Supramolecular nanogels fabricated via host-guest molecular recognition as penetration enhancer for dermal drug delivery.

Nanogels that are assembled by supramolecular interactions as compared to covalent crosslinked nanogels, exhibit new functionalities with potential for easy processability, recycling and self-healing due to the nature of dynamic and reversible non-covalent interactions. Here we design a supramolecular polymer nanogel that utilize host-guest interactions between the groups pillar [5] arene and alkyl chains on hyperbranched polyglycerol backbone as crosslinking agents for a new dermal drug delivery system. The anti-inflammatory drug Dexamethasone (Dexa) can be efficiently loaded into the nanogels and released from the assemblies. Besides, the supramolecular polymer nanogels exhibit better drug loading capacity and skin penetration enhancement than the individual host polymer and guest polymer. In vitro skin permeation studies show that supramolecular polymer nanogels can improve the Nile red penetration through the skin by up to 9 fold, compared to the individual polymers or a conventional cream formulation on a barrier deficient skin model.

Galectin-1 Inhibitor OTX008 Induces Tumor Vessel Normalization and Tumor Growth Inhibition in Human Head and Neck Squamous Cell Carcinoma Models.

Galectin-1 is a hypoxia-regulated protein and a prognostic marker in head and neck squamous cell carcinomas (HNSCC). Here we assessed the ability of non-peptidic galectin-1 inhibitor OTX008 to improve tumor oxygenation levels via tumor vessel normalization as well as tumor growth inhibition in two human HNSCC tumor models, the human laryngeal squamous carcinoma SQ20B and the human epithelial type 2 HEp-2. Tumor-bearing mice were treated with OTX008, Anginex, or Avastin and oxygen levels were determined by fiber-optics and molecular marker pimonidazole binding. Immuno-fluorescence was used to determine vessel normalization status. Continued OTX008 treatment caused a transient reoxygenation in SQ20B tumors peaking on day 14, while a steady increase in tumor oxygenation was observed over 21 days in the HEp-2 model. A >50% decrease in immunohistochemical staining for tumor hypoxia verified the oxygenation data measured using a partial pressure of oxygen (pO2) probe. Additionally, OTX008 induced tumor vessel normalization as tumor pericyte coverage increased by approximately 40% without inducing any toxicity. Moreover, OTX008 inhibited tumor growth as effectively as Anginex and Avastin, except in the HEp-2 model where Avastin was found to suspend tumor growth. Galectin-1 inhibitor OTX008 transiently increased overall tumor oxygenation via vessel normalization to various degrees in both HNSCC models. These findings suggest that targeting galectin-1-e.g., by OTX008-may be an effective approach to treat cancer patients as stand-alone therapy or in combination with other standards of care.

Ex-vivo complexation, skin permeation, interaction and cytodermal toxicity studies of p-tertbutylcalix[4]arene nanoemulsion for radiation decontamination.

AIMS: p-tertbutylcalix[4]arene loaded nanoemulsion has been designed, characterized and evaluated for skin decontamination of radionuclides of interest in nuclear and radiological emergencies. Further, nanoemulsion was evaluated for Ex-vivo complexation, skin permeation, interaction and cytodermal toxicity. MATERIALS AND METHODS: Ex-vivo skin complexation studies were conducted using High-resolution sector field inductively coupled plasma mass spectroscopy (HR-SF-ICPMS). Skin studies at dermal and cyto-dermal level have been carried out using techniques such as florescence microscopy, Differential scanning calorimetry (DSC), Flow cytometry, Confocal microscopy, Prestoblue and Comet assay. KEY FINDINGS: HR-SF-ICPMS study confirmed >95% complexation of surrogate nuclides of thallium and Iodine applied on excised rat skin mounted over Franz diffusion cell. Temporal analysis of aliquots obtained from Franz diffusion cell using UV-Vis absorption spectroscopy indicated that only 3.37% of formulation permeates through the skin. Skin penetration study of rhodamine 123 nanoemulsion carried out using florescence microscopy confirmed that formulation remains localised in epidermis of rat skin. DSC data confirmed skin compatibility of nanoemulsion, as no lipid extraction was observed from skin. In-vitro cell viability and cellular uptake assays performed on human skin fibroblasts prove no cellular uptake and cytotoxic effects. Comet assay, cell cycle arrest, and apoptosis-inducing mechanistic studies prove that prepared nanoemulsion is safe at cellular level. SIGNIFICANCE: Taken together, data indicate that p-tertbutylcalix[4]arene nanoemulsion is both effective and safe formulation to use on skin for radio-decontamination.

Applications of calixarenes in cancer chemotherapy: facts and perspectives.

Research on the therapeutic applications of calixarene derivatives is an emerging area of interest. The anticancer activity of various functionalized calixarenes has been reported by several research groups. Due to their superior geometric shape, calixarenes can accommodate drug molecules by forming inclusion complexes. Controlled release of anticancer drugs by calixarenes might help in targeted chemotherapy. This review summarizes the anticancer potential of the calixarenes and their drug loading properties. The potential use of calixarenes in chemoradiotherapy is also highlighted in brief.

Preparation and characterization of amphiphilic calixarene nanoparticles as delivery carriers for paclitaxel.

Two types of amphoteric calix[n]arene carboxylic acid (CnCA) derivative, i.e., calix[6]arene hexa-carboxylic acid (C6HCA) and calix[8]arene octo-carboxylic acid (C8OCA), were synthesized by introducing acetoxyls into the hydroxyls of calix[n]arene (n=6, 8). C6HCA and C8OCA nanoparticles (NPs) were prepared successfully using the dialysis method. CnCA NPs had regular spherical shapes with an average diameter of 180-220 nm and possessed negative charges of greater than -30 mV. C6HCA and C8OCA NPs were stable in 4.5% bovine serum albumin solutions and buffers (pH 5-9), with a low critical aggregation concentration value of 5.7 mg·L(-1) and 4.0 mg·L(-1), respectively. C6HCA and C8OCA NPs exhibited good paclitaxel (PTX) loading capacity, with drug loading contents of 7.5% and 8.3%, respectively. The overall in vitro release behavior of PTX from the CnCA NPs was sustained, and C8OCA NPs had a slower release rate compared with C6HCA NPs. These favorable properties of CnCA NPs make them promising nanocarriers for tumor-targeted drug delivery.

Pharmacokinetics and antineoplastic activity of galectin-1-targeting OTX008 in combination with sunitinib.

PURPOSE: OTX008 is a galectin-1-targeting compound, currently undergoing a phase I clinical trial. This study aimed at investigating OTX008 pharmacokinetics (PK) and antineoplastic activity. METHODS: Pharmacokinetics and activity of OTX008 were analyzed in the human ovarian carcinoma A2780-1A9 and glioblastoma U87MG xenografted in nude mice. In vitro, OTX008 was tested on tumor and endothelial cells. RESULTS: After 5 mg/kg i.v., OTX008 achieved plasma Cmax of 14.39 µg/mL, distributed rapidly, and was eliminated with a half-life of 31.4 h. Tumor OTX008 Cmax (1.65 µg/g, 1.76 µM), achieved at 0.5 h, remained high at 24 h (0.516 µg/g, 0.55 µM) with AUC of 15.76 µg/g*h. OTX008 accumulated in the tumor after repeated administrations achieving a concentration of 2.3 µM, compatible with the concentrations active in vitro. OTX008 (5 mg/kg i.v., every other day for 3 weeks) inhibited the in vivo growth of A2780-1A9, whereas U87MG was not sensitive. In vitro, OTX008 affected endothelial cell proliferation, motility, invasiveness, and cord formation. Tumor cell proliferation was also inhibited, with differences in sensitivity among cell lines (IC50 from 1 to 190 µM). OTX008 potentiated the activity of the tyrosine kinase inhibitor sunitinib on A2780-1A9 in vivo and in vitro, where the combination showed synergistic (endothelial cells) and additive (A2780-1A9) antiproliferative activity, indicating that the combination targets both the tumor and vascular compartments. CONCLUSIONS: OTX008-alone or in combination with sunitinib-has a favorable PK and antineoplastic activity on selected tumor models through the effects on both endothelial and tumor cells.

A new formulation containing calixarene molecules as an emergency treatment of uranium skin contamination.

Cutaneous contamination represents the second highest contamination pathway in the nuclear industry. Despite that the entry of actinides such as uranium into the body through intact or wounded skin can induce a high internal exposure, no specific emergency treatment for cutaneous contamination exists. In the present work, an innovative formulation dedicated to uranium skin decontamination was developed. The galenic form consists in an oil-in-water nanoemulsion, which contains a tricarboxylic calixarene known for its high uranium affinity and selectivity. The physicochemical characterization of this topical form revealed that calixarene molecules are located at the surface of the dispersed oil droplets of the nanoemulsion, being thus potentially available for uranium chelation. It was demonstrated in preliminary in vitro experiments by using an adapted ultrafiltration method that the calixarene nanoemulsion was able to extract and retain more than 80% of uranium from an aqueous uranyl nitrate contamination solution. First ex vivo experiments carried out in Franz diffusion cells on pig ear skin explants during 24 h showed that the immediate application of the calixarene nanoemulsion on a skin contaminated by a uranyl nitrate solution allowed a uranium transcutaneous diffusion decrease of about 98% through intact and excoriated skins. The calixarene nanoemulsion developed in this study thus seems to be an efficient emergency system for uranium skin decontamination.

Calixarene-entrapped nanoemulsion for uranium extraction from contaminated solutions.

Accidental cutaneous contamination by actinides such as uranium occurring to nuclear power plant workers can lead to their dissemination in other tissues and induce severe damages. Until now, no specific emergency treatment for such contamination has been developed. The aim of the present work was to formulate a tricarboxylic calix[6]arene molecule, known to exhibit good affinity and selectivity for complexing uranium, within a topical delivery system for the treatment of skin contamination. Since calixarene was shown to reduce oil/water interfacial tension, we have designed an oil-in-water nanoemulsion, taking advantage of the small droplet size offering a high contact surface with the contaminated aqueous medium. Characterization of the calixarene nanoemulsion was performed by determination of the oily droplet size, zeta potential and pH, measured as a function of the calixarene concentration. The obtained results have confirmed the surface localization of calixarene molecules being potentially available to extract uranyl ions from an aqueous contaminated solution. In a preliminary experiments, the calixarene nanoemulsion was used for the removal of free uranium from an aqueous contaminated solution. Results showed that the calixarene nanoemulsion extracted up to 80 +/- 5% of uranium, which demonstrates the potential interest of this delivery system for uranium skin decontamination.

Side-on binding of p-sulphonatocalix[4]arene to the dinuclear platinum complex trans-[{PtCl(NH3)2}2mu-dpzm]2+ and its implications for anticancer drug delivery.

The utility of p-sulphonatocalix[4]arene (s-CX[4]) as a drug delivery vehicle for multinuclear platinum anticancer agents, using trans-[{PtCl(NH(3))(2)}(2)mu-dpzm](2+) (di-Pt; where dpzm=4,4'-dipyrazolylmethane) as a model complex, has been examined using (1)H nuclear magnetic resonance, electrospray ionisation mass spectrometry, molecular modelling and in vitro growth inhibition assays. s-CX[4] binds di-Pt in a side-on fashion in a ratio of 1:1, with the dpzm ligand of the metal complex located within the s-CX[4] cavity with binding further stabilised by ion-ion interactions and hydrogen bonding between the metal complex am(m)ine groups and the s-CX[4] sulphate groups. Partial encapsulation of di-Pt within the cavity does not prevent binding of 5'-guanosine monophosphate to the metal complex. When bound to two individual guanosine molecules, di-Pt also remains partially bound by s-CX[4]. The cytotoxicity of free di-Pt and s-CX[4] and their host guest complex was examined using in vitro growth inhibition assays in the A2780 and A2780cis human ovarian cancer cell lines. Free di-Pt has an IC(50) of 100 and 60 microM, respectively, in the cell lines, which is significantly less active than cisplatin (1.9 and 8.1 microM, respectively). s-CX[4] displays no cytotoxicity at concentrations up to 1.5mM and does not affect the cytotoxicity of di-Pt, probably because its low binding constant to the metal complex (6.8 x 10(4)M(-1)) means the host-guest complex is mostly disassociated at biologically relevant concentrations.

Synthesis and characterization of Sn(IV) complexes of lower rim 1,3-diacid derivative of calix[4]arene and their protective effects on tissue oxidative stress and essential metal concentration in lead exposed male Wistar rats.

The two Sn(IV) complexes synthesized using calix[4]arene-1,3-di-acid derivative were characterized by analytical, (1)H, (13)C and (119)Sn NMR, matrix assisted laser desorption ionization mass, and (119)Sn Mossbauer techniques and found that the complexes are tetranuclear possessing structurally two different types of tin centers. These complexes were evaluated for their protective value against blood and tissue oxidative stress in lead exposed male albino rats of Wistar strain. The results suggest that the two tin complexes significantly protect changes in lead induced biochemical variables indicative of heme synthesis pathway and exhibit only moderate effect on tissue oxidative stress. The beneficial effects could be attributed mainly to the ability of Sn(IV) complexes in preventing absorption of lead to the target sites/tissues.