Exploring In Vitro Antibiofilm Potential and In Vivo Toxicity Assessment of Gold Nanoparticles.

In this study, biogenically synthesized AuNPs were first characterized via UV visible spectroscopy, SEM, XRD, and FTIR followed by toxicity evaluation using mice model. UV-visible spectroscopy of biogenic AuNPs showed peaks at 540-549 nm, while FTIR spectrum showed various functional groups involving O-H, Amide I, Amide II, O-H, C-H groups, and so on. SEM showed the size variation from 30 to 60 nm. Antibacterial potential against pathogenic isolates showed bigger ZOI (31.0 mm) against Pseudomonas aeruginosa AuNPs. Antibiofilm activity showing up to 100% inhibition at 90 µg mL-1 concentration of AuNPs. Toxicity evaluation showed LD50 as 70 mg kg-1. Exposure to AuNPs caused significant changes in the levels of serum AST (p < 0.05) at 100-150 mg kg-1 of AuNPs exposure. Histopathology of male albino mice kidney and liver revealed that mice exposed to maximum concentration of AuNPs showed necrosis, cell distortion, and hepatocytes detachment. Present study showed that biologically synthesized AuNPs possess effective antimicrobial and biofilm inhibitory potential. AuNPs strong bactericidal effect even at lower concentration suggest that NPs could have excellent potential for combating pathogens. In conclusion, nanotechnology may revolutionize human life and medical industry by developing innovative drugs with the potential to treat diseases in shorter and noninvasive time period. Hence, in vitro biosafety and experimental observations followed by in vivo outcomes are crucial in shifting the novel therapeutics into medical practice thus leading further into their future development.

Population dynamics of pelagic rotifers in Marala Headworks (Pakistan).

Research work was designed to investigate the density and diversity of pelagic rotifers in a Lake near Marala Headworks. The physico-chemical parameters of water such as pH, dissolved oxygen, temperature, electrical conductivity, transparency and turbidity were evaluated. Correlation between rotifers and these parameters was also studied. Plankton sampling was done on monthly basis in order to check the population density of rotifers. In total, 18 species of rotifers were identified which belonged to 11 genera. The highest number of rotifers and their diversity was shown by genera namely Brachionus, Keratella, and Filinia. The Brachionus calyciflorus was dominant species in all the samples with mean population density (41%). Analysis of variance of physico-chemical parameters presented that the air and water temperature, electrical conductivity, transparency, dissolved oxygen and oxygen saturation were statistically significant in all the months. While pH was statistically non-significant (p≥0.05. Pearson correlation showed that oxygen and transparency were negatively correlated with rotifers density and diversity. Air and water temperature, concentration of hydrogen ions (pH), electrical conductivity and salinity showed positive relationship with density and diversity of rotifers.

Bacillus licheniformis (MN900686) Mediated Synthesis, Characterization and Antimicrobial Potential of Silver Nanoparticles.

The use of bacteria in the synthesis of silver nanoparticles (AgNPs) emerges as an ecofriendly and exciting approach. In the present study, we reported the biosynthesis of AgNPs by using culture supernatant of the bacteria Bacillus licheniformis (MN900686). The biogenically synthesized AgNPs were confirmed by the change in the color of the culture filtrate from yellow to brown after the addition of AgNO3. Further characterization performed by means of UV vis-spectroscopy showed absorption peak at 414 nm which confirmed the formation of AgNPs. Fourier Transfer infrared (FTIR) confirmed the involvement of biological molecules in the formation of nanoparticles (NPs). The SEM revealed that the NPs have approximately 38 nm size. The agar well diffusion assay was used to determine antibacterial activity while tube dilution method was used to determine minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The human pathogenic bacterial strains i.e., P. aeruginosa (MN900691) and B. subtilis (MN900684), were used as test strains. The anti-bacterial assay against test strains revealed that these NPs showed concentration dependent increased zone of inhibition (ZOI). The maximum ZOI at 25 µL of AgNPs was 20 mm against B. subtilis after 24 hours of incubation. One-way ANOVA test showed significant ZOI (p ≤ 0.05) against B. subtilis. The MIC was ranged from 4.3-6.6 µg/mL while MBC ranged from 8.3 to 6.6 µg/mL. Overall, this study suggested that the biogenically synthesized NPs are an effective alternative source of antimicrobials against pathogenic bacteria.