Green synthesis of silver and iron oxide nanoparticles mediated photothermal effects on Blastocystis hominis

Reducing the effective dose of doxycycline using chitosan silver nanocomposite as a carriers on gram positive and gram-negative bacteria

Doxycycline (Doxy) is a tetracycline antibiotic with a potent antibacterial activity against a broad range of bacteria. Using nanotechnology is one feasible way to increase the antibiotics' ability to penetrate the body and increase their antibacterial effectiveness. In this work, we report the formation of a stable green synthesized silver nanoparticles (AgNPs) by chitosan with Doxy nanocomposite for the first time. The obtained nanoparticles were characterized by transmission electron microscopy (TEM), zeta-potential, UV-Visible spectroscopy and four transform infrared spectroscopy (FTIRs). The antibacterial effect of doxy, AgNPs and doxy/AgNPs were determined on Gram-positive Staphylococcus aureus, Streptococcus mutans and Gram-negative Escherichia coli, Klebsiella pneumonia. This combined therapeutic agent restored the susceptibility of doxy and showed an antibacterial activity against tested bacteria. AgNPs has absorption peak at 445 nm, mixing of Doxy with AgNPs causes all doxy absorptions to red shift and a broadening in surface plasmon resonance (SPR) for AgNPs and show a slight increase in particle size of AgNPs from 12 ± 2 nm to 14 ± 2 nm with high stability as zeta potential was 29 mv and 48.5mv for AgNPs and Doxy/AgNPs respectively. The antibacterial effect of Doxy/AgNPs nanocomposite was found to be twice effect of free doxy, suggesting a synergistic interaction between the two components. In conclusion, synergy of doxy with AgNPs is quite promising for antibiotic resistant strains. These results highlight the ability of AgNPs to boost the efficacy of the doxycycline.

Laser enhanced photothermal effect of silver nanoparticles synthesized by chemical and green method on Gram-positive and Gram-negative bacteria

PURPOSE

The antibacterial properties of silver nanoparticles (AgNPs) are extensively identified. In large quantities, they might be harmful. So many fields of nanotechnology have shown a great deal of interest in the development of an environmentally friendly, efficient method for synthesizing metal nanoparticles. Because of its antibacterial and antifungal properties toward a wide range of microbes, chitosan silver nanoparticles (AgNPs@Cs) constitute a newly developing class of bio-nanostructured hybrid materials. Furthermore, the use of photothermal therapy (PTT) has been suggested as a means of elimination of germs. These light-stimulated treatments are minimally invasive and have a few side effects. In the present work, the antibacterial effect of AgNPs at low concentrations; prepared by chemical and green methods as antimicrobial and photothermal agents in photothermal therapy; with laser irradiation were explored as combined treatment against MRSA, Pseudomonas aeruginosa, and Klebsiella pneumoniae.

METHODS

Silver nanoparticles were produced in two ways. First, by sodium borohydrides, second, by chitosan (as a natural eco-friendly reducing, and capping agent). The nanostructure of AgNPs and AgNPs@Cs was confirmed by UV-visible spectrometer, transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIRs), and direct light scattering (DLS). The antibacterial activity of the prepared nanoparticles and the laser irradiation was tested against three bacterial species of zoonotic importance; MRSA, Pseudomonas aeruginosa, and Klebsiella pneumoniae; and was evaluated by measuring their minimum inhibitory concentrations (MIC).

RESULTS

Silver nanoparticles produced by the two methods had spherical shapes with nearly the same particle size. The analysis of DLS showed that AgNPs were very stable with zeta potential - 28.8 mv, and 47.7 mv by chemical and chitosan synthesis, respectively. Furthermore, AgNPs@Cs showed higher antibacterial activity toward the tested bacterial species than AgNPs by chemical method. Additionally, the bacterial viability using photothermal laser therapy was reduced compared to laser and AgNPs alone. The bactericidal activities were higher when laser diode was coupled with AgNPs@Cs than by chemical reduction.

CONCLUSION

The laser combined treatment had a higher antimicrobial effect than AgNPs alone or laser irradiation alone.

Reducing the effective dose of cisplatin using cobalt modified silver nano-hybrid as a carriers on MCF7 and HCT cell models

Cancer is a deadly illness with a convoluted pathogenesis. The most prevalent restrictions that frequently result in treatment failure for cancer chemotherapy include lack of selectivity, cytotoxicity, and multidrug resistance. Thus, considerable efforts have been focused in recent years on the establishment of a modernistic sector termed nano-oncology, which offers the option of employing nanoparticles (NPs) with the objective of detecting, targeting, and treating malignant disorders. NPs offer a focused approach compared to conventional anticancer methods, preventing negative side effects. In the present work, a successful synthetic process was used to create magnetic cobalt cores with an AgNPs shell to form bimetallic nanocomposites CoAg, then functionalized with Cis forming novel CoAg@Cis nanohybrid. The morphology and optical properties were determined by TEM, DLS, FTIRs and UV-vis spectroscopy, furthermore, anticancer effect of CoAg and CoAg@Cis nanohybrids were estimated using MTT assay on MCF7 and HCT cell lines. Our results showed that Co@Ag core shell is about 15 nm were formed with dark CoNPs core and AgNPs shell with less darkness than the core, moreover, CoAg@Cis has diameter about 25 nm which are bigger in size than Co@Ag core shell demonstrating the loading of Cis. It was observed that Cis, CoAg and CoAg@Cis induced a decline in cell survival and peaked at around 65%, 73%and 66% on MCF7 and 80%, 76%and 78% on HCT at 100 µg/ml respectively. Compared to Cis alone, CoAg and CoAg@Cis caused a significant decrease in cell viability. These findings suggest that the synthesized CoAg can be used as a powerful anticancer drug carrier.