Title:	Engineering stability: cholesterol-modulated liposome response to physical and chemical stressors for enhanced antimicrobial activity.
Authors:	RIBEIRO, L. M. BONATTO, C. C. SILVA, L. P. da
Affiliation:	LUÍSA MORATO RIBEIRO, UNIVERSITY OF BRASÍLIA; CÍNTHIA CAETANO BONATTO; LUCIANO PAULINO DA SILVA, CENARGEN.
Date Issued:	2026
Citation:	Pharmaceuticals, v. 19, n. 3, 366, 2026.
Description:	Liposomes are promising carriers for enhancing antibiotic delivery, but their stability under various stress conditions is crucial for clinical applicability. Methods: This study aimed to evaluate the physicochemical and antimicrobial stability of streptomycin-loaded liposomes subjected to mechanical (bath ultrasonication, probe ultrasonication, ultra-turrax homogenization), thermal (freezing, heating), and chemical (H2O2, Triton X-100, sodium dodecyl sulfate—SDS) stressors. Results: Isolated mechanical stresses (probe ultrasonication, ultrasonic bath, and ultra-turrax) did not significantly affect hydrodynamic diameter (DH), polydispersity index (PdI), or Zeta potential (ZP) (p > 0.05). In contrast, combined ultrasound–freezing stress induced marked destabilization, with DH increasing from ~110 nm to 362 nm (Lc0uf) and from 109 nm to 334 nm (Lc1uf), accompanied by PdI increases from ~0.13 to 0.37–0.41 and a ZP shift in Lc1uf from −43.1 mV to −60.1 mV. Thermal exposure at 75 °C and freezing at −30 °C caused no significant changes in DH or PdI, whereas freezing at −80 °C led to severe destabilization, with over fourfold increases in DH and fivefold increases in PdI; the cholesterol-free formulation (Lc0t−80) reached ~664 nm and a PdI of 0.609. Chemical oxidation with 1% H2O2 did not affect DH, PdI, or ZP, while surfactants (1% Triton X-100 and 1% SDS) significantly altered PdI and ZP in a cholesterol-dependent manner. MIC assays showed that formulations stressed by freezing at −80 °C or by combined ultrasound–freezing retained activity against Escherichia coli (MIC = 50 µg/mL), whereas SDS abolished activity. For Staphylococcus aureus, all stressed formulations remained active, and SDS reduced the MIC from 12.5 to 5.625 µg/mL. Conclusions: These findings demonstrate the robustness and stress-specific stabilization of these liposomal formulations, confirming that the antibiotic’s activity is preserved, which highlights their potential for therapeutic use.
Thesagro:	Stress
NAL Thesaurus:	Cholesterol Streptomycin Microorganisms
Keywords:	Liposomes
DOI:	https://doi.org/10.3390/ph19030366
Notes:	Na publicação: Luciano Paulino Silva.
Type of Material:	Artigo de periódico
Access:	openAccess
Appears in Collections:	Artigo em periódico indexado (CENARGEN)