posted on 2021-06-25, 03:43authored byMaria
Daniela Silva, Juan L. Paris, Francisco Miguel Gama, Bruno F. B. Silva, Sanna Sillankorva
Local delivery of antimicrobials
for otitis media treatment would
maximize therapeutic efficacy while minimizing side effects. However,
drug transport across the tympanic membrane in the absence of a delivery
system is challenging. In this study, the MSlys endolysin was encapsulated
in deformable liposomes for a targeted treatment of S. pneumoniae, one of the most important causative
agents of otitis media. MSlys was successfully encapsulated in liposomes
composed of l-alpha-lecithin and sodium cholate (5:1) or l-alpha-lecithin and PEG2000 PE (10:1), with encapsulation efficiencies
of about 35%. The PEGylated and sodium cholate liposomes showed, respectively,
mean hydrodynamic diameters of 85 and 115 nm and polydispersity indices
of 0.32 and 0.42, both being stable after storage at 4 °C for
at least one year. Both liposomal formulations showed a sustained
release of MSlys over 7 days. Cytotoxicity studies against fibroblast
and keratinocyte cell lines revealed the biocompatible nature of both
MSlys and MSlys-loaded liposomes. Additionally, the encapsulated MSlys
showed prompt antipneumococcal activity against planktonic and biofilm S. pneumoniae, thus holding great potential for transtympanic
treatment against S. pneumoniae otitis
media.