Engineered dry powders for the nose-to-brain delivery of transforming growth factor-beta.

Nose-to-brain delivery is increasing in popularity as an alternative to other invasive delivery routes. However, targeting the drugs and bypassing the central nervous system are challenging. We aim to develop dry powders composed of nanoparticles-in-microparticles for high efficiency of nose-to-brain delivery. The size of microparticles (between 250 and 350 µm), is desired for reaching the olfactory area, located below the nose-to-brain barrier. Moreover, nanoparticles with a diameter between 150 and 200 nm are desired for traveling through the nose-to-brain barrier. The materials of PLGA or lecithin were used in this study for nanoencapsulation. Both types of capsules showed no toxicology on nasal (RPMI 2650) cells and a similar permeability coefficient (Papp) of Flu-Na, which was about 3.69 ± 0.47 × 10-6 and 3.88 ± 0.43 × 10-6 cm/s for TGF-ß-Lecithin and PLGA, respectively. The main difference was related to the location of deposition; the TGF-ß-PLGA showed a higher drug deposition in the nasopharynx (49.89 ± 25.90 %), but the TGF-ß-Lecithin formulation mostly placed in the nostril (41.71 ± 13.35 %).

Upper Airway Mucociliary Clearance is Impaired in Dyspneic COVID-19 Patients.

Covid-19 is transmitted mainly by respiratory droplets and as the upper airway mucosa is the first innate immune barrier, it is crucial to understand the effects of SARS-CoV-2 on this system. In the current study, we aimed to evaluate the nasal mucociliary clearance in patients with SARS-CoV-2 infection and their symptom development. Observational cross-sectional study. The nasal mucociliary clearance (NMC) time was evaluated by the saccharin test and the results were compared between patients with SARS-CoV-2 infection (group 1) and controls (group 2, asymptomatic patients with a negative polymerase chain reaction test). We also compared the NMC time for each specific symptom suffered by participants in group 1 with the NMC time of the control group as well as with the patients in group 1 who were asymptomatic. There was a significant increase in NMC time in group 1 with dyspnea when compared to the control group (p = 0.032) and also when compared to patients who were infected were not dyspneic (p = 0.04). There were no differences in the clearance times when considering other symptoms. COVID-19 patients with dyspnea present with altered nasal mucociliary clearance.

Engineered nasal dry powder for the encapsulation of bioactive compounds.

In this review, we present the potential of nasal dry powders to deliver stable bioactive compounds and their manufacture using spray-drying (SD) techniques to achieve encapsulation. We also review currently approved and experimental excipients used for powder manufacturing for specific target drugs. Polymers, sugars, and amino acids are recommended for specific actions, such as mucoadhesive interactions, to increase residence time on the nasal mucosa; for example, high-molecular weight polymers, such as hydroxypropyl methylcellulose, or mannitol, which protect the bioactive compounds, increase their stability, and enhance drug absorption in the nasal mucosa; and leucine, which promotes particle formation and improves aerosol performance.