known as a heparin-binding growth factor, but the localization of the heparin binding site has not been fully investigated until now. We used two potential heparin binding domains of FGF-2, the residues 105–111 (F105, YKRSRYT) and 119–135 (F119, KRTGQYKLGSKTGPGQK). Peptides could be stably immobilized onto the surface of tissue culture plates. Using solid phase binding assays, we demonstrated that both peptides had higher binding affinity toward heparin compared with nonbinding control sequence. The biological significance of these sites was tested by cell attachment and osteoblast differentiation studies. Cell attachment to the peptides F105 and F119 increased in a dose-dependent manner. Heparin and heparinase treatments decreased cell adhesion to both F105 and F119. This demonstrates that both F105 and F119 interact with cell-surface heparan sulfate proteoglycans, suggesting that FGF-2 has two heparin binding sites. In addition, osteoblast differentiation, confirmed by ALPase activity and mineralization, was increased by surface immobilized peptide F105 and F119. Taken together, these heparin binding peptides could be applied as biological agents enhancing osteoblast differentiation as well as surface modification tools in the tissue regeneration area, especially for bone regeneration. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2007</P>

Injectable microsphere/hydrogel hybrid system containing heat shock protein as therapy in a murine myocardial infarction model

Lee, Jangwook,Cha, Min-Ji,Lim, Kwang Suk,Kim, Jang-Kyung,Lee, Sang-Kyung,Kim, Yong-Hee,Hwang, Ki-Chul,Lee, Kuen Yong Informa UK Ltd. 2013 Journal of drug targeting Vol.21 No.9

<P>Heat shock proteins, acting as molecular chaperones, protect heart muscle from ischemic injury and offer a potential approach to therapy. Here we describe preparation of an injectable form of heat shock protein 27, fused with a protein transduction domain (TAT-HSP27) and contained in a hybrid system of poly(<SMALL>D</SMALL>,<SMALL>L</SMALL>-lactic-<I>co</I>-glycolic acid) microsphere and alginate hydrogel. By varying the porous structure of the microspheres, the release of TAT-HSP27 from the hybrid system was sustained for two weeks <I>in vitro</I>. The hybrid system containing TAT-HSP27 was intramyocardially injected into a murine myocardial infarction model, and its therapeutic effect was evaluated <I>in vivo</I>. The sustained delivery of TAT-HSP27 substantially suppressed apoptosis in the infarcted site, and improved the ejection fraction, end-systolic volume and maximum pressure development in the heart. Local and sustained delivery of anti-apoptotic proteins such as HSP27 using a hybrid system may present a promising approach to the treatment of ischemic diseases.</P>

T Cell-Specific siRNA Delivery Using Antibody-Conjugated Chitosan Nanoparticles

Lee, Jangwook,Yun, Kyoung-Soo,Choi, Chang Seon,Shin, Seung-Hwa,Ban, Hong-Seok,Rhim, Taiyoun,Lee, Sang Kyung,Lee, Kuen Yong American Chemical Society 2012 Bioconjugate chemistry Vol.23 No.6

<P>The intracellular delivery of small interfering RNA (siRNA) plays a key role in RNA interference (RNAi) and provides an emerging technique to treat various diseases, including infectious diseases. Chitosan has frequently been used in gene delivery applications, including siRNA delivery. However, studies regarding the modification of chitosan with antibodies specifically targeting T cells are lacking. We hypothesized that chitosan nanoparticles modified with T cell-specific antibodies would be useful for delivering siRNA to T cells. CD7-specific single-chain antibody (scFvCD7) was chemically conjugated to chitosan by carbodiimide chemistry, and nanoparticles were prepared by a complex coacervation method in the presence of siRNA. The mean diameter and zeta potential of the scFvCD7-chitosan/siRNA nanoparticles were approximately 320 nm and +17 mV, respectively, and were not significantly influenced by the coupling of antibody to chitosan. The cellular association of antibody-conjugated nanoparticles to CD4+ T cell lines as well as gene silencing efficiency in the cells was significantly improved compared to nonmodified chitosan nanoparticles. This approach to introducing T cell-specific antibody to chitosan nanoparticles may find useful applications for the treatment of various infectious diseases.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/bcches/2012/bcches.2012.23.issue-6/bc2006219/production/images/medium/bc-2011-006219_0006.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/bc2006219'>ACS Electronic Supporting Info</A></P>

Design Parameters of Polymers for Tissue Engineering Applications

Kuen Yong Lee 한국고분자학회 2005 Macromolecular Research Vol.13 No.4