Nanoformulated Antiretrovirals for Penetration of the Central Nervous System: State of the Art

The central nervous system is a very challenging HIV-1 sanctuary. But, despite complete suppression of plasmatic viral replication with current antiretroviral therapy, signs of HIV-1 replication can still be found in the cerebrospinal fluid in some patients. The main limitation to achieving HIV-1 eradication from the brain is related to the suboptimal concentrations of antiretrovirals within this site, due to their low permeation across the blood\u2013brain barrier. In recent years, a number of reliable nanotechnological strategies have been developed with the aim of enhancing antiretroviral drug penetration across the blood\u2013brain barrier. The aim of this review is to provide an overview of the different nanoformulated antiretrovirals, used in both clinical and preclinical studies, that are designed to improve their delivery into the brain by active or passive permeation mechanisms through the barrier. Different nanotechnological approaches have proven successful for optimizing antiretrovirals delivery to the central nervous system, with a likely benefit for HIV-associated neurocognitive disorders and a more debated contribution to the complete eradication of the HIV-1 infection

A viral chitinase enhances oral activity of TMOF

In this study we investigate the combined effect on Heliothis virescens (Lepidoptera, Noctuidae) larvae of Aedes aegypti-Trypsin Modulating Oostatic Factor (. Aea-TMOF), a peptide that inhibits trypsin synthesis by the gut, impairing insect digestive function, and Autographa californica nucleopolyhedrovirus Chitinase A (AcMNPV ChiA), an enzyme that is able to alter the permeability of the peritrophic membrane (PM). Aea-TMOF and AcMNPV ChiA were provided to the larvae by administering transgenic tobacco plants, co-expressing both molecules. Experimental larvae feeding on these plants, compared to those alimented on plants expressing only one of the two molecules considered, showed significantly stronger negative effects on growth rate, developmental time and mortality. The impact of AcMNPV ChiA on the PM of H. virescens larvae, measured as increased permeability to molecules, was evident after five days of feeding on transgenic plants expressing ChiA. This result was confirmed by in vitro treatment of PM with recombinant ChiA, extracted from the transgenic plants used for the feeding experiments. Collectively, these data indicate the occurrence of a positive interaction between the two transgenes concurrently expressed in the same plant. The hydrolytic activity of ChiA on the PM of tobacco budworm larvae enhances the permeation of TMOF molecules to the ectoperitrophic space, and its subsequent absorption. The permeation through the paracellular route of Aea-TMOF resulted in a spotted accumulation on the basolateral domain of enterocytes, which suggests the occurrence of a receptor on the gut side facing the haemocoel. The binding of the peptide, permeating at increased rates due to the ChiA activity, is considered responsible for the enhanced insecticide activity of the transgenic plants expressing both molecules. These data corroborate the idea that ChiA can be effectively used as gut permeation enhancer in oral delivery strategies of bioinsecticides targeting haemocoelic receptors

What is the role of nanotechnology in diagnosis and treatment of metastatic breast cancer? Promising scenarios for the near future

Metastatic breast cancer represents a diagnostic and therapeutic challenge due to tumor heterogeneity and to various physiological barriers that hinder drug delivery to the metastatic sites. To overcome these limitations, nanoformulated drugs have been developed and tested in preclinical studies, and few of them have been successfully translated into clinical practice. In particular, liposomal anthracyclines and nanoformulated albumin-bound paclitaxel have revealed an improved therapeutic index when compared to conventional chemotherapy, with significant reduction of drugs toxicity. Several strategies for nanoparticles engineering have more recently been explored to increase selectivity for tumor cells and to reach poorly accessible metastatic districts. Targeted nanoparticles, directed toward tumor markers and tissue-specific metastases, may provide effective devices in case of lowvascularized and small-sized metastases, thus paving the way for a real change in the natural history of metastatic disease. A number of targets have been identified and exploited for surface functionalization of different types of nanoparticles, which are currently undergoing preclinical studies. The aim of this review is to provide an overview of current nanotechnology applied to metastatic breast cancer diagnosis and treatment. Promising results encourage an upcoming translation of this research into clinical practice for an effective management of the disease in the near future

Ferritin nanocages : A biological platform for drug delivery, imaging and theranostics in cancer

Nowadays cancer represents a prominent challenge in clinics. Main achievements in cancer management would be the development of highly accurate and specific diagnostic tools for early detection of cancer onset, and the generation of smart drug delivery systems for targeted chemotherapy release in cancer cells. In this context, protein-based nanocages hold a tremendous potential as devices for theranostics purposes. In particular, ferritin has emerged as an excellent and promising protein-based nanocage thanks to its unique architecture, surface properties and high biocompatibility. By exploiting natural recognition of the Transferrin Receptor 1, which is overexpressed on tumor cells, ferritin nanocages may ensure a proper drug delivery and release. Moreover, researchers have applied surface functionalities on ferritin cages for further providing active tumor targeting. Encapsulation strategies of non metal-containing drugs within ferritin cages have been explored and successfully performed with encouraging results. Various preclinical studies have demonstrated that nanoformulation within ferritin nanocages significantly improved targeted therapy and accurate imaging of cancer cells. Aims of this review are to describe structure and functions of ferritin nanocages, and to provide an overview about the nanotechnological approaches implemented for applying them to cancer diagnosis and treatment

Antiretroviral therapy through barriers : a prominent role for nanotechnology in HIV-1 eradication from sanctuaries

In HIV-1 management, eradication of the virus from sanctuaries represents a major and challenging goal. The genital tract, gut associated lymphoid tissue, lymph nodes, central nervous system, macrophages and latently infected CD4+ T lymphocytes are typical sites where HIV-1 compartmentalizes. To circumvent this problem, a consistent number of studies have focused on improving ARVs (antiretroviral drugs) delivery into sanctuary sites and different nanotechnological approaches have been developed. Cellular HIV-1 sanctuaries (i.e. macrophages) can be reached by nanoformulation of ARVs or by activation of latently infected cells. Anatomical sanctuaries (i.e. brain or male genital tract) can be addressed by increasing the permeation of ARVs across tissue barriers, such as the blood-brain barrier or the blood-testis barrier, while ARVs concentration in lymph nodes can be enhanced by drug encapsulation in CD4-targeted nanoparticles

Concurrent chemoradiation in anal cancer patients delivered with bone marrow-sparing imrt: Final results of a prospective phase ii trial

We investigated the role of the selective avoidance of haematopoietically active pelvic bone marrow (BM), with a targeted intensity-modulated radiotherapy (IMRT) approach, to reduce acute hematologic toxicity (HT) in anal cancer patients undergoing concurrent chemo-radiation. We designed a one-armed two-stage Simon’s design study to test the hypothesis that BM-sparing IMRT would improve by 20% the rate of G0–G2 (vs. G3–G4) HT, from 42% of RTOG 0529 historical data to 62% (α = 0.05; β = 0.20). A minimum of 21/39 (54%) with G0–G2 toxicity represented the threshold for the fulfilment of the criteria to define this approach as ‘promising’. We employed18 FDG-PET to identify active BM within the pelvis. Acute HT was assessed via weekly blood counts and scored as per the Common Toxicity Criteria for Adverse Effects version 4.0. From December 2017 to October 2020, we enrolled 39 patients. Maximum observed acute HT comprised 20% rate of ≥G3 leukopenia and 11% rate of ≥G3 thrombocytopenia. Overall, 11 out of 39 treated patients (28%) experienced ≥G3 acute HT. Conversely, in 28 patients (72%) G0–G2 HT events were observed, above the threshold set. Hence,18 FDG-PET-guided BM-sparing IMRT was able to reduce acute HT in this clinical setting