Development and characterization of spray-drying microparticles loaded with chestnut shells extract: New insights for oral mucositis therapy

Chestnut shells (CS) are fruit by-products with a high content of (poly)phenols that may play a key role in the oral mucositis (OM) pathogenesis. OM is an inflammatory condition and a common side effect of oncological treatments, being characterized by painful ulceration, difficulty in swallowing and speaking, and an increased risk of infection that can compromise the primary treatment outcome. Natural antioxidants have emerged as an interesting approach to the prevention and treatment of OM by inhibiting the redox imbalance responsible for its development. To overcome the instability and poor water solubility of (poly)phenols, CS extract was encapsulated by spray-drying. The results attested the successful microencapsulation with a product yield of 44%, a total phenolic content of 9.73 mg GAE/g, an antioxidant activity of 91.76 μmol FSE/g and an antiradical ability of 7.83 mg TE/g. FTIR results showed successful encapsulation. The CS-loaded microparticles revealed a median size of 1.95 μm (Dv50), a moisture content of 4.33% and a swelling capacity of 98.16%. The thermal properties of the extract were preserved, while rheological studies evidenced the microparticles pseudoplastic behavior. The microparticles safety was demonstrated through experiments on oral epithelial cell lines, where no adverse effects were observed at concentrations up to 1 mg/mL. Additionally, the (poly)phenols permeation, such as vanillin, succinic acid, protocatechuic acid, pyrocatechol, and 4-hydroxybenzoic acid, was confirmed by LC-HRMS using an in vitro buccal model. This study demonstrated the potential application of CS-loaded microparticles for the prevention/treatment of OM.