Self-Assembled Nanoparticles of Bile Acid-Modified Glycol Chitosans and Their Applications for Cancer Therapy

Kim Kwangmeyung,Kim Jong-Ho,Kim Sungwon,Chung Hesson,Choi Kuiwon,Kwon Ick Chan,Park Jae Hyung,Kim Yoo-Shin,Park Rang-Won,Kim In-San,Jeong Seo Young The Polymer Society of Korea 2005 Macromolecular Research Vol.13 No.3

This review explores recent works involving the use of the self-assembled nanoparticles of bile acid-modified glycol chitosans (BGCs) as a new drug carrier for cancer therapy. BGC nanoparticles were produced by chemically grafting different bile acids through the use of l-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC). The precise control of the size, structure, and hydrophobicity of the various BGC nanoparticles could be achieved by grafting different amounts of bile acids. The BGC nanoparticles so produced formed nanoparticles ranging in size from 210 to 850 nm in phosphate-buffered saline (PBS, pH=7.4), which exhibited substantially lower critical aggregation concentrations (0.038-0.260 mg/mL) than those of other low-molecular-weight surfactants, indicating that they possess high thermodynamic stability. The SOC nanoparticles could encapsulate small molecular peptides and hydrophobic anticancer drugs with a high loading efficiency and release them in a sustained manner. This review also highlights the biodistribution of the BGC nanoparticles, in order to demonstrate their accumulation in the tumor tissue, by utilizing the enhanced permeability and retention (EPR) effect. The different approaches used to optimize the delivery of drugs to treat cancer are also described in the last section.

MicroRNA-mediated non-viral direct conversion of embryonic fibroblasts to cardiomyocytes: comparison of commercial and synthetic non-viral vectors

Kim, Hyosuk,Kim, Dongkyu,Ku, Sook Hee,Kim, Kwangmeyung,Kim, Sun Hwa,Kwon, Ick Chan Informa UK (TaylorFrancis) 2017 Journal of Biomaterials Science. Polymer Edition Vol. No.

<P>Technological advances opened up new ways of directing cell fate conversion from one cell lineage to another. The direct cell conversion technique has recently attracted much attention in regenerative medicine to treat devastated organs and tissues, particularly having limited regenerative capacity such as the heart and brain. Unfortunately, its clinical application is severely limited due to a safety concern and immunogenicity of viral vectors, as human gene therapy did in the beginning stages. In this study, we examined the possibility of adopting non-viral vectors to direct cell conversion from mouse embryonic fibroblasts to induced cardiomyocytes (iCM) by transient transfection of four types of chemically synthesized microRNA mimics (miRNA-1, 133, 208, and 499). Herein, we tested several commercial and synthetic non-viral gene delivery carriers, which could be divided into three different categories: polymers [branched PEI (bPEI), bioreducible PEI (PEI-SS), deoxycholic acid-conjugated PEI (DAPEI), jetPEI T, SuperFect T], lipids (Lipofectamine 2000 T), and peptides (PepMute T). According to the analyses of physicochemical properties, cellular uptake, and cytotoxicity of the carrier/miRNA complexes, DAPEI exhibited excellent miRNA delivery efficiency to mouse embryonic fibroblasts. One week after a single treatment of DA-PEI/miRNA without other adjuvants, the cells started to express cardiomyocyte-specific markers, such as alpha-actinin and alpha-MHC, indicating the formation of cardiomyocyte-like cells. Although the overall frequency of non-viral vector induced cardiomyogenic transdifferentiation was quite low (ca. 0.2%), this study can provide compelling support to develop clinically applicable transdifferentiation techniques.</P>

Comparison of <i>in vivo</i> targeting ability between cRGD and collagen-targeting peptide conjugated nano-carriers for atherosclerosis

Kim, Manse,Sahu, Abhishek,Kim, Gi Beom,Nam, Gi Hoon,Um, Wooram,Shin, So Jin,Jeong, Yong Yeon,Kim, In-San,Kim, Kwangmeyung,Kwon, Ick Chan,Tae, Giyoong Elsevier 2018 Journal of controlled release Vol.269 No.-

<P><B>Abstract</B></P> <P>Atherosclerosis plaque is a major cause of cardiovascular diseases across the globe and a silent killer. There are no physical symptoms of the disease in its early stage and current diagnostic techniques cannot detect the small plaques effectively or safely. Plaques formed in blood vessels can cause serious clinical problems such as impaired blood flow or sudden death, regardless of their size. Thus, detecting early stage of plaques is especially more important to effectively reduce the risk of atherosclerosis. Nanoparticle based delivery systems are recognized as a promising option to fight against this disease, and various targeting ligands are typically used to improve their efficiency. So, the choice of appropriate targeting ligand is a crucial factor for optimal targeting efficiency. cRGD peptide and collagen IV targeting peptide, which binds with the α<SUB>v</SUB>β<SUB>3</SUB> integrin overexpressed in the neovasculature of the plaque and collagen type IV present in the plaque, respectively, are frequently used for the targeting of nanoparticles. However, at present no study has directly compared these two peptides. Therefore, in this study, we have prepared cRGD or collagen IV targeting (Col IV-tg-) peptide conjugated and iron oxide nanoparticle (IONP) loaded Pluronic based nano-carriers for systemic comparison of their targeting ability towards <I>in vivo</I> atherosclerotic plaque in Apolipoprotein E deficient (<I>Apo E</I> <SUP>−/−</SUP>) mouse model. Nano-carriers with similar size, surface charge, and IONP loading content but with different targeting ligands were analyzed through <I>in vitro</I> and <I>in vivo</I> experiments. Near infrared fluorescence imaging and magnetic resonance imaging techniques as well as Prussian blue staining were used to compare the accumulation of different ligand conjugated nano-caariers in the aorta of atherosclerotic mice. Our results indicate that cRGD based targeting is more efficient than Col IV-tg-peptide in the early stage of atherosclerosis.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Hydrophobically modified glycol chitosan nanoparticles as carriers for paclitaxel

Kim, Jong-Ho,Kim, Yoo-Shin,Kim, Sungwon,Park, Jae Hyung,Kim, Kwangmeyung,Choi, Kuiwon,Chung, Hesson,Jeong, Seo Young,Park, Rang-Woon,Kim, In-San,Kwon, Ick Chan Elsevier 2006 Journal of controlled release Vol.111 No.1-2

<P><B>Abstract</B></P><P>Self-assembled nanoparticles based on hydrophobically modified glycol chitosan (HGC) were prepared as a carrier for paclitaxel. HGC conjugates were prepared by chemically linking 5β-cholanic acid to glycol chitosan chains using 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide chemistry. In phosphate-buffered saline (PBS; pH 7.4), the synthesized HGC conjugates formed nano-sized particles with a diameter of 200 nm and exhibited high thermodynamic stability as reflected by their low critical aggregation concentration (0.03 mg/ml). Paclitaxel was efficiently loaded into HGC nanoparticles up to 10 wt.% using a dialysis method. The paclitaxel-loaded HGC (PTX-HGC) nanoparticles were 400 nm in diameter and were stable in PBS for 10 days. These PTX-HGC nanoparticles also showed sustained release of the incorporated of paclitaxel (80% of the loaded dose was released in 8 days at 37 °C in PBS). Owing to sustained release, the PTX-HGC nanoparticles were less cytotoxic to B16F10 melanoma cells than free paclitaxel formulated in Cremophor EL. Injection of PTX-HGC nanoparticles into the tail vein of tumor-bearing mice prevented increases in tumor volume for 8 days. Finally, PTX was less toxic to the tumor-bearing mice when formulated in HGC nanoparticles than when formulated with Cremophor EL.</P>

Injectable <i>In Situ</i>-Forming pH/Thermo-Sensitive Hydrogel for Bone Tissue Engineering

Kim, Hea Kyung,Shim, Woo Sun,Kim, Sung Eun,Lee, Kweon-Haeng,Kang, Eunah,Kim, Jong-Ho,Kim, Kwangmeyung,Kwon, Ick Chan,Lee, Doo Sung Mary Ann Liebert 2009 Tissue engineering. Part A Vol.15 No.4

<P>We developed a novel pH- and thermo-sensitive hydrogel as a scaffold for autologous bone tissue engineering. We synthesized this polymer by adding pH-sensitive sulfamethazine oligomers (SMOs) to both ends of a thermo-sensitive poly(epsilon-caprolactone-co-lactide)-poly(ethylene glycol)-poly(epsilon-caprolactone-co-lactide) (PCLA-PEG-PCLA) block copolymer, yielding a pH/thermo-sensitive SMO-PCLA-PEG-PCLA-SMO block copolymer. The synthesized block copolymer solution rapidly formed a stable gel under physiological conditions (pH 7.4 and 37 degrees C), whereas it formed a sol at pH 8.0 and 37 degrees C, making it injectable. This pH/thermo-sensitive hydrogel exhibited high biocompatibility in a Dulbecco's modified Eagle's medium extract test. Under physiological conditions, the hydrogel easily encapsulated human mesenchymal stem cells (hMSCs) and recombinant human bone morphogenetic protein-2 (rhBMP-2), with encapsulating efficiencies of about 90% and 85%, respectively. To assay for ectopic bone formation in vivo, we subcutaneously injected a polymer solution containing hMSCs and rhBMP-2 into the back of mice, after which we could observe hMSC differentiation for up to 7 weeks. Histological studies revealed mineralized tissue formation and high levels of alkaline phosphatase activity in the mineralized tissue. Therefore, this pH/thermo-sensitive SMO-PCLA-PEG-PCLA-SMO block copolymer demonstrated potential as an injectable scaffold for bone tissue engineering, with in situ formation capabilities.</P>

Induced Phenotype Targeted Therapy: Radiation-Induced Apoptosis-Targeted Chemotherapy

Lee, Beom Suk,Cho, Yong Woo,Kim, Gui Chul,Lee, Do Hee,Kim, Chang Jin,Kil, Hee Seup,Chi, Dae Yoon,Byun, Youngro,Yuk, Soon Hong,Kim, Kwangmeyung,Kim, In-San,Kwon, Ick Chan,Kim, Sang Yoon U.S. Dept. of Health, Education, and Welfare, Publ 2015 Journal of the National Cancer Institute Vol.107 No.2

<P><B>Background:</B></P><P>Tumor heterogeneity and evolutionary complexity may underlie treatment failure in spite of the development of many targeted agents. We suggest a novel strategy termed induced phenotype targeted therapy (IPTT) to simplify complicated targets because of tumor heterogeneity and overcome tumor evolutionary complexity.</P><P><B>Methods:</B></P><P>We designed a caspase-3 specific activatable prodrug, DEVD-S-DOX, containing doxorubicin linked to a peptide moiety (DEVD) cleavable by caspase-3 upon apoptosis. To induce apoptosis locally in the tumor, we used a gamma knife, which can irradiate a very small, defined target area. The in vivo antitumor activity of the caspase-3–specific activatable prodrug combined with radiation was investigated in C3H/HeN tumor-bearing mice (n = 5 per group) and analyzed with the Student’s <I>t</I> test or Mann-Whitney U test. All statistical tests were two-sided. We confirmed the basic principle using a caspase-sensitive nanoprobe (Apo-NP).</P><P><B>Results:</B></P><P>A single exposure of radiation was able to induce apoptosis in a small, defined region of the tumor, resulting in expression of caspase-3. Caspase-3 cleaved DEVD and activated the prodrug. The released free DOX further activated DEVD-S-DOX by exerting cytotoxic effects on neighboring tumor or supporting cells, which repetitively induced the expression of caspase-3 and the activation of DEVD-S-DOX. This sequential and repetitive process propagated the induction of apoptosis. This novel therapeutic strategy showed not only high efficacy in inhibiting tumor growth (14-day tumor volume [mm<SUP>3</SUP>] vs radiation alone: 848.21±143.24 vs 2511.50±441.89, <I>P</I> < .01) but also low toxicity to normal cells and tissues.</P><P><B>Conclusion:</B></P><P>Such a phenotype induction strategy represents a conceptually novel approach to overcome tumor heterogeneity and complexity as well as to substantially improve current conventional chemoradiotherapy with fewer sequelae and side effects.</P>

Synergistic antitumor effects of combination treatment with metronomic doxorubicin and VEGF-targeting RNAi nanoparticles

Kwak, Gijung,Jo, Sung Duk,Kim, Dongkyu,Kim, Hyosuk,Kim, Myung Goo,Kim, Kwangmeyung,Kwon, Ick Chan,Kim, Sun Hwa Elsevier 2017 Journal of controlled release Vol.267 No.-

<P><B>Abstract</B></P> <P>Conventional cancer treatment strategies have been aimed at eradicating all cancer cells. To this end, standard chemotherapeutic approaches have relied on the maximum tolerated dose (MTD) of cytotoxic drugs with a long off-therapy interval, leading to heavy toxic side effects accompanied by drug resistance. To avoid the problems associated with the traditional MTD chemotherapy, metronomic chemotherapy with relatively low dose continuous treatments of cytotoxic drugs has been proposed as an alternative to the predominant paradigm of directly killing all cancer cells. Low-dose metronomic (LDM) chemotherapy is expected to have not only antitumor effects without toxicity and drug resistance, but also beneficial anti-angiogenic effects by causing selective apoptosis of tumor endothelial cells. In an attempt to keep the drug resistance under control and halt exponential tumor growth, herein, we combined LDM chemotherapy with a second anti-angiogenic strategy. The selective blockade of vascular endothelial growth factor (VEGF) in combination with metronomic doxorubicin (Dox) induced synergistic antitumor effects mainly through an antiangiogenic mechanism. For specific VEGF suppression, VEGF-targeting siRNA was delivered to tumor tissue using polymerized siRNA/thiolated glycol chitosan (poly-siVEGF/tGC) nanoparticles, leading to efficient VEGF gene knockdown in tumor tissue with a sequence-specific manner. Although the single treatment with metronomic Dox and poly-siVEGF/tGC nanoparticles alone showed some antitumor activity, notably, the combination of the two therapies resulted in superb tumor regression without causing systemic toxicity or drug resistance. Thus, these results suggest that the VEGF-targeted RNAi using poly-siRNA/tGC nanoparticles in combination with LDM chemotherapy could be a promising synergistic strategy for controlling tumor growth by enhancing the efficacy of anti-angiogenesis while minimizing toxicity and drug resistance.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Conjugated polymer nanoparticles for biomedical <i>in vivo</i> imaging

Kim, Sehoon,Lim, Chang-Keun,Na, Jinhee,Lee, Yong-Deok,Kim, Kwangmeyung,Choi, Kuiwon,Leary, James F.,Kwon, Ick Chan Royal Society of Chemistry 2010 Chemical communications Vol.46 No.10

<P>Conjugated polymer nanoparticles, produced by <I>in situ</I> colloidal Knoevenagel polymerization, show advantageous properties (bright emission, colloidal/chemical stability and mesoscopic size range) that allow the successful <I>in vivo</I> application to real-time sentinel lymph node mapping in a mouse model.</P> <P>Graphic Abstract</P><P>Conjugated polymer nanoparticles, produced by <I>in situ</I> colloidal Knoevenagel polymerization, show advantageous properties that allow the successful <I>in vivo</I> application to real-time sentinel lymph node mapping in a mouse model. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=b923309a'> </P>

Structural Modified siRNAs for Systemic siRNA Delivery

Kwangmeyung Kim 한국생물공학회 2013 한국생물공학회 학술대회 Vol.2013 No.4

<i>In-vivo</i> tumor targeting of pluronic-based nano-carriers

Kim, Ja-Young,Choi, Won Il,Kim, Young Ha,Tae, Giyoong,Lee, Seung-Young,Kim, Kwangmeyung,Kwon, Ick Chan Elsevier 2010 Journal of controlled release Vol.147 No.1

<P><B>Abstract</B></P><P>Pluronic-based nano-carriers including bare forms that were composed of Pluronic F 68(NC(PF 68)) or Pluronic F 127(NC(PF 127)), and chitosan-conjugated forms (Chito-NC(PF 68) or Chito-NC(PF 127)) were prepared by photo-polymerizing two kinds of diacrylated Pluronic (F 68 and F 127) and acrylated chitosan to investigate the effect of chitosan conjugation and their physicochemical characteristics (size and hydrophilicity) of Pluronic-based nano-carriers on the tumor targeting efficiency. All of the nano-carriers were stable in serum-containing media without forming any aggregation and did not show any acute cytotoxicity to both normal (NIH3T3 fibroblast) and tumor (SCC7) cells. Chitosan conjugation did not change their sizes or thermo-sensitive properties of the nano-carriers, but significantly increased their <I>in-vitro</I> cellular uptake compared to the corresponding bare forms. The <I>in-vivo</I> tumor accumulation of these nano-carriers was optically monitored by using Cy5.5-attached nano-carriers in SCC7 tumor-bearing mice. For all cases, local accumulation of the injected nano-carriers in liver was not dominant compared to the tumor site, demonstrating good tumor targeting efficacy of the Pluronic-based nano-carriers. Among different samples, chitosan-conjugated nano-carriers showed much better tumor accumulation than bare forms, and mostly remained up to 72h, implying prolonged blood circulation and more efficient tumor accumulation. Between Chito-NC(PF 68) and Chito-NC(PF 127), Chito-NC(PF 68) showed a little better tumor accumulation and retention, suggesting the difference in Pluronic, thus difference in hydrophilicity and the size of the nano-carriers also might affect the tumor targeting. In contrast, bare nano-carriers were initially accumulated well in tumor, but they were excreted from the tumor site relatively rapidly. Therefore, chitosan-functionalization was very effective for improving the tumor targeting efficacy of Pluronic-based nano-carriers.</P> <P><B>Graphical abstract</B></P><P>Chitosan-conjugated, Pluronic-based nano-carriers were very effective for tumor targeting and prolonged circulation <I>in vivo</I>.<ce:figure></ce:figure></P>