Skin is the largest mechanical barrier against invading pathogens. Following skin injury, the healing process immediately starts to regenerate the damaged tissues and to avoid complications that usually include colonization by pathogenic bacteria, leading to fever and sepsis, which further impairs and complicates the healing process. So, there is an urgent need to develop a novel pharmaceutical material that promotes the healing of infected wounds. The present work aimed to prepare and evaluate the efficacy of novel azithromycin-loaded zinc oxide nanoparticles (AZM-ZnONPs) in the treatment of infected wounds. The Box–Behnken design and response surface methodology were used to evaluate loading efficiency and release characteristics of the prepared NPs. The minimum inhibitory concentration (MIC) of the formulations was determined against Staphylococcus aureus and Escherichia coli. Moreover, the anti-bacterial and wound-healing activities of the AZM-loaded ZnONPs impregnated into hydroxyl propyl methylcellulose (HPMC) gel were evaluated in an excisional wound model in rats. The prepared ZnONPs were loaded with AZM by adsorption. The prepared ZnONPs were fully characterized by XRD, EDAX, SEM, TEM, and FT-IR analysis. Particle size distribution for the prepared ZnO and AZM-ZnONPs were determined and found to be 34 and 39 nm, respectively. The mechanism by which AZM adsorbed on the surface of ZnONPs was the best fit by the Freundlich model with a maximum load capacity of 160.4 mg/g. Anti-microbial studies showed that AZM-ZnONPs were more effective than other controls. Using an experimental infection model in rats, AZM-ZnONPs impregnated into HPMC gel enhanced bacterial clearance and epidermal regeneration, and stimulated tissue formation. In conclusion, AZM -loaded ZnONPs are a promising platform for effective and rapid healing of infected wounds.

Calligonum polygonoides L. subsp. comosum (Polygonaceae) is a wild shrub that grows on the sandy deserts of various regions in North Africa, Western Asia and Southern Europe. In some of Asian countries, the flower buds and young branches of the plant are used to prepare traditional food dishes. Also, different organs of C. polygonoides L. are used traditionally in treatment of stomach diseases. The isolation of anti-inflammatory lead compounds was performed by using different normal silica gel, reversed phase C-18, and sephadex LH-20 open columns. The identification of the isolated compounds was done using NMR spectral techniques. The isolated compounds are of different flavonoid classes; two flavonol glycosides; kaempferol-3-O-β-D-glucuronide and mequilianin, one flavan-3-ol; catechin, and one dihydro-flavonol; taxifolin. The methanol extract and ethyl acetate fraction of Calligonum polygonoides L. subsp. comosum exhibited anti-inflammatory activity against NF-κB translocation pathway on HEK293 cells. All of them were active against NF-κB translocation, and previously isolated from the plant under study. Kaempferol-3-O-β-D-glucuronide, a flavonoid glycoside demonstrated the most potent NF-κB inhibition in comparing with other flavonoids; taxifolin, catechin, and mequilianin. Therefore, the food plant aerial parts of C. polygonoides are rich in nutraceuticals (flavonoids and flavonoid glycosides) that can be utilized in the treatment of vascular inflammation.

In our ongoing effort to investigate active specialised metabolites from genus Glandularia, phytochemical studies on the ethanolic extract of Glandularia × hybrida (Groenl. & Rümpler) G.L. Nesom & Pruski leaves resulted in the isolation of three undescribed compounds, a dibenzylbutyrolactolic lignan and two echinocystic acid based triterpenoid saponins, in addition to two known compounds. Interestingly, this study reports isolation of chemosystematically valuable specialised metabolites for the first time from the genus under investigation. Additionally, the isolated metabolites were evaluated for their iNOS inhibition and cytotoxic activities using a combination of in silico and in vitro studies. The pharmacokinetics properties (ADMET) of some of the isolated compounds were determined using pkCSM-pharmacokinetics server. Molecular docking analysis showed that saponin compound possesses higher negative score (− 9.59 kcal/mol) than the lignan compound (− 6.56 kcal/ mol). The isolated compounds also showed iNOS inhibition activity with IC50 values ranging between 6.6 and 49.7 μM and significant cytotoxic activity against a series of cell lines including SK-MEL, KB, BT-549, SK-OV-3, LLC-PK1 and VERO cells. Hence, this study reveals that specialised metabolites from G. hybrida plant are of significant anti-inflammatory and cytotoxicity potentials.

Keywords: Glandularia × hybrida Verbenaceae Triterpenoidal saponins Lignans X-ray crystallography iNOS inhibition Molecular docking

Background and aim:

The poultry meat and its products are considered ideal media for bacterial growth and spoilage, as they are highly nutritive with a favorable pH. The food industry has focused its attention on a great diversity of plant species as food preservatives. The aim of this study was to investigate the presence of Staphylococcus aureus, Escherichia coli O157: H7, and Klebsiella pneumonia in food samples and to evaluate of the antibacterial activity of some medicinal plant extracts against these bacteria.

Methods:

Raw and processed meat samples (n = 60) were collected from abattoirs and local markets. S. aureus, E. coli O157: H7, and K. pneumonia were isolated, identified by phenotypic methods, and then confirmed by 16S rRNA gene sequencing. The antibacterial activity and spectrum of essential oils and spices powder of cumin, black seeds, cloves, cinnamon, and marjoram was determined against the isolated strains in this study by microbial count and well-diffusion techniques.

Results:

A total of 33 isolates have been identified as S. aureus, 30 isolates were identified as E. coli O157: H7, and 15 isolates were identified as K. pneumonia. S. aureus, E. coli O157: H7, and K. pneumonia could be detected in both fresh and processed food with higher prevalence in the processed meat. There was a significant decrease in microbial count in treated samples either with the spices powder or essential oils of the tested medicinal plants compared to control samples during storage time period. Furthermore, while the microbial count increased in the control samples, the microbial count decreased to reach zero in almost all treated samples …

Aim

The essential protein element of spider silk ‘spidroin’ was used to assess its impact on the wound-healing process.

Methods

Spidroin nanoparticles (NPs) were prepared using poly(lactic-co-glycolic acid) polymer (PLGA/spidroin NPs) at different weight ratios (5:1, 10:1, 15:1) and were in vitro characterized. The optimized NPs were tested in vitro for release and antibacterial activity. To assess wound-healing effects, NPs were topically applied on surgically induced injuries in Allolobophora caliginosa earthworms as a robust human skin model.

Results

Optimized NPs (173 ± 3 nm) revealed considerable antibacterial effect against Staphylococcus aureus and Escherichia coli. After 4 days of NPs application on wounds, macroscopical and histological examinations revealed a significant reduction in wound and re-epithelialization times.

Conclusion

PLGA/spidroin NPs may represent a promising option for wound …

We aimed to isolate Acinetobacter baumannii (A. baumannii) from wound infections, determine their resistance and virulence profile, and assess the impact of Silver nanoparticles (AgNPs) on the bacterial growth, virulence and biofilm‐related gene expression. AgNPs were synthesized and characterized using TEM, XRD and FTIR spectroscopy. A. baumannii (n = 200) were isolated and identified. Resistance pattern was determined and virulence genes (afa/draBC, cnf1, cnf2, csgA, cvaC, fimH, fyuA, ibeA, iutA, kpsMT II, PAI, papC, PapG II, III, sfa/focDE and traT) were screened using PCR. Biofilm formation was evaluated using Microtiter plate method. Then, the antimicrobial activity of AgNPs was evaluated by the well‐diffusion method, growth kinetics and MIC determination. Inhibition of biofilm formation

and the ability to disperse biofilms in exposure to AgNPs were evaluated. The effect of AgNPs on the expression of virulence and biofilm‐related genes (bap, OmpA, abaI, csuA/B, A1S_2091, A1S_1510, A1S_0690, A1S_0114) were estimated using QRT‐PCR. In vitro infection model for analyzing the antibacterial activity of AgNPs was done using a co‐culture infection model of A. baumannii with human fibroblast skin cell line HFF‐1 or Vero cell lines. A. baumannii had high level of resistance to antibiotics. Most of the isolates harbored the fimH, afa/draBC, cnf1, csgA and cnf2, and the majority of A. baumannii produced strong biofilms. AgNPs inhibited the growth of A. baumannii efficiently with MIC ranging from 4 to 25 μg/ml. A. baumannii showed a reduced growth rate in the presence of AgNPs. The inhibitory activity and the anti‐biofilm activity of AgNPs were more pronounced against the weak biofilm producers. Moreover, AgNPs decreased the expression of kpsMII , afa/draBC,bap, OmpA,

and csuA/B genes. The in vitro infection model revealed a significant antibacterial activity of AgNPs against extracellular and intracellular A. baumannii. AgNPs highly interrupted bacterial multiplication and biofilm formation. AgNPs downregulated the transcription level of important virulence andbiofilm‐related genes. Our findings provide an additional step towards understanding the mechanisms by which sliver nanoparticles interfere with the microbial spread and persistence.

An innovative and reliable electrochemical sensor was proposed for simple, sensitive and selective determination of F⁻ ions. The sensor based on the fabrication of porous and electroactive Fe-based metal organic frameworks [MIL-101(Fe)]. It was blended with graphite powder and liquid paraffin oil to from carbon paste electrode (CPE). The MIL-101(Fe)@CPE was characterized using different techniques such as scanning electron microscope, powder X-ray diffraction spectroscopy, Fourier transform infrared spectroscopy, energy dispersive X-ray, cyclic voltammetry, electrochemical impedance spectroscopy, differential pulse voltammetry. The MIL-101(Fe)@CPE exhibited two redox peaks (anodic and cathodic) corresponding to Fe³⁺ and Fe²⁺, respectively. The determination of F⁻ ions based on the formation of a stable fluoroferric complex with Fe³⁺/ Fe²⁺, decreasing the currents of redox species. It was found that the anodic peak current (Ipa) is linearly proportional to the concentration of F⁻ in the range of 0.67–130 μM with a limit of detection (S/N = 3) of 0.201 μM. The electrode exhibited good selectivity towards F^- detection with no significant interferences from common anions. The as-fabricated sensor was applied for the determination of F⁻ in environmental water samples with recoveries % and RSDs % in the range of 98.1%–102.4% and 2.4%–3.7%, respectively.

A molecularly imprinted electrochemical sensor was fabricated for sensitive and selective detection of anti-COVID 19 drug favipiravir (FAV). The sensor is based on the synthesis of biomass-derived carbon (BC) and nickel disulfide nanospheres (NiS₂ NS), which were used to decorate glassy carbon electrode (GCE). Then, the gold nanoparticles (AuNPs) were electro- deposited on the surface of NiS₂ NS/BC/GCE to enhance conductivity, increase electron transfer, and aid polymerization of p-aminothiophenol (p-ATP) functional monomer. The fabrication steps were characterized using different morphological and electrochemical techniques. Variables affecting the formation of molecularly imprinted layers and the determination of FAV were optimized. Under optimum conditions, the oxidation current (Ipa) was increased upon addition of FAV in the range of 0.42–1100 nM with a limit of detection (LOD, S/N) of 0.13 nM. The as-fabricated sensor possesses several advantages such as high sensitivity and selectivity, good reproducibility, and acceptable stability. Furthermore, the proposed molecularly imprinted –based electrochemical sensor was efficiently applied for the determination of FAV in tablets and human serum samples with recoveries % of 99.2 to 102.1 % and RSDs % in the range of 2.4–3.2 %, which confirms the reliability of the sensor to detect FAV in different matrices.

Graphical abstract

Copper based-metal organic frameworks modified with gold nanoparticles (AuNPs@Cu-MOF) was fabricated via facile approach. The nanocomposite was used to decorate glassy carbon electrode (GCE) for the electrochemical sensing of D- penicillamine (D-PA). The nanocomposite was characterized using different techniques such as scanning electron microscope (SEM), transmission electron microscope (TEM), energy dispersive X-ray spectroscopy (EDX), powder X-ray spectroscopy (PXRD), thermogravimetry (TGA), nitrogen adsorption–desorption isotherms, and Fourier Transform infrared spectroscopy (FTIR). Formation of a new anodic peak of Cu(II)-D-PA complex at + 0.38 V was used to detect D-PA. Cyclic and square wave voltammetric studies proved that AuNPs elevated the conductivity of Cu-MOF. The sensor exhibited wide linear range (0.4–75 × 10⁻⁷ M) and low detection limit (0.11 × 10⁻⁷ M) with a good sensitivity (0.9 ± 0.01 μA/μM). It was successfully applied for the estimation of D-PA in different real samples with recoveries % and relative standard deviations % (RSDs %) in the range of 95.6–102.5% and 2.4–3.3%, respectively.