Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_5642_Библиотеки_им_академика_М_И_Перельмана

charge and PEGylation would be considered a preferable option [50]. Generally, physical entanglement and electrostatic interactions with mucin are known as the main driving forces that increase adhesiveness within mucus. The high lexibility and high hydration potential can attenuate the molecular interactions between mucus and PEG, resulting in improved diffusiveness in the mucus layer (mucopenetrating property) [69]. PEGylation also contributes to the improvement of dispersibility and protection from enzymatic degradation via steric hindrance derived from the PEG chains. Despite the advantage of PEGylation of molecules, the existence of a PEG chain would inluence its pharmacological action because of steric hindrance against the pharmacophore, suggesting the necessity of considering an appropriate balance between stabilization and pharmacological actions [9]. In addition to the PEGylation of drug molecules, PEGylated carriers, especially PEG-coated nanoparticle like liposomes, and polymeric nanoparticles are an available strategy to overcome the barrier of the mucus layer [69]. It has been reported that a PEG chain with a molecular weight range of 1000–2000 Da is a suitable characteristic for drug delivery [50]. The reduction in phagocytosis by alveolar macrophages was also reported to enhance the delivery eficiency of PEG-coated macromolecule-loaded nanoparticles. Some mucoadhesive excipients have also been reported, including chitosan, alginate, hyaluronic acid, and hydroxypropyl cellulose, which enable prolonged retention of drug-loaded particles by slowing their clearance from the lungs [5, 46, 51].