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The anti-angiogenic agent, diamino propane tetraiodothyroacetic acid (DAT), is a thyro-integrin (integrin αvβ3) antagonist anticancer agent that works via genetic and nongenetic actions. Tetraiodothyroacetic acid (tetrac) and DAT as thyroid hormone derivatives influence gene expression after they transport across cellular membranes. To restrict the action of DAT to the integrin αvβ3 receptors on the cell surface, we used DAT-conjugated PLGA nanoparticles (NDAT) in an active targeting mode to bind to these receptors. Preparation and characterization of NDAT is described, and both in vitro and in vivo experiments were done to compare DAT to NDAT. Intracellular uptake and distribution of DAT and NDAT in U87 glioblastoma cells were evaluated using confocal microscopy and showed that DAT reached the nucleus, but NDAT was restricted from the nucleus. Pharmacokinetic studies using LC-MS/MS analysis in male C57BL/6 mice showed that administration of NDAT improved the area under the drug concentration curve AUC (0-48 h) by 4-fold at a dose of 3 mg/kg when compared with DAT, and C max of NDAT (4363 ng/mL) was 8-fold greater than that of DAT (548 ng/mL). Biodistribution studies in the mice showed that the concentrations of NDAT were higher than DAT/Cremophor EL micelles in heart, lung, liver, spleen, and kidney. In another mouse model using female NCr nude homozygous mice with U87 xenografts, tumor growth was significantly decreased at doses of 1 and 3 mg/kg of NDAT. In the chick chorioallantoic membrane (CAM) assay used to measure angiogenesis, DAT (500 ng/CAM) resulted in 48% inhibition of angiogenesis levels. In comparison, NDAT at low dose (50 ng/CAM) showed 45% inhibition of angiogenesis levels. Our investigation of NDAT bridges the study of polymeric nanoparticles and anti-angiogenic agents and offers new insight for the rational design of anti-angiogenic agents.

Lycopene is a natural anti-oxidant that has attracted much attention due to its varied applications such as protection against loss of bone mass, chronic diseases, skin cancer, prostate cancer, and cardiovascular disease. However, high instability and extremely low oral bioavailability limit its further clinical development. We selected a green tea catechin derivative, oligomerized (-)-epigallocatechin-3-O-gallate (OEGCG) as a carrier for oral lycopene delivery. Lycopene-loaded OEGCG nanoparticles (NPs) were prepared by a nano-precipitation method, followed by coating with chitosan to form a shell. This method not only can easily control the size of the NP to be around 200nm to improve its bioavailability, but also can effectively protect the lycopene against degradation due to EGCG's anti-oxidant property. OEGCG was carefully characterized with nuclear magnetic resonance spectroscopy and mass spectrometry. Lycopene-loaded polylactic-co-glycolic acid (PLGA) NPs were prepared by the same method. Chitosan-coated OEGCG/lycopene NPs had a diameter of 152±32nm and a ζ-potential of 58.3±4.2mv as characterized with transmission electron microscopy and dynamic light scattering. The loading capacity of lycopene was 9% and encapsulation efficiency was 89%. FT-IR spectral analysis revealed electrostatic interaction between OEGCG and chitosan. Freeze drying of the NPs was also evaluated as a means to improve shelf life. Dynamic light scattering data showed that no aggregation occurred, and the size of the NP increased 1.2 times (S f /S i ratio) in the presence of 10% sucrose after freeze drying. The in vitro release study showed slow release of lycopene in simulated gastric fluid at acidic pH and faster release in simulated intestinal fluid. In an in vivo study in mice, lycopene pharmacokinetic parameters were improved by lycopene/OEGCG/chitosan NPs, but not improved by lycopene/PLGA/chitosan NPs. The self-assembled nanostructure of OEGCG combined with lycopene may be a promising application in oral drug delivery in various indications., (Copyright © 2017 Elsevier B.V. All rights reserved.)

The tetraiodothyroacetic acid (tetrac) component of nano-diamino-tetrac (NDAT) is chemically bonded via a linker to a poly(lactic- co -glycolic acid) nanoparticle that can encapsulate anticancer drugs. Tetrac targets the plasma membrane of cancer cells at a receptor on the extracellular domain of integrin αvβ3. In this study, we evaluate the efficiency of NDAT delivery of paclitaxel and doxorubicin to, respectively, pancreatic and breast cancer orthotopic nude mouse xenografts. Intra-tumoral drug concentrations were 5-fold (paclitaxel; P <0.001) and 2.3-fold (doxorubicin; P <0.01) higher than with conventional systemic drug administration. Tumor volume reductions reflected enhanced xenograft drug uptake. Cell viability was estimated by bioluminescent signaling in pancreatic tumors and confirmed an increased paclitaxel effect with drug delivery by NDAT. NDAT delivery of chemotherapy increases drug delivery to cancers and increases drug efficacy., Competing Interests: Disclosure The coauthors Paul J Davis and Shaker A Mousa are stockholders in NanoPharmaceuticals LLC that is commercially developing NDAT, and Paul J Davis is an officer of the company. Kelly A Keating is paid as a consultant by NanoPharmaceuticals LLC. The other authors report no conflicts of interest in this work.

Aim: Nano-diamino-tetrac (NDAT) targets a receptor on integrin αvβ3; αvβ3 is generously expressed by cancer cells and dividing endothelial cells and to a small extent by nonmalignant cells. The tetrac (tetraiodothyroacetic acid) of NDAT is covalently bound to a poly(lactic-co-glycolic acid) nanoparticle that encapsulates anticancer drugs. We report NDAT delivery efficiency of cisplatin to agent-susceptible urinary bladder cancer xenografts., Materials & Methods: Cisplatin-loaded NDAT (NDAT-cisplatin) was administered to xenograft-bearing nude mice. Tumor size response and drug content were measured., Results: Intratumoral drug concentration was up to fivefold higher (p < 0.001) in NDAT-cisplatin-exposed lesions than with conventional systemic administration. Tumor volume reduction achieved was NDAT-cisplatin > NDAT without cisplatin > cisplatin alone., Conclusion: NDAT markedly enhances cisplatin delivery to urinary bladder cancer xenografts and increases drug efficacy.

Aim: The aim was to evaluate tetraiodothyroacetic acid (tetrac), a thyroid hormone analog of L-thyroxin, conjugated to poly(lactic-co-glycolic acid) nanoparticles (T-PLGA-NPs) both in vitro and in vivo for the treatment of drug-resistant breast cancer., Materials & Methods: The uptake of tetrac and T-PLGA-NPs in doxorubicin-resistant MCF7 (MCF7-Dx) cells was evaluated using confocal microscopy. Cell proliferation assays and a chick chorioallantoic membrane model of FGF2-induced angiogenesis were used to evaluate the anticancer effects of T-PLGA-NPs. In vivo efficacy was examined in a MCF7-Dx orthotopic tumor BALBc nude mouse model., Results: T-PLGA-NPs were restricted from entering into the cell nucleus, and T-PLGA-NPs inhibited angiogenesis by 100% compared with 60% by free tetrac. T-PLGA-NPs enhanced inhibition of tumor-cell proliferation at a low-dose equivalent of free tetrac. In vivo treatment with either tetrac or T-PLGA-NPs resulted in a three- to five-fold inhibition of tumor weight., Conclusion: T-PLGA-NPs have high potential as anticancer agents, with possible applications in the treatment of drug-resistant cancer.

Tetraiodothyroacetic acid (tetrac) and its nanoparticle formulation (Tetrac NP) act at an integrin cell surface receptor to inhibit tumor cell proliferation and tumor-related angiogenesis. Human pancreatic cancer cell (PANC-1 and MPanc96) xenografts were established in nude mice, and the effects of tetrac versus Tetrac NP on tumor growth and tumor angiogenesis were determined. The in vitro effects of tetrac and Tetrac NP were also determined by reverse transcription polymerase chain reaction or immunoblot on gene expression or gene products relevant to cell cycle arrest, apoptosis, or angiogenesis. Tetrac and Tetrac NP reduced both PANC-1 tumor mass by 45-55 % and PANC-1 tumor hemoglobin content, a marker of angiogenesis, by 50-60 % (*P < 0.05) in treated groups vs. controls by treatment day 15. Comparable results were obtained with tetrac and Tetrac NP in suppressing tumor growth and tumor angiogenesis in MPanc96 xenografts. In vitro studies showed that tetrac and Tetrac NP caused accumulation of pro-apoptotic protein BcLx-s. Tetrac NP was more effective than tetrac in increasing cellular abundance of mRNAs of pro-apoptotic p53 and p21 and anti-angiogenesis thrombospondin 1 protein in PANC-1 and MPanc96 cancer cell lines. Tetrac NP noticeably decreased expression of EGFR and of anti-apoptosis gene XIAP; tetrac did not affect EGFR and increased XIAP mRNA in both MPanc96 and PANC-1. In conclusion, tetrac or Tetrac NP effectively inhibited human pancreatic xenograft growth and tumor angiogenesis via a plasma membrane receptor that downstream modulated cellular abundance of proteins or mRNAs relevant to apoptosis and angiogenesis.

Thyroid hormone stimulates cell proliferation of several types of cancers and stimulates cancer-relevant angiogenesis. In the present study, we investigated the proliferative effect of thyroid hormone and the anti-proliferative and anti-angiogenic action of its nano-derivative, tetrac-NP, on human non-small cell lung cancer (NSCLC) H1299 cells in vitro and in xenografts. The anti-proliferative activity of unmodified tetrac and tetrac-NP against human H1299 cells was determined in three models: (a) cultured H1299 cells in vitro, (b) tumor cell implants in the fertilized chick chorioallantoic membrane (CAM) system and (c) xenografts in the nude mouse. An integrin αvβ3 antibody inhibited thyroid hormone-induced cell proliferation in vitro, as did unmodified tetrac and tetrac-NP. Pharmacologic inhibition of the mitogen-activated protein kinase pathway also blocked NSCLC cell proliferation in response to thyroid hormone. Tetrac and tetrac-NP arrested tumor growth and tumor-related angiogenesis in H1299 cells grown in the CAM model and both agents prevented chick embryo mortality. Xenografts of H1299 cells were established in nude mice (n=8, treatment and control groups) and when tumor volumes reached 250-300 mm3, tetrac (1 mg/kg) or tetrac-NP (1mg tetrac as the nanoparticle/kg) were administered intraperitoneally every 2 days. Tetrac and tetrac-NP significantly suppressed tumor growth and angiogenesis. Thus, both tetrac and tetrac-NP effectively arrest human NSCLC tumor cell proliferation in vitro and in the CAM assay and in murine xenograft models., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)

Background: Tetraiodothyroacetic acid (tetrac) is a deaminated analogue of L-thyroxine that blocks the actions of L-thyroxine and 3,5,3'-triiodo-L-thyronine at the cell surface receptor for thyroid hormone on integrin alpha v beta 3. Tetrac blocks the proliferative effects of thyroid hormone on tumor cells and the proangiogenesis actions of the hormone. In the absence of thyroid hormone, tetrac also blocks angiogenesis induced by various growth factors. Covalently linked to poly(lactide-co-glycolide), tetrac nanoparticles (tetrac NP) do not gain access to the cell interior and act exclusively at the integrin receptor. Here, the activity of tetrac and tetrac NP against follicular thyroid carcinoma (FTC)-236 cells was studied in two models: (1) tumor cell implants in the chick chorioallantoic membrane (CAM) system and (2) xenografts in the nude mouse., Methods: FTC-236 cells (10(6)) were implanted in the CAM (n = 8 each for control, and for tetrac and tetrac NP, both at 1 microg/CAM) and the actions of tetrac and tetrac NP were determined after 8 days on tumor-related angiogenesis and tumor growth. Xenografts of 10(7) FTC-236 cells were implanted in nude mice (n = 8 per group). Tetrac or tetrac NP was administered intraperitoneal (1 mg/kg and 1 mg tetrac equivalent/kg, respectively) every other day for 32 days beginning on day 10, when tumor volume was 200-250 mm(3). Animals were monitored after discontinuation of treatment up to day 40., Results: In the CAM paradigm, tetrac and tetrac NP arrested tumor-related angiogenesis and tumor growth. In the xenograft model, tetrac and tetrac NP promptly and progressively reduced tumor volume (p < 0.01) over 32 days. There was some regrowth of tumor after interruption of tetrac treatment, but at day 40, tumor volume and tumor weight at sacrifice were 45-55% below those of controls (p < 0.01). Animal weight gain was comparable in the control and treatment groups of animals., Conclusions: Tetrac and tetrac NP effectively arrest FTC-236 cell tumor growth in the CAM and xenograft models, suggesting its potential utility against FTC.

The article titled "Retraction Note: Pharmacokinetics, Biodistribution, and Anti-Angiogenesis Efficacy of Diamino Propane Tetraiodothyroacetic Acid-conjugated Biodegradable Polymeric Nanoparticle" has been retracted by the Editors of Scientific Reports. An investigation by Albany College of Pharmacy and Health Sciences found that four images in the article were misrepresented. The Editors no longer have confidence in the results and conclusions presented. Some of the authors did not respond to the correspondence from the Editors regarding this retraction. [Extracted from the article]

Abstract: There is a need for a comprehensive anti-cancer strategy that simultaneously targets abnormal proliferation, angiogenesis rates, and development of chemotherapy resistance. We have identified a small molecule, OT-404, that effectively inhibited proliferation and angiogenesis of either chemo-sensitive or -resistant human cancer cells and enhanced cancer cell sensitivity to different chemotherapy. In vivo studies of human tumor xenografts in nude mice showed that OT-404, used alone or encapsulated into nanoparticles, inhibited the growth of doxorubicin-resistant breast cancer MCF-7 by more than 80%, and by 95% when combined with doxorubicin. These findings provide evidence for the potential of OT-404 in cancer management. [Copyright &y& Elsevier]

Abstract: Novel thyroxine analogs with hindered phenol, amino and carboxylic acid groups have been synthesized and the effects of the synthesized compounds on angiogenesis using the chick chorioallantoic membrane and mouse matrigel models have been tested. Pharmacological profiles revealed that thyroxine tolerates numerous modifications on the amino group and remains active. These results provide the rationale for the selection of a novel thyroxine nanoparticle precursor. [Copyright &y& Elsevier]