Publications

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 second-line antileishmanial compound pentamidine is administered intramuscularly or, preferably, by intravenous infusion, with its use limited by severe adverse effects, including diabetes, severe hypoglycemia, myocarditis and renal toxicity. We sought to test the potential of phospholipid vesicles to improve the patient compliance and efficacy of this drug for the treatment of leishmaniasis by means of aerosol therapy. The targeting to macrophages of pentamidine-loaded liposomes coated with chondroitin sulfate or heparin increased about twofold (up to ca. 90%) relative to noncoated liposomes. The encapsulation of pentamidine in liposomes ameliorated its activity on the amastigote and promastigote forms of Leishmania infantum and Leishmania pifanoi, and it significantly reduced cytotoxicity on human umbilical endothelial cells, for which the concentration inhibiting 50% of cell viability was 144.2 ± 12.7 µM for pentamidine-containing heparin-coated liposomes vs. 59.3 ± 4.9 µM for free pentamidine. The deposition of liposome dispersions after nebulization was evaluated with the Next Generation Impactor, which mimics human airways. Approximately 53% of total initial pentamidine in solution reached the deeper stages of the impactor, with a median aerodynamic diameter of ~2.8 µm, supporting a partial deposition on the lung alveoli. Upon loading pentamidine in phospholipid vesicles, its deposition in the deeper stages significantly increased up to ~68%, and the median aerodynamic diameter decreased to a range between 1.4 and 1.8 µm, suggesting a better aptitude to reach the deeper lung airways in higher amounts. In all, nebulization of liposome-encapsulated pentamidine improved the bioavailability of this neglected drug by a patient-friendly delivery route amenable to self-administration, paving the way for the treatment of leishmaniasis and other infections where pentamidine is active.

JTD Keywords: aerosol therapy, delivery-systems, drug encapsulation, drugs, ex-vivo models, formulation, leishmania infantum, leishmania pifanoi, leishmaniasis, liposomes, macrophages, miltefosine, pentamidine, pharmacology, pulmonary absorption, visceral leishmaniasis, Aerosol therapy, Amphotericin-b treatment, Drug encapsulation, Leishmania infantum, Leishmania pifanoi, Leishmaniasis, Liposomes, Pentamidine