Self-assembling antitumour prodrugs for localised drug delivery

Localised cancer therapy is a developing strategy used to overcome the systemic toxicity associated with intravenous systemic chemotherapy, which still represents the primary route of administration for the majority of current anticancer agents. Low molecular weight gelators (LMWGs) have recently gained increasing popularity as drug delivery platforms for localised cancer therapy: they are small molecules, which self-assemble into a 3D network via non-covalent interactions. Due to their inherent biocompatibility, LMWGs represent a viable alternative to the extensively explored polymer based drug delivery systems. One such drug delivery approach, based on LMWGs, involves the synthesis of gelator-based prodrugs of chemotherapeutic agents; however, to date, there remains a limited number of anticancer prodrugs that have gelation properties. Therefore, the present work aims to find new chemotherapeutic agents that display gelation properties by modification of the parent drug with known self-assembling groups. Two anticancer agents have been evaluated: the clinical antimetabolite methotrexate (MTX) and the experimental benzothiazole derivative 5F 203, both characterised by significant anticancer activity but systemic toxicity. Therefore, formulation of MTX and 5F 203 as LMWGs-based prodrugs for localised cancer therapy was considered a useful strategy to overcome the systemic toxicity of these antitumour drugs. Different synthetic approaches were explored to formulate self-assembling MTX prodrugs. The most successful one involved the synthesis of MTX derivatives bearing alkyl chains and aromatic groups at the α or both α and γ carboxylic acid terminals of MTX. Unfortunately, preliminary gelation tests performed on MTX acyl derivatives via a solvent-switch method, revealed lack of self-assembling properties. Therefore, the MTX conjugates developed were not suitable for localised drug delivery applications. Due to the absence of self-assembling properties of MTX conjugates, the potential gelation behaviour of novel derivatives of another anticancer candidate, the benzothiazole agent 5F 203, was considered, and two amide prodrugs series of 5F 203 were investigated. Amongst the compounds tested for gelation, 5F 203 succinic acid conjugate (68a) revealed formation of a hydrogel at physiological pH. Rheological measurements confirmed its LMWG nature, showing formation of a cross-linked gel network. In vitro growth inhibitory assays against breast (MCF-7) and ovarian (IGROV-1 and OVCAR-4) carcinoma cell lines showed overall activity of 5F 203 amide prodrugs in inhibiting cell proliferation. Release studies from the gel matrix of 68a revealed a release of the derivative and the active drug over 3 days, thus confirming its potential application as a depot formulation for localised delivery of 5F 203. In order to improve the rate of conversion of prodrugs into the parent amine 5F 203, compared to the previous amide series developed, acyloxyalkoxycarbonyl derivatives of 5F 203 were synthesised. Gelation tests displayed self-assembling behaviour for derivatives 76a-76c and rheological studies confirmed the LMWG nature of the new entities. The acyloxyalkoxycarbonyl prodrugs revealed in vitro potencies similar to those displayed by 5F 203, when tested against MCF-7 and IGROV-1 cell lines. The isobutyl carbamate prodrug (76a) proved to be the most potent of the series, showing hydrolysis into the active drug 5F 203, when incubated in either PBS buffer, rat or human plasma; release from the gel matrix also showed release of 5F 203 in PBS within 72 h. The outcomes from this work have therefore provided a basis for future optimisation and development of LMWG derivatives of 5F 203, as depot formulations for localised delivery of this anticancer agent

Kinetically controlled coassembly of multichromophoric peptide hydrogelators and the impacts on energy transport

We report a peptide-based multichromophoric hydrogelator system, wherein π-electron units with different inherent spectral energies are spatially controlled within peptidic 1-D nanostructures to create localized energy gradients in aqueous environments. This is accomplished by mixing different π-conjugated peptides prior to initiating self-assembly through solution acidification. We can vary the kinetics of the assembly and the degree of self-sorting through the choice of the assembly trigger, which changes the kinetics of acidification. The hydrolysis of glucono-δ-lactone (GdL) provides a slow pH drop that allows for stepwise triggering of peptide components into essentially self-sorted nanostructures based on subtle pKa differences, whereas HCl addition leads to a rapid formation of mixed components within a nanostructure. Using 1H NMR spectroscopy and fiber X-ray diffraction, we determine the conditions and peptide mixtures that favor self-sorting or intimate comixing. Photophysical investigations in the solution phase provide insight into the correlation of energy-transport processes occurring within the assemblies to the structural organization of the π-systems

Alzheimer's disease-like paired helical filament assembly from truncated tau protein is independent of disulphide cross-linking

Abstract Alzheimer's disease is characterised by the self-assembly of tau and amyloid β proteins into oligomers and fibrils. Tau protein assembles into paired helical filaments (PHFs) that constitute the neurofibrillary tangles observed in neuronal cell bodies in individuals with Alzheimer's disease. The mechanism of initiation of tau assembly into {PHFs} is not well understood. Here we report that a truncated 95-amino acid tau fragment (corresponding to residues 297-391 of full-length tau) assembles into PHF-like fibrils in vitro without the need for other additives to initiate or template the process. Using electron microscopy, circular dichroism and X-ray fibre diffraction, we have characterised the structure of the fibrils formed from truncated tau for the first time. To explore the contribution of disulphide formation to fibril formation, we have compared the assembly of tau(297-391) under reduced and non-reducing conditions and for truncated tau carrying a {C322A} substitution. We show that disulphide bond formation inhibits assembly and that the {C322A} variant rapidly forms long and highly ordered PHFs

Self-assembling benzothiazole-based gelators: a mechanistic understanding of in vitro bioactivation and gelation

Low molecular weight gelators (LMWGs) of chemotherapeutic drugs represent a valid alternative to the existing poly-mer-based formulations used for targeted delivery of anticancer drugs. Herein we report the design and development of novel self-assembling gelators of the antitumour benzothiazole 5F 203 (1). Two different types of derivatives of 1 were synthesized, formed by an amide (2) and a carbamate (3a-3d) linker, respectively, which showed potent in vitro anti-tumour activity against MCF-7 mammary and IGROV-1 ovarian carcinoma cells. In contrast, MRC-5 fibroblasts were inherently resistant to the above derivatives (GI50>10 μM), thus revealing stark selectivity against the malignant cell lines over the non-transformed fibroblasts. Western blots assays demonstrated induction of CYP1A1 by 1 and its deriva-tives only in sensitive malignant cells (MCF-7), corroborating conservation of CYP1A1-mediated mechanism of action. The ability to form stable gels under relatively high strains was supported by rheological tests; in addition, their inner morphology was characterized as possessing a crossed-linked nanostructure, with formation of thick aggregates with variable widths between 1100 nm and 400 nm and lengths from 8 μm to 32 μm. Finally, in vitro dissolution studies proved the ability of hydrogel 2 to release 48% of 2 within 80 hours, therefore demonstrating its ability to act as a plat-form for localized delivery

Self-assembling antitumour prodrugs for localised drug delivery

Localised cancer therapy is a developing strategy used to overcome the systemic toxicity associated with intravenous systemic chemotherapy, which still represents the primary route of administration for the majority of current anticancer agents. Low molecular weight gelators (LMWGs) have recently gained increasing popularity as drug delivery platforms for localised cancer therapy: they are small molecules, which self-assemble into a 3D network via non-covalent interactions. Due to their inherent biocompatibility, LMWGs represent a viable alternative to the extensively explored polymer based drug delivery systems. One such drug delivery approach, based on LMWGs, involves the synthesis of gelator-based prodrugs of chemotherapeutic agents; however, to date, there remains a limited number of anticancer prodrugs that have gelation properties. Therefore, the present work aims to find new chemotherapeutic agents that display gelation properties by modification of the parent drug with known self-assembling groups. Two anticancer agents have been evaluated: the clinical antimetabolite methotrexate (MTX) and the experimental benzothiazole derivative 5F 203, both characterised by significant anticancer activity but systemic toxicity. Therefore, formulation of MTX and 5F 203 as LMWGs-based prodrugs for localised cancer therapy was considered a useful strategy to overcome the systemic toxicity of these antitumour drugs. Different synthetic approaches were explored to formulate self-assembling MTX prodrugs. The most successful one involved the synthesis of MTX derivatives bearing alkyl chains and aromatic groups at the α or both α and γ carboxylic acid terminals of MTX. Unfortunately, preliminary gelation tests performed on MTX acyl derivatives via a solvent-switch method, revealed lack of self-assembling properties. Therefore, the MTX conjugates developed were not suitable for localised drug delivery applications. Due to the absence of self-assembling properties of MTX conjugates, the potential gelation behaviour of novel derivatives of another anticancer candidate, the benzothiazole agent 5F 203, was considered, and two amide prodrugs series of 5F 203 were investigated. Amongst the compounds tested for gelation, 5F 203 succinic acid conjugate (68a) revealed formation of a hydrogel at physiological pH. Rheological measurements confirmed its LMWG nature, showing formation of a cross-linked gel network. In vitro growth inhibitory assays against breast (MCF-7) and ovarian (IGROV-1 and OVCAR-4) carcinoma cell lines showed overall activity of 5F 203 amide prodrugs in inhibiting cell proliferation. Release studies from the gel matrix of 68a revealed a release of the derivative and the active drug over 3 days, thus confirming its potential application as a depot formulation for localised delivery of 5F 203. In order to improve the rate of conversion of prodrugs into the parent amine 5F 203, compared to the previous amide series developed, acyloxyalkoxycarbonyl derivatives of 5F 203 were synthesised. Gelation tests displayed self-assembling behaviour for derivatives 76a-76c and rheological studies confirmed the LMWG nature of the new entities. The acyloxyalkoxycarbonyl prodrugs revealed in vitro potencies similar to those displayed by 5F 203, when tested against MCF-7 and IGROV-1 cell lines. The isobutyl carbamate prodrug (76a) proved to be the most potent of the series, showing hydrolysis into the active drug 5F 203, when incubated in either PBS buffer, rat or human plasma; release from the gel matrix also showed release of 5F 203 in PBS within 72 h. The outcomes from this work have therefore provided a basis for future optimisation and development of LMWG derivatives of 5F 203, as depot formulations for localised delivery of this anticancer agent

Antitumour benzothiazoles. Part 32: DNA adducts and double strand breaks correlate with activity; synthesis of 5F203 hydrogels for local delivery

Potent, selective antitumour AhR ligands 5F 203 and GW 610 are bioactivated by CYPs 1A1 and 2W1. Herein we reason that DNA adducts’ generation resulting in lethal DNA double strand breaks (DSBs) underlies benzothiazoles’ activity. Treatment of sensitive carcinoma cell lines with GW 610 generated co-eluting DNA adducts (R2 > 0.7). Time-dependent appearance of γ-H2AX foci revealed subsequent DNA double strand breaks. Propensity for systemic toxicity of benzothiazoles steered development of prodrugs’ hydrogels for localised delivery. Clinical applications of targeted therapies include prevention or treatment of recurrent disease after surgical resection of solid tumours. In vitro evaluation of 5F 203 prodrugs’ activity demonstrated nanomolar potency against MCF-7 breast and IGROV-1 ovarian carcinoma cell lines

The scientific payload on-board the HERMES-TP and HERMES-SP CubeSat missions

none103siHERMES (High Energy Rapid Modular Ensemble of Satellites) Technological and Scientific pathfinder is a space borne mission based on a LEO constellation of nano-satellites. The 3U CubeSat buses host new miniaturized detectors to probe the temporal emission of bright high-energy transients such as Gamma-Ray Bursts (GRBs). Fast transient localization, in a field of view of several steradians and with arcmin-level accuracy, is gained by comparing time delays among the same event detection epochs occurred on at least 3 nano-satellites. With a launch date in 2022, HERMES transient monitoring represents a keystone capability to complement the next generation of gravitational wave experiments. In this paper we will illustrate the HERMES payload design, highlighting the technical solutions adopted to allow a wide-energy-band and sensitive X-ray and gamma-ray detector to be accommodated in a CubeSat 1U volume together with its complete control electronics and data handling system.noneEvangelista, Yuri; Fiore, Fabrizio; Fuschino, Fabio; Campana, Riccardo; Ceraudo, Francesco; Demenev, Evgeny; Guzman, Alejandro; Labanti, Claudio; La Rosa, Giovanni; Fiorini, Mauro; Gandola, Massimo; Grassi, Marco; Mele, Filippo; Morgante, Gianluca; Nogara, Paolo; Piazzolla, Raffaele; Pliego Caballero, Samuel; Rashevskaya, Irina; Russo, Francesco; Sciarrone, Giulia; Sottile, Giuseppe; Milankovich, Dorottya; Pál, András; Ambrosino, Filippo; Auricchio, Natalia; Barbera, Marco; Bellutti, Pierluigi; Bertuccio, Giuseppe; Borghi, Giacomo; Cao, Jiewei; Chen, Tianxiang; Dilillo, Giuseppe; Feroci, Marco; Ficorella, Francesco; Lo Cicero, Ugo; Malcovati, Piero; Morbidini, Alfredo; Pauletta, Giovanni; Picciotto, Antonino; Rachevski, Alexandre; Santangelo, Andrea; Tenzer, Chistoph; Vacchi, Andrea; Wang, Lingjun; Xu, Yupeng; Zampa, Gianluigi; Zampa, Nicola; Zorzi, Nicola; Burderi, Luciano; Lavagna, Michèle; Bertacin, Roberto; Lunghi, Paolo; Monge, Angel; Negri, Barbara; Pirrotta, Simone; Puccetti, Simonetta; Sanna, Andrea; Amarilli, Fabrizio; Amelino-Camelia, Giovanni; Bechini, Michele; Citossi, Marco; Colagrossi, Andrea; Curzel, Serena; Della Casa, Giovanni; Cinelli, Marco; Del Santo, Melania; Di Salvo, Tiziana; Feruglio, Chiara; Ferrandi, Fabrizio; Fiorito, Michele; Gacnik, Dejan; Galgóczi, Gabor; Gambino, Angelo Francesco; Ghirlanda, Giancarlo; Gomboc, Andreja; Karlica, Mile; Efremov, Pavel; Kostic, Uros; Clerici, Aurora; Lopez Fernandez, Borja; Maselli, Alessandro; Nava, Lara; Ohno, Masanori; Ottolina, Daniele; Pasquale, Andrea; Perri, Matteo; Piccinin, Margherita; Prinetto, Jacopo; Riggio, Alessandro; Ripa, Jakub; Papitto, Alessandro; Piranomonte, Silvia; Scala, Francesca; Selcan, David; Silvestrini, Stefano; Rotovnik, Tomaz; Virgilli, Enrico; Troisi, Ivan; Werner, Norbert; Zanotti, Giovanni; Anitra, Alessio; Manca, Arianna; Clerici, AuroraEvangelista, Yuri; Fiore, Fabrizio; Fuschino, Fabio; Campana, Riccardo; Ceraudo, Francesco; Demenev, Evgeny; Guzman, Alejandro; Labanti, Claudio; La Rosa, Giovanni; Fiorini, Mauro; Gandola, Massimo; Grassi, Marco; Mele, Filippo; Morgante, Gianluca; Nogara, Paolo; Piazzolla, Raffaele; Pliego Caballero, Samuel; Rashevskaya, Irina; Russo, Francesco; Sciarrone, Giulia; Sottile, Giuseppe; Milankovich, Dorottya; Pál, András; Ambrosino, Filippo; Auricchio, Natalia; Barbera, Marco; Bellutti, Pierluigi; Bertuccio, Giuseppe; Borghi, Giacomo; Cao, Jiewei; Chen, Tianxiang; Dilillo, Giuseppe; Feroci, Marco; Ficorella, Francesco; Lo Cicero, Ugo; Malcovati, Piero; Morbidini, Alfredo; Pauletta, Giovanni; Picciotto, Antonino; Rachevski, Alexandre; Santangelo, Andrea; Tenzer, Chistoph; Vacchi, Andrea; Wang, Lingjun; Xu, Yupeng; Zampa, Gianluigi; Zampa, Nicola; Zorzi, Nicola; Burderi, Luciano; Lavagna, Michèle; Bertacin, Roberto; Lunghi, Paolo; Monge, Angel; Negri, Barbara; Pirrotta, Simone; Puccetti, Simonetta; Sanna, Andrea; Amarilli, Fabrizio; Amelino-Camelia, Giovanni; Bechini, Michele; Citossi, Marco; Colagrossi, Andrea; Curzel, Serena; Della Casa, Giovanni; Cinelli, Marco; Del Santo, Melania; Di Salvo, Tiziana; Feruglio, Chiara; Ferrandi, Fabrizio; Fiorito, Michele; Gacnik, Dejan; Galgóczi, Gabor; Gambino, Angelo Francesco; Ghirlanda, Giancarlo; Gomboc, Andreja; Karlica, Mile; Efremov, Pavel; Kostic, Uros; Clerici, Aurora; Lopez Fernandez, Borja; Maselli, Alessandro; Nava, Lara; Ohno, Masanori; Ottolina, Daniele; Pasquale, Andrea; Perri, Matteo; Piccinin, Margherita; Prinetto, Jacopo; Riggio, Alessandro; Ripa, Jakub; Papitto, Alessandro; Piranomonte, Silvia; Scala, Francesca; Selcan, David; Silvestrini, Stefano; Rotovnik, Tomaz; Virgilli, Enrico; Troisi, Ivan; Werner, Norbert; Zanotti, Giovanni; Anitra, Alessio; Manca, Arianna; Clerici, Auror

The HERMES-technologic and scientific pathfinder

HERMES-TP/SP (High Energy Rapid Modular Ensemble of Satellites Technologic and Scientific Pathfinder) is a constellation of six 3U nano-satellites hosting simple but innovative X-ray detectors, characterized by a large energy band and excellent temporal resolution, and thus optimized for the monitoring of Cosmic High Energy transients such as Gamma Ray Bursts and the electromagnetic counterparts of Gravitational Wave Events, and for the determination of their positions. The projects are funded by the Italian Ministry of University and Research and by the Italian Space Agency, and by the European Union's Horizon 2020 Research and Innovation Program under Grant Agreement No. 821896. HERMES-TP/SP is an in-orbit demonstration, that should be tested starting from 2022. It is intrinsically a modular experiment that can be naturally expanded to provide a global, sensitive all sky monitor for high-energy transients