The evolution of respiratory diseases represents a considerable public health challenge, as they are among the leading causes of death worldwide. In this sense, in addition to the high prevalence of diseases such as asthma, chronic obstructive pulmonary disease, pneumonia, cystic fibrosis, and lung cancer, emerging respiratory diseases, particularly those caused by members of the coronavirus family, have contributed to a significant number of deaths on a global scale over the last two decades. Therefore, several studies have been conducted to optimize the efficacy of treatments against these diseases, focusing on pulmonary drug delivery using nanomedicine. Thus, the development of nanocarriers has emerged as a promising alternative to overcome the limitations of conventional therapy, by increasing drug bioavailability at the target site and reducing unwanted side effects. In this context, nanoparticles composed of chitosan (CS) show advantages over other nanocarriers because chitosan possesses intrinsic biological properties, such as anti-inflammatory, antimicrobial, and mucoadhesive capacity. Moreover, CS nanoparticles have the potential to enhance drug stability, prolong the duration of action, improve drug targeting, control drug release, optimize dissolution of poorly soluble drugs, and increase cell membrane permeability of hydrophobic drugs. These properties could optimize the performance of the drug after its pulmonary administration. Therefore, this review aims to discuss the potential of chitosan nanoparticles for pulmonary drug delivery, highlighting how their biological properties can improve the treatment of pulmonary diseases, including their synergistic action with the encapsulated drug.

Background: Schistosomiasis remains a major neglected tropical disease, with praziquantel (PZQ) as the only widely used treatment, despite its limitations. Parthenolide (PTL), a sesquiterpene lactone, exhibits potent in vitro antischistosomal activity; however, its poor aqueous solubility, low oral bioavailability, and chemical instability may limit its in vivo efficacy. Objective: This study investigated whether nanoencapsulation in nanostructured lipid carriers (NLC) could enable the in vivo antischistosomal activity of PTL. Methods: PTL was isolated from Tanacetum parthenium and incorporated into NLC using hot emulsification followed by ultrasonication. The resulting formulation (NLC-PTL) was physicochemically characterized, and its in vivo antischistosomal efficacy was evaluated in a murine model of Schistosoma mansoni infection. Results: NLC-PTL exhibited nanoscale size, low polydispersity, high encapsulation efficiency, and sustained drug release. In vivo, free PTL showed no significant effect on worm burden, whereas NLC-PTL achieved a marked reduction (77.9%) in adult worms and significantly decreased egg output compared to controls (p < 0.001). Blank NLC had no antiparasitic effect. Conclusions: Nanoencapsulation was associated with in vivo antischistosomal activity of PTL compared to the free compound. These findings suggest that formulation strategies may influence the in vivo performance of lipophilic natural products in schistosomiasis.