Design, fabrication, and in vitro-in vivo evaluation of surface-engineered pyrazinamide-loaded lipid nanoparticles for tuberculosis therapy

Pyrazinamide (PYZ), a nicotinamide derivative, is an essential first-line anti-TB drug. However, its dose-dependent hepatotoxicity poses a considerable challenge, accentuating the need for improved delivery approaches. The key objective of the research work was to develop mannose-appended pyrazinamide-containing solid-lipid nanoparticles (Mn-PYZ-SNs) for the targeted management of TB. The developed Mn-PYZ-SNs depicted a particle size of 422±09 nm, which was slightly higher than that of unconjugated PYZ-SNs (Un-PYZ-SNs)(401±08 nm), with a minimal reduction in entrapment efficiency(83.64±1.42%). The in vitro drug release studies demonstrated comparable sustained release patterns for both formulations, with a similarity factor (f2) of 77.33, indicating that the structural integrity of PYZ-SNs was maintained during mannose conjugation. Fluorescence imaging and flow cytometric analysis revealed significantly enhanced cellular uptake of Mn-C6-SNs, with a 1.60-fold increase compared to Un-C6-SNs. The in vivo pharmacokinetic studies conducted on Sprague-Dawley rats showed a 4.7-fold improvement in relative bioavailability for Mn-PYZ-SNs. Biodistribution studies demonstrated significantly higher lung accumulation of Mn-PYZ-SNs (1.93-fold) compared to Un-PYZ-SNs at 24 hours. The aforementioned results imply that the developed Mn-PYZ-SNs could be a promising carrier for the treatment of TB. via the oral intestinal lymphatic pathway, circumventing its hepatic first-pass metabolism, and thereby preventing hepatic adverse effects.