Photodynamic Antimicrobial Chemotherapy Research Articles

Exploring the efficacy of photodynamic antimicrobial chemotherapy on diabetic foot ulcers in rats.

We investigate the efficacy of photodynamic antimicrobial chemotherapy (PACT) and its combination with an antibiotic in the treatment of diabetic foot ulcers (DFUs) in rats using a novel cationic amino acid porphyrin-based photosensitizer. The research findings demonstrate that the combination of novel cationic photosensitizer-mediated PACT and an antibiotic exhibits significant therapeutic efficacy in treating deep ulcers in a rat model of DFUs. Moreover, the PACT + Antibiotic group displays enhanced angiogenesis, improved tissue maturation, and superior wound healing effect. Micro-computed tomography examination showed that the periosteal reaction was most obvious in the PACT + Antibiotic group. The cortical bone volume ratio (BV/TV), the bone mineral density, and trabecular thickness were significantly higher in the PACT + Antibiotic group than in the model group (p < 0.05). The combination of PACT and antibiotic plays a sensitizing therapeutic role, which provides a new idea for the clinical treatment of DFUs.

Easy and versatile cellulosic support inhibiting broad spectrum strains: synergy between photodynamic antimicrobial therapy and polymyxin B.

Despite advances achieved in the health field over the last decade, infections caused by resistant bacterial strains are an increasingly important societal issue that needs to be addressed. New approaches have already been developed to overcome this problem. Photodynamic antimicrobial chemotherapy (PACT) could provide a promising alternative method to eradicate microbes. This approach has already inspired the development of innovative surfaces. Interesting results were achieved against Gram-positive bacteria, but it also appeared that Gram-negative strains, especially Pseudomonas aeruginosa, were less sensitive to PACT. However, materials coated with cationic porphyrins have already proven their wide-spectrum activity, but these materials were not suitable for industrial-scale production. The main aim of this work was the design of a large-scale evolutionary material based on PACT and antibiotic prophylaxis. Transparent regenerated cellulose has been simply impregnated with a usual cationic porphyrin (N-methylpyridyl) and an antimicrobial peptide (polymyxin B). In addition to its photophysical properties, this film exhibited a wide-spectrum bactericidal activity over 4days despite daily application of fresh bacterial inoculums. The efficiency of PACT and polymyxin B combination could help to reduce the emergence of bacterial multi-resistant strains and we believe that this kind of material would provide an excellent opportunity to prevent bacterial contamination of bandages or packaging.

Photodynamic antimicrobial activities of a series of meso-substituted 2,6-dibrominated 1,3,5,7-tetramethylBODIPY dyes

The photodynamic antimicrobial chemotherapy (PACT) activities of seven 1,3,5,7-tetramethyl-2,6-dibromoBODIPY dyes with 4-acetamidophenyl (2a), 2-iodophenyl (2b), 3-iodophenyl (2c), 4-iodophenyl (2d), 2-bromophenyl (2e), 5-bromothien-2-yl (2f), and methylphenyl ester (2g) meso-substituents were studied against Staphylococcus aureus through irradiation with a 530 nm Thorlabs M530L3 light emitting diode (LED) (110 mW.cm[Formula: see text] to identify structure-property relationships related to modifying the meso-substituent. Significant differences are observed in the log[Formula: see text] reduction values obtained with 1 [Formula: see text]M of 2a exhibiting the highest PACT activity with a value of 9.60 after 15 min of photoirradiation. In contrast, log[Formula: see text] reduction values &lt; 1.20 were obtained after 60 min of photoirradiation for iodophenyl dyes 2b-2d. The data demonstrate that the singlet oxygen quantum yield of the dye is not the most important factor determining the PACT activity properties.

Photodynamic Antimicrobial Chemotherapy Reduces Bacterial Load in Live Feeds in Aquaculture

Live feeds are one of the route of entry of pathogenic bacteria in larval rearing systems in aquaculture. Current study discusses the disinfection of bacteria associated with live feed (Artemia nauplii) using photodynamic antimicrobial chemotherapy (PACT). More than 90 % of Aeromonas hydrophila in solution and total bacteria associated with live feed were killed on exposure to 5 μM of curcumin under photoexcitation for 30 minutes. The cell wall of A. hydrophila was disrupted by the reactive oxygen species generated by photoexcited curcumin. Up to 50 μM curcumin and their photoexcitation products were not toxic to Artemia nauplii. The findings of the current study propose photodynamic antimicrobial chemotherapy as a propitious tool for One Health approach and restricting the use of antibiotics in aquaculture settings. SAARC J. Agric., 21(2): 239-250 (2023)

Photodynamic antimicrobial chemotherapy activities of phthalocyanine-antibiotic conjugates against bacterial biofilms and interactions with extracellular polymeric substances

This study sheds light on how to rationally design efficient photodynamic antimicrobial chemotherapy (PACT) agents by covalently linking phthalocyanines (Pcs) as photosensitizers with an antibiotic: Ciprofloxacin (CIP). Pcs used are zinc (II) 3-(4-((3,17,23-tris(4-(Benzo(d)thiazol-2-yl] thiol) phthalocyanine-9-yl) oxy) phenyl) propanoic acid (1) and zinc (II) 3-(4-(3,17,23-tris(3-(4-(triphenylphosphine) butyl) benzo[d]thiazol-3-ium bromide phthalocyanine-9-yl) oxy) phenyl) propanoic acid (2). High singlet oxygen quantum yields are observed in the presence of CIP. Square wave voltammetry was used to analyse the Pc-CIP uptake by bacteria biofilms of Streptococcus pneumoniae (S. pneumonia) and Escherichia coli (E. coli). Electrochemical impedance spectroscopy and scanning electron spectroscopy were used to study the stability of the biofilms in the presence Pc-CIP complexes and when exposed to light. Raman and time of flight-secondary ion mass spectrometry (TOF-SIMS) are used to identify the breakdown of cellular components of the biofilm and penetration of the Pc-CIP into the biofilms, respectively.

Bactericidal effect of Iberin combined with photodynamic antimicrobial chemotherapy against Pseudomonas aeruginosa biofilm cultured on ex vivo wound model

Wounds infected by Pseudomonas aeruginosa (P. aeruginosa) biofilms are characterized by poor healing and by being long lasting. Pyocyanin and pyoverdine are exotoxins that contribute to P. aeruginosa pathogenicity in wound infections and are known as virulence factors. Despite the usefulness of antimicrobial photodynamic therapy (PDT) in the management of wound infections, biofilms are hurdle for microbial photoinactivation. Quorum sensing (QS) is a cell density-dependent chemical signaling system P. aeruginosa uses to regulate biofilm formation and virulence factors production. In the current study, QS attenuation was used in combination with PDT against P. aeruginosa biofilm cultured on skin explant. Iberin is a QS inhibitor that attenuates P. aeruginosa virulence and affects biofilm integrity. The antibiofilm and QS inhibitory activities of iberin in combination with either riboflavin or 5,10,15,20-Tetrakis(1-methyl-4-pyridinio) porphyrin tetra p-toluenesulfonate (TMP) mediated PDT were investigated using viable count method and pyocyanin and pyoverdine assays, respectively.No bactericidal activity was reported when iberin was added to a mature biofilm (24 h) followed by PDT. When added to a growing biofilm at multiple time points (0 h, 24 h and 48 h), iberin inhibited P. aeruginosa biofilm QS signaling system. This inhibitory effect resulted in an observable decrease in the levels of the QS-regulated virulence factors, pyocyanin and pyoverdine, without any effect on the growth of the biofilm cultures. These changes in biofilm virulence were associated with a decrease in biofilm resistance to PDT and caused bactericidal effect upon photosensitizers treatment and irradiation. Iberin-treated-riboflavin-mediated PDT resulted in a significant 1.3 log reduction in biofilm population. Similarly, iberin-treated-TMP-mediated PDT caused a significant 1.8 log reduction in biofilm population. The combination of QS inhibitor with PDT is a promising alternative antimicrobial therapy for the management of biofilms.

Photoinactivation of microorganisms and photodegradation of pollutants using phthalocyanines supported on nanofibers and glass wool

Neutral and cationic zinc and indium phthalocyanines (Pcs) are anchored onto polyacrylonitrile nanofibers (NFs) and glass wools (GWs). The properties of these composites were evaluated and compared. Thermal gravimetric analysis showed that GWs had higher stability than NFs. The nanofibers had a higher loading of > 50 % compared to < 35 % for glass wools. The singlet oxygen quantum yield was proportional to the loading. The degradation of 4-chlorophenol, methyl orange, and methylene blue, and the antimicrobial activity (photodynamic antimicrobial chemotherapy) of the composites were evaluated. It was revealed that the NFs showed a combination of photocatalytic and adsorption properties against methylene blue. The NFs degraded the organic pollutants faster than GWs. The cationic composites showed higher antimicrobial activities than their neutral derivates. The results show a promising application window of the cationic Pc-nanofibers.

Performance comparison of photodynamic antimicrobial chemotherapy with visible-light-activated organic dyes: Rose bengal, crystal violet, methylene blue, and toluidine blue O

This study evaluated the photobiocidal performance of four widely distributed visible-light-activated (VLA) dyes against two bacteria (Staphylococcus epidermidis and Escherichia coli) and two bacteriophages (phages MS2 and phi 6): rose bengal (RB), crystal violet, methylene blue, and toluidine blue O (TBO). The photobiocidal performance of each dye depended on the relationship between the type of dye and microorganism. Gram-negative E. coli and the non-enveloped structure of phage MS2 showed more resistance to the photobiocidal reaction than Gram-positive S. epidermidis and the enveloped structure of phage phi 6. RB had the highest potential to yield reactive oxygen species. However, the photobiocidal performance of RB was dependent on the magnitude of the surface charge of the microorganisms; for example, anionic RB induced a negative surface charge and thus electrical repulsion. On the other hand, the photobiocidal performance of TBO was observed to be less affected by the microorganism type. The comparative results presented in our study have significant implications for selecting photodynamic antimicrobial chemotherapy (PACT) dyes suitable for specific situations and purposes. Furthermore, they contribute to the advancement of PACT-related technologies by enhancing their applicability and scalability.

The application of Sn(IV)Cl2 and In(III)Cl porphyrin-dyed TiO2 nanofibers in photodynamic antimicrobial chemotherapy for bacterial inactivation in water

The World Health Organization has reported that antimicrobial resistance is one of the top 10 health threats that humanity faces today. Due to this, alternative therapies to the common antimicrobials are being explored and among these is photodynamic antimicrobial chemotherapy, where a combination of light, a photosensitizer and reactive oxygen species can be used to target microbial cells. In this research, free base, tin (IV) and indium (III) tetramethoxyporphyrins photosensitizers are adsorbed onto inorganic titanium dioxide nanofibers in an effort to create reusable fibers that are effective against Staphylococcus aureus. The photodynamic antimicrobial chemotherapy studies indicate that the metalloporphyrin adsorbed nanofibers exhibit good photodynamic antimicrobial activity against Staphylococcus aureus where the Cl2Sn(IV) tetramethoxyporphyrin dyed TiO2 exhibited 100% bacterial inhibition after a 30 min irradiation period.

Synthesis and photodynamic antimicrobial chemotherapy against multi-drug resistant Proteus mirabilis of ornithine-porphyrin conjugates in vitro and in vivo.

For the treatment of bacterial infections, photodynamic antimicrobial chemotherapy (PACT) has the advantage of circumventing multi-drug resistance. In this work, new cationic photosensitizers against multi-drug resistant Proteus mirabilis (MRPM) were designed and synthesized by the conjugation of amino phenyl porphyrin with basic amino acid L-ornithine. Their photoinactivation efficacies against MRPM in vitro were reported and include the influence of laser energy, uptake, MIC and MBC, dose-dependent photoinactivation effects, membrane integrity, and fluorescence imaging. The PACT in vivo was evaluated using a wound mouse model infected by MRPM. Photosensitizer 4d displayed high photo inactivation efficacy against MRPM at 7.81 μM under illumination, and it could accelerate wound healing via bactericidal effect. These ornithine-porphyrin conjugates are potential photosensitizers for PACT in the treatment of MRPM infection.

Advances in efficacy enhancement of photosensitizer-mediated photodynamic antimicrobial chemotherapy

The fight against pathogenic microorganisms has in recent decades been met with fierce setbacks owing to the antimicrobial resistance phenomenon. Conventional antimicrobials have thus weakened in their effectiveness against microbes, calling for the development of innovative strategies to combat the emerging global health crisis. A promising therapy for filling this gap is photodynamic antimicrobial chemotherapy which destroys microorganisms by making use of the combined action of a photosensitizer, light, and oxygen. The modality inactivates a wide range of pathogens, including bacteria, fungi, protozoa, and viruses. Of greater interest in photodynamic antimicrobial chemotherapy is the ability to destroy resistant strains of microbes without encouraging selection for resistance genes, thus immensely contributing to the fight against antimicrobial resistance. Different PSs vary in their microbial inactivation efficacies. Therefore, various structural modification approaches are being adopted to improve their respective activities. In this paper, recent studies focusing on strategies employed to improve the effectiveness and efficacies of PSs used in photodynamic antimicrobial chemotherapy are reviewed.

ADHERENCE REDUCTION OF PSEUDOMONAS AERUGINOSA UFPEDA 416 UNDER BLUE LED LIGHT IRRADIATION AND CURCUMIN EXPOSURE

This study assessed the adhesion of Pseudomonas aeruginosa UFPEDA 416 (ATCC 27853) exposed to curcumin-mediated Photodynamic Antimicrobial Chemotherapy (PACT). Initially, the Minimum Inhibitory Concentration of curcumin was determined (0.63 μg/mL). After, P. aeruginosa UFPEDA 416 was exposed to the MIC solution of curcumin and then irradiated with a high-power blue LED light at 480 nm for 20, 40, 60 and 120 minutes (28.03 mW/cm2). At each interval, 100 µL aliquots were transferred to microtubes containing Müeller-Hinton broth and incubated at 30ºC for 24 h. The biofilm formed was quantified by the crystal violet method. The adherence rate was calculated using the difference in the absorbance of the treatment, compared to the control. There was a reduction in adhesion capacity from 40.8% in the first 20 minutes to approximately 11% after 60 minutes. The reduction in the adhesion rate accompanied the decrease in planktonic cells, determined from the measurement of the absorbance of the supernatant at 620 nm. The results indicated action by bacteriostasis.

The Photodynamic Anticancer and Antibacterial Activity Properties of a Series of meso-Tetraarylchlorin Dyes and Their Sn(IV) Complexes.

A series of tetraarylchlorins with 3-methoxy-, 4-hydroxy- and 3-methoxy-4-hydroxyphenyl meso-aryl rings (1-3-Chl) and their Sn(IV) complexes (1-3-SnChl) were synthesized and characterized so that their potential utility as photosensitizer dyes for use in photodynamic therapy (PDT) and photodynamic antimicrobial chemotherapy (PACT) can be assessed. The photophysicochemical properties of the dyes were assessed prior to in vitro PDT activity studies against MCF-7 breast cancer cells through irradiation with Thorlabs 625 or 660 nm LED for 20 min (240 or 280 mW·cm-2). PACT activity studies were performed against both planktonic bacteria and biofilms of Gram-(+) S. aureus and Gram-(-) E. coli upon irradiation with Thorlabs 625 and 660 nm LEDs for 75 min. The heavy atom effect of the Sn(IV) ion results in relatively high singlet oxygen quantum yield values of 0.69-0.71 for 1-3-SnChl. Relatively low IC50 values between 1.1-4.1 and 3.8-9.4 µM were obtained for the 1-3-SnChl series with the Thorlabs 660 and 625 nm LEDs, respectively, during the PDT activity studies. 1-3-SnChl were also found to exhibit significant PACT activity against planktonic S. aureus and E. coli with Log10 reduction values of 7.65 and >3.0, respectively. The results demonstrate that the Sn(IV) complexes of tetraarylchlorins merit further in depth study as photosensitizers in biomedical applications.

Evaluation of the antibacterial activity of gallic acid anchored phthalocyanine-doped silica nanoparticles towards Escherichia coli and Staphylococcus aureus biofilms and planktonic cells

In this work, we have described the synthesis of phthalocyanine complexes Zn(II) tetrakis 4-(5-formylpyridin-2-yl)oxy) phthalocyanine (2), Zn(II) tetrakis-1‑butyl‑4-(2-(6- (tetra-phenoxy)pyridin-3-yl) vinyl)pyridin-1-ium phthalocyanine (3) and Zn(II) tetrakis 1‑butyl‑5-(2-(1-butylpyridin-1-ium-4-yl)vinyl)-2-(tetra-phenoxy)pyridin-1-ium phthalocyanine (4). The effect of a varying number of charges when the Pc complexes are alone or grafted in gallic acid (GA) tagged silica nanoparticles on photodynamic antimicrobial chemotherapy (PACT) is investigated toward Staphylococcus aureus (S.aureus) and Escherichia coli (E.coli) in both planktonic and biofilm forms. Complex 4, bearing a total of 8 cationic charges, displayed the highest activity with log CFU (colony forming units) values of 8.60 and 6.42 against E.coli and S.aureus biofilms, respectively. The surface stability of E.coli and S.aureus biofilms in the presence of 4 and its conjugate was analyzed using cyclic voltammetry. Scanning electron microscopy (SEM) and Raman spectra are also used to study the conformational and biochemical changes within biofilm upon subjecting them to PACT.

The Dual Synergy of Photodynamic and Sonodynamic Therapy in the Eradication of Methicillin-Resistant Staphylococcus aureus

Recently, the combined application of synergistic therapies for photodynamic antimicrobial chemotherapy has become important to obtain more efficient results. The synergism between two sensitizers, rose bengal (RB) and chlorin e6 (Ce6), excited by two different methods, was evaluated as a novel approach to both photodynamic and sonodynamic therapy against methicillin-resistant Staphylococcus aureus. The sonostability and singlet oxygen generation (with 1,3-diphenylisobenzofuran for RB and tetrathiafulvalene for Ce6) were measured under sonication (1 MHz, 3 W) using a spectrophotometer. RB and Ce6 remained stable during sonication. RB was a more efficient sonosensitizer than Ce6. The dual synergism between RB and Ce6 was noticed, achieving a &gt;3 log reduction for molar ratios RB:Ce6 of 1:1 and 1:3, while, alone, the sensitizers excited with ultrasound and light, respectively, achieved only ca. a 1 log reduction.

Photodynamic Inhibition of Herpes Simplex Virus 1 Infection by Tricationic Amphiphilic Porphyrin with a Long Alkyl Chain.

Photodynamic therapy (PDT) is broadly used to treat different tumors, and it is a rapidly developing approach to inactivating or inhibiting the replication of fungi, bacteria, and viruses. Herpes simplex virus 1 (HSV-1) is an important human pathogen and a frequently used model to study the effects of PDT on enveloped viruses. Although many photosensitizers (PSs) have been tested for their antiviral properties, analyses are usually limited to assessing the reduction in viral yield, and thus the molecular mechanisms of photodynamic inactivation (PDI) remain poorly understood. In this study, we investigated the antiviral properties of TMPyP3-C17H35, a tricationic amphiphilic porphyrin-based PS with a long alkyl chain. We show that light-activated TMPyP3-C17H35 can efficiently block virus replication at certain nM concentrations without exerting obvious cytotoxicity. Moreover, we show that the levels of viral proteins (immediate-early, early, and late genes) were greatly reduced in cells treated with subtoxic concentrations of TMPyP3-C17H35, resulting in markedly decreased viral replication. Interestingly, we observed a strong inhibitory effect of TMPyP3-C17H35 on the virus yield only when cells were treated before or shortly after infection. In addition to the antiviral activity of the internalized compound, we show that the compound dramatically reduces the infectivity of free virus in the supernatant. Overall, our results demonstrate that activated TMPyP3-C17H35 effectively inhibits HSV-1 replication and that it can be further developed as a potential novel treatment and used as a model to study photodynamic antimicrobial chemotherapy.

Xylan–Porphyrin Hydrogels as Light-Triggered Gram-Positive Antibacterial Agents

In the present work, we report on the synthesis of light-triggered antibacterial hydrogels, based on xylan chains covalently bound to meso-tetra(4-carboxyphenyl)porphyrin (TCPP). Not only does TCPP act as a photosensitizer efficient against Gram-positive bacteria, but it also serves as a cross-linking gelator, enabling the simple and easy building of xylan conjugate hydrogels. The hydrogels were characterized by infrared spectroscopy (ATR-FTIR), scanning electron microscopy (SEM), along with swelling and rheological tests. The antimicrobial activity of the hydrogels was tested under visible light irradiation against two Gram-positive bacterial strains, Staphylococcus aureus and Bacillus cereus. The preliminary results showed an interesting activity on these bacteria, indicating that these hydrogels could be of great potential in the treatment of skin bacterial infections with this species by photodynamic antimicrobial chemotherapy (PACT).

Photo-Inactivation of Staphylococcus aureus by Diaryl-Porphyrins.

Photodynamic Antimicrobial Chemotherapy (PACT) has received great attention in recent years since it is an effective and promising modality for the treatment of human oral and skin infections with the advantage of bypassing pathogens' resistance to antimicrobials. Moreover, PACT applications demonstrated a certain activity in the inhibition and eradication of biofilms, overcoming the well-known tolerance of sessile communities to antimicrobial agents. In this study, 13 diaryl-porphyrins (mono-, di-cationic, and non-ionic) P1-P13 were investigated for their potential as photosensitizer anti-Staphylococcus aureus. The efficacy of the diaryl-porphyrins was evaluated through photo-inactivation tests. Crystal-violet staining combined with viable count techniques were aimed at assaying their anti-biofilm activity. Among the tested compounds, the neutral photosensitizer P4 was better than the cationic ones, irrespective of their corresponding binding rates. In particular, P4 was active in inhibiting the biofilm formation and in impairing the viability of the adherent and planktonic populations of a 24 h old biofilm. The inhibitory activity was also efficient against a methicillin resistant S. aureus strain. In conclusion, the diaryl-porphyrin family represents a reservoir of promising compounds for photodynamic applications against the pathogen S. aureus and in preventing the formation of biofilms that cause many infections to become chronic.

Sn(IV)-porphyrinoids for photodynamic anticancer and antimicrobial chemotherapy.

Photodynamic therapy (PDT) is a mode of treatment for different types of cancers, which involves a nontoxic photosensitizer (PS), a light source to activate the PS, and ground-state molecular oxygen (3O2). Light activation of the PS leads to the generation of reactive oxygen species (ROS), which initiates a toxic effect on the surrounding cellular substrates, thereby destroying the cancerous cells. The commercially used PDT drug Photofrin® which is a tetrapyrrolic porphyrin-based photosensitizer has drawbacks such as aggregation in water, prolonged skin photosensitivity, variability in chemical compositions, and minimal absorbance in the red-light region. Metallation of the porphyrin core with diamagnetic metal ions aids the photogeneration of singlet oxygen (ROS). Metalating with Sn(IV) provides a six-coordination octahedral geometry with trans-diaxial ligands. This approach suppresses aggregation in aqueous media and increases ROS generation upon light exposure due to the heavy atom effect. Bulky trans-diaxial ligation hinders the approach of the Sn(IV) porphyrins, thereby suppressing aggregation effects. In this review, we document the recently reported Sn(IV) porphyrinoids and their photodynamic therapy (PDT) and photodynamic antimicrobial chemotherapy (PACT) activity properties. In a similar manner to PDT, the photosensitizer is used to kill the bacteria upon irradiation with light during PACT. Often, bacteria develop resistance against conventional chemotherapeutic drugs over time, decreasing their antibacterial properties. However, in the case of PACT, it is difficult to generate resistance against singlet oxygen produced by the photosensitizer.

In vitro photoinactivation of S. aureus and E. coli using 5,10,15,20-tetrakis[4-(benzyloxy) phenyl] porphyrin and its metal derivatives conjugated to pristine graphene quantum dots

Antimicrobial resistance is a matter of concern to all biological systems. This work investigates the antimicrobial activity of porphyrins conjugated to pristine graphene quantum dots (pGQDs) through non-covalent linking. A novel In 5,10,15,20-tetrakis[4-(benzyloxy) phenyl] porphyrin (InTBnOPP) was synthesized and fully characterized. The photophysicochemical parameters of H2TBnOPP, ZnTBnOPP, InTBnOPP, and their conjugates were investigated. It was found that pGQDs improved the singlet oxygen quantum yield upon conjugation with the porphyrins. pGQDs-InTBnOPP had a higher singlet oxygen quantum yield of 0.80 when compared to all other conjugates. Porphyrins are well-known photosensitizers for photodynamic antimicrobial chemotherapy (PACT); this was also confirmed by pGQDs-ZnTBnOPP and pGQDs-InTBnOPP which completely inhibited both S. aureus and E. coli with log reduction values of 9.42 and 8.59 with an irradiated time of 5 and or 10 min, respectively. The porphyrins alone had significant antibacterial activities. In general, the obtained results demonstrate a good response of these nanoconjugates against Gram (+) and Gram (-) bacteria.