Design and development of novel self-assembled catechol-modified bile acid conjugates as pH-responsive apical sodium-dependent bile acid transporter targeting nanoparticles

Catechol-based biomaterials demonstrate biocompatibility, making them suitable for a wide range of therapeutic applications when integrated into various molecular frameworks. However, the development of orally available catechol-based biomaterials has been hindered by significant pH variations and complex interactions in the gastrointestinal (GI) tract. In this study, we introduce a novel catechol-modified bile acid (CMBA), which is synthesized by anchoring the FDA-approved drug, ursodeoxycholic acid to the neurotransmitter dopamine. This modification could form a new apical sodium-dependent bile acid transporter (ASBT) inhibitor (ASBTi) due to the bile acid moiety. The computational analysis using the TRAnsient Pockets in Proteins (TRAPP) module, coupled with MD simulations, revealed that CMBA exhibits a strong binding affinity at residues 51-55 of ASBT with a low inhibitory constant (Ki) value. Notably, in slightly alkaline biological conditions, CMBA molecules self-assemble into carrier-free nanoparticles with an average size of 240.2 ± 44.2 nm, while maintaining their ability to bind with ASBT. When administered orally, CMBA accumulates in the ileum and liver over 24 h, exhibiting significant therapeutic effects on bile acid (BA) metabolism in a high-fat diet (HFD)-fed mouse model. This study underscores the therapeutic potential of the newly developed catechol-based, pH-responsive ASBT-inhibiting nanoparticles presenting a promising avenue for advancing therapy.

In situ hypoxia modulating nano-catalase for amplifying DNA damage in radiation resistive colon tumors

Radiation therapy (RT) is a mainstream clinical approach in cancer treatment. However, the therapeutic efficacy of RT is greatly hindered by the presence of excessive hydrogen peroxide (H2O2) in the hypoxic region of the solid tumor, thus leading to tumor recurrence and metastasis. Herein, a thioketal-linked amphiphilic nano-assembly (MTS) loaded with hydrophobic manganese oxide (HMO) nanoparticles (MTS@HMO) is examined as a promising multi-purpose reactive oxygen species (ROS)-catalytic nanozyme for transforming an RT-resistant hypoxic tumor microenvironment (TME) into an RT-susceptible one by scavenging ROS in the hypoxic core of the solid tumor. After intravenous injection, the MTS@HMO nano-assembly was able to sense and be degraded by the abundant ROS in the hypoxic TME, thereby releasing HMO particles for subsequent scavenging of H2O2. The oxygen generated during peroxide scavenging then relieved the hypoxic TME, thereby resulting in an increased sensitivity of the hypoxic tumor tissue towards RT. Moreover, the in situ hypoxic status was monitored via the T1-enhanced magnetic resonance (MR) imaging of the Mn2+ ions generated by the ROS-mediated degradation of HMO. The in vitro results demonstrated a significant H2O2 elimination and enhanced oxygen generation after the treatment of the MTS@HMO nano-assembly with tumor cells under hypoxic conditions, compared to the control MTS group. In addition, the combination of RT and pre-treatment with MTS@HMO nano-assembly significantly amplified the permanent DNA strand breaks in tumor cells compared to the control RT group. More importantly, the in vivo results proved that the systemic injection of the MTS@HMO nano-assembly prior to RT irradiation enhanced the RT-mediated tumor suppression and down-regulated the hypoxic marker of HIF-1α in the solid tumor compared to the control RT group. Overall, the present work demonstrates the great potential of the versatile ROS-catalytic hypoxia modulating strategy using the MTS@HMO nano-assembly to enhance the RT-induced antitumor efficacy in hypoxic solid tumors.

Design of chimeric GLP-1A using oligomeric bile acids to utilize transporter-mediated endocytosis for oral delivery

BACKGROUND

Despite the effectiveness of glucagon-like peptide-1 agonist (GLP-1A) in the treatment of diabetes, its large molecular weight and high hydrophilicity result in poor cellular permeability, thus limiting its oral bioavailability. To address this, we developed a chimeric GLP-1A that targets transporter-mediated endocytosis to enhance cellular permeability to GLP-1A by utilizing the transporters available in the intestine, particularly the apical sodium-dependent bile acid transporter (ASBT).

METHODS

In silico molecular docking and molecular dynamics simulations were used to investigate the binding interactions of mono-, bis-, and tetra-deoxycholic acid (DOCA) (monoDOCA, bisDOCA, and tetraDOCA) with ASBT. After synthesizing the chimeric GLP-1A-conjugated oligomeric DOCAs (mD-G1A, bD-G1A, and tD-G1A) using a maleimide reaction, in vitro cellular permeability and insulinotropic effects were assessed. Furthermore, in vivo oral absorption in rats and hypoglycemic effect on diabetic db/db mice model were evaluated.

RESULTS

In silico results showed that tetraDOCA had the lowest interaction energy, indicating high binding affinity to ASBT. Insulinotropic effects of GLP-1A-conjugated oligomeric DOCAs were not different from those of GLP-1A-Cys or exenatide. Moreover, bD-G1A and tD-G1A exhibited improved in vitro Caco-2 cellular permeability and showed higher in vivo bioavailability (7.58% and 8.63%) after oral administration. Regarding hypoglycemic effects on db/db mice, tD-G1A (50 μg/kg) lowered the glucose level more than bD-G1A (50 μg/kg) compared with the control (35.5% vs. 26.4%).

CONCLUSION

GLP-1A was conjugated with oligomeric DOCAs, and the resulting chimeric compound showed the potential not only for glucagon-like peptide-1 receptor agonist activity but also for oral delivery. These findings suggest that oligomeric DOCAs can be used as effective carriers for oral delivery of GLP-1A, offering a promising solution for enhancing its oral bioavailability and improving diabetes treatment.

Abstract 2710: Developing a novel doppel-targeting antibody-drug conjugate (ADC) for solid cancer

The development of anticancer therapeutics has two main objectives: enhancing efficacy and lowering toxicity. Given these goals, an antibody-drug conjugate (ADC), which delivers highly cytotoxic payloads to tumor tissue specifically, is one of the most favorable treatments. ADC is a growing drug delivery technology, with twelve FDA-approved ADCs as of 2022. Most of ADCs in use today target particular molecules for hematologic malignancies. ADCs for solid tumors are relatively in the early stages of development due to the lack of well-defined solid tumor-specific target molecules. To put it another way, the market has an enormous unmet demand for solid cancer-specific ADCs. As seen by recently approved ADCs and ADCs in clinical trials, finding novel targets for solid cancer has drawn a lot of attention in current development trends. Doppel, a prion-like protein, is transiently expressed in the neonatal brain endothelium; in adults, it is exclusively present in testicular cells. In our previous study, we found that Doppel is specifically expressed only in tumor tissues and tumor blood vessels, but not in normal adult tissues; its expression promoted cancerous blood vessel formation. Then, we generated several monoclonal antibodies which target Doppel; the most effective clone was selected. We observed that angiogenesis-related factors were suppressed in the tumor endothelial cells treated with the Doppel-targeting antibody. In addition, we injected the antibody into mouse models and visualized the tumor-targeting efficacy using in vivo imaging system (IVIS); the antibody accumulates in the tumor significantly higher compared to non-targeting IgG. We suggest what we believe to be a novel strategy to target a molecular marker that is altered and overexpressed specifically in tumor tissues and tumor endothelial cells. Based on the above discoveries, we have developed the Doppel-targeting ADC; this drug, according to our hypothesis, will target only cancer cells that express Doppel and result in apoptotic cell death. The ADC has demonstrated remarkable anticancer efficacy in both cell and mouse models, although it is still in the early stages of research. We believe that the enhanced specificity for targeting tumors, the high tumor-to-organ ratio, and the bystander killing effect would make this Doppel-targeting ADC a successful “solid cancer-specific” one.

Citation Format: Ha Kyeong Lee, Byoungmo Kim, Seho Kweon, Jeong Uk Choi, Sang Yoon Kim, Youngro Byun. Developing a novel doppel-targeting antibody-drug conjugate (ADC) for solid cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2710.

Abstract 5091: Potentiating immunogenicity of PD1 blockage with metronomic Oral CAPOX for local and liver metastasized colorectal cancer

Since the appearance of oxaliplatin, FOLFOX therapy is positioned as the standard of care for colorectal cancer (CRC). And after the advent of capecitabine, an oral prodrug of 5-FU, both FOLFOX and CAPOX remain the first-line treatment for local and advanced CRC. Even though oral 5-FU prodrug has approved more than two decades ago, orally available oxaliplatin has not been developed yet. Oral chemotherapy has garnered attention in the era of cancer immunotherapy because oral form of the therapy makes metronomic therapy feasible. In this regard, we invented orally absorbable oxaliplatin exploiting complexation with bile acid moiety. The invention encouraged to expand the dosing of combination treatment of 5-FU and oxaliplatin, the most established chemotherapy combination of CRC, into metronomic scheduling. Oral CAPOX therapy is developed to administrate 5-FU and oxaliplatin combination (FOX) metronomically for chemo-immunotherapy. Metronomic dosage successfully induced immunogenic cancer cell death in colorectal cancer xenograft mouse model not exerting toxicity to other organs abolishing immune suppressive effect of chemotherapy. Oral CAPOX boosted tumor immunity translating immune microenvironment. Immune cell population and activation was analyzed using flow cytometry. Suppressive immune cell population decreased after Oral CAPOX treatment. Especially, immune-suppressive macrophage population diminished. Macrophages became immunogenic and presented antigen more frequently. Improved tumor microenvironment combined with anti-PD1 treatment activated and proliferated T cells locally and systemically. Oral CAPOX and anti-PD1 combination therapy activated cytotoxic T cell in tumor tissue and tumor draining lymph node. This therapy also activated NK cells systemically. Oral CAPOX and anti-PD1 combination treatment regressed established tumor completely in more than 90% of the mouse showing its capacity for clinical usage. Liver is the region which makes CRC least immunogenic among metastatic site and the organ CRC is metastasized most abundantly. Immuno-suppresive macrophage in liver is known for the factor discriminating liver metastasized CRC from other organs metastasized one suppressing T cells. Because Oral CAPOX therapy converts macrophage more immunogenic, Oral CAPOX therapy could reverse immunosuppressive tumor microenvironment of liver metastasized colorectal cancer. Oral CAPOX and anti-PD1 combination is treated liver metastasized CRC model and showed standing out antitumor efficacy, and T cell activation.

Citation Format: Seong Jin Park, Seho Kweon, Moyo Knowledge Mudhibadhi, Ha Rin Kim, Youngro Byun. Potentiating immunogenicity of PD1 blockage with metronomic Oral CAPOX for local and liver metastasized colorectal cancer. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5091.

Abstract 2730: Metronomic dose-finding approach of oral chemotherapy by experimentally-driven integrated mathematical modeling

Conventional chemotherapy with maximum tolerated dose (MTD) has shown confident anti-cancer effect and when combined with targeted therapy, immunotherapy. Yet, understanding about how the MTD regimen is optimized has lacked due to its high tumor burdens. In this study, the oral doxorubicin (DOX) formulation was shown to improve oral bioavailability by 12.1% and sustain the metronomic concentration through the flexible protocol. Since the optimizing dose and schedules of DOX in metronomic chemotherapy (MCT) is essential to maximize efficacy and minimize toxicity, which is determined by the exposure of drugs based on pharmacokinetic-pharmacodynamic (PK/PD) correlation, we developed an integrated systemic mathematical model that can evaluate the anti-tumor effect and the toxicity of oral DOX formulation simultaneously. Oral physiologically-based pharmacokinetic (PBPK) models were established with dose dependency, and creatine kinase-MB (CK-MB) and tumor growth profiles were assessed as markers for toxicodynamic (TD) and PD models, respectively. Each model was validated and then integrated into the PK-TD/PD model and the effects of various oral metronomic regimens were predicted. In conclusion, the finalized oral metronomic dosing regimen (10 mg/kg, QD) showed 83.3% tumor growth inhibition without cardiotoxicity. In this study, we defined the MCT regimen using a mathematical model and suggested a dose selection method for developing oral drugs from injections, to efficiently utilize the preclinical results and apply to clinical practice.

Citation Format: Seho Kweon, Yoo-Seong Jeong, Yoon Gun Ko, Seung Woo Chung, Ha Kyeong Lee, Suk-Jae Chung, Youngro Byun, Sang Yoon Kim. Metronomic dose-finding approach of oral chemotherapy by experimentally-driven integrated mathematical modeling [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2730.

A novel oral metronomic chemotherapy provokes tumor specific immunity resulting in colon cancer eradication in combination with anti-PD-1 therapy

In this study, we investigated the immune-modulating effects of a novel metronomic chemotherapy (MCT) featuring combined oral oxaliplatin (OXA) and pemetrexed (PMX) for colon cancer. OXA and PMX were ionically complexed with lysine derivative of deoxycholic acid (DCK), and incorporated into nanoemulsions or colloidal dispersions, yielding OXA/DCK-NE and PMX/DCK-OP, respectively, to improve their oral bioavailabilities. MCT was not associated with significant lymphotoxicity whereas the maximum tolerated dose (MTD) afforded systemic immunosuppression. MCT was associated with more immunogenic cell death and tumor cell MHC-class I expression than was MTD. MCT improved the tumor antigen presentation of dendritic cells and increased the number of functional T cells in the tumor. MCT also helped to enhance antigen-specific memory responses both locally and systemically. By combining MCT with anti-programmed cell death protein-1 (αPD-1) therapy, the tumor volume was suppressed by 97.85 ± 84.88% compared to the control, resulting in a 95% complete response rate. Upon re-challenge, all tumor-free mice rejected secondary tumors, indicating the induction of a tumor specific memory response. Thus, MCT using an OXA and PMX combination, together with αPD-1, successfully treated colon cancer by activating both innate and adaptive immune cells and elicited tumor-specific long-term immune memory while avoiding toxicity caused by MTD treatment.

Anticoagulation therapy promotes the tumor immune-microenvironment and potentiates the efficacy of immunotherapy by alleviating hypoxia

Purpose

Here, this study verifies that cancer-associated thrombosis (CAT) accelerates hypoxia, which is detrimental to the tumor immune microenvironment by limiting tumor perfusion. Therefore, we designed an oral anticoagulant therapy to improve the immunosuppressive tumor microenvironment and potentiate the efficacy of immunotherapy by alleviating tumor hypoxia.

Experimental design

A novel oral anticoagulant (STP3725) was developed to consistently prevent CAT formation. Tumor perfusion and hypoxia were analyzed with or without treating STP3725 in wild-type and P selectin knockout mice. Immunosuppressive cytokines and cells were analyzed to evaluate the alteration of the tumor microenvironment. Effector lymphocyte infiltration in tumor tissue was assessed by congenic CD45.1 mouse lymphocyte transfer model with or without anticoagulant therapy. Finally, various tumor models including K-Ras mutant spontaneous cancer model were employed to validate the role of the anticoagulation therapy in enhancing the efficacy of immunotherapy.

Results

CAT was demonstrated to be one of the perfusion barriers, which fosters immunosuppressive microenvironment by accelerating tumor hypoxia. Consistent treatment of oral anticoagulation therapy was proved to promote tumor immunity by alleviating hypoxia. Furthermore, this resulted in decrease of both hypoxia-related immunosuppressive cytokines and myeloid-derived suppressor cells while improving the spatial distribution of effector lymphocytes and their activity. The anticancer efficacy of αPD-1 antibody was potentiated by co-treatment with STP3725, also confirmed in various tumor models including the K-Ras mutant mouse model, which is highly thrombotic.

Conclusions

Collectively, these findings establish a rationale for a new and translational combination strategy of oral anticoagulation therapy with immunotherapy, especially for treating highly thrombotic cancers. The combination therapy of anticoagulants with immunotherapies can lead to substantial improvements of current approaches in the clinic.

Dual mechanistic TRAIL nanocarrier based on PEGylated heparin taurocholate and protamine which exerts both pro-apoptotic and anti-angiogenic effects

The selective cytotoxicity of tumor necrosis factor-related apoptosis inducing ligand (TRAIL) to cancer cells but not to normal cells makes it an attractive candidate for cancer therapeutics. However, the disadvantages of TRAIL such as physicochemical instability and short half-life limit its further clinical applications. In this study, TRAIL was encapsulated into a novel anti-angiogenic nanocomplex for both improved drug distribution at the tumor site and enhanced anti-tumor efficacy. A nanocomplex was prepared firstly by entrapping TRAIL into PEG-low molecular weight heparin-taurocholate conjugate (LHT7), which is previously known as a potent angiogenesis inhibitor. Then, protamine was added to make a stable form of nanocomplex (PEG-LHT7/TRAIL/Protamine) by exerting electrostatic interactions. We found that entrapping TRAIL into the nanocomplex significantly improved both pharmacokinetic properties and tumor accumulation rate without affecting the tumor selective cytotoxicity of TRAIL. Furthermore, the anti-tumor efficacy of nanocomplex was highly augmented (73.77±4.86%) compared to treating with only TRAIL (18.49 ± 19.75%), PEG-LHT7/Protamine (47.84 ± 14.20%) and co-injection of TRAIL and PEG-LHT7/Protamine (56.26 ± 9.98%). Histological analysis revealed that treatment with the nanocomplex showed both anti-angiogenic efficacy and homogenously induced cancer cell apoptosis, which suggests that accumulated TRAIL and LHT7 in tumor tissue exerted their anti-tumor effects synergistically. Based on this study, we suggest that PEG-LHT7/Protamine complex is an effective nanocarrier of TRAIL for enhancing drug distribution as well as improving anti-tumor efficacy by exploiting the synergistic mechanism of anti-angiogenesis.

Improvements in the Oral Absorption and Anticancer Efficacy of an Oxaliplatin-Loaded Solid Formulation: Pharmacokinetic Properties in Rats and Nonhuman Primates and the Effects of Oral Metronomic Dosing on Colorectal Cancer

Objective

The anticancer efficacy of orally administered chemotherapeutics is often constrained by low intestinal membrane permeability and oral bioavailability. In this context, we designed a solid oral formulation of oxaliplatin (OP), a third-generation cisplatin analog, to improve oral bioavailability and investigate its application in metronomic chemotherapy.

Methods

An ion-pairing complex of OP with a permeation enhancer, N^α-deoxycholyl-l-lysyl-methylester (DLM), was successfully prepared and then mixed with dispersing agents (including poloxamer 188 and Labrasol) to form the solid, amorphous oral formulation OP/DLM (OP/DLM-SF; hereafter, ODSF).

Results

The optimized powder formulation was sized in the nanoscale range (133±1.47 nm). The effective permeability of OP increased by 12.4-fold after ionic complex formation with DLM and was further increased by 24.0-fold after incorporation into ODSF. ODSF exhibited respective increases of 128% and 1010% in apparent permeability across a Caco-2 monolayer, compared to OP/DLM and OP. Furthermore, inhibition of bile acid transporters by actinomycin D and caveola-mediated uptake by brefeldin in Caco-2 cell monolayers reduced the apparent permeability values of ODSF by 58.4% and 51.1%, respectively, suggesting predominant roles for bile acid transporters and caveola-mediated transport in intestinal absorption of ODSF. In addition, macropinocytosis and paracellular and transcellular passive transport significantly influenced the intestinal permeation of ODSF. The oral bioavailabilities of ODSF in rats and monkeys were 68.2% and 277% higher, respectively, than the oral bioavailability of free OP. In vivo analyses of anticancer efficacy in CT26 and HCT116 cell-bearing mice treated with ODSF demonstrated significant suppression of tumor growth, with respective maximal tumor volume reductions of 7.77-fold and 4.07-fold, compared to controls.

Conclusion

ODSF exhibits therapeutic potential, constituting an effective delivery system that increases oral bioavailability, with applications to metronomic chemotherapy.

Enhanced oral bioavailability of an etoposide multiple nanoemulsion incorporating a deoxycholic acid derivative-lipid complex

In this study, a system for oral delivery of etoposide (ETP) was designed to avoid the problems associated with low and variable bioavailability of a commercially available ETP emulsion comprised of polyethylene glycol, glycerol, and citric acid anhydrous. ETP was complexed with low-molecular-weight methylcellulose (ETP/LMC) and loaded into a water-in-oil-in-water multiple nanoemulsion to formulate an ETP/LMC-nanoemulsion (ELNE). To further enhance the oral bioavailability, an ionic complex formed by anionic lipid 1,2-didecanoyl-sn-glycero-3-phosphate (sodium salt) and cationic N^α-deoxycholyl-l-lysyl-methylester was incorporated into ELNE, yielding ELNE#7. As expected, ELNE#7 showed 4.07- and 2.25-fold increases in artificial membrane and Caco-2/HT29-MTX-E12 permeability (P_app), respectively, resulting in 224% greater oral bioavailability compared with the commercially available ETP emulsion. In contrast, inhibition of clathrin- and caveola-mediated endocytosis, macropinocytosis, and bile acid transporters by chlorpromazine, genistein, amiloride, and actinomycin D in Caco-2/HT-29-MTX-E12 monolayers reduced the P_app by 45.0%, 20.5%, 28.8%, and 31.1%, respectively. These findings suggest that these routes play important roles in enhancing the oral absorption of ELNE#7. In addition, our mechanistic study suggested that P-glycoprotein did not have an inhibitory effect on the permeation of ELNE#7. Notably, ELNE#7 showed significantly enhanced toxicity in LLC and A549 cells compared with ETP-E. These observations support the improved oral absorption of ETP in ELNE#7, suggesting that it is a better alternative than ETP emulsion.

Modulating tumor immunity by metronomic dosing of oxaliplatin incorporated in multiple oral nanoemulsion

In this study, a system for oral delivery of oxaliplatin (OXA) was prepared for metronomic chemotherapy to enhance antitumor efficacy and modulate tumor immunity. OXA was complexed with N^α-deoxycholyl-l-lysyl-methylester (DCK) (OXA/DCK) and formulated as a nanoemulsion (OXA/DCK-NE). OXA/DCK-NE showed 3.35-fold increased permeability across a Caco-2 cell monolayer, resulting in 1.73-fold higher oral bioavailability than free OXA. In addition, treatment of the B16F10.OVA cell line with OXA/DCK-NE resulted in successful upregulation of immunogenic cell death (ICD) markers both in vitro and in vivo. In a B16F10.OVA tumor-bearing mouse model, treatment with OXA/DCK-NE substantially impeded tumor growth by 63.9 ± 13.3% compared to the control group, which was also greater than the intravenous (IV) OXA group. Moreover, treatment with a combination of oral OXA/DCK-NE and anti-programmed cell death protein-1 (αPD-1) antibody resulted in 78.3 ± 9.67% greater inhibition compared to controls. More important, OXA/DCK-NE alone had immunomodulatory effects, such as enhancement of tumor antigen uptake, activation of dendritic cells in tumor-draining lymph nodes, and augmentation of both the population and function of immune effector cells in tumor tissue as well as in the spleen; no such effects were seen in the OXA IV group. These observations provide a rationale for combining oral metronomic OXA with immunotherapy to elicit synergistic antitumor effects.

Abstract 4390: Metronomic maintenance chemotherapy of orally active pemetrexed for effective treatment of lung cancer

At present, most of the anticancer drugs are given parenterally, showing drug concentration above the maximum tolerable concentration (MTC) followed by rapid elimination from the plasma that causes enhanced side effects and lower efficacy. In contrast, low dose oral maintenance therapy may increase therapeutic efficacy by increasing the exposure time to cancer cells and also reduce the side effects by maintaining the drug concentration below MTC level. Pemetrexed is a folate antagonist approved for maintenance chemotherapy in lung cancer. However, a major limitation of Pemetrexed is the poor oral bioavailability which imposes IV administration. In this context, we have developed a physical complex of Pemetrexed with lysine conjugated deoxycholic acid (DCK) in water (mole ratio 1:2) for the purpose of oral delivery. The DSC thermogram of Pemetrexed/DCK complex showed the complex formation due to disappearance of exothermic and endothermic peaks from Pemetrexed. The pharmacokinetic studies of Pemetrexed/DCK were done in SD rats and analyzed by HPLC method. In antitumor study, low dose continuous oral therapy from 2.5 mg/kg to 20 mg/kg showed substantial tumor inhibition in SCC7 tumor bearing C3H mice. We also evaluated maintenance chemotherapy as oral Pemetrexed/DCK administration in A549 tumor bearing nude mice. We found that 5 mg/kg dose of oral Pemetrexed successfully inhibited tumor progression and also showed additional antitumor effects when given with Cisplatin as maintenance chemotherapy. In the context of oral anticancer drugs, we need to consider the toxicities in GI tracts (GIT). For this purpose, apoptosis in GI tracts and morphology of different organs were assessed by TUNEL and H&E staining. One month toxicity studies have been conducted in nude mice and we found that 5 mg/kg oral dose did not produce any abnormalities in hematological and serological parameters in mice having intact morphology of GI tracts. Our studies offer safe and effective oral maintenance chemotherapy of pemetrexed for cancer patients at home.

Citation Format: Foyez Mahmud, Seho Kweon, Hyo Won Chang, Hae Yoon Nam, Mi Ra Kim, Jung Je Park, Sang Yoon Kim, Youngro Byun. Metronomic maintenance chemotherapy of orally active pemetrexed for effective treatment of lung cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4390. doi:10.1158/1538-7445.AM2015-4390

Absorption Mechanism of a Physical Complex of Monomeric Insulin and Deoxycholyl-l-lysyl-methylester in the Small Intestine

Currently, oral administration of insulin still remains the best option to avoid the burden of repeated subcutaneous injections and to improve its pharmacokinetics. The objective of the present investigation was to demonstrate the absorption mechanism of insulin in the physical complexation of deoxycholyl-l-lysyl-methylester (DCK) for oral delivery. The oral insulin/DCK complex was prepared by making a physical complex of insulin aspart with DCK through ion-pair interaction in water. For the cellular uptake study, fluorescein-labeled insulin or DCK were prepared according to a standard protocol and applied to Caco-2 or MDCK cell lines. For the PK/PD studies, we performed intrajejunal administration of different formulation of insulin/DCK complex to diabetic rats. The resulting insulin and DCK complex demonstrated greatly enhanced lipophilicity as well as increased permeation across Caco-2 monolayers. The immunofluorescence study revealed the distribution of the complex in the cytoplasm of Caco-2 cells. Moreover, in the apical sodium bile acid transporter (ASBT) transfected MDCK, the insulin/DCK complex showed interaction with ASBT, and also demonstrated absorption through passive diffusion. We could not find that any evidence of endocytosis in relation to the uptake of insulin complex in vitro. In the rat intestine model, the highest absorption of insulin complex was observed in the jejunum at 1 h and then in the ileum at 2-4 h. In PK/PD study, the complex showed a similar PK profile to that of SC insulin. Overall, the study showed that the effect of DCK on enhancing the absorption of insulin resulted from transcellular processes as well as bile acid transporter activity.

Multilayer nanoparticles for sustained delivery of exenatide to treat type 2 diabetes mellitus

A method for the sustained delivery of exenatide was proposed using nanoparticles (NPs) with a core/shell structure. The interactions between lipid bilayers and Pluronics were utilized to form various NPs using a layer-by-layer approach. Transmittance electron microscopy and dynamic light scattering were used to examine the morphology of the NPs. The in vitro release pattern was observed as a function of changes in the structure of the NPs, and the structural integrity of exenatide released was examined by SDS-PAGE analysis. Pharmacokinetics and antidiabetic effects were also observed with the structural change of NPs using in vivo animal models. In vitro-in vivo correlation was discussed in relation to manipulation of the NP structures.