Simona Bertoni

Background: Cyclosporine is widely used to prevent transplant rejection; however, its systemic administration is associated with low bioavailability and a risk of severe adverse side effects. In the context of lung transplantation, local pulmonary delivery represents a promising strategy to reduce the required dose while enhancing local anti-inflammatory efficacy and limiting systemic toxicity. Methods: In this study, cyclosporine was encapsulated in liposomes coated with calcium phosphate to improve cellular uptake. The liposomal formulation was subsequently converted into a dry powder for inhalation to enable pulmonary administration, combining cyclosporine-loaded liposomes with a calcium phosphate coating, extending prior work on inhaled liposomal cyclosporine and mineral-coated liposomes into a single platform. The cyclosporine loading was optimised to achieve an efficient drug content in the final formulation. Results: The presence of the calcium phosphate coating on the liposomal surface was confirmed by the shift in zeta potential and by cryo-transmission electron microscopy. The resulting dry powder exhibited suitable aerodynamic properties for pulmonary delivery with a fine particle fraction of 33.6 ± 1.6%. In vitro biocompatibility studies performed on A549 epithelial cells and THP-1 monocytic cells demonstrated that the formulation did not affect cell viability. Furthermore, the formulation containing calcium phosphate-coated liposomes showed a stronger anti-inflammatory effect compared with both uncoated liposomal formulations and the corresponding raw material, consisting of a physical mixture of phospholipids and cyclosporine. Conclusions: Overall, despite limitations on respirability and efficacy that will require further in vivo studies, this calcium phosphate-coated liposomal dry powder could represent a promising strategy for targeted pulmonary delivery of cyclosporine, with potential to improve the prevention of lung transplant rejection while minimising systemic side effects.

Background/Objectives: IBDs are chronic relapsing inflammatory intestinal disorders whose precise etiology is still only poorly defined: critical for their pathogenesis is the CCL20/CCR6 axis, whose modulation by small molecules may represent an innovative therapeutic approach. The aim of the present work is to test the potential efficacy of two molecules, MR120, a small selective CCR6 antagonist, active in TNBS- and chronic DSS-induced murine models of intestinal inflammation, and its derivative MR452, a well-tolerated agent endowed with improved anti-chemotactic in vitro properties, in the adoptive transfer colitis model. To the best of our knowledge, this is the first attempt to use adoptive transfer colitis to test modulators of the CCL20/CCR6 axis. Methods and Results: The induction of colitis in immunocompromised mice receiving CD4⁺CD25⁻ T cells i.p. resulted in a moderate inflammation and was met with limited protective responses following daily subcutaneous administration of MR120 or MR452 for 8 weeks. Both compounds significantly reduced colonic myeloperoxidase activity, and MR452 also lowered CCL20 levels in the gut, but they failed to prevent the increase in the Disease Activity Index, colon wall thickening, and macroscopic inflammation score. Conclusions: Our findings suggest that, despite the beneficial effects played by MR120 against subacute TNBS- and chronic DSS-induced colitis, the pharmacological targeting of the CCL20/CCR6 axis in the adoptive transfer model has a negligible effect in ameliorating the IBD-like phenotype driven by the altered intestinal immune homeostasis and by the disrupted function of immune-suppressive Treg cells.

Background/Objectives: IBDs are chronic relapsing inflammatory intestinal disorders whose precise etiology is still only poorly defined: critical for their pathogenesis is the CCL20/CCR6 axis, whose modulation by small molecules may represent an innovative therapeutic approach. The aim of the present work is to test the potential efficacy of two molecules, MR120, a small selective CCR6 antagonist, active in TNBS- and chronic DSS-induced murine models of intestinal inflammation, and its derivative MR452, a well-tolerated agent endowed with improved anti-chemotactic in vitro properties, in the adoptive transfer colitis model. To the best of our knowledge, this is the first attempt of using adoptive transfer colitis to test modulators of the CCL20/CCR6 axis. Methods and Results: The induction of colitis in immunocompromised mice receiving CD4⁺CD25⁻ T cells i.p. resulted in a moderate inflammation and was met with limited protective responses following daily subcutaneous administration of MR120 or MR452 for 8 weeks. Both compounds significantly reduced colonic myeloperoxidase activity, MR452 also lowered CCL20 levels in the gut, but they failed to prevent the increase in disease activity index, colon wall thickening, and macroscopic inflammation score. Conclusions: Our findings suggest that the pharmacological targeting of the CCL20/CCR6 axis in the adoptive transfer model has only a modest effect in ameliorating the IBD-like phenotype driven by the altered balance between Treg and Th17. The CCL20/CCR6 inhibitors MR120 and MR452 appear more clearly involved in the control of Th1 and Th2 adaptive immune responses, as it results from the beneficial effects displayed by MR120 against subacute TNBS- and chronic DSS-induced colitis.

This work illustrates the development of a dry inhalation powder of cyclosporine-A for the prevention of rejection after lung transplantation and for the treatment of COVID-19. The influence of excipients on the spray-dried powder’s critical quality attributes was explored. The best-performing powder in terms of dissolution time and respirability was obtained starting from a concentration of ethanol of 45% (v/v) in the feedstock solution and 20% (w/w) of mannitol. This powder showed a faster dissolution profile (Weibull dissolution time of 59.5 min) than the poorly soluble raw material (169.0 min). The powder exhibited a fine particle fraction of 66.5% and an MMAD of 2.97 µm. The inhalable powder, when tested on A549 and THP-1, did not show cytotoxic effects up to a concentration of 10 µg/mL. Furthermore, the CsA inhalation powder showed efficiency in reducing IL-6 when tested on A549/THP-1 co-culture. A reduction in the replication of SARS-CoV-2 on Vero E6 cells was observed when the CsA powder was tested adopting the post-infection or simultaneous treatment. This formulation could represent a therapeutic strategy for the prevention of lung rejection, but is also a viable approach for the inhibition of SARS-CoV-2 replication and the COVID-19 pulmonary inflammatory process.