Publications by authors named "Glen S Kwon"

Progressive forms of interstitial lung diseases, including idiopathic pulmonary fibrosis (IPF), are deadly disorders lacking non-invasive biomarkers for assessment of early disease activity, which presents a major obstacle in disease management. Excessive extracellular matrix (ECM) deposition is a hallmark of these disorders, with fibronectin being an abundant ECM glycoprotein that is highly upregulated in early fibrosis and serves as a scaffold for the deposition of other matrix proteins. Due to its role in active fibrosis, we are targeting fibronectin as a biomarker of early lung fibrosis disease activity via the PEGylated fibronectin-binding polypeptide (PEG-FUD).

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Idiopathic pulmonary fibrosis (IPF) is a chronic lung disease resulting in irreversible scarring within the lungs. However, the lack of biomarkers that enable real-time assessment of disease activity remains a challenge in providing efficient clinical decision-making and optimal patient care in IPF. Fibronectin (FN) is highly expressed in fibroblastic foci of the IPF lung where active extracellular matrix (ECM) deposition occurs.

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In recent years, liquid-liquid phase separation (LLPS) has been recognized to act as a precursor to self-assembly in amphiphilic systems. In this study, we propose the use of entropy-driven LLPS to obtain a tunable precursor for polymeric micelle formation. In this new approach, an oligomer is utilized as a nonselective solvent for the block copolymer, allowing for the tuning of entropy and subsequent LLPS.

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Tissue fibrosis is characterized by excessive deposition of extracellular matrix (ECM) molecules. Fibronectin (FN) is a glycoprotein found in the blood and tissues, a key player in the assembly of ECM through interaction with cellular and extracellular components. Functional Upstream Domain (FUD), a peptide derived from an adhesin protein of bacteria, has a high binding affinity for the N-terminal 70-kDa domain of FN that plays a crucial role in FN polymerization.

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Paclitaxel (PTX) is a frequently prescribed chemotherapy drug used to treat a wide variety of solid tumors. Oligo(lactic acid)-PTX prodrug (o(LA)-PTX) loaded poly(ethylene glycol)-b-poly(lactic acid) (PEG-b-PLA) micelles have higher loading, slower release and higher antitumor efficacy in murine tumor models over PTX-loaded PEG-b-PLA micelles. The goal of this work is to study plasma stability of o(LA)-PTX-loaded PEG-b-PLA micelles and its pharmacokinetics after IV injection in rats.

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In breast cancer, the extracellular matrix (ECM) undergoes remodeling and changes the tumor microenvironment to support tumor progression and metastasis. Fibronectin (FN) assembly is an important step in the regulation of the tumor microenvironment since the FN matrix precedes the deposition of various other ECM proteins, controls immune cell infiltration, and serves as a reservoir for cytokines and growth factors. Therefore, FN is an attractive target for breast cancer therapy and imaging.

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A new approach named PEG-assist is introduced for the production of drug-loaded polymeric micelles. The method is based on the use of PEG as the non-selective solvent for PEG-b-PLA in the fabrication procedure. Both hydration temperature and PEG molecular weight are shown to have a significant effect on the encapsulation efficiency of PTX in PEG-b-PLA micelles.

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Docetaxel (DTX) is among the most frequently prescribed chemotherapy drugs and has recently been shown to extend survival in advanced prostate cancer patients. However, the poor water solubility of DTX prevents full exploitation of this potent anticancer drug. The current marketed formulation, Taxotere, contains a toxic co-solvent that induces adverse reactions following intravenous injection.

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Poly(ethylene glycol)-block-poly(D,L-lactic acid) (PEG-b-PLA) and poly(ethylene glycol)-block-poly(ε-caprolactone) (PEG-b-PCL) form nano-assemblies, including micelles and nanoparticles, that increase the water solubility of anticancer drugs for injection. PEG-b-PLA and PEG-b-PCL are less toxic than commonly used organic solvents or solubilizers for injection, such as Cremophor EL® in Taxol®. Formulating paclitaxel in PEG-b-PLA micelles, as Genexol-PM®, permits dose escalation over Taxol®, enhancing antitumor efficacy in breast, lung and ovarian cancers.

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Although many solid tumors use the lymphatic system to metastasize, there are few treatment options that directly target cancer present in the lymphatic system, and those that do are highly invasive, uncomfortable, and/or have limitations. In this review we provide a brief overview of lymphatic function and anatomy, discusses changes that befall the lymphatics in cancer and the mechanisms by which these changes occur, and highlight limitations of lymphatic drug delivery. We then go on to summarize relevant techniques and new research for targeting cancer populations in the lymphatics and enhancing drug delivery intralymphatically, including intralymphatic injections, isolated limb perfusion, passive nano drug delivery systems, and actively targeted nanomedicine.

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The Functional Upstream Domain (FUD) peptide is a potent inhibitor of fibronectin assembly and a therapeutic candidate for disorders linked with hyperdeposition of fibronectin-modulated ECM proteins. Most recently, experiments involving subcutaneous (s.c.

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Purpose: To prepare an oligo(lactic acid)-rapamycin prodrug (o(LA)-RAP)-loaded poly(ethylene glycol)-block-poly(lactic acid) (PEG-b-PLA) micelle for injection and characterize its compatibility and performance versus a RAP-loaded PEG-b-PLA micelle for injection in vitro and in vivo.

Methods: Monodisperse o(LA) was coupled on RAP at the C-40 via DCC/DMAP chemistry, and conversion of o(LA)-RAP prodrug into RAP was characterized in vitro. Physicochemical properties of o(LA)-RAP- and RAP-loaded PEG-b-PLA micelles and their antitumor efficacies in a syngeneic 4 T1 breast tumor model were compared.

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Poly(ethylene glycol)-block-poly(d,l-lactic acid) (PEG-b-PLA) micelles affect drug solubilization, and a paclitaxel (PTX) loaded-PEG-b-PLA micelle (PTX-PM) is approved for cancer treatment due to injection safety and dose escalation (Genexol-PM®) compared to Taxol®. However, PTX-PM is unstable in blood, has rapid clearance, and causes dose-limiting toxicity. We have synthesized a prodrug for PTX (7-OH), using oligo(lactic acid) as a novel pro-moiety (o(LA)-PTX) specifically for PEG-b-PLA micelles, gaining higher loading and slower release of o(LA)-PTX over PTX.

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Fibronectin is a blood and extracellular matrix glycoprotein that plays important roles in wound healing and fibrosis since it controls the deposition of collagen and other extracellular matrix molecules and is a substrate for infiltrating lymphocytes. Using a high-affinity fibronectin-binding peptide (FUD/pUR4) that inhibits fibronectin deposition into extracellular matrix (ECM), we tested the ability of a PEGylated FUD/pUR4 (PEG-FUD) to inhibit fibrosis in the Unilateral Ureteral Obstruction (UUO) kidney disease model. Fibronectin fibrillogenesis assays, using human fibroblasts and human proximal tubular epithelial cultures, showed that PEG-FUD can inhibit fibronectin fibrillogenesis in vitro with an IC50 similar to unconjugated FUD, in the order of 20-35 nM.

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Herein we demonstrate the formation of stereocomplex prodrugs of oligo(l-lactic acid) -gemcitabine (o(LLA) -GEM) and oligo(d-lactic acid) -gemcitabine (o(DLA) -GEM) for stable incorporation in poly(ethylene glycol)- block-poly(d,l-lactic acid) (PEG- b-PLA) micelles. O(LLA) or o(DLA) was attached at the amino group (4-( N)) of GEM via an amide linkage. When n = 10, a 1:1 mixture of o(LLA)-GEM and o(DLA)-GEM (o(L+DLA)-GEM) was able to form a stereocomplex with a distinctive crystalline pattern.

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Purpose: To develop PEGylated variants of pUR4/FUD (FUD), a fibronectin assembly inhibitor, using 10 kDa, 20 kDa, and 40 kDa PEGs to evaluate their binding affinity and inhibitory potency.

Methods: The FUD peptide was recombinantly expressed, purified, and PEGylated at the N-terminus using 10 kDa, 20 kDa, and 40 kDa methoxy-PEG aldehyde. The PEGylates were purified and fractionated using ion-exchange chromatography.

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Despite clinical remission of epithelial ovarian cancer (EOC) after surgical resection and first-line chemotherapy, about 60% of patients will re-develop peritoneal metastasis and about 50% will relapse with chemoresistant disease. Clinical studies suggest that intra-peritoneal (i.p.

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Spherical nucleic acid gold nanoparticles represent a unique nanotechnology in which the spherical arrangement of oligonucleotides enables the nanoparticles to be efficiently internalized into cells expressing scavenger receptors class A (SR-A). Herein, we seek to replace the gold core with a biodegradable polymeric construct and explore their potential applications in targeted drug delivery. Oligonucleotide-conjugated poly(ethylene glycol)-block-poly(ε-caprolactone) was synthesized and characterized by H NMR and gel electrophoresis.

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Purpose: Amphotericin B (AmB) and 5-fluorocytosine (5-FC) exhibit additive to synergistic activity against systemic mycoses. Incompatibility of prescribed formulations precludes concomitant IV administration, a route with distinct advantages. Previously, we used PEG-DSPE micelles to produce a reformulation of Fungizone (AmB-SD), AmB solubilized by sodium deoxycholate, called mAmB-90.

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Epothilones are microtubule inhibitors that are promising alternatives to paclitaxel due to enhanced anticancer efficacy. While epothilones are slightly more water soluble than paclitaxel and more active against paclitaxel-resistant cells, they still require formulation with Cremophor EL and/or cosolvents and drug resistance still limits therapeutic efficacy. In this report, we showed that the combinational treatment of epothilone B (EpoB), 17-N-allylamino-17-demethoxygeldanamycin (17-AAG, Hsp90 inhibitor), and rapamycin (mTOR inhibitor) displays strong anticancer activity in vitro and in vivo.

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Purpose: The aim of tumor-specific chemoradiotherapy is to achieve synergistic anticancer effects with clinically acceptable toxicity. Our previous studies showed that Pluronic P85 augments radiation cancer cell killing of (±)-gossypol in vitro. In this study, the radiosensitizing effect of (-)-gossypol, more potent Bcl protein inhibitor, with Pluronic P85 was investigated.

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Background: Delivery of monomeric Amphotericin B (AmB), i.e. deaggregated AmB, has been a major tactic in the reduction of renal toxicity at a membrane level, taking advantage of the selectivity of monomeric AmB for binding ergosterol over cholesterol.

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Poly(ethylene glycol)-block-poly(d,l-lactic acid) (PEG-b-PLA) micelles are nanocarriers for poorly water-soluble anticancer agents and have advanced paclitaxel (PTX) to humans due to drug solubilization, biocompatibility, and dose escalation. However, PEG-b-PLA micelles rapidly release PTX, resulting in widespread biodistribution and low tumor exposure. To improve delivery of PTX by PEG-b-PLA micelles, monodisperse oligo(l-lactic acid), o(LA)8 or o(LA)16, has been coupled onto PTX at the 7-OH position, forming ester prodrugs: o(LA)8-PTX and o(LA)16-PTX, respectively.

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Triolimus is a multi-drug loaded polymeric micelle containing paclitaxel (PTX), 17-allylamino-17-demethoxygeldanamycin (17-AAG), and rapamycin (RAP). This study examines the radiosensitizing effect of Triolimus in vitro and in vivo. Radiosensitizing effects of Triolimus on A549 cells are dose dependent and at 2 × 10 m, Triolimus shows significant radiosensitization even at low radiation doses (2 Gy).

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Purpose: The purpose of this study is to investigate a sol-gel transition property and content release profiles for thermosensitive poly-(D,L-lactide-co-glycolide)-block-poly-(ethylene glycol)-block-poly-(D,L-lactide-co-glycolide) (PLGA-b-PEG-b-PLGA) hydrogels carrying paclitaxel, rapamycin, and LS301, and to present a proof-of-concept that PLGA-b-PEG-b-PLGA hydrogels carrying paclitaxel, rapamycin, and LS301, called TheranoGel, exhibit excellent theranostic activity in peritoneal ES-2-luc ovarian cancer xenograft mice.

Methods: Thermosensitive PLGA-b-PEG-b-PLGA hydrogels carrying paclitaxel, rapamycin, and LS301, individually or in combination, were prepared via a lyophilization method, characterized with content release kinetics, and assessed with theranostic activity in ES-2-luc xenograft mice.

Results: A thermosensitive PLGA-b-PEG-b-PLGA sol-gel system was able to entrain 3 poorly water-soluble payloads, paclitaxel, rapamycin, and LS301 (TheranoGel).

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