Utah Inha and Advanced Therapeutics Research Center

Incheon, South Korea

Utah Inha and Advanced Therapeutics Research Center

Incheon, South Korea
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Ramasamy T.,Utah Inha and Advanced Therapeutics Research Center | Kandhasami U.D.S.,Tamil University | Shanmugam S.,Tamil University
Brazilian Journal of Pharmaceutical Sciences | Year: 2011

The objective of the present study is to develop a colon targeted drug delivery systems for Aceclofenac using xanthan gum as a carrier. In this study, multilayer coated system that is resistant to gastric and small intestinal conditions but can be easily degraded by colonic bacterial enzymes was designed to achieve effective colon delivery of Aceclofenac. The xanthan gum, the drug and the physical mixture were characterized by Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). All the formulations were evaluated for hardness, drug content uniformity and other physical properties. Release aspects of Aceclofenac in simulated gastrointestinal fluid and colonic fluid with enzymes were investigated. From these results, Eudragit coated system exhibited gastric and small intestinal resistance to the release of Aceclofenac. The rapid increase in release of Aceclofenac in SCF was revealed as due to the degradation of the xanthan gum membrane by bacterial enzymes. The designed system could be used potentially as a carrier for colon delivery of Aceclofenac by regulating drug release in stomach and the small intestine.

Hu S.,Zhejiang University | Lee E.,Utah Inha and Advanced Therapeutics Research Center | Wang C.,University of Chinese Academy of Sciences | Wang J.,Zhejiang University | And 7 more authors.
Journal of Controlled Release | Year: 2015

Nanoformulations have been extensively explored to deliver water-insoluble drugs, but they generally use exotic new materials, for instance, amphiphilic block copolymers, which must first go through extensively clinical trials and be approved as drug excipients before any clinical uses. We hypothesize that using clinical amphiphilic drugs as surfactants to self-assemble with and thus solubilize hydrophobic drugs will lead to readily translational nanoformulations as they contain no new excipients. Herein, we show the first example of such excipient-free nanodispersions using an amphiphilic anti-tumor drug, irinotecan hydrochloride (CPT11). CPT11 self-assembles with its insoluble active parent drug, 7-ethyl-10-hydroxy camptothecin (SN38), into stable and water-dispersible nanoparticles, increasing SN38's water solubility by thousands of times up to 25mg/mL with a loading efficiency close to 100%. The versatility of this approach is also demonstrated by fabricating nanodispersions of CPT11 with other water-insoluble drugs including paclitaxel (PTX) and camptothecin (CPT). These nanodispersions have much increased bioavailability and thereby improved anti-cancer activities. Thus, this strategy, using clinically proven amphiphilic drugs as excipients to fabricate nanodispersions, avoids new materials and makes readily translational nanoformulations of hydrophobic drugs. © 2015 Elsevier B.V. All rights reserved.

Stirland D.L.,University of Utah | Matsumoto Y.,University of Tokyo | Toh K.,University of Tokyo | Kataoka K.,University of Tokyo | And 2 more authors.
Journal of Controlled Release | Year: 2016

A dose circulating through the blood at one time will have different opportunities to access the tumor compared to a dose circulating hours later. Methods to test this hypothesis allowed us to differentiate two uniquely fluorescent doses of nanoparticles (administered as a mixture or sequentially) and to measure the distribution and correlation of these nanoparticle doses in three dimensions. Multiple colocalization analyses confirm that silica nanoparticles separated into different dose administrations will not accumulate in the same location. Decreased colocalization between separate doses implies dynamic extravasation events on the scale of microns. Further, the perfusion state of different blood vessels can change across the dosing period. Lastly, analyzing the distance traveled by these silica nanoparticles in two dimensions can be an overestimation when compared with three-dimensional distance analysis. Better understanding intratumoral distribution of delivered drugs will be crucial to overcoming the various barriers to transport in solid tumors. © 2016 Elsevier B.V. All rights reserved.

Ramasamy T.,Utah Inha and Advanced Therapeutics Research Center | Ramasamy T.,Vels University | Ramasamy T.,P.A. College | Khandasami U.S.,P.A. College | And 3 more authors.
Macromolecular Research | Year: 2012

The aim of this study was to formulate and evaluate Ketoconazole-loaded solid lipid nanoparticles (KSLN) for topical application. The purpose of this study was to improve the therapeutic activity of Ketoconazole. KSLN was prepared by a hot homogenization method and characterized for shape, surface morphology, particle size, drug entrapment, cytotoxicity, and rheological analysis. The optimized formulation of solid lipid nanoparticles (SLN) was spherical in shape with a smooth surface and possessed an average size of 172.2±0.75 nm with zeta potential of -44.12±0.76 mV. To guarantee the stability of the desired SLN, they were lyophilized using cryo-protectants. The particle size of the SLN significantly enlarged for formulations which were lyophilized without the cryo-protectants. Cell viability assay performed on National Institute of Health-3-day transfer, inoculum 3×105 cells (NIH-3T3) fibroblast cells showed that properties of the SLN remain unchanged during the process of freeze-drying and were not cytotoxic. An in vitro drug release study showed that KSLN-incorporated hydrogel exhibited a sustained drug release comparing to KSLN dispersion and Ketoconazole loaded hydrogel over a 24 h period. The in vivo studies suggested that the KSLN-incorporated hydrogel was more efficient in the treatment of candidiasis. It may therefore be interpreted that the KSLN-incorporated hydrogel provides a sustained release of Ketoconazole for topical fungal infections and might be a promising delivery system to enhance the therapeutic activity of Ketoconazole.

Nadithe V.,University of Utah | Bae Y.H.,University of Utah | Bae Y.H.,Utah Inha and Advanced Therapeutics Research Center
International Journal of Biological Macromolecules | Year: 2010

Hemoglobin (Hb) conjugated with the antioxidant enzymes (SOD and CAT), by employing dicarboxymethylated poly(ethylene glycol), was designed for protection of hemoglobin against free radicals. In this study, the conjugation process was confirmed by employing SDS-PAGE and SEC techniques. The average molecular weight of the conjugates was estimated to be around 1000. kDa. The enzymatic activities of the SOD and CAT in the conjugates (Hb-SOD-CAT) after conjugation were found to retain greater than 70% and 90% of the original bioactivity. Results show that antioxidant enzymes helped minimize methemoglobin (non-carrier of oxygen) formation during the conjugation process and also during storage at 4 °C over a period of 1 month. In summary, the optimized (1:10 Hb/PEG) crosslinked conjugates with antioxidant enzymes showed protective properties from severe free radical stresses when incubated with hydrogen peroxide (0.1 and 1. mM) and xanthine (1. mM)/xanthine oxidase (10 and 20. mU/ml) system © 2010 Elsevier B.V.

Nadithe V.,University of Utah | Bae Y.H.,University of Utah | Bae Y.H.,Utah Inha and Advanced Therapeutics Research Center
Tissue Engineering - Part A | Year: 2011

A low p50 hemoglobin (Hb) (p50 indicates O2 tension at which Hb is half-saturated)-based oxygen carrier conjugated to antioxidant enzymes via dicarboxymethylated poly(ethylene glycol) (PEG) linker may have the beneficial effect in protecting pancreatic beta cells from severe hypoxia at transplantation sites. In this study, the oxygen dissociation curves, Hill plots, Bohr Effect, and oxygen content of Hb conjugates were measured. The protective effect due to incubation of Hb-conjugates (Hb/PEG molar ratio 1:10) with pancreatic beta cells (RINm5F) against hypoxia (6%, 3%, and 1% oxygen) was evaluated by an MTT assay and confocal microscopy. Quantitatively, Hb conjugates with antioxidant enzymes offered statistically significant protection (p<0.01, increased viability ∼80%) from hypoxia compared to control cells in 1% oxygen environment. Confocal images also showed that the low p50Hb conjugates with antioxidants protected RINm5F cells from hypoxia. © 2011 Mary Ann Liebert, Inc.

Jin Y.-J.,Inha University | Jeong S.,Inha University | Lee D.H.,Inha University | Lee D.H.,Utah Inha and Advanced Therapeutics Research Center
Gastrointestinal Endoscopy | Year: 2016

Background/Aims: The aim of this study was to assess the feasibility of needle-knife fistulotomy (NKF) as an initial procedure for biliary access in patients with stones in the common bile duct (CBD) who were at increased risk for post-ERCP pancreatitis (PEP). Method: Fifty-five patients who underwent ERCP with NKF for CBD stones at our institution between July 2013, and May 2015, were prospectively enrolled in this study. They had one or more of the following risk factors for PEP: young age (<60 years), female sex, or normal CBD diameter (≤9 mm). The procedure was performed by an expert biliary endoscopist (S.J.). The success rate of biliary cannulation and CBD stone removal, and the incidence rate of adverse events were assessed. Results: Seventeen patients had 1 risk factor for PEP, 27 had 2, and 11 had 3. The median procedure times for NKF and CBD stone removal after NKF were 2.1 minutes (range, 0.2-8.7 min) and 6.5 minutes (range, 1.1-28.3 min), respectively. Success rates of CBD cannulation and stone removal using NKF were 96.3% (53/55) and 92.7% (51/55), respectively. None of the patients experienced PEP. Retroperitoneal duodenal perforation occurred in 1 patient (1.8%), but it was successfully treated by conservative management. Conclusion: NKF might be feasible as an initial procedure for biliary access in patients with CBD stones who are at high risk for PEP if the procedure is performed by an expert biliary endoscopist. (Clinical trial registration number: KCT0001698.). © 2016 American Society for Gastrointestinal Endoscopy.

Kim M.,Inha University | Kim M.,Utah Inha and Advanced Therapeutics Research Center | Yang S.-G.,Utah Inha and Advanced Therapeutics Research Center | Kim J.M.,Inha University | And 3 more authors.
International Journal of Molecular Medicine | Year: 2012

Non-alcoholic steatohepatitis (NASH) is characterized by hepatocellular injury and initial fibrosis severity has been suggested as an important prognostic factor of NASH. Silymarin was reported to improve carbon tetrachloride-induced liver fibrosis and reduce the activation of hepatic stellate cells (HSC). We investigated whether silymarin could suppress the activation of HSCs in NASH induced by methionine- and choline-deficient (MCD) diet fed to insulin-resistant rats. NASH was induced by feeding MCD diet to obese diabetic Otsuka Long-Evans Tokushima Fatty (OLETF) rats. Non-diabetic Long-Evans Tokushima Otsuka (LETO) rats were fed with standard chow and served as the control. OLETF rats were fed on either standard laboratory chow, or MCD diet or MCD diet mixed with silymarin. Histological analysis of the liver showed improved non-alcoholic fatty liver disease (NAFLD) activity score in silymarin-fed MCD-induced NASH. Silymarin reduced the activation of HSCs, evaluated by counting α-smooth muscle actin (SMA)-positive cells and measuring α-SMA mRNA expression in the liver lysates as well as in HSCs isolated from the experimental animals. Although silymarin decreased α 1-procollagen mRNA expression in isolated HSCs, the anti-fibrogenic effect of silymarin was not prominent so as to show significant difference under histological analysis. Silymarin increased the nuclear translocation of nuclear factor erythroid 2-related factor 2 (Nrf2) and decreased tumor necrosis factor (TNF)-α mRNA expression in the liver. Our study suggested that the possible protective effect of silymarin in diet induced NASH by suppressing the activation of HSCs and disturbing the role of the inflammatory cytokine TNF-α.

Ahn S.,Korea Advanced Institute of Science and Technology | Lee I.-H.,Korea Advanced Institute of Science and Technology | Lee E.,Utah Inha and Advanced Therapeutics Research Center | Kim H.,Gwangju Institute of Science and Technology | And 2 more authors.
Journal of Controlled Release | Year: 2013

Despite the therapeutic potential of exendin-4 asa glucagon-like peptide-1 (GLP-1) mimetic for the treatment of type 2 diabetes, its utility has so far been limited because of the low level of patient compliance due to the requirement for frequent injections. In this study, an orally available exendin-4 was produced by conjugating it to low molecular weight chitosan (LMWC). Conjugation between the LMWC and cysteinylated exendin-4 was carried out using a cleavable linker system in order to maximize the availability of the active peptide. The LMWC-exendin-4 conjugate formed a nanoparticle structure with a mean particle size of 101 ± 41 nm through complexation between the positively charged LMWC backbone and the negatively charged exendin-4 of individual conjugate molecules. The biological activity of the LMWC-exendin-4 conjugate was evaluated inanINS-1 cell line. The LMWC-exendin-4 conjugate stimulated insulin secretion in a dose dependent manneras similar as that of native exendin-4. From the pharmacokinetic study after oral administration of the conjugate, a Cmax value of 344 pg/mL and a Tmax of 6 h were observed, and the bioavailability, relative to the subcutaneous counterpart, was found to be 6.4%. Furthermore, the absorbed exendin-4 demonstrated a significantly enhanced hypoglyce-mic effect. These results suggest that the LMWC-exendin-4 conjugate could be used as a potential oral anti-diabetic agent for the treatment of type 2 diabetes. © 2013 Elsevier B.V. All rights reserved.

Jeong Y.-I.,Pusan National University | Kim D.-G.,Utah Inha and Advanced Therapeutics Research Center | Kang D.-H.,Pusan National University
Journal of Chemistry | Year: 2013

We synthesized a block copolymer composed of dextran and methoxy poly(ethylene glycol) (mPEG). To accomplish this, the end group of dextran was modified by reductive amination. The aminated dextran (Dextran-NH2) showed the intrinsic peaks of both dextran at 35.5 ppm and hexamethylene diamine at 12.6 ppm at 1H nuclear magnetic resonance (NMR) spectrum. The amino end group of dextran was conjugated with mPEG to make the block copolymer consisting of dextran/mPEG (abbreviated as DexPEG). The synthesized aminated dextran and DexPEG were characterized using 1H NMR and gel permeation chromatography (GPC). The molecular weight and conjugation yield were estimated by comparing the intensity ratio of the proton peaks of the glucose molecule (4.9 ppm and 3.34.0 ppm) to that of the ethylene group of mPEG (3.7 ppm). Abundant hydroxyl group in the dextran chain can be used as a source of bioactive agent conjugation. © 2013 Young-Il Jeong et al.

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