Novel Biological-Based Strategy for Synthesis of Green Nanochitosan and Copper-Chitosan Nanocomposites: Promising Antibacterial and Hematological Agents.

Two novel samples of nanoparticles based on chitosan were greenly synthesized using pomegranate peel extract. The extract served as a nanoparticle precursor, facilitating the precipitation of nanosized chitosan through the ionic gelation method. Additionally, by mixing the green chitosan nanoparticles with copper ions, a nanoscale composite of chitosan and copper oxide was also produced. Structural and morphological investigations (FTIR, XRD, SEM, EDX, and TGA analyses) were performed for greenly synthesized chitosan nanoparticles and their copper oxide composite to determine all the significant characteristics of those nanoparticles. In addition, both samples were tested using some biological investigations, such as antimicrobial activity and hematological effects. The antimicrobial tests yielded promising results for both the green chitosan nanoparticles and the CuO composite when tested using two bacterial strains and two fungal strains. Moreover, the results showed that using a similar concentration of both green-based chitosan samples resulted in a slightly larger inhibition zone and a lower minimum inhibition concentration (MIC) for the copper oxide chitosan composite compared to the chitosan nanoparticles for all microorganisms included in the test. The mean count of blood components (RBCs and platelets), clotting time, and cholesterol levels in three different blood samples were used to indicate the hematological activity of both greenly synthesized nanoparticles. The results verified a slight reduction in blood component count after the addition of green chitosan nanoparticles, but the chitosan copper oxide composite did not have a noticeable effect on the three blood samples. The chitosan nanoparticles were able to cause a considerable reduction in clotting time and cholesterol levels for all blood samples, thus acting as procoagulants. However, the mixing of CuO with chitosan nanoparticles prolonged the rate of clotting in blood samples from hypercholesteremic individuals, and thus, the mixture acted as an anticoagulant agent.

Investigation of the antimicrobial activity and hematological pattern of nano-chitosan and its nano-copper composite.

Novel synthesized Chitosan-Copper oxide nanocomposite (Cs-CuO) was prepared using pomegranate peels extract as green precipitating agents to improve the biological activity of Cs-NP's, which was synthesized through the ionic gelation method. The characterization of biogenic nanoparticles Cs-NP's and Cs-CuO-NP's was investigated structurally, morphologically to determine all the significant characters of those nanoparticles. Antimicrobial activity was tested for both Cs-NP's and Cs-CuO-NP's via minimum inhibition concentration and zone analysis against fungus, gram-positive and gram-negative. The antimicrobial test results showed high sensitivity of Cs-CuO-NP's to all microorganisms tested in a concentration less than 20,000 mg/L, while the sensitivity of Cs-NP's against all microorganisms under the test started from a concentration of 20,000-40,000 mg/L except for the C. albicans species. The hematological activity was also tested via measuring the RBCs, platelet count, and clotting time against healthy, diabetic, and hypercholesteremia blood samples. The measurement showed a decrease in RBCs and platelet count by adding Cs-NP's or Cs-CuO-NP's to the three blood samples. Cs-NP's success in decreasing the clotting time for healthy and diabetic blood acting as a procoagulant agent while adding biogenic CuO-NP's to Cs-NP's increased clotting time considering as an anti-coagulant agent for hypercholesteremia blood samples.

Innovative coating based on graphene and their decorated nanoparticles for medical stent applications.

Novel coating for stainless steel stent was developed. Graphene sheets were exfoliated directly in chitosan solution as biopolymer and then decorated with TiO2 nanoparticles of an average size of 21 nm. Coating solutions of chitosan, graphene sheets and graphene sheets decorated TiO2NPs were coated on stainless steel stent in uniform form. The average thickness of the coated layer was found to be 6 and 10.6 µm for graphene and TiO2NPs decorated graphene coatings, respectively. The mechanical properties and hematological properties of the developed coated and uncoated stents were studied. The graphene sheets based coated stent showed good mechanical properties compared to chitosan and decorated coated stents. Furthermore, the mechanical properties of the coating layer based graphene on stent surface were investigated reflecting very good mechanical properties compared to graphene nanoparticles decorated coating layer. Also, the coated stent based on graphene sheets reflects very good behaviour regarding no platelets adhesion in healthy and diabetic human blood compared to uncoated, chitosan and TiO2NPs decorated graphene coated stents. The graphene sheets and their decorated composites with TiO2NPs were characterized using transmission electron microscopy. Also, the uncoated and coated stents morphologies were evaluated using scanning electron microscopy. This study presents new approach for developing and engineering medical stent using green and cost-effective graphene sheets for enhancing its performance.