Silver nanoparticles (AgNPs) have demonstrated numerous physicochemical, biological, and functional properties suitable for biomedical applications, including antibacterial and drug carrier properties. In the present study, the antibiotic, ciprofloxacin (CIP), was loaded onto AgNPs, which were synthesized via the chemical reduction method, thereby enhancing CIP’s antibacterial activity against Gram-negative (Acinetobacter baumannii and Serratia marcescens) and Gram-positive (Staphylococcus aureus) bacterial strains. Polyethylene glycol–400 (PEG) was used to prepare an AgNPs-PEG conjugate with enhanced stability and to act as the linker between CIP and AgNPs, to produce the novel nanocomposite, AgNPs-PEG-CIP. The prepared AgNPs and their conjugates were characterized by ultraviolet-visible spectrophotometry, Fourier-transform infrared spectroscopy, X-ray diffraction, field emission scanning electron microscopy with energy-dispersive X-ray spectroscopy, transmission electron microscopy, zeta potential analysis, and dynamic light scattering techniques. The inhibitory activity of AgNPs and their conjugates on the growths of pathogenic bacteria was assessed using the well-diffusion method. The results showed the enhanced antibacterial effects of AgNPs-CIP compared to CIP alone. The AgNPs-PEG-CIP nanocomposite showed excellent inhibitory effects against bacterial isolates, with its inhibition zones diameters reaching 39, 36, and 40 mm in S. aureus, A. baumannii, and S. marcescens, respectively. The minimum inhibitory concentration and minimum bactericidal concentration of fogNPs and their conjugates and their antibiofilm effects were also determined. The antioxidant potentials of AgNPs and their conjugates, tested via their 1,1-diphenyl-2-picryl-hydrazyl (DPPH) scavenging ability, showed that the activity increased with increasing AgNPs concentration and the addition of the PEG and/or CIP. Overall, according to the results obtained in the present study, the new nanocomposite, AgNPs-PEG-CIP, showed the highest antibacterial, antibiofilm, and antioxidant activity against the pathogenic bacteria tested, compared to CIP alone. The preparation has high clinical potential for prospective use as an antibacterial agent.

Diabetic foot is a catastrophic complication of diabetes. This study included isolation and identification of three types of bacteria that cause diabetic foot ulcers,  fifty-five isolates of Staphylococcus aureus, thirty-five isolates of Acinetobacter baumannii, and thirty isolates of Serratia marcescens. These isolates were obtained from diabetic foot patients at different private clinics in and around Baghdad and Medical City Hospital. The proportion of male patients was greater than females, and it was noted that the age group (51-68 years) was more ages affected by diabetic foot. These isolates showed high resistance to most of the antibiotics used, Staphylococcus aureus was resistant to Penicillin, Tetracycline, and Ciprofloxacin in the percentage of 100 %, 65 %, and 26 %, respectively. Acinetobacter baumannii, showed high resistance to Penicillin, at a percentage of 80%, and Ciprofloxacin at  60%. Serratia marcescens was resistant to most antibiotics that were used in this study, Tetracycline, Penicillin, Cefotaxime, and Amoxicillin in the percent of (100, 95, 91, 88,70, and 64) %, respectively. The chemical reduction method was used in this study to synthesize silver nanoparticles. The characterization of silver nanoparticles was done by Field Emission Scanning Electron Microscope, and transmission electron microscope, which showed particle sizes of 24.56 to 66.2 nm, which proved that silver nanoparticles had nano size and spherical shape. The result of antibacterial activity of silver nanoparticles and silver nitrate against Staphylococcus aureus bacteria showed the highest effect of silver nitrate than other bacteria tested in this study, the diameter of the inhibition zone reached 15.66mm. Likewise for silver nanoparticles where the diameter of the inhibition zone of highest effect reached 29.33mm for Staphylococcus aureus bacteria. The test of silver nanoparticles' ability to inhibit bacterial growth produced the greatest results for Staphylococcus aureus bacteria, which were inhibited after 60 minutes. Based on these research findings, silver nanoparticles have demonstrated their efficacy in this study against isolated bacteria from diabetic feet.

For the treatment of pathogenic bacterial infections, multidrug resistance (MDR) has become a major issue. The use of nanoparticles is a promising strategy for combating medication resistance in a variety of pathogens that cause deadly diseases. The goal of our research was to extract multidrug-resistant bacteria from wound infections and then use iron oxide nanoparticles (Fe3O4) as alternative therapeutic agents in vitro. Gram staining, morphological attributes evaluation, and biochemical testing were used to assess the microbes. The Kirby-Bauer disk diffusion method was used to test MDR-bacterial strains against several antibiotics; the majority of these isolates were resistant to ceftazidime, amoxicillin, Gentamicin, and tetracycline. the iron oxide nanoparticles were produced by the co-precipitation method and were confirmed by changing the color to dark black as well as the Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM) analysis that shows the shape and average size between (29.03-56.54) nm. The highest effect of iron oxide nanoparticles (Fe3O4) on the growth of Proteus.mirabilis (P.mirabilis) was as it was found that the average diameter of the inhibition zone was 22.66±1.15 mm, followed by Staphylococcus.epidermidis (S.epidermidis), Acinetobacter.baumannii (A.baumannii) with the average diameter of the inhibitory zone it was 21.66±1.52 mm, 20.33±1.53 mm respectively, and Candida.albicans (C.albicans) was 18.33±1.15 mm at 100 µgmL-1 (stock). The synthesized iron oxide nanoparticles (Fe3O4) are used to capture rapidly microbes under the magnetic field effect. The antioxidant activity DPPH of the iron oxide nanoparticles (Fe3O4) showed 29.3%, 42.2%, 58.6%, 67.4%, and 74 % at a concentration (6.25, 12.5, 25, 50, 100) µgmL-1 respectively, it demonstrated that the scavenging percentage increase with increasing the iron oxide nanoparticles (Fe3O4) concentrations.