RT Journal Article
T1 Nanoemulsion-based colistin for pulmonary delivery: Enhanced antibacterial efficacy against Acinetobacter baumannii
A1 Martínez Guitián, Marta
A1 Sanjurjo Bouza, Lucía
A1 Vázquez Ucha, Juan Carlos
A1 Muras Mora, Andrea
A1 Beceiro Casas, Alejandro
A1 Crecente Campo, José
A1 Alonso Fernández, María José
AB Infections caused by Acinetobacter baumannii, which frequently result in pneumonia and/or bacteraemia, represent a significant clinical challenge. Colistin, an antimicrobial peptide used as a last-resort therapy due to its high toxicity, is employed to treat severe infections, i.e. those caused by A. baumannii. The aim of this study was to develop a colistin-loaded nanoformulation (COL-NE) capable of targeting infected cells in the lung, thereby enhancing antibacterial efficacy while reducing toxicity. After screening multiple formulations, an optimized colistin nanoemulsion (COL-NE) was developed, exhibiting a particle size of 180 nm and a 1–4-fold reduction in MIC against A. baumannii compared to free colistin. The nanoemulsion also displayed significant antibiofilm activity, enhanced cellular penetration, and a 27–45% reduction in in vitro toxicity relative to colistin. Notably, following intratracheal administration, COL-NE improved the elimination of intracellular bacteria in macrophages through passive targeting while maintaining activity against extracellular bacteria. In a murine pneumonia model, COL-NE reduced lung bacterial burden by 2 log₁₀ CFU/mL compared with untreated controls and by 1.25 log₁₀ CFU/mL relative to colistin-treated mice. These findings highlight the potential of colistin-loaded nanoemulsions as a promising therapeutic strategy against A. baumannii infections, enhancing antibacterial efficacy while mitigating colistin-associated toxicity.
PB Springer
YR 2026
FD 2026-03-30
LK https://hdl.handle.net/10347/46877
UL https://hdl.handle.net/10347/46877
LA eng
NO Martínez-Guitián, M., Sanjurjo, L., Vázquez-Ucha, J.C., Muras, A., Beceiro, A., Crecente-Campo, J., & Alonso, M.J. (2026) Nanoemulsion-based colistin for pulmonary delivery: Enhanced antibacterial efficacy against Acinetobacter baumannii. Drug Delivery and Translational Research. https://doi.org/10.1007/s13346-026-02083-z
NO Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. This work has received financial support from the Xunta de Galicia (Centro singular de Investigación de Galicia accreditation ED431G/2023/02) and the European Union (European Regional Development Fund—ERDF) and Competitive Reference Groups, Consellería de Educación e Ordenación Universitaria, Xunta de Galicia, Ref: ED431C 2021/17.
DS Minerva
RD 5 may 2026