Publications

Gamma aminobutyric acid type A receptors (GABA(A)Rs) play a key role in the mammalian central nervous system (CNS) as drivers of neuroinhibitory circuits, which are commonly targeted for therapeutic purposes with potentiator drugs. However, due to their widespread expression and strong inhibitory action, systemic pharmaceutical potentiation of GABA(A)Rs inevitably causes adverse effects regardless of the drug selectivity. Therefore, therapeutic guidelines must often limit or exclude clinically available GABA(A)R potentiators, despite their high efficacy, good biodistribution, and favorable molecular properties. One solution to this problem is to use drugs with light-dependent activity (photopharmacology) in combination with on-demand, localized illumination. However, a suitable light-activated potentiator of GABA(A)Rs has been elusive so far for use in wildtype mammals. We have met this need by developing azocarnil, a diffusible GABAergic agonist-potentiator based on the anxiolytic drug abecarnil that is inactive in the dark and activated by visible violet light. Azocarnil can be rapidly deactivated with green light and by thermal relaxation in the dark. We demonstrate that it selectively inhibits neuronal currents in hippocampal neurons in vitro and in the dorsal horns of the spinal cord of mice, decreasing the mechanical sensitivity as a function of illumination without displaying systemic adverse effects. Azocarnil expands the in vivo photopharmacological toolkit with a novel chemical scaffold and achieves a milestone toward future phototherapeutic applications to safely treat muscle spasms, pain, anxiety, sleep disorders, and epilepsy.

JTD Keywords: A receptor, Abecarnil, Affinity, Beta-carboline, Efficacy, Modulator, Optical control, Pain, Site, Subtype

Objective: Most endodontic diseases are bacterium-mediated inflammatory or necrotic process induced by contaminated dental pulp. Although great advances are being performed to obtain more efficient antibacterial strategies for persistent infections, most studies lack of representative models to test their antibacterial effects and their outcomes cannot be promptly translated to clinical practice. Therefore, this study aimed to refine an ex vivo endodontic biofilm model combining human tooth, computer guided design and 3D printing to obtain a more reproducible and predictable model. Methods: Monoradicular teeth were cut using three different methods: hand-held (HCC), mechanical precision (MPC) and computer aid guided cutting (CGC). Then, blocks were reassembled. The different model preparations were assessed in terms of dimensional tolerance, surface analysis, liquid tightness and Enterococcus faecalis biofilm development for 21 days, which was studied by metabolic assays and confocal microscopy. Then, the proposed model was validated using different commercial disinfecting treatments. Results: CGC exhibited significantly lower deviation and surface without defects compared to HHC and MPC, leading to superior liquid tightness. Similarly, mature biofilms with high metabolic activity and vitality were observed in all conditions, CGC showing the lowest variation. Regarding the model validation, all antibacterial treatments resulted in the complete eradication of bacteria in the standard 2D model, whereas commercial treatments exhibited varying levels of efficacy in the proposed ex vivo model, from moderately reduction of metabolic activity to complete elimination of biofilm. Conclusions: The novel guided approach represents a more reliable, standardized, and reproducible model for the evaluation of endodontic disinfecting therapies. Clinical Significance: During antibacterial treatment development, challenging 3D models using teeth substrates to test antibacterial treatments novel guided approach represents a more reliable, standardized, and reproducible model for the evaluation of endodontic disinfecting therapies.

JTD Keywords: 3d printin, Bacteria, Biofilm, Computer-aided manufacturing, Dental model, Dentin, Efficacy, Endodontics, Enterococcus faecalis, Enterococcus-faecalis, Irrigation, Protocols, Removal, Resistance, Susceptibility, Syste

Bladder cancer treatment via intravesical drug administration achieves reasonable survival rates but suffers from low therapeutic efficacy. To address the latter, self-propelled nanoparticles or nanobots have been proposed, taking advantage of their enhanced diffusion and mixing capabilities in urine when compared with conventional drugs or passive nanoparticles. However, the translational capabilities of nanobots in treating bladder cancer are underexplored. Here, we tested radiolabelled mesoporous silica-based urease-powered nanobots in an orthotopic mouse model of bladder cancer. In vivo and ex vivo results demonstrated enhanced nanobot accumulation at the tumour site, with an eightfold increase revealed by positron emission tomography in vivo. Label-free optical contrast based on polarization-dependent scattered light-sheet microscopy of cleared bladders confirmed tumour penetration by nanobots ex vivo. Treating tumour-bearing mice with intravesically administered radio-iodinated nanobots for radionuclide therapy resulted in a tumour size reduction of about 90%, positioning nanobots as efficient delivery nanosystems for bladder cancer therapy.© 2024. The Author(s).

JTD Keywords: cell, drug-delivery, nanomotors, tissue, Bladder cancers, Cancer therapy, Diseases, Drug administration, Drug delivery, Enhanced diffusion, Enhanced mixing, Ex-vivo, In-vivo, Mammals, Nanobots, Nanoparticles, Nanosystems, Oncology, Positron emission tomography, Radioisotopes, Silica, Survival rate, Therapeutic efficacy, Tumor penetration, Tumors

The rampant evolution of resistance in Plasmodium to all existing antimalarial drugs calls for the development of improved therapeutic compounds and of adequate targeted delivery strategies for them. Loading antimalarials in nanocarriers specifically targeted to the parasite will contribute to the administration of lower overall doses, with reduced side effects for the patient, and of higher local amounts to parasitized cells for an increased lethality toward the pathogen. Here, we report the development of dendronized hyperbranched polymers (DHPs), with capacity for antimalarial loading, that are coated with heparin for their specific targeting to red blood cells parasitized by Plasmodium falciparum. The resulting DHP-heparin complexes exhibit the intrinsic antimalarial activity of heparin, with an IC50 of ca. 400 nM, added to its specific targeting to P. falciparum-infected (vs noninfected) erythrocytes. DHP-heparin nanocarriers represent a potentially interesting contribution to the limited family of structures described so far for the loading and targeted delivery of current and future antimalarial compounds.© 2022 The Authors. Published by American Chemical Society.

JTD Keywords: carriers, drug-delivery, efficacy, heparin, malaria, mosquito, nanocarriers, parasite, plasmodium, targeted drug delivery, Dendritic polymers, Red-blood-cells

About 50% of human epidermal growth factor receptor 2 (HER2)+ breast cancer patients do not benefit from HER2-targeted therapy and almost 20% of them relapse after treatment. Here, we conduct a detailed analysis of two independent cohorts of HER2+ breast cancer patients treated with trastuzumab to elucidate the mechanisms of resistance to anti-HER2 monoclonal antibodies. In addition, we develop a fully humanized immunocompetent model of HER2+ breast cancer recapitulating ex vivo the biological processes that associate with patients’ response to treatment. Thanks to these two approaches, we uncover a population of TGF-beta-activated cancer-associated fibroblasts (CAF) specific from tumors resistant to therapy. The presence of this cellular subset related to previously described myofibroblastic (CAF-S1) and podoplanin+ CAF subtypes in breast cancer associates with low IL2 activity. Correspondingly, we find that stroma-targeted stimulation of IL2 pathway in unresponsive tumors restores trastuzumab anti-cancer efficiency. Overall, our study underscores the therapeutic potential of exploiting the tumor microenvironment to identify and overcome mechanisms of resistance to anti-cancer treatment.

JTD Keywords: activation, cells, efficacy, enrichment analysis, expression, infiltrating lymphocytes, survival, therapy, trastuzumab, Her2-positive breast-cancer

Mycobacterium bovis bacillus Calmette-Guérin (BCG) efficacy as an immunotherapy tool can be influenced by the genetic background or immune status of the treated population and by the BCG substrain used. BCG comprises several substrains with genetic differences that elicit diverse phenotypic characteristics. Moreover, modifications of phenotypic characteristics can be influenced by culture conditions. However, several culture media formulations are used worldwide to produce BCG. To elucidate the influence of growth conditions on BCG characteristics, five different substrains were grown on two culture media, and the lipidic profile and physico-chemical properties were evaluated. Our results show that each BCG substrain displays a variety of lipidic profiles on the outermost surface depending on the growth conditions. These modifications lead to a breadth of hydrophobicity patterns and a different ability to reduce neutral red dye within the same BCG substrain, suggesting the influence of BCG growth conditions on the interaction between BCG cells and host cells.

JTD Keywords: cell wall, efficacy, glycerol, hydrophobicity, lipid, neutral red, pdim, pgl, protein, strains, viability, virulence, Acylglycerol, Albumin, Article, Asparagine, Bacterial cell wall, Bacterial gene, Bacterium culture, Bcg vaccine, Catalase, Cell wall, Chloroform, Controlled study, Escherichia coli, Gene expression, Genomic dna, Glycerol, Glycerol monomycolate, Hexadecane, Housekeeping gene, Hydrophobicity, Immune response, Immunogenicity, Immunotherapy, Lipid, Lipid fingerprinting, Magnesium sulfate, Mercaptoethanol, Methanol, Methylglyoxal, Molybdatophosphoric acid, Mycobacterium bovis bcg, Neutral red, Nonhuman, Pdim, Petroleum ether, Pgl, Phenotype, Physical chemistry, Real time reverse transcription polymerase chain reaction, Rna 16s, Rna extraction, Rv0577, Staining, Thin layer chromatography, Unclassified drug

Modulation of metabotropic glutamate receptor 5 (mGlu5) with partial allosteric antagonists has received increased interest due to their favourable in vivo activity profiles compared to the unfavourable side-effects of full inverse agonists. Here we report on a series of bispyridine benzene derivatives with a functional molecular switch affecting antagonistic efficacy, shifting from inverse agonism to partial antagonism with only a single change in the substitution pattern of the benzene ring. These efficacy changes are explained through computational docking, revealing two different receptor conformations of different energetic stability and different positional isomer binding preferences.

JTD Keywords: mGlu5, Isomers, Partial efficacy, NAM, Antagonist, Inverse agonist

JTD Keywords: antimalarial, heparin, magic bullet, malaria, nanomedicine, nanotechnology, nanovector, Plasmodium, polymers, targeted drug delivery, chloroquine, immunoliposome, liposome, nanoparticle, solid lipid nanoparticle, Anopheles, antimalarial activity, drug delivery system, drug efficacy, erythrocyte, human, IC50, malaria, malaria control, nanoencapsulation, nonhuman, pathophysiology, Plasmodium, Review