Saeed, N. | Search bioRxiv

bioRxiv2026

Electrically Enhanced Intraperitoneal Drug Delivery Resolved by Fluorescence Lifetime Imaging Microscopy

Intraperitoneal delivery of nanoparticles (NPs) holds promise in the treatment of peritoneal metastases (PM), and the use of electric fields may enhance their tissue penetration. Evaluating NP delivery requires evidence of intracellular payload release, which is challenging in autofluorescent tissues. Here, we combined electromotive drug administration (EMDA) with cationic RL-100 NPs co-loaded with doxorubicin (DOX) and a near-infrared aza-BODIPY tracer, reporting carrier-associated distribution, while phasor fluorescence lifetime imaging microscopy (FLIM) characterized the molecular environment of DOX. In colorectal carcinoma, NP-delivered DOX progressed from cytoplasmic puncta to nuclear accumulation, while carrier-associated fluorescence remained cytoplasmic, supporting intracellular release. EMDA enhanced NP penetration in ex vivo human peritoneum and healthy rat peritoneum. In a syngeneic rat model of colorectal PM, both free and NP-delivered DOX remained detectable to approximately 1200 um after EMDA, compared with < 200 um after passive delivery. NP-delivered DOX remained detectable 24 h after EMDA. Whole-animal and ex vivo imaging showed the highest carrier-associated signals in tumor nodules and tumor-bearing omentum. These findings support electrically enhanced intraperitoneal delivery and a dual-reporter approach to evaluate carrier distribution, drug penetration, and intracellular release, with potential applications in other autofluorescent tissues. Together, these capabilities provide a preclinical basis for investigating NP-assisted delivery.

pharmacology and toxicology↗

bioRxiv2021

An evolutionary genomic approach reveals both conserved and species-specific genetic elements related to human disease in closely related Aspergillus fungi

Aspergillosis is an important opportunistic human disease caused by filamentous fungi in the genus Aspergillus. Roughly 70% of infections are caused by Aspergillus fumigatus, with the rest stemming from approximately a dozen other Aspergillus species. Several of these pathogens are closely related to A. fumigatus and belong in the same taxonomic section, section Fumigati. Pathogenic species are frequently most closely related to non-pathogenic ones, suggesting Aspergillus pathogenicity evolved multiple times independently. To understand the repeated evolution of Aspergillus pathogenicity, we performed comparative genomic analyses on 18 strains from 13 species, including 8 species in section Fumigati, which aimed to identify genes, both ones previously connected to virulence as well as ones never before implicated, whose evolution differs between pathogens and non-pathogens. We found that most genes were present in all species, including approximately half of those previously connected to virulence, but a few genes were section- or species-specific. Evolutionary rate analyses identified hundreds of genes in pathogens that were faster-evolving than their orthologs in non-pathogens. For example, over 25% of all single-copy genes examined in A. fumigatus were faster-evolving. Functional testing of deletion mutants of 17 transcription factor-encoding genes whose evolution differed between pathogens and non-pathogens identified eight genes that affect either fungal survival in a model of phagocytic killing, host survival in an animal model of fungal disease, or both. These results suggest that the evolution of pathogenicity in Aspergillus involved both conserved and species-specific genetic elements, illustrating how an evolutionary genomic approach informs the study of fungal disease.

evolutionary biology↗