Novel Siwa propolis and colistin-integrated chitosan nanoparticles: elaboration; in vitro and in vivo appraisal

Evaluating the antibacterial effect of meropenem-loaded chitosan/sodium tripolyphosphate (TPP) nanoparticles on Acinetobacter baumannii isolated from hospitalized patients

BACKGROUND

Acinetobacter baumannii is a health threat due to its antibiotic resistance. Herein, antibiotic susceptibility and its association with the Toxin-antitoxin (TA) system genes in A. baumannii clinical isolates from Iran were investigated. Next, we prepared meropenem-loaded chitosan nanoparticles (MP-CS) and investigated their antibacterial effects against meropenem-susceptible bacterial isolates.

METHODS

Out of 240 clinical specimens, 60 A. baumannii isolates were assessed. Antibiotic resistance of the isolates against conventional antibiotics was determined alongside investigating the presence of three TA system genes (mazEF, relBE, and higBA). Chitosan nanoparticles were characterized in terms of size, zeta potential, encapsulation efficiency, and meropenem release activity. Their antibacterial effects were assessed using the well diffusion method, minimum inhibitory concentration (MIC), and colony-forming unit (CFU) counting. Their cytotoxic effects and biocompatibility index were determined via the MTT, LDH, and ROS formation assays.

RESULTS

Ampicillin, ceftazidime, and colistin were the least effective, and amikacin and tobramycin were the most effective antibiotics. Out of the 60 isolates, 10 (16.7%), 5 (8.3%), and 45 (75%) were multidrug-resistant (MDR), extensively drug-resistant (XDR), and pandrug-resistant (PDR), respectively. TA system genes had no significant effect on antibiotic resistance. MP-CS nanoparticles demonstrated an average size of 191.5 and zeta potential of 27.3 mV alongside a maximum encapsulation efficiency of 88.32% and release rate of 69.57%. MP-CS nanoparticles mediated similar antibacterial effects, as compared with free meropenem, against the A. baumannii isolates with significantly lower levels of meropenem. MP-CS nanoparticles remarkably prevented A549 and NCI-H292 cell infection by the A. baumannii isolates alongside demonstrating a favorable biocompatibility index.

CONCLUSION

Antibiotic-loaded nanoparticles should be further designed and investigated to increase their antibacterial effect against A. baumannii and assess their safety and applicability in vivo settings.

Selenium nanoparticles coated bacterial polysaccharide with potent antimicrobial and anti-lung cancer activities

Bacterial exopolysaccharides are homopolymeric or heteropolymeric polysaccharides with large molecular weights (10-1000 kDa). Exopolysaccharides' functional uses and potential have revolutionized the industrial and medicinal industries. Hence, the aim of the present study was to optimize the production of bacterial exopolysaccharide and apply it as a capping agent for selenium nanoparticles synthesis. Exopolysaccharide (EPS) producing Lactic acid bacteria (LAB) were isolated from dairy products then biochemically characterized and assessed for their potential antimicrobial effect. The most potent EPS producer was identified as Lactiplantibacillus plantarum strain A2 with accession number OP218384 using 16S rRNA sequencing. Overall, FTIR data of the extracted EPS revealed similarity with amylopectin spectrum. 1H NMR spectrum revealed an α-anomeric configuration of the glycosidic linkage pattern in the polysaccharides while the 13C NMR spectrum can also be separated into two main portions, the anomeric carbons region (δ 98-102 ppm) and the non-anomeric carbons region (δ 60-81 ppm). Antimicrobial activity of the produced EPS showed maximum activity against Staphylococcus aureus, MRSA, Enterobacter aerogenes, Klebsiella pneumoniae and Candida albicans respectively. The EPS capsule layer surrounding the bacterial cells was detected by TEM study. Optimization of EPS production was evaluated using Taguchi design, trial 23 reported the highest biomass yield and EPS output (6.5 and 27.12 g/L respectively) with 2.4 and 3.3 folds increase (from the basal media) respectively. The optimized exopolysaccharide was used as a capping and stabilizing agent for selenium nanoparticles (EPS-SeNPs) synthesis. Zeta potential, size and PDI of the synthesized nanoparticles were - 19.7 mV, 45-65 nm and 0.446 respectively with strong bactericidal and fungicidal effect against the tested pathogens. Complete microbial growth eradication was recorded after 6, 8 and 10 h against Staphylococcus aureus, Candida albicans and Klebsiella pneumoniae respectively. EPS-SeNPs showed a potent antioxidant effect reached 97.4% and anticancer effect against A549 lung cancer cell line (IC50 reached 5.324 µg/mL). EPS-SeNPs inhibited cancerous cell growth at S phase. Moreover, molecular studies revealed the anti-apoptotic activity of Bcl2's was inhibited and Bax was activated. The present investigation successfully synthesized selenium nanoparticles through bacterial EPS with significantly high antimicrobial and anticancer activity.

Nanoemulsion of Lavandula angustifolia Essential Oil/Gold Nanoparticles: Antibacterial Effect against Multidrug-Resistant Wound-Causing Bacteria

Hospitalized patients are severely impacted by delayed wound healing. Recently, there has been a growing focus on enhancing wound healing using suitable dressings. Lavandula angustifolia essential oil (LEO) showed potential antibacterial, anti-inflammatory, and wound healing properties. However, the prepared gold nanoparticles possessed multifunctional properties. Consequently, the present investigation aimed to synthesize a novel nanosystem consisting of nano-Lavandula angustifolia essential oil and gold nanoparticles prepared through ultrasonic nanoemulsifying techniques in order to promote wound healing and combat bacterial infection. LEO showed potent antibacterial activity against Klebsiella pneumoniae, MRSA and Staphylococcus aureus with minimum inhibitory concentration (MIC) values of 32, 16 and 16 µg/mL, respectively, while exhibiting low activity against Proteus mirabilis. Interestingly, the newly formulated nano-gold/nano-Lavandula angustifolia penetrated the preformed P. mirabilis biofilm with a full eradication of the microbial cells, with MIC and MBEC (minimal biofilm eradication concentration) values reaching 8 and 16 µg/mL, respectively. The cytotoxic effect of the novel nanoformula was also assessed against WI-38 fibroblasts vero (normal) cells (IC50 = 0.089 mg/mL) while nano-gold and nano-Lavandula angustifolia showed higher results (IC50 = 0.529, and 0.209 mg/mL, respectively). Nano-gold/nano-Lavandula angustifolia formula possessed a powerful wound healing efficacy with a 96.78% wound closure. These findings revealed that nano-gold/nano-Lavandula angustifolia nanoemulsion can inhibit bacterial growth and accelerate the wound healing rate.

Nanoformulation-Based 1,2,3-Triazole Sulfonamides for Anti-Toxoplasma In Vitro Study

Toxoplasma gondii is deemed a successful parasite worldwide with a wide range of hosts. Currently, a combination of pyrimethamine and sulfadiazine serves as the first-line treatment; however, these drugs have serious adverse effects. Therefore, it is imperative to focus on new therapies that produce the desired effect with the lowest possible dose. The designation and synthesis of sulfonamide-1,2,3-triazole hybrids (3a-c) were performed to create hybrid frameworks. The newly synthesized compounds were loaded on chitosan nanoparticles (CNPs) to form nanoformulations (3a.CNP, 3b.CNP, 3c.CNP) for further in vitro investigation as an anti-Toxoplasma treatment. The current study demonstrated that all examined compounds were active against T. gondii in vitro relative to the control drug, sulfadiazine. 3c.CNP showed the best impact against T. gondii with the lowest IC50 value of 3.64 µg/mL. Using light microscopy, it was found that Vero cells treated with the three nanoformulae showed remarkable morphological improvement, and tachyzoites were rarely seen in the treated cells. Moreover, scanning and transmission electron microscopic studies confirmed the efficacy of the prepared nanoformulae on the parasites. All of them caused parasite ultrastructural damage and altered morphology, suggesting a cytopathic effect and hence confirming their promising anti-Toxoplasma activity.

Cinnamon Oil-Loaded Nanoliposomes with Potent Antibacterial and Antibiofilm Activities

Despite recent scientific advances, the global load of bacterial disease remains high and has been established against a backdrop of increasing antimicrobial resistance. Therefore, there is a pressing need for highly effective and natural antibacterial agents. In the present work, the antibiofilm effect provided by essential oils was evaluated. Of these, cinnamon oil extract showed potent antibacterial and antibiofilm activities against Staphylococcus aureus at an MBEC of 75.0 µg/mL. It was revealed that benzyl alcohol, 2-propenal-3-phenyl, hexadecenoic acid, and oleic acid were the major components of the tested cinnamon oil extract. In addition, the interaction between the cinnamon oil and colistin showed a synergistic effect against S. aureus. Cinnamon oil that had been combined with colistin was encapsulated by liposomes to enhance the essential oil's chemical stability, demonstrating a particle size of 91.67 nm, a PDI of 0.143, a zeta potential of -0.129 mV, and an MBEC of 50.0 µg/mL against Staphylococcus aureus. Scanning electron microscopy was employed to observe the morphological changes in the Staphylococcus aureus biofilm that was treated with the encapsulated cinnamon oil extract/colistin. As a natural and safe option, cinnamon oil exhibited satisfactory antibacterial and antibiofilm performance. The application of liposomes further improved the stability of the antibacterial agents and extended the essential oil release profile.

Fungal Secondary Metabolites/Dicationic Pyridinium Iodide Combinations in Combat against Multi-Drug Resistant Microorganisms

The spread of antibiotic-resistant opportunistic microbes is a huge socioeconomic burden and a growing concern for global public health. In the current study, two endophytic fungal strains were isolated from Mangifera Indica roots and identified as Aspergillus niger MT597434.1 and Trichoderma lixii KU324798.1. Secondary metabolites produced by A. niger and T. lixii were extracted and tested for their antimicrobial activity. The highest activity was noticed against Staphylococcus aureus and E. coli treated with A. niger and T. lixii secondary metabolites, respectively. A. niger crude extract was mainly composed of Pentadecanoic acid, 14-methyl-, methyl ester and 9-Octadecenoic acid (Z)-, methyl ester (26.66 and 18.01%, respectively), while T. lixii crude extract's major components were 2,4-Decadienal, (E,E) and 9-Octadecenoic acid (Z)-, and methyl ester (10.69 and 10.32%, respectively). Moreover, a comparative study between the fungal extracts and dicationic pyridinium iodide showed that the combination of A. niger and T. lixii secondary metabolites with dicationic pyridinium iodide compound showed a synergistic effect against Klebsiella pneumoniae. The combined formulae inhibited the bacterial growth after 4 to 6 h through cell wall breakage and cells deformation, with intracellular components leakage and increased ROS production.

Nanostructured γ-Al2O3 Synthesis Using an Arc Discharge Method and its Application as an Antibacterial Agent against XDR Bacteria

In the last few years, many efforts have been devoted to investigating the antibacterial activity of metal nanoparticles, especially against multidrug-resistant bacteria. Recently extensively drug-resistant (XDR) bacteria have emerged and caused a global threat. The purpose of this manuscript was to synthesize nanostructured γ-Al2O3 as an antibacterial agent against some XDRs. The results showed that Al2O3 was a mix of rod and spherical shapes in the nano range with diameters of less than 30 nm. The zeta potential was determined to estimate the surface charge for the synthesized γ-Al2O3, which was recorded as −34 ± 1.8 mV, indicating good stability. The synthesized nanostructured γ-Al2O3 showed a potent antibacterial activity against extensively drug-resistant Acinetobacter baumanii, with an inhibition zone diameter that reached 19 mm and a minimum inhibitory concentration (MIC) value that reached 2 µg/mL. The observed antibacterial activity of the prepared Al2O3 nanoparticles confirmed that the main mechanistic actions include bacterial cells apoptosis, ROS increment, cellular membrane disruption, and DNA damage. The cytotoxic effect (CC50) of the prepared γ-Al2O3-NPs was 1250 µg/mL in a normal human lung fibroblast cell line (WI-38 cells). It can be concluded that the synthesized γ-Al2O3 had an acceptable toxicity, which may pave the way for its use as a potent agent in the fight against XDR bacteria.

Arc discharge rapid synthesis of engineered copper oxides nano shapes with potent antibacterial activity against multi-drug resistant bacteria

Nowadays Nano metals have received an eminent compromise of attention. Even though different nanostructure of same metal maybe gives different results in wide range applications. Copper oxide (CuO-NPs) and Copper Nano wires (CuO-NWs) were prepared in controlled size via the alternating current Arc discharge process. Deionized water and argon gas were the chosen dielectric medium during the process to obtain 2 different forms of copper oxides. By changing the dielectric material from deionized water to argon gas the shape of CuO nanoparticles changed from spherical (CuO-NPs) to wires (CuO-NWS). The yield prepared depicted the purity of the prepared CuO, and their diameters were about 10 ± 5 nm and 30 ± 3 nm for CuO-NWs and CuO-NPs respectively. In vitro cytotoxic effect of the prepared CuO-NWs & CuO-NPs using human normal lung fibroblast cell line (WI-38 cells) revealed that CuO-NWs & CuO-NPs CC₅₀ values were 458.8 and 155.6 µg/mL respectively. Both yields showed potent antibacterial activity against different multi-drug resistant Acinetobacter baumannii strains. A complete eradication of the bacterial growth was noticed after 4 Hrs incubation with CuO-NWs. Moreover, CuO-NWs showed superior antibacterial activity (with minimum inhibitory concentration reached 1.8 µg/mL) over CuO-NPs. The detailed antibacterial activity mechanism of CuO-NWs was further investigated; data proved the precipitation and adsorption of the nanoparticles on the bacterial cell surface leading to cell deformation with reactive oxygen species increment. The results explicated that the nanoparticles shape plays an essential role in the antibacterial activity. Rotational Arc discharge machine might be a promising tool to obtain various metal nanostructures with low cost and environmentally friendly with potent activity.

Novel Amoxicillin-Loaded Sericin Biopolymeric Nanoparticles: Synthesis, Optimization, Antibacterial and Wound Healing Activities

Infected wounds are a major threat among diabetic patients. Technological advancements are currently increasing the number of new adjunctive therapies that may be potent agents for speeding recovery, lowering the amputation rate and limiting infection recurrences. A novel formula with promising antibacterial activity, namely sericin/propolis/Amoxicillin nanoparticles, was assessed as a potent treatment of infected wounds in normal and diabetic rats. Skin wound healing efficiency was assessed through wound healing scorings, bacterial load assessment and histological examinations. It was revealed that upon using sericin/propolis/Amoxicillin nanoparticles, complete wound healing was successfully achieved after 10 and 15 days postinjury for nondiabetic and diabetic rats, respectively. However, the bacterial load in the induced infected wounds was extremely low (0-10 CFU/mL) after 15 days post-treatment. The histological studies revealed that the dermis was more organized with new matrix deposition, and mature collagen fibers were observed among the treated animal groups. The present study is the first preclinical study which reported the importance of silk sericin in the form of nano-sericin/propolis loaded with Amoxicillin as an effective treatment against bacterial wound infections.

Molasses-Silver Nanoparticles: Synthesis, Optimization, Characterization, and Antibiofilm Activity

Biofilms are matrix-enclosed communities of bacteria that are highly resistant to antibiotics. Adding nanomaterials with antibacterial activity to the implant surfaces may be a great solution against biofilm formation. Due to its potent and widespread antibacterial effect, silver nanoparticles were considered the most potent agent with different biological activities. In the present investigation, silver nanoparticles (AgNPs) were newly synthesized as antibiofilm agents using sugarcane process byproduct (molasses) and named Mo-capped AgNPs. The synthesized nanoparticles showed promising antimicrobial activity against S. aureus ATCC 6538 and C. albicans DAY185. Statistically designed optimization through response surface methodology was evaluated for maximum activity and better physical characteristics, namely the nanoparticles’ size and polydispersity index (PDI), and it was revealed that molasses concentration was the main effective factor. Minimal biofilm eradication concentration (MBEC) of Mo-capped AgNPs against S. aureus ATCC 6538 and C. albicans DAY185 was 16 and 32 µg/mL, respectively. Scanning electron microscope study of Mo-capped AgNP-treated biofilm revealed that AgNPs penetrated the preformed biofilm and eradicated the microbial cells. The optimally synthesized Mo-capped AgNPs were spherically shaped, and the average size diameter ranged between 29 and 88 nm with high proportions of Ag⁺ element (78.0%) recorded. Fourier-transform infrared spectroscopy (FTIR) analysis indicated the importance of molasses ingredients in capping and stabilizing the produced silver nanoparticles.

Date Fruit (Phoenix dactylifera L.) Cultivar Extracts: Nanoparticle Synthesis, Antimicrobial and Antioxidant Activities

The pharmaceutical research sector’s inability to produce new drugs has made it difficult to keep up with the rate at which microbial resistance is developing. Recently, nanotechnology and its combinations with natural products have been the saviors against multidrug resistant bacteria. In the present investigation, different Egyptian and Saudi date cultivars were extracted and then phytochemically analyzed and tested for possible antimicrobial activities against multidrug resistant (MDR) microbes. The results revealed that extract of the flesh of fresh “Hayany” fruit (Egyptian date) showed the highest antimicrobial activity, with high levels of phenolic, flavonoid, and tannin concentrations (538.578 µg/mL, 28.481 µg/mL, and 20.888 µg/mL, respectively) and high scavenging activity, with an IC50 reaching 10.16 µg/mL. The highest synergistic activity was found between fresh “Hayany” fruit extract and amikacin. Novel nano-fresh fruit of “Hayany” date extract was synthesized using a ball-milling technique. The vesicle size was 21.6 nm, while the PDI and zeta potential were 0.32 and +38.4 mV, respectively. The inhibition zone diameters of nano-fresh fruit of “Hayany” date extract/amikacin reached 38 mm and 34 mm, with complete microbial eradication after 9 h and 6 h, against Candida albicans and Staphylococcus aureus, respectively. In conclusion, date fruit extract could be used as a candidate bioactive compound in the fight against infectious diseases.

Micrococcus lylae MW407006 Pigment: Production, Optimization, Nano-Pigment Synthesis, and Biological Activities

Simple Summary

The global crisis of increased mortality rates due to the emergence of antimicrobial resistance and cancers has increased researchers’ efforts to find new, potent solutions through implementing natural products in the pharmaceutical industry. The present investigation produced echinenone (yellowish-orange pigment) from Micrococcus lylae MW407006 with potent pharmacological activities. A response surface methodology statistical design was used to optimize the biomass production, pigment concentration, and antimicrobial activity. The Spearman correlation coefficient was assessed, which indicated a strong linear relationship between biomass production, pigment concentration, and antimicrobial activity. Nano-echinenone was physically synthesized through the ball-milling technique. The synthesized nano-echinenone showed higher pharmacological activities (antimicrobial, antioxidant, and antitumor activities) in comparison with the crude pigment. The significantly high selectivity index of the synthesized nano-echinenone proved its safety and paved the way for its possible use in the pharmaceutical industry.

Abstract

Bacterial pigments (e.g., melanin and carotenoids) are considered to be among the most important secondary metabolites due to their various pharmacological activities against cancer and microbial resistance. Different pigmented bacterial strains were isolated from soil samples from El Mahmoudiyah governance and screened for their antimicrobial activity. The most promising pigment producer was identified as Micrococcus lylae MW407006; furthermore, the produced pigment was identified as echinenone (β-carotene pigment). The pigment production was optimized through a central composite statistical design to maximize the biomass production, pigment concentration, and the antimicrobial activity. It was revealed that the most significant fermentation parameters were the glucose (as a carbon source) and asparagine (as a nitrogen source) concentrations. Nano-echinenone was synthesized using the ball milling technique, characterized, and finally assessed for potential antimicrobial, antioxidant, and antitumor activities. The data revealed that the synthesized nano-echinenone had higher antimicrobial activity than the crude pigment. The cytotoxic potency of echinenone and nano-echinenone was investigated in different cell lines (normal and cancer cells). The inhibition of cell proliferation and induction of cell death was observed in Caco-2 and Hep-G2 cells. The data proved that nano-echinenone is a suitable candidate for use as a safe antimicrobial and anti-hepatocellular-carcinoma agent.

Novel 1,2,3-Triazole-sulphadiazine-ZnO Hybrids as Potent Antimicrobial Agents against Carbapenem Resistant Bacteria

Bacterial pneumonia is considered one of the most virulent diseases with high morbidity and mortality rates, especially in hospitalized patients. Moreover, bacterial resistance increased over the last decades which limited the therapy options to carbapenem antibiotics. Hence, the metallo-β-lactamase-producing bacteria were deliberated as the most deadly and ferocious infectious agents. Sulphadiazine-ZnO hybrids biological activity was explored in vitro and in vivo against metallo-β-lactamases (MBLs) producing Klebsiella pneumoniae. Docking studies against NDM-1 and IMP-1 MBLs revealed the superior activity of the 3a compound in inhibiting both MBLs enzymes in a valid reliable docking approach. The MBLs inhibition enzyme assay revealed the remarkable sulphadiazine-ZnO hybrids inhibitory effect against NDM-1 and IMP-1 MBLs. The tested compounds inhibited the enzymes both competitively and noncompetitively. Compound 3b-ZnO showed the highest antibacterial activity against the tested metallo-β-lactamase producers with an inhibition zone (IZ) diameter reaching 43 mm and a minimum inhibitory concentration (MIC) reaching 2 µg/mL. Sulphadiazine-ZnO hybrids were tested for their in vitro cytotoxicity in a normal lung cell line (BEAS-2Bs cell line). Higher cell viability was observed with 3b-ZnO. Biodistribution of the sulphadiazine-ZnO hybrids in the lungs of uninfected rats revealed that both [124I]3a-ZnO and [124I]3b-ZnO hybrids remained detectable within the rats’ lungs after 24 h of endotracheal aerosolization. Moreover, the residence duration in the lungs of [124I]3b-ZnO (t1/2 4.91 h) was 85.3%. The histopathological investigations confirmed that compound 3b-ZnO has significant activity in controlling bacterial pneumonia infection in rats.

Silver/Snail Mucous PVA Nanofibers: Electrospun Synthesis and Antibacterial and Wound Healing Activities

Healthcare textiles are gaining great attention in the textile industry. Electrospun nanofibers are considered the golden soldiers due to their strength, flexibility, and eco-friendly properties. The present study aimed to evaluate the potency of polyvinyl alcohol (PVA) nanofibers loaded with newly biosynthesized silver nanoparticles (Ag-NPs) as a wound healing dressing. Chocolate-band snail (Eobania vermiculata) mucus (which is part of the Mollusca defense system) was used as a novel reducing and stabilizing agent. Data indicated the effectiveness of Eobania vermiculata’s mucus in silver nanoparticle synthesis after a 24 h incubation time. The biosynthesized AgNPs-SM showed a 13.15 nm particle size, −22.5 mV ζ potential, and 0.37 PDI, which proved the stability of the synthesized nanoparticles. Eobania vermiculata mucus and AgNPs-SM showed potent antibacterial activity, especially against Pseudomonas aeruginosa. The electrospinning technique was applied in the fabrication of PVA/AgNPs-SM nanofibers, which were homogenous with a fine diameter of about 100–170 nm and showed a significantly high antimicrobial activity. In vitro and in vivo studies revealed that PVA/AgNPs-SM nanofibers were safe and efficiently enhanced the wound healing process (typical histological picture of the proliferative phase with compact and well aligned collagen fibers in the dermal tissue after 12 days) together with bacterial growth inhibition in the infected skin area.

In vivo bio-distribution and acute toxicity evaluation of greenly synthesized ultra-small gold nanoparticles with different biological activities

Ultra-small gold nanoparticles (Au-NPs) “≤ 10 nm diameters” have potent biomedical applications. Hence, the present study aimed to greenly synthesize ultra-small gold nanoparticles using Egyptian propolis extract. Different biological activities, in vivo bio-distribution and acute toxicity study were assessed. Results revealed that, Egyptian propolis extract can successfully synthesize the highly pure and stable ultra-small Au-NPs with average diameter 7.8 nm. In vitro antimicrobial and antimycobacterial activities revealed the powerful effect of the prepared Au-NPs. Moreover, the cytotoxic effect on human cancer cell lines revealed the potent inhibition of the cancer cells’ proliferation with high reactive oxygen species-mediated apoptosis induction. In vivo bio-distribution and acute toxicity studies were performed (10 and 100 mg/kg doses) in male albino rats. The ultra-small Au-NPs showed low or no toxicity upon using the Au-NPs low dose. The mean area accumulation (%) of the Au-NPs was higher in the liver, kidney, and brain tissues (4.41, 2.96, and 0.3 times, respectively) treated with high Au-NPs dosage compared to those treated with the low dose. Surprisingly, Au-NP accumulation in brain tissue was observed in the glial cells only. Accordingly, the low dose (10 mg/kg) of Au-NPs can be used safely in a variety of biomedical applications.

Synthesis, Characterization and Nanoformulation of Novel Sulfonamide-1,2,3-triazole Molecular Conjugates as Potent Antiparasitic Agents

Toxoplasma gondii (T. gondii) is a highly prevalent parasite that has no gold standard treatment due to the poor action or the numerous side effects. Focused sulfonamide-1,2,3-triazole hybrids 3a–c were wisely designed and synthesized via copper catalyzed 1,3-dipolar cycloaddition approach between prop-2-yn-1-alcohol 1 and sulfa drug azides 2a–c. The newly synthesized click products were fully characterized using different spectroscopic experiments and were loaded onto chitosan nanoparticles to form novel nanoformulations for further anti-Toxoplasma investigation. The current study proved the anti-Toxoplasma effectiveness of all examined compounds in experimentally infected mice. Relative to sulfadiazine, the synthesized sulfonamide-1,2,3-triazole (3c) nanoformulae demonstrated the most promising result for toxoplasmosis treatment as it resulted in 100% survival, 100% parasite reduction along with the remarkable histopathological improvement in all the studied organs.

The powerful synergistic effect of spiramycin/propolis loaded chitosan/alginate nanoparticles on acute murine toxoplasmosis

The novel formula of spiramycin/propolis loaded chitosan (CS)/alginate (Alg) nanoparticles (NPs) was assessed for Toxoplasma gondii (T. gondii) treatment in comparison with the commercially available spiramycin regarding tissue penetration and blood brain barrier (BBB) passage. Swiss Albino mice were inoculated intraperitoneally by 2500 tachyzoites of the virulent T. gondii RH strain. The experimental groups were treated with oral spiramycin, propolis, CS/Alg NPs, spiramycin loaded CS/Alg NPs, propolis loaded CS/Alg NPs, and spiramycin/propolis loaded CS/Alg NPs. The results demonstrated that spiramycin/propolis loaded CS/Alg NPs exerted the longest survival time with no mortality on the sacrifice day (8^th) in addition to representing the highest significant parasite percent reduction of (≥96% reduction) in liver, spleen and brain designating successful tissue penetration and BBB passage. Tachyzoites treated with spiramycin/propolis loaded CS/Alg NPs demonstrated the most disfigured rapturing organism via scanning electron microscope examination along with representing an overall remarkable improvement of the histopathological pictures of liver, spleen and brain. In conclusion, spiramycin/propolis loaded CS/Alg NPs showed the uppermost efficacy in the treatment of acute murine toxoplasmosis. The safe nature and the anti-parasitic effect of each of CS, Alg, spiramycin and propolis encourage the synergistic use of spiramycin/propolis loaded CS/Alg NPs as a potent treatment for human toxoplasmosis.

Toxoplasmosis is a disease that results from infection with a parasite known as Toxoplasma gondii (T. gondii). The parasite is considered to be one of the world’s most common parasites. Infection frequently occurs by eating undercooked contaminated meat, exposure to infected cat faeces, or mother-to-fetus transmission throughout pregnancy. The parasite has the ability to reach all body organs including the brain. This in turn, may lead to death specially among people with weakened immune systems and infants born to infected mothers. There are many treatment options for the disease, however they may have severe side effects or can’t fully reach the brain. Consequently, the present work focused on the formulation of a safe novel formula at the nano size for better tissue penetration. The novel treatment was achieved by preparing the natural organic chitosan/alginate nanoparticles and loading them with spiramycin (the safest drug used in toxoplasmosis) along with propolis (a natural bee product). The treatment efficacy of the novel spiramycin/propolis loaded chitosan/alginate nanoparticles was compared with the commercial spiramycin. The used drug showed a marked potency in toxoplasmosis treatment. The anti-parasitic effect and the safe nature of each of the used components potentiate its use as a promising treatment.

From propolis to nanopropolis: An exemplary journey and a paradigm shift of a resinous substance produced by bees

Propolis, a natural resinous mixture produced by honey bees is poised with diverse biological activities. Owing to the presence of flavonoids, phenolic acids, terpenes, and sesquiterpenes, propolis has garnered versatile applications in pharmaceutical industry. The biopharmaceutical issues associated with propolis often beset its use as being too hydrophobic in nature; it is not absorbed in the body well. To combat the problem, various nanotechnological approaches for the development of novel drug delivery systems are generally applied to improve its bioavailability. This paradigm shift and transition of conventional propolis to nanopropolis are evident from the literature wherein a multitude of studies are available on nanopropolis with improved bioavailability profile. These approaches include preparation of gold nanoparticles, silver nanoparticles, magnetic nanoparticles, liposomes, liquid crystalline formulations, solid lipid nanoparticles, mesoporous silica nanoparticles, etc. Nanopropolis has further been explored to assess the potential benefits of propolis for the development of futuristic useful products such as sunscreens, creams, mouthwashes, toothpastes, and nutritional supplements with improved solubility, bioavailability, and penetration profiles. However, more high-quality clinical studies assessing the effects of propolis either alone or in combination with synthetic drugs as well as natural products are warranted and its safety needs to be firmly established.

Novel Clotrimazole and Vitis vinifera loaded chitosan nanoparticles: Antifungal and wound healing efficiencies

Chitosan integrated nanoparticles of clotrimazole and Egyptian Vitis vinifera juice extract was evaluated in order to maximize the antifungal activity and reduce the gross side effects. In the present study Egyptian Thompson Seedless Vitis vinifera and Clotrimazole (Cz) loaded chitosan nanoparticles (NCs/VJ/Cz) showed a promising antifungal effect with average inhibition zone diameters of 74 and 72 mm against Candida albicans and Aspergillus niger respectively. NCs/VJ /Cz was stable with significant drug entrapment efficiency reached 94.7%; PDI 0.24; zeta potential value + 31 and average size 35.4 nm diameter. Ex vivo and in vivo evaluation of skin retention, permeation and wound repair potentialities of NCs/VJ /Cz ointment was examined by experimental rats with wounded skin fungal infection. Data proved the ability of NCs/VJ /Cz to gradually release the drugs in a sustained manner with complete wound healing effect and tissue repair after 7 days administration. As a conclusion NCs/VJ /Cz ointment can be used as a novel anti-dermatophytic agent with high wound healing capacity.

Elastic Nanofibrous Membranes for Medical and Personal Protection Applications: Manufacturing, Anti-COVID-19, and Anti-Colistin Resistant Bacteria Evaluation

Herein, in the present work two series of thermoplastic polyurethane (TPU) nanofibers were manufactured using the electrospinning techniques with ZnO and CuO nanoparticles for a potential use as an elastic functional layer in antimicrobial applications. Percentages of 0%, 2 wt%, and 4 wt% of the nanoparticles were used. The morphological characterization of the electrospun TPU and TPU/NPs composites nanofibers were observed by using scanning electron microscopy to show the average fiber diameter and it was in the range of 90-150 nm with a significant impact of the nanoparticle type. Mechanical characterization showed that TPU nanofiber membranes exhibit excellent mechanical properties with ultra-high elastic properties. Elongation at break reached up to 92.5%. The assessment of the developed nanofiber membranes for medical and personal protection applications was done against various colistin resistant bacterial strains and the results showed an increment activity by increasing the metal oxide concentration up to 83% reduction rate by using TPU/ZnO 4% nanofibers against K. pneumoniae strain 10. The bacterial growth was completely eradicated after 8 and 16 h incubation with TPU/ZnO and TPU/CuO nanofibers, respectively. The nanofibers SEM study reveals the adsorption of the bacterial cells on the metal oxides nanofibers surface which led to cell lysis and releasing of their content. Finally, in vitro study against Spike S-protein from SARS-CoV-2 was also evaluated to investigate the potent effectiveness of the proposed nanofibers in the virus deactivation. The results showed that the metal oxide concentration is an effective factor in the antiviral activity due to the observed pattern of increasing the antibacterial and antiviral activity by increasing the metal oxide concentration; however, TPU/ZnO nanofibers showed a potent antiviral activity in relation to TPU/CuO.

Antibiotics Combinations and Chitosan Nanoparticles for Combating Multidrug Resistance Acinetobacter baumannii

Background

Successful treatment of Acinetobacter (A.) baumannii-associated infection is complicated by the emergence of multidrug resistance (MDR), particularly in clinical settings. This urges searching for new alternatives to encounter such health problem.

Aim

This study aimed to evaluate certain antibiotic combinations and CNPs either alone or in combination of some selected antibiotics for the purpose of combating MDR A. baumannii clinical isolates.

Methods

A total of 51 A. baumannii clinical isolates were recovered from discharged clinical specimens of the Clinical Microbiology Central Laboratory of AL Kasr Al Aini hospital, Cairo, Egypt. Conventional standard Lab tests were used for identification followed by recA gene testing for confirmation. Antimicrobial susceptibility tests were conducted out according to CLSI guidelines. Genotypic analysis using Enterobacterial Repetitive Intergenic Consensus-polymerase chain reaction (ERIC-PCR) of the respective isolates showed that they were clustered in nine clones. The prepared CNPs were characterized by dynamic light scattering and HR-transmission electron microscope imaging. Antibiotic combinations and co-effect of CNPs with some selected antibiotics (either each alone or in combination of two) were evaluated using the Checkerboard microdilution and minimum inhibitor concentration decrease factor (MDF) methods, respectively.

Results

The recovered 51 A. baumannii clinical isolates were MDR (100%) of these 92% (47/51) were extensively drug resistance (XDR). Combinations of colistin (CT)+meropenem (MEM) and MEM+tigecycline (TGC) showed synergism in 77.7% and 44.4% and additive effects in 22.3% and 55.6% of the tested MDR A. baumannii isolates (n=51), respectively. However, CT+TGC combination showed antagonism. CNPs exhibited good inhibitory activity (inhibition zones ranged from 24 to 31 mm) against selected nine MDR A. baumannii isolates (one isolate from each clone). The MIC of CNPs at concentrations (ranging from 1 to 5 mg/mL) were from 0.16 to 0.25 mg/mL, indicating good in vitro antimicrobial activities. CNPs (5 mg/mL) when combined with CT, TGC or MEM, CT+MEM and TGC+MEM significantly increased the susceptibilities of the MDR A. baumannii isolates to these antibiotics by 88.8%, 66.6%, 100%, 77.7%, and 44.4%, respectively. No significant effects were observed when CNPs (5 mg/mL) were combined with CT+TGC.

Conclusion

The current study demonstrated the significant in-vitro activities of CNPs either alone or in combination with CT, TGC or MEM, CT+MEM and TGC+MEM and the successful combinations of MEM either with CT or with TGC against the MDR A. baumannii pathogens. However, further in vivo studies should be conducted to verify such activities and their potential use in human.

Novel Synthesis of Titanium Oxide Nanoparticles: Biological Activity and Acute Toxicity Study

Titanium oxide nanoparticles (TiO₂ NPs) have been attracting numerous research studies due to their activity; however, there is a growing concern about the corresponding toxicity. Here in the present study, titanium oxide nanoparticles were newly synthesized using propolis extract followed by antimicrobial activity, cytotoxicity assay using human cancer cell lines, and acute toxicity study. The physicochemical characterization of the newly synthesized TiO₂ NPs had average size = 57.5 nm, PdI = 0.308, and zeta potential = −32.4 mV. Antimicrobial activity assessment proved the superior activity against Gram-positive compared to Gram-negative bacteria and yeast (lowest MIC values 8, 32, and 32, respectively). The newly synthesized TiO₂ NPs showed a potent activity against the following human cancer cell lines: liver (HepG-2) (IC50 8.5 µg/mL), colon (Caco-2), and breast (MDA-MB 231) (IC50 11.0 and 18.7 µg/mL). In vivo acute toxicity study was conducted using low (10 mg/kg) and high (1000 mg/kg) doses of the synthesized TiO₂ NPs in albino male rats. Biochemistry and histopathology of the liver, kidney, and brain proved the safety of the synthesized TiO₂ NPs at low dose while at high dose, there was TiO₂ NPs deposit in different vital organs except the cerebral tissue.