An investigation has been conducted to assess the in vivo stability of a series of astatinated benzamides and astatinated nido-carborane compounds in mice. It was hypothesized that the higher bond strength of boron-astatine bonds in the nido-carboranes might provide increased stability toward in vivo deastatination. Four tri-n-butylstannylbenzamides were prepared for radiohalogenation and evaluation in vivo. Those compounds were N-propyl-4-(tri-n-butylstannyl)benzamide 1a, N-propyl-3-(tri-n-butylstannyl)benzamide 2a, ethyl 4-tri-n-butylstannylhippurate 3a, and 4-tri-n-butylstannyl-hippuric acid 4a. Seven mono-nido-carboranyl derivatives were prepared for radiohalogenation and in vivo evaluation. Four of the seven mono-carboranyl derivatives (5a, 6a, 7a, 13a) contained a 3-(nido-carboranyl)propionamide functionality, and the remaining compounds (8a, 8g, 10a) contained a 4-(nido-carboranyl)aniline functionality. Two additional derivatives (11a, 12a) were prepared that contained bis-(nido-carboranylmethyl)benzene moieties (also referred to as Venus flytrap complexes (VFCs). All benzamide and nido-carborane compounds underwent facile iodination and radiohalogenation, except a 4-(nido-carboranyl)aniline derivative, 8a. Iodination of 8a resulted in a mixture, of which the desired iodinated product was a minor component. Therefore, radiohalogenation was not attempted. It is believed that the mixture of products is due to the presence of a thiourea bond. Previous studies have shown that thiourea bonds can interfere with halogenation reactions. In vivo comparisons of the compounds were conducted by co-injection of dual labeled (125/131I and 211At) compounds. Tissue distribution data were obtained at 1 and 4 h postinjection of the radiolabeled compounds, as that was sufficient to determine if astatine was being released. Stability of the astatinated compound was assessed by the difference in concentration of radioiodine and astatine in lung and spleen. All of the benzamides were found to undergo rapid deastatination in vivo. The nido-carborane derivatives appeared to be slightly more stable to in vivo deastatination; however, they had long blood residence times. The surprising finding was that the VFC derivatives did not release 211At in vivo, even though they rapidly localized to liver. This finding provides encouragement that stable conjugates of 211At may be attained if appropriate modifications of the VFC can be made to redirect their excretion through the renal system.

tothermally triggered on-demand insulin release from reduced graphene oxide modified hydrogels. Journal of Controlled Release, Elsevier, 2017Elsevier, , 246, pp.164-173. 10.1016Elsevier, /j.jconrel.2016 Abstract.On-demand delivery of therapeutics plays an essential role in simplifying and improving patient care. The high loading capacity of reduced graphene oxide (rGO) for drugs has made this matrix of particular interest for its hybridization with therapeutics. In this work, we describe the formulation of rGO impregnated poly(ethylene glycol) dimethacrylate based hydrogels (PEGDMA-rGO) and their efficient loading with insulin. Near-infrared (NIR) light induced heating of the PEGDMA-rGO hydrogels allows for highly efficient insulin release. Most importantly, we validate that the NIR irradiation of the hydrogel has no effect on the biological and metabolic activities of the released insulin. The ease of insulin loading/reloading makes this photothermally triggered release strategy of interest for diabetic patients. Additionally, the rGO-based protein releasing platform fabricated here can be expanded towards 'on demand' release of various other therapeutically relevant biomolecules. The table of contents entry: Poly(ethylene glycol) based hydrogels impregnated with rGO allow efficient loading and 'on demand' photothermal release of insulin while preserving its biological and metabolic activity.

cCompetence for natural DNA transformation is a tightly controlled developmental process in streptococci. In mutans and salivarius species, the abundance of the central competence regulator X is regulated at two levels: transcriptional, by the ComRS signaling system via the X /ComX/SigX-inducing peptide (XIP), and posttranscriptional, by the adaptor protein MecA and its associated Clp ATPase, ClpC. In this study, we further investigated the mechanism and function of the MecA-ClpC control system in the salivarius species Streptococcus thermophilus. Using in vitro approaches, we showed that MecA specifically interacts with both X and ClpC, suggesting the formation of a ternary X -MecA-ClpC complex. Moreover, we demonstrated that MecA ultimately targets X for its degradation by the ClpCP protease in an ATP-dependent manner. We also identify a short sequence (18 amino acids) in the N-terminal domain of X as essential for the interaction with MecA and subsequent X degradation. Finally, increased transformability of a MecA-deficient strain in the presence of subinducing XIP concentrations suggests that the MecA-ClpCP proteolytic complex acts as an additional locking device to prevent competence under inappropriate conditions. A model of the interplay between ComRS and MecA-ClpCP in the control of X activity is proposed.

The development of a skin-mounted patch capable of controlled transcutaneous delivery of therapeutics through thermal activation provides a unique solution for the controlled release of active principles over long-term periods. Here, we report on a flexible transdermal patch for photothermal triggered release of ondansetron (ODS), a commonly used drug for the treatment of chemotherapy-induced nausea and vomiting and used as model compound here. To achieve this, a dispersion of ODS-loaded reduced graphene oxide (rGO-ODS) nanosheets were deposited onto Kapton to produce a flexible polyimide-based patch. It is demonstrated that ODS loaded Kapton/rGO patches have a high drug delivery performance upon irradiation with a continuous laser beam at 980nm for 10min due to an induced photothermal heating effect. The ability of ODS impregnated Kapton/rGO patches as transdermal delivery scaffolds for ODS across the skin is in addition investigated using porcine ear skin as a model. We show that the cumulative quantity and flux of ODS passing the skin are highly depending on the laser power density used. At 5Wcm irradiation, the ODS flux across pig skin was determined to be 1.6μgcmh comparable to other approaches. The use of tween 20 as skin enhancer could significantly increase the ODS flux to 13.2μgcmh. While the skin penetration enhancement is comparable to that obtained using other well-known permeation enhancers, the actual superiority and interest of the proposed approach is that the Kapton/rGO photoactivatable skin patch can be loaded with any drugs and therapeutics of interest, making the approach extremely versatile. The on demand delivery of drugs upon local laser irradiation and the possibility to reload the interface with the drug makes this new drug administration route very appealing.

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Intrinsically disordered protein YAP (yes-associated protein) interacts with TEADs transcriptional factors family (transcriptional enhancer associated domain) creating three interfaces. Interface 3, between the Ω-loop of YAP and a shallow pocket of TEAD was identified as the most important TEAD zone for YAP-TEAD interaction. Using the first X-ray structure of the hYAP50–71-hTEAD1209–426 complex (PDB 3KYS) published in 2010, a protein-protein interaction inhibitors-enriched library (175,000 chemical compounds) was screened against this hydrophobic pocket of TEAD. Four different chemical families have been identified and evaluated using biophysical techniques (thermal shift assay, microscale thermophoresis) and in cellulo assays (luciferase activity in transfected HEK293 cells, RTqPCR in MDA-MB231 cells). A first promising hit with micromolar inhibition in the luciferase gene reporter assay was discovered. This hit also decreased mRNA levels of TEAD target genes.

A new class of radioiodinated biotin conjugated is described in which the amido bond between biotin and the labeled prosthetic group is reversed. One conjugate, (3-[125I]iodobenzoyl)norbiotinamide (4c, [125I]IBB) was labeled with Na125I in one step from (3-(tributylstannyl)benzoyl)norbiotinamide (4b, TBB) via a demetalation reaction. However, the analogous reaction with ((5-(tributylstannyl)-3-pyridinyl)carbonyl)norbiotinamide (6b, TPB) failed to yield ((5-[131I]iodo-3-pyridinyl)carbonyl)norbiotinamide (6c, [131I]IPB, necessitating a two-step approach for synthesizing [131I]IPB. The binding of [125I]IBB and [131I]IPB to streptavidin in vitro was identical to that of biotinyl-3-[125I]iodoanilide, a conjugate with an amido bond with normal configuration. Both [125I]IBB and [131I]IPB were stable in serum while the first-generation compound was rapidly degraded. The biodistribution patterns of [125I]IBB and [131I]IPB in mice are consistent with limited degradation of these conjugates by biotinidase and deiodinases.

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