Fungal infections in focus: accelerating non-invasive imaging from preclinical insights to clinical breakthroughs

Invasive fungal diseases (IFDs) present a growing clinical challenge, underscoring the urgent need for improved diagnostics, therapeutics and mechanistic understanding. This review highlights the key role of innovative imaging techniques across all scales - ranging from whole-body-level diagnostics and therapy monitoring to host-pathogen interactions at cellular resolution in both clinical and preclinical settings. These imaging modalities facilitate translation of preclinical innovations into clinical applications, accelerating research and advancing IFD management

Pathogenesis of Encephalitis

Many infectious agents, such as viruses, bacteria, and parasites, can cause inflammation of the central nervous system (CNS). Encephalitis is an inflammation of the brain parenchyma, which may result in a more advanced and serious disease meningoencephalitis. To establish accurate diagnosis and develop effective vaccines and drugs to overcome this disease, it is important to understand and elucidate the mechanism of its pathogenesis. This book, which is divided into four sections, provides comprehensive commentaries on encephalitis. The first section (6 chapters) covers diagnosis and clinical symptoms of encephalitis with some neurological disorders. The second section (5 chapters) reviews some virus infections with the outlines of inflammatory and chemokine responses. The third section (7 chapters) deals with the non-viral causative agents of encephalitis. The last section (4 chapters) discusses the experimental model of encephalitis. The different chapters of this book provide valuable and important information not only to the researchers, but also to the physician and health care workers

A new method for studying cryptococcosis in a murine model using 99mTc-Cryptococcus gattii

Cryptococcus gattii is one of the etiologic agents of cryptococcosis, a systemic mycosis that occurs in healthy and immunosuppressed humans and animals worldwide. Primary pulmonary infection caused by C. gattii is usually followed by fungal dissemination to the central nervous system, resulting in high mortality rates. In this context, animal models of cryptococcosis are useful in the study of fungal pathogenesis and host response against the pathogen, and for testing novel therapeutic options. The most frequently applied method to study fungal dissemination from the lungs to other organs is by culturing tissues, which is not accurate for the detection and quantification of fungal load at early stages of the infection. To overcome this problem, the purpose of this study was to develop a new method for the quantification of Cryptococcus dissemination. One C. gattii strain was efficiently radiolabeled with technetium-99m (99mTc), without affecting viability of the cells. Further, the 99mTc-C. gattii (111 MBq) strain was used to infect mice by intratracheal and intravenous route for biodistribution studies. 99mTc-C. gattii was successfully used in detection of the yeast in the brain of mice 6 hours postinoculation, while the detection using colony forming units was possible only 24 hours postinfection. Our results provided an alternative method that could be applied in further investigations regarding the efficacy of antifungals, fungal virulence, and host-pathogen interactions.CNPq - Conselho Nacional de Desenvolvimento Científico e TecnológicoFAPEMIG - Fundação de Amparo à Pesquisa do Estado de Minas GeraisCAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superio

Delivery of nanocarrier-loaded hydrophobic drugs via the airways

BACKGROUND AND PURPOSE: Systemic delivery of hydrophobic therapeutics represents substantial formulation challenges impeding optimal benefits due to side effects and sub-therapeutic drug levels at the target site consequently leading to progression of multi-drug resistance. This thesis describes three distinct novel nanotechnology-based strategies with desirable aerosolization characteristics for delivery via the airways, aimed at enhancing the therapeutic efficacy of hydrophobic drugs for pulmonary and neurological disorders. METHODS: The first approach involved the development of dry powder microparticles for pulmonary delivery of antifungal amphotericin B nanocomplexes, prepared by co-grinding the drug with ascorbic acid. Nanocomplexes developed were characterized for molecular interactions by FT-IR, size, zeta potential, morphology, in vitro aerodynamic behavior and antifungal activity. The second strategy entailed design of liposomes co-encapsulating rifampicin and ibuprofen using Design of Experiment, targeted to the mannose and/or scavenger receptors on the alveolar macrophages where TB infection resides. Spray dried microparticles were characterized for in vitro aerodynamic behavior and macrophage uptake using the flow cytometer in RAW 264.7 cells. The third approach involved the development of Kolliphor® HS 15 micelles incorporating neuroprotective agents CNB001 or curcumin and Kolliphor® TPGS micelles encapsulating curcumin for the treatment of neurodegeneration and neuroblastoma respectively. Nasal delivery of these micellar systems was intended for brain targeting. Micelles were characterized for size, charge, aerosol droplet size distribution, drug release, morphology and in vitro cellular studies on SH-SY5Y cells. RESULTS: Successful development of nanocarrier-based systems with a high encapsulation efficiency greater than 80% for all the systems was achieved, with particle size desirable for the end-use. Spray dried microparticles of amphotericin B nanocomplexes with L-leucine showed a high fine particle fraction of around 58% signifying likely deposition in the peripheral airways, to the areas of fungal infection. There was no loss of antifungal activity against Candida spp on complexation of amphotericin B. Microparticles of liposomes encapsulating antitubercular drugs showed good aerosolization, and up to 65% fine particle fraction on addition of L-leucine could be achieved. An enhanced in vitro cellular uptake was evident for negative-charged liposomes targeted to the scavenger receptors and the mannosylated liposomes targeted to the mannose receptors on the macrophage cell line RAW 264.7. Finally, Kolliphor® micelles encapsulating CNB001 or curcumin showed desired aerosol droplet size for delivery to the posterior nasal olfactory epithelium with median size of 42.75-54.86 μm when aerosolized by the Nasal™ Mucosal Atomization Device. The formulations intended for neuroprotection showed improved cellular viability, reduction in reactive oxygen species and nuclear morphology in the in vitro Parkinson’s model. CONCLUSION: The nanotechnology-based formulations combined with administration to or through the airways using commercially available delivery devices, represent a highly attractive formulation strategy for delivery of hydrophobic agents to the target site at a therapeutic level to combat issues of multi-drug resistance