Development and evaluation of novel nanophotosensitizers as photoantimicrobial agents against Staphylococcus aureus

Gualdesi, María Soledad; Aiassa, Virginia; Vara, Jimena; Igarzabal, Cecilia Inés Álvarez; Ortiz, Cristina S.

doi:10.1016/j.msec.2018.09.040

Cited by 12 publications

(8 citation statements)

References 25 publications

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“…It should be noted that the analysis time exceeds the period involved in the photodynamic treatment for which these nanophotosensitizers were designed. The results obtained were compared with the degradation of the free PS (NR or NRBr, as appropriate) in PBS with 5% ethanol 15,29 …”

Section: Methodsmentioning

confidence: 99%

“…The results obtained were compared with the degradation of the free PS (NR or NRBr, as appropriate) in PBS with 5% ethanol. 15,29…”

Section: Photosensitizer Stability In Micellar Mediamentioning

confidence: 99%

“…These systems could increase their solubility in aqueous media and enhance both the production of 1 O 2 and the antimicrobial activity against different bacteria. The use of other polymeric carrier systems have shown improvements of this nature for the phenazine PSs 15,16 …”

Section: Introductionmentioning

confidence: 99%

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Polymeric micelles as a strategy to enhance the phototoxic efficacy of phenazine photosensitizers

Vara

Gualdesi

Aiassa

et al. 2023

Polymers for Advanced Techs

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Antimicrobial photodynamic therapy (aPDT) is a promising therapeutic strategy for treating bacterial infections resistant to conventional antibiotics. In the search for ideal photosensitizers (PSs), we became interested in phenazine compounds, such as Neutral Red (NR) and its halogenated derivative (NRBr). Although they have shown good results in the inactivation of Staphylococcus aureus in their free form, they have some undesirable properties that could be overcome by using drug delivery systems. In this work, we propose the use of polymeric micelles for the development of nanophotosensitizers from Pluronic P123 and F108. The micellar systems developed had a size close to 30–40 nm and allowed us to obtain seven nanophotosensitizers. All of them increased the chemical stability of NRBr and did not modify the stability of NR, which was already stable in buffer solution (pH = 7.4). Furthermore, the Pluronic micelles markedly decreased the aggregation of PSs and increased their photochemical reactivity. The nanophotosensitizers prepared from Pluronic P123 micelles (5% wt/vol) gave the best results and optimized the properties of NR and NRBr. In agreement with that, the new nanophotosensitizers of P123‐5% showed better photodynamic inactivation of NR and NRBr against methicillin resistant S. aureus than the free photosensitizers and the other micellar systems. Both photosensitizers loaded into the P123‐5% eradicated this microorganism using 30 min of irradiation. Therefore, it is concluded that these polymeric micelles are an excellent alternative for the vehiculization of PSs and that their combination with NR and NRBr enhances the photodynamic efficiency for their use in aPDT.

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Section: Methodsmentioning

confidence: 99%

“…The results obtained were compared with the degradation of the free PS (NR or NRBr, as appropriate) in PBS with 5% ethanol. 15,29…”

Section: Photosensitizer Stability In Micellar Mediamentioning

confidence: 99%

See 1 more Smart Citation

Polymeric micelles as a strategy to enhance the phototoxic efficacy of phenazine photosensitizers

Vara

Gualdesi

Aiassa

et al. 2023

Polymers for Advanced Techs

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“…For example, most photosensitizers (PSs) have poor water solubility/dispersibility, low ROS release efficiency caused by unstable photophysical properties, and side effects due to lack of biocompatibility, which limit their application in photomedicine. Recently, biocompatible nanomaterials such as liposomes, , mesoporous silica nanoparticles, , metal–organic framework (MOF), , carbon nanotube/nanoparticle, − nanofibers, , and GO, have been investigated in antimicrobial therapy as PSs drug delivery carriers to improve the defects of photosensitizers . Herein, biocompatible carbon dots (CDs) as a new kind of optical nanomaterials have attracted increasing attention.…”

Section: Introductionmentioning

confidence: 99%

Fluorescent Carbon Dot–Curcumin Nanocomposites for Remarkable Antibacterial Activity with Synergistic Photodynamic and Photothermal Abilities

Yan

Zhang

et al. 2021

ACS Appl. Bio Mater.

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Photosensitizer (PS)-mediated photodynamic therapy (PDT) has attracted more and more attention as an alternative to traditional antibiotic therapy. Nevertheless, the limitations of traditional photosensitizers seriously hinder their practical application, as a result, the methods to improve the antibacterial properties of traditional photosensitizers have become a hot topic in the field of photomedicine. Herein, a compound nano-PS system has been constructed with synergistic photodynamic and photothermal (PTT) antibacterial effects, triggered by a dual-wavelength illumination. Fluorescent carbon dots (CDs) were synthesized and employed as carriers for the delivery of curcumin (Cur) to obtain CDs/Cur. Upon combined near-infrared and 405 nm visible dual-wavelength irradiation, CDs/Cur could simultaneously generate ROS and a moderate temperature increase, triggering synergistic antibacterial effects against both Gram-positive and Gram-negative bacteria. The results of scanning electron microscopy and fluorescence confocal imaging showed that the combined effect of CDs/Cur with PDT and PTT caused more serious damage to the cell membrane. In addition, CDs/Cur exhibited low cytotoxicity and negligible hemolytic activity, showing great biocompatibility. Therefore, the construction of CDs/Cur by employing CDs as photosensitizer delivery carriers provides a strategy for the improvement of the antibacterial effect of the photosensitizer and the design of next-generation antibacterial agents in photomedicine.

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“…In our earlier work, the synthesis of a new compound, monobrominated Neutral Red (NRBr) was described . Subsequently, the effect of different experimental conditions on the lethal photosensitization of Staphylococcus aureus mediated by NR and NRBr was investigated . The improved properties of NRBr were accompanied by a significant increase in the photoantimicrobial action, in conventional‐sensitive and ‐resistant isolates.…”

Section: Introductionmentioning

confidence: 99%

Mechanistic Insight into the Photodynamic Effect Mediated by Neutral Red and a New Azine Compound in Staphylococcus aureus Cells

Urrutia

Ortiz

Alovero

2019

Chemistry & Biodiversity

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The photodynamic activity of Neutral Red and the new monobrominated Neutral Red was studied in suspensions of Staphylococcus aureus. The effect of mannitol and sodium azide in the presence of 25 μm photosensitizer on lethal photosensitization were investigated. The results of the mechanistic evaluation of Neutral Red showed that both mannitol and sodium azide produced a completed protective effect after irradiation without significant differences between them. The evaluation of monobrominated Neutral Red also showed a protective effect of microorganisms with the addition of mannitol. Although sodium azide produced a protective effect of the photoinactivation, it was incomplete and less than that exhibited by mannitol. The results indicate that the starting reagent, Neutral Red, is a producer of radical species, acting through a type I mechanism, whereas the halogenated derivative of Neutral Red produced reactive oxygen species and a contribution of singlet molecular oxygen cannot be discarded in the photoinactivation of Staphylococcus aureus cells. These results, analyzed together with the previously evaluated properties of the dyes, allow us to explain the differences observed in the photoinactivation of Staphylococcus aureus mediated by both azine photosensitizers.

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Development and evaluation of novel nanophotosensitizers as photoantimicrobial agents against Staphylococcus aureus

Cited by 12 publications

References 25 publications

Polymeric micelles as a strategy to enhance the phototoxic efficacy of phenazine photosensitizers

Polymeric micelles as a strategy to enhance the phototoxic efficacy of phenazine photosensitizers

Fluorescent Carbon Dot–Curcumin Nanocomposites for Remarkable Antibacterial Activity with Synergistic Photodynamic and Photothermal Abilities

Mechanistic Insight into the Photodynamic Effect Mediated by Neutral Red and a New Azine Compound in Staphylococcus aureus Cells

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