INVESTIGADORES
BAUMGARTNER Maria Teresa Del V.
congresos y reuniones científicas
Título:
Liposomes as drug delivery systems for photoinactivation of methicillin-resistant Staphylococcus aureus (MRSA)
Autor/es:
MIRETTI, M; GONZALEZ GRAGLIA, M A; GUALDESI, MS; VARA, J; BAUMGARTNER, M. T
Lugar:
Còrdoba
Reunión:
Encuentro; LI Reuniòn Anual Sociedad Argentina de Biofisica; 2023
Institución organizadora:
SAIB
Resumen:
Staphylococcus aureus (S. aureus) is part of the normal microbiota; it can cause infectionsranging from superficial skin and localized abscesses to severe infections such asosteomyelitis, endocarditis, and other life-threatening diseases. Methicillin-resistant S.aureus (MRSA) is resistant to many antibiotics such as methicillin, penicillin, cefazolin,cefoxitin, and other common antibiotics. [1] Antimicrobial photodynamic therapy (aPDT)has emerged over the last decade as an alternative to eliminate pathogens, principallythose antimicrobials resistant. The aPDT involves a photosensitizer (PS) (innocuous in thedarkness), light, and oxygen. The excitation of PS leads to the generation of singletoxygen and other reactive oxygen species (ROS) capable of reacting with biomolecules,producing cell damage and microbial inactivation.[2] Among PS, phthalocyanines (Pcs)are considered excellent PS. However, the efficiency of Pcs in aqueous media decreasesdue to their lipophilic nature and limited solubility in water, leading to aggregatesforming. Incorporating Pcs in delivery systems such as liposomes (LP) improves solubilityand reduces aggregation. LP are vesicles biocompatible and biodegradable, constitutedby phospholipid bilayers surrounding an aqueous compartment. Thus, hydrophobic PSscan be entrapped in the center of phospholipid bilayers.[3] In this work, aPDT was appliedusing Zn(II) phthalocyanine (ZnPc) loaded into liposomes against MRSA. LP are composedof DPPC and cholesterol. LP mean size of control and loaded with ZnPc was ~130 nm. Inthe dark, the MRSA viability was not affected. As expected, control liposomes did not showactivity against MRSA. ZnPc free was not effective in eliminating MRSA. Indeed, liposomesloaded with ZnPc photoinactivated MRSA successfully. Thus, combining DPPC-colliposomes with ZnPc allows photoinactivating MRSA.