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Wound infections with rising incidences of multi-drug resistant bacteria are among the public health problems worldwide. The current study describes wound dressing materials made from biodegradable polyhydroxybutyrate (PHB) combined with AgNPs and gelatin (AgNPs/Gelatin/PHB). Microbial PHB was mixed with gelatin (1:2) to form a polymer matrix which was loaded with different concentrations of AgNPs (8.3-133 μg/mL). The statistical results of AgNPs synthesizing based on Box-Behnken design revealed that 1.247 mM silver nitrate and 24.054 % of Corchorus olitorius leaf extract concentration at pH (8.07) were the optimum values for the biosynthesis. UV-Vis spectroscopy, FTIR study and XRD reflects that nanoparticles are formed. The UV-Vis spectroscopy of Gelatin/PHB/AgNPs exhibited two specific bands at 298 nm and 371 nm, which confirm the formation of the conjugate. AgNPs had MICs and MBCs of (24.9, 24.9, and 12.45 μg/mL) and (33.25, 33.25, and 16.6 μg/mL) against (Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus). The MIC and MBC of AgNPs/Gelatin/PHB against the same tested bacteria were 31.1 μg and 41.5 μg, respectively. AgNPs/Gelatin/PHB exhibit excellent antimicrobial efficacy against bacteria. Sterilized gauze loaded with 31.1 μg of AgNPs/Gelatin/PHB acted as an effective wound dressing. Thus, the study highlights the importance of wound dressings developed from degradable AgNPs/Gelatin/PHB in enhancing antimicrobial efficiency and facilitating a better wound healing process., Competing Interests: Declaration of competing interest The authors have declared no conflict of interest., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Objectives: Due to the expanded bacterial genetic tolerance to antibiotics through different mechanisms, infectious diseases of MDR bacteria are difficult for treatment. Consequently, we synthesized drug conjugated nanoparticles to dissolve this problem. Moreover, the present study aims to display the cell death status treated with cefotaxime-CS-AgNPs and also, apoptosis pathways of human RPE-1 normal cells and human MCF-7 breast cancer cells., Methods: Here, we demonstrate the possibility to synthesize AgNPs and conjugate them with cefotaxime to survey the probability of cefotaxime-CS-AgNPs as an antimicrobial agent against cefotaxime-resistant strains E. coli and MRSA., Results: TEM showed the size of AgNPs, CS-AgNPs and cefotaxime-CS-AgNPs ranged from 7.42 to 18.3 nm, 8.05-23.89 nm and 8.48-25.3 nm, respectively, with a spherical shape. The cefotaxime-CS-AgNPs enhanced the high antimicrobial properties compared to AgNPs or pure antibiotic. The MIC of Cefotaxime-CS-AgNPs ranged from 3 µg/mL to 8 µg/mL against tested E. coli and MRSA bacteria. Consequently, the highest reduction in the MIC of cefotaxime-CS-AgNPs was noted against tested strains ranging from 22% to 96%. Comparing cefotaime-CS-AgNPs to AgNPs we showed that cefotaime-CS-AgNPs have no cytotoxic effect on normal cells at even 12 µg/mL for 24 hrs. The IC50 for the AgNPs and cefotaxime-CS-AgNPs was 12 µg/mL for human RPE-1 normal cells and human MCF-7 breast cancer cell lines. The pro-apoptotic genes p53, p21, and Bax of cancer cell lines significantly upregulated followed by downregulated by anti-apoptotic gene Bcl-2 after 48 hrs at 24 µg/mL, and this concentration represents the most effective dose., Conclusion: Results enhanced the conjugating utility in old unresponsive cefotaxime to AgNPs to restore its efficiency against previous strains and demonstrated potential therapeutic applications of cefotaxime-CS-AgNPs. Moreover, this research gives remarkable insights for designing nanoscale delivery and curative systems that have a pronounced cytotoxic activity on cancer cells and are safe to normal cells., Competing Interests: The authors declare that they have no conflicts of interest in this work., (© 2020 Halawani et al.)

Gold nanoparticles (AuNP) and their conjugates have been gaining a great deal of recognition in the medical field. Meanwhile, extended-spectrum β-lactamases (ESBL)-producing bacteria are also demonstrating a challenging problem for health care. The aim of this study was the biosynthesis of AuNP using Rosa damascenes petal extract and conjugation of ceftriaxone antibiotic (Cef-AuNP) in inhibiting ESBL-producing bacteria and study of in vitro anticancer activity. Characterization of the synthesized AuNP and Cef-AuNP was studied. ESB-Lproducing strains, Acinetobacter baumannii ACI1 and Pseudomonas aeruginosa PSE4 were used for testing the efficacy of Cef-AuNP. The cells of MCF-7 breast cancer were treated with previous AuNP and Cef-AuNP at different time intervals. Cytotoxicity effects of apoptosis and its molecular mechanism were evaluated. Ultraviolet-visible spectroscopy and Fourier transform infrared spectroscopy established the formation of AuNP and Cef-AuNP. Transmission electron microscope demonstrated that the formed nanoparticles were of different shapes with sizes of 15~35 nm and conjugation was established by a slight increase in size. Minimum inhibitory concentration (MIC) values of Cef-AuNP against tested strains were obtained as 3.6 and 4 μg/ml, respectively. Cef-AuNP demonstrated a decrease in the MIC of ceftriaxone down to more than 27 folds on the studied strains. The biosynthesized AuNP displayed apoptotic and time-dependent cytotoxic effects in the cells of MCF-7 at a concentration of 0.1 μg/ml medium. The Cef-AuNP have low significant effects on MCF-7 cells. These results enhance the conjugating utility in old unresponsive ceftriaxone with AuNP to restore its efficiency against otherwise resistant bacterial pathogens. Additionally, AuNP may be used as an alternative chemotherapeutic treatment of MCF-7 cancer cells.