Structural, thermal and electrical studies of polyethylene oxide/starch blend containing green synthesized gold nanoparticles

Biogenic synthesis of gold nanoparticles using dual extract of tulsi-Vinca for breast cancer tumor regression in mice

Aim: This work aims to synthesize the gold nanoparticles (GNPs) using a dual extract of tulsi and Vinca (T+V-Gold) for breast cancer tumor regression. Methods: The GNPs were synthesized and characterized for their microscopic, spectroscopic and crystalline properties. Further, the GNPs were investigated for in vitro and in vivo studies for the treatment of the 4T1-induced triple-negative breast cancer murine model. Results: The GNPs for 4T1 tumor-challenged mice resulted in delayed tumor development and lower tumor burden, with T+V-Gold demonstrating the highest prevention of tumor spread. The antitumor effect of T+V-Gold is highly significant in the glutathione family antioxidants glutathione S-transferase and glutathione in tumor tissue samples. Conclusion: The bioefficacy and anticancer outcomes of T+V-Gold nanoformulation can be used as therapeutic agents and drug-delivery vehicles.

Physicochemical Properties and Antibacterial Activity of Gellan Gum Incorporating Zinc Oxide/Carbon Nanotubes Bionanocomposite Film for Wound Healing

Wound healing dressing based on a natural polymer of gellan gum incorporating zinc oxide nanoparticles and multiwall carbon nanotubes (GG/ZnONP + MWCNT) bionanocomposite film was fabricated via the solution casting method. The physicochemical properties of the film were characterized using X-ray diffraction (XRD), Fourier transform infrared (FTIR), and scanning electron microscopy (SEM). Moreover, the antibacterial properties of the bionanocomposite film were investigated for wound healing applications. The characterization results confirmed the reinforcement of the gellan gum (GG) matrix with zinc oxide nanoparticles (ZnONP) and multiwall carbon nanotubes (MWCNT), as an amorphous GG/ZnONP + MWCNT bionanocomposite film was obtained. SEM morphological analysis shows that the addition of ZnONP and MWCNT nanofillers changed the film microstructure into a sponge-like structure that is more suitable for fluid uptake and thus more useful for wound healing. The GG/ZnONP + MWCNT bionanocomposite film demonstrated good antibacterial activity against all strains tested. Furthermore, macroscopic analysis shows that the wound treated with GG/ZnONP + MWCNT bionanocomposite film recovered completely (100%) in 14 days, compared to pure GG film (90.76%) and negative control (77.40%). As a result, the GG/ZnONP + MWCNT bionanocomposite film could be a promising wound dressing material.

Influence of Electric Field on Proliferation Activity of Human Dermal Fibroblasts

In this work, an electrically conductive composite based on thermoplastic polyimide and graphene was obtained and used as a bioelectrode for electrical stimulation of human dermal fibroblasts. The values of the electrical conductivity of the obtained composite films varied from 10-15 to 102 S/m with increasing graphene content (from 0 to 5.0 wt.%). The characteristics of ionic and electronic currents flowing through the matrix with the superposition of cyclic potentials ± 100 mV were studied. The high stability of the composite was established during prolonged cycling (130 h) in an electric field with a frequency of 0.016 Hz. It was established that the composite films based on polyimide and graphene have good biocompatibility and are not toxic to fibroblast cells. It was shown that preliminary electrical stimulation increases the proliferative activity of human dermal fibroblasts in comparison with intact cells. It is revealed that an electric field with a strength E = 0.02-0.04 V/m applied to the polyimide films containing 0.5-3.0 wt.% of the graphene nanoparticles activates cellular processes (adhesion, proliferation).

Bombesin Peptide Conjugated Water-Soluble Chitosan Gallate-A New Nanopharmaceutical Architecture for the Rapid One-Pot Synthesis of Prostate Tumor Targeted Gold Nanoparticles

PURPOSE

We report herein bombesin peptide conjugated water-soluble chitosan gallate as a template for rapid one-pot synthesis of gold nanoparticles (AuNPs) with capabilities to target receptors on prostate cancer cells.

METHODS

Water-soluble chitosan (WCS), anchored with gallic acid (GA) and LyslLys3 (1,4,7,10-tetraazacyclo dodecane-1,4,7,10-tetraacetic acid) bombesin 1-14 (DBBN) peptide, provides a tumor targeting nanomedicine agent. WCS nanoplatforms provide attractive strategies with built-in capabilities to reduce gold (III) to gold nanoparticles with stabilizing and tumor-targeting capabilities. WCS-GA-DBBN encapsulation around gold nanoparticles affords optimum in vitro stability.

RESULTS

The DBBN content in the WCS-GA-DBBN sample was ~27%w/w. The antioxidant activities of WCS-GA and WCS-GA-DBBN nanocolloids were enhanced by 12 times as compared to the nascent WCS. AuNPs with a desirable hydrodynamic diameter range of 40-60 nm have been efficiently synthesized using WCS-GA and WCS-GA-DBBN platforms. The AuNPs were stable over 4 days after preparation and ~3 days after subjecting to all relevant biological fluids. The AuNPs capped with WCS-GA-DBBN peptide exhibited superior cellular internalization into prostate tumor (PC-3) cells with evidence of receptor mediated endocytosis.

CONCLUSION

The AuNPs capped with WCS-GA-DBBN exhibited selective affinity toward prostate cancer cells. AuNPs conjugated with WCS-GA-DBBN serve as a new generation of theranostic agents for treating various neoplastic diseases, thus opening-up new applications in oncology.

Microstructural features, spectroscopic study and thermal analysis of potassium permanganate filled PVA-PVP blend films

Potassium permanganate (KMnO₄) filled polyvinyl alcohol (PVA)-polyvinylpyrrolidone (PVP) polymeric blend films have been prepared by solution casting technique, with filler levels (FL) varying from 0.01 up to 4.70 mass%. The microstructural features, thermal properties and spectroscopic properties of these films have been studied using powder XRD, AFM, Fe-SEM, DSC, TG and FTIR. FTIR spectra for filled samples indicated a major molecular structural modification, involving conversion of the hydroxyl (OH) group into ketones at higher FLs. The bands showed a clear distortion in the wide OH band especially at higher FLs of 3.80 mass% and 4.70 mass%. This is confirmed from the TG scans, whose thermal degradation signature reveals multiple stages of degradation for FL of 2.8 mass%, 3.8 mass% and 4.7 mass%. The DSC, TG and DTA curves revealed that value ofT_gwas found to decrease on addition of filler in the PVA-PVP blend, whereas the thermal stability of the filled samples was found to increase. The XRD results revealed that the incorporation of KMnO₄in PVA-PVP blend made the sample more amorphous. At low FLs, AFM and SEM micrographs show evidence for formation of nano-particles in the host polymeric material only at the lowest FL of 0.01 mass% with uniform dispersion of nano-structures, whereas at moderate FLs, there are micro-structures in the polymeric host, followed by agglomeration of filler induced chemical species as the FL increases beyond 2.8 mass%. Therefore, KMnO₄filled PVA-PVP blend films show desirable properties expected from a good solid polymeric electrolyte, for FLs below 1.5 mass%.

Optical and dielectric characteristics of polyethylene oxide/sodium alginate-modified gold nanocomposites

Films of polyethylene oxide and sodium alginate polymer blend (50/50 wt%) embedded with different quantities of Au nanoparticles with size 3–32 nm were made using the casting process. The nanocomposite films were examined by XRD analysis, FT-IR spectroscopy, TEM, UV/vis spectroscopy, and AC conductivity and dielectric parameter measurements. The XRD spectra revealed the amorphous nature of the prepared films (PEO/SA–Au NPs). From the Fourier transform infrared spectra it can be seem that the intensity of the FT-IR bands decreased which depicted the existence of the interaction between (PEO/SA) virgin polymer and gold nanoparticles. The TEM micrographs showed a cubic-structure for Au NPs with an average size of 15–20 nm. The optical properties of the polymer composite were examined by ultraviolet-visible techniques. In a direct transition the optical energy gap (E_g) of the prepared films is decreased from 4.73 to 2.92 eV and in an indirect transition decreased from 2.95 to 1.50 eV. The dielectric and electrical spectra of the obtained films were examined via dielectric broad-band spectroscopy. The electrical and dielectric measurements are appropriate for the use of the polymer nanocomposite films in the fabrication of electroactive materials.

Films of polyethylene oxide and sodium alginate polymer blend (50/50 wt%) embedded with different quantities of Au nanoparticles with size 3–32 nm were made using the casting process.

Vegetable Additives in Food Packaging Polymeric Materials

Plants are the most abundant bioresources, providing valuable materials that can be used as additives in polymeric materials, such as lignocellulosic fibers, nano-cellulose, or lignin, as well as plant extracts containing bioactive phenolic and flavonoid compounds used in the healthcare, pharmaceutical, cosmetic, and nutraceutical industries. The incorporation of additives into polymeric materials improves their properties to make them suitable for multiple applications. Efforts are made to incorporate into the raw polymers various natural biobased and biodegradable additives with a low environmental fingerprint, such as by-products, biomass, plant extracts, etc. In this review we will illustrate in the first part recent examples of lignocellulosic materials, lignin, and nano-cellulose as reinforcements or fillers in various polymer matrices and in the second part various applications of plant extracts as active ingredients in food packaging materials based on polysaccharide matrices (chitosan/starch/alginate).