Modular nanotransporters: a multipurpose in vivo working platform for targeted drug delivery

Tatiana A Slastnikova1,2, Andrey A Rosenkranz1,2, Pavel V Gulak1, Raymond M Schiffelers3, Tatiana N Lupanova1,4, Yuri V Khramtsov1, Michael R Zalutsky5, Alexander S Sobolev1,21Laboratory of Molecular Genetics of Intracellular Transport, Institute of Gene Biology, Moscow, Russia; 2Department of Biophysics, Biological Faculty, Moscow State University, Vorobyevy Gory, Moscow, Russia; 3Laboratory for Clinical Chemistry and Haematology, University Medical Center Utrecht, Utrecht, the Netherlands; 4Department of Bioengineering, Biological Faculty, Moscow State University, Vorobyevy Gory, Moscow, Russia; 5Department of Radiology, Duke University Medical Center, Durham, NC, USABackground: Modular nanotransporters (MNT) are recombinant multifunctional polypeptides created to exploit a cascade of cellular processes, initiated with membrane receptor recognition to deliver selective short-range and highly cytotoxic therapeutics to the cell nucleus. This research was designed for in vivo concept testing for this drug delivery platform using two modular nanotransporters, one targeted to the α-melanocyte-stimulating hormone (αMSH) receptor overexpressed on melanoma cells and the other to the epidermal growth factor (EGF) receptor overexpressed on several cancers, including glioblastoma, and head-and-neck and breast carcinoma cells.Methods: In vivo targeting of the modular nanotransporter was determined by immunofluorescence confocal laser scanning microscopy and by accumulation of 125I-labeled modular nanotransporters. The in vivo therapeutic effects of the modular nanotransporters were assessed by photodynamic therapy studies, given that the cytotoxicity of photosensitizers is critically dependent on their delivery to the cell nucleus.Results: Immunohistochemical analyses of tumor and neighboring normal tissues of mice injected with multifunctional nanotransporters demonstrated preferential uptake in tumor tissue, particularly in cell nuclei. With 125I-labeled MNT{αMSH}, optimal tumor:muscle and tumor:skin ratios of 8:1 and 9.8:1, respectively, were observed 3 hours after injection in B16-F1 melanoma-bearing mice. Treatment with bacteriochlorin p-MNT{αMSH} yielded 89%–98% tumor growth inhibition and a two-fold increase in survival for mice with B16-F1 and Cloudman S91 melanomas. Likewise, treatment of A431 human epidermoid carcinoma-bearing mice with chlorin e6- MNT{EGF} resulted in 94% tumor growth inhibition compared with free chlorin e6, with 75% of animals surviving at 3 months compared with 0% and 20% for untreated and free chlorin e6-treated groups, respectively.Conclusion: The multifunctional nanotransporter approach provides a new in vivo functional platform for drug development that could, in principle, be applicable to any combination of cell surface receptor and agent (photosensitizers, oligonucleotides, radionuclides) requiring nuclear delivery to achieve maximum effectiveness.Keywords: drug delivery, nanobiotechnology, nanomedicine, cancer therapy, photosensitizers, multifunctional nanotransporte

Global Phylogeography of the Dusky Shark Carcharhinus obscurus: Implications for Fisheries Management and Monitoring the Shark Fin Trade

Genetic stock structure information is needed to delineate management units and monitor trade in sharks, many of which are heavily exploited and declining. The dusky shark Carcharhinus obscurus is a large apex predator that is sought after for its fins and is considered highly susceptible to overexploitation. The International Union for the Conservation of Nature (IUCN) classifies this species as ‘Vulnerable’ globally and ‘Endangered’ in the northwest Atlantic. We make the first assessment of global stock structure of C. obscurus by analyzing part of the mitochondrial control region (mtCR) in 255 individuals sampled from 8 geographically dispersed locations. We found 25 mtCR haplotypes and rejected a null hypothesis of panmixia (analysis of molecular variance, ΦST = 0.55, p \u3c 0.000001), detecting significant differentiation between 3 management units: US Atlantic (USATL), South Africa (SAF), and Australia (AUS). We also found preliminary evidence of population structure between the USATL and southwest Atlantic (Brazil). There were no shared haplotypes between the western Atlantic and Indo-Pacific. These analyses suggest that replenishment of the collapsed USATL management unit via immigration of females from elsewhere is unlikely. Mixed stock analysis (MSA) simulations show that reconstruction of the relative contributions of USATL, SAF, and AUS management units to the Asian fin trade is possible using these mtCR sequences. We suggest avenues for obtaining samples to conduct MSA of the shark fin trade, which could enhance management of dusky sharks and other species that are exploited for their fins

The OpenMolcas Web: A Community-Driven Approach to Advancing Computational Chemistry

The developments of the open-source OpenMolcas chemistry software environment since spring 2020 are described, with a focus on novel functionalities accessible in the stable branch of the package or via interfaces with other packages. These developments span a wide range of topics in computational chemistry and are presented in thematic sections: electronic structure theory, electronic spectroscopy simulations, analytic gradients and molecular structure optimizations, ab initio molecular dynamics, and other new features. This report offers an overview of the chemical phenomena and processes OpenMolcas can address, while showing that OpenMolcas is an attractive platform for state-of-the-art atomistic computer simulations

Domain II of Thermus thermophilus ribosomal protein L1 hinders recognition of its mRNA

The two-domain ribosomal protein L1 has a dual function as a primary rRNA-binding ribosomal protein and as a translational repressor that binds its own mRNA. Here, we report the crystal structure of a complex between the isolated domain I of L1 from the bacterium Thermus thermophilus and a specific mRNA fragment from Methanoccocus vannielii. In parallel, we report kinetic characteristics measured for complexes formed by intact TthL1 and its domain I with the specific mRNA fragment. Although, there is a close similarity between the RNA-protein contact regions in both complexes, the association rate constant is higher in the case of the complex formed by the isolated domain I. This finding demonstrates that domain II hinders mRNA recognition by the intact TthL1

Domain II of Thermus thermophilus ribosomal protein L1 hinders recognition of its mRNA

The two-domain ribosomal protein L1 has a dual function as a primary rRNA-binding ribosomal protein and as a translational repressor that binds its own mRNA. Here, we report the crystal structure of a complex between the isolated domain I of L1 from the bacterium Thermus thermophilus and a specific mRNA fragment from Methanoccocus vannielii. In parallel, we report kinetic characteristics measured for complexes formed by intact TthL1 and its domain I with the specific mRNA fragment. Although, there is a close similarity between the RNA-protein contact regions in both complexes, the association rate constant is higher in the case of the complex formed by the isolated domain I. This finding demonstrates that domain II hinders mRNA recognition by the intact TthL1

Implementing A One-Day Testing Model Improves Timeliness of Workup for Patients with Lung Cancer

Background: Patients with lung cancer often experience stressful delays throughout the diagnostic phase of care. To address that situation, our multidisciplinary team created a “Navigation Day,” during which patients partake in a single-day visit that comprises nurse-led teaching, social work, smoking cessation counselling, symptom control, and dedicated test slots for integrated positron-emission tomography and computed tomography (PET/CT), pulmonary function tests (PFTS), and magnetic resonance imaging (MRI) of the brain. We evaluated the effects of that program on wait times and patient satisfaction. Methods: Patients with a suspicion of lung cancer on chest ct imaging referred during 3 time periods were reviewed: 1 year before launch of the Navigation Day, 1 year post-launch, and 2 years post-launch. Patients were further stratified according to concordance of their test date with a Navigation Day date. Mean wait times for PET/CT, PFTS, and MRI brain were calculated for each group. Patient satisfaction was measured using a standardized provincial survey. The Student t-test and analysis of variance were used to assess for significance. Results: After implementation, mean wait times in the first year improved to 9.2 days from 15.5 days for PET/CT (p < 0.0001), to 9.6 days from 15.7 days for PFTS (p < 0.0001), and to 10.2 days from 16.0 days for MRI brain (p < 0.0001). Patients who used a dedicated test slot experienced the shortest wait times, at 5.8 days for PET/CT, 5.8 days for pfts, and 6.3 days for mri brain (p < 0.0001). Those improvements were sustained at 2 years post-launch. Conclusions: Patient satisfaction in the categories of assistance, emotional support, and clarity remained high post-launch. Navigation Day significantly improved the timeliness of diagnostic testing services in patients with suspected lung cancer