Effect of Gelatin-Stabilized Copper Nanoparticles on Catalytic Reduction of Methylene Blue

Promising biomedical systems based on copper nanoparticles: Synthesis, characterization, and applications

Copper and copper oxide nanoparticles (CuNPs) have unique physicochemical properties that make them highly promising for biomedical applications. This review discusses the application of CuNPs in biomedicine, including diagnosis, therapy, and theranostics. Recent synthesis methods, with an emphasis on green approaches, are described, and the latest techniques for nanoparticle characterization are critically analyzed. CuNPs, including Cu2O, CuO, and Cu, have significant potential as anti-cancer agents, drug delivery systems, and photodynamic therapy enhancers, among other applications. While challenges such as ensuring biocompatibility and stability must be addressed, the state-of-the-art research reviewed here provides strong evidence for the efficacy and versatility of CuNPs. These multifunctional properties have been extensively researched and documented, showcasing the immense potential of CuNPs in biomedicine. Overall, the evidence suggests that CuNPs are a promising avenue for future research and development in biomedicine. We strongly support further progress in the development of synthesis and application strategies to enhance the effectiveness and safety of CuNPs for clinical purposes.

Efficacy of a New Hemostatic Dental Sponge in Controlling Bleeding, Pain, and Dry Socket Following Mandibular Posterior Teeth Extraction-A Split-Mouth Randomized Double-Blind Clinical Trial

AIMS

This study aimed to clinically evaluate of a novel gelatin-based biodegradable sponge after mandibular posterior teeth extraction to assess its abilities in controlling bleeding, pain, and dry socket compared a commercial sponge.

TRIAL DESIGN

In this study, 26 patients who needed the extraction of two mandibular molar teeth were selected and, in each patient, after tooth extraction, the prepared gelatin sponge was used in the test group and the commercial sponge was used in the control group in the form of a randomized, double-blind, split-mouth clinical trial. The sterile gauzes were used on top of each sponge to absorb the extra blood (unabsorbed blood of sponges) to assess the blood absorption amount. Also, the amount of bleeding was recorded for 1 and 4 h after extraction for two groups. The amount of pain was measured for 12, 24, and 48 h after tooth extraction by Visual Analogue Scale (VAS). All patients also returned for examination four days after extraction to assess the occurrence of dry socket.

RESULTS

The results showed that the average weight of absorbed blood by sterile gauze in the control group (6.32 ± 1.06 g) was higher than in test group (3.97 ± 1.1 g), e.g., the bleeding control was better for the test group (p < 0.05). Bleeding was observed to be significantly reduced in the test group within 1 h (p = 0.003), within 1-4 h (p = 0.002), and after 4 h (p = 0.042) post-operatively in comparison to the control group. The average pain decreased significantly over time in both groups and the reduction of the pain was significantly higher for the test group (p < 0.05). Just one dry socket case occurred in the control group.

CONCLUSION

The prepared sponge is recommended for use in dental surgeries because of its abilities in bleeding, pain, and dry socket control.

Characterization of a Graphene Oxide-Reinforced Whey Hydrogel as an Eco-Friendly Absorbent for Food Packaging

This study presents a structural analysis of a whey and gelatin-based hydrogel reinforced with graphene oxide (GO) by ultraviolet and visible (UV-VIS) spectroscopy, Fourier transform infrared spectroscopy (FT-IR), and X-ray diffraction (XRD). The results revealed barrier properties in the UV range for the reference sample (containing no graphene oxide) and the samples with minimal GO content of 0.66×10−3% and 3.33×10−3%, respectively, in the UV-VIS and near-IR range; for the samples with higher GO content, this was 6.67×10−3% and 33.33×10−3% as an effect of the introduction of GO into the hydrogel composite. The changes in the position of diffraction angles 2θ from the X-ray diffraction patterns of GO-reinforced hydrogels indicated a decrease in the distances between the turns of the protein helix structure due to the GO cross-linking effect. Transmission electron spectroscopy (TEM) was used for GO, whilst scanning electron microscopy (SEM) was used for the composite characterization. A novel technique for investigating the swelling rate was presented by performing electrical conductivity measurements, the results of which led to the identification of a potential hydrogel with sensor properties.

A Biodegradable Flexible Micro/Nano-Structured Porous Hemostatic Dental Sponge

A biodegradable micro/nano-structured porous hemostatic gelatin-based sponge as a dentistry surgery foam was prepared using a freeze-drying method. In vitro function evaluation tests were performed to ensure its hemostatic effect. Biocompatibility tests were also performed to show the compatibility of the sponge on human fetal foreskin fibroblasts (HFFF2) cells and red blood cells (RBCs). Then, 10 patients who required the extraction of two teeth were selected, and after teeth extraction, for dressing, the produced sponge was placed in one of the extracavities while a commercial sponge was placed in the cavity in the other tooth as a control. The total weight of the absorbed blood in each group was compared. The results showed a porous structure with micrometric and nanometric pores, flexibility, a two-week range for degradation, and an ability to absorb blood 35 times its weight in vitro. The prepared sponge showed lower blood clotting times (BCTs) (243.33 ± 2.35 s) and a lower blood clotting index (BCI) (10.67 ± 0.004%) compared to two commercial sponges that displayed its ability for faster coagulation and good hemostatic function. It also had no toxic effects on the HFFF2 cells and RBCs. The clinical assessment showed a better ability of blood absorption for the produced sponge (p-value = 0.0015). The sponge is recommended for use in dental surgeries because of its outstanding abilities.

Green synthesis of copper oxide and manganese oxide nanoparticles from watermelon seed shell extract for enhanced photocatalytic reduction of methylene blue

In the current study, copper oxide (CuO) and manganese oxide (MnO) nanoparticles (NPs) were synthesized through a simple, cost-efficient, and green method using watermelon seed shell extract as a stabilizing and reducing agent. The synthesized CuO and MnO NPs were characterized by using scanning electron microscopy (SEM), Energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), Transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR) and Ultraviolet spectroscopy (UV). The particle sizes of CuO and MnO NPs were determined to be in the range of 15-97 and 6-51 nm, respectively, by TEM and XRD analysis. The photocatalytic performance of the CuO and MnO NPs used as catalysts were investigated for the photocatalytic reduction of methylene blue in an aqueous solution. In the photocatalytic reduction of methylene blue, sodium borohydride (NaBH₄) was used as the reducing agent. The CuO and MnO NPs were capable to remove 96.58% (in 70 min) and 96.60% (in 140 min) of methylene blue from aqueous media, respectively. Besides, the kinetics of the photocatalytic reaction was investigated by a pseudo-first order model, and the reaction rate coefficient for methylene blue with CuO and MnO NPs were calculated as 0.0426 and 0.0235 min^-1, respectively. The results demonstrated that the synthesized CuO and MnO NPs through the green method were promising catalysts to improve the photocatalytic reduction performance of methylene blue.

Progresses in chitin, chitosan, starch, cellulose, pectin, alginate, gelatin and gum based (nano)catalysts for the Heck coupling reactions: A review

Heck cross-coupling reaction (HCR) is one of the few transition metal catalyzed CC bond-forming reactions, which has been considered as the most effective, direct, and atom economical synthetic method using various catalytic systems. Heck reaction is widely employed in numerous syntheses including preparation of pharmaceutical and biologically active compounds, agrochemicals, natural products, fine chemicals, etc. Commonly, Pd-based catalysts have been used in HCR. In recent decades, the application of biopolymers as natural and effective supports has received attention due to their being cost effective, abundance, and non-toxicity. In fact, recent studies demonstrated that biopolymer-based catalysts had high sorption capacities, chelating activities, versatility, and stability, which make them potentially applicable as green materials (supports) in HCR. These catalytic systems present high stability and recyclability after several cycles of reaction. This review aims at providing an overview of the current progresses made towards the application of various polysaccharide and gelatin-supported metal catalysts in HCR in recent years. Natural polymers such as starch, gum, pectin, chitin, chitosan, cellulose, alginate and gelatin have been used as natural supports for metal-based catalysts in HCR. Diverse aspects of the reactions, different methods of preparation and application of polysaccharide and gelatin-based catalysts and their reusability have been reviewed.

Extreme biomimetics: Preservation of molecular detail in centimeter-scale samples of biological meshes laid down by sponges

Fabrication of biomimetic materials and scaffolds is usually a micro- or even nanoscale process; however, most testing and all manufacturing require larger-scale synthesis of nanoscale features. Here, we propose the utilization of naturally prefabricated three-dimensional (3D) spongin scaffolds that preserve molecular detail across centimeter-scale samples. The fine-scale structure of this collagenous resource is stable at temperatures of up to 1200°C and can produce up to 4 × 10-cm-large 3D microfibrous and nanoporous turbostratic graphite. Our findings highlight the fact that this turbostratic graphite is exceptional at preserving the nanostructural features typical for triple-helix collagen. The resulting carbon sponge resembles the shape and unique microarchitecture of the original spongin scaffold. Copper electroplating of the obtained composite leads to a hybrid material with excellent catalytic performance with respect to the reduction of p-nitrophenol in both freshwater and marine environments.

Intracellular Dynamic Disentangling of Doxorubicin Release from Luminescent Nanogold Carriers by Fluorescence Lifetime Imaging Microscopy (FLIM) under Two-Photon Excitation

There is still a lack of available techniques to follow noninvasively the intracellular processes as well to track or disentangle various signals from the therapeutic agents at the site of action in the target cells. We present here the assessment of the intracellular kinetics of doxorubicin (DOX) and gold nanoparticle (AuNP) carriers by mapping simultaneously fluorescence and photoluminescence signals by fluorescence lifetime imaging microscopy under two-photon excitation (TPE-FLIM). The new nano-chemotherapeutic system AuNPs@gelatin-hyd-DOX has been fabricated by DOX loading onto the surface of gelatin-biosynthesized AuNPs (AuNPs@gelatin) through a pH-sensitive hydrazone bond. The successful loading of DOX onto the AuNPs was studied by spectroscopic methods and steady-state fluorescence, and the nanosystem pH-responsive character was validated under simulated biological conditions at different pH values (i.e., pH 4.6, 5.3, and 7.4). Considering that the fluorescence lifetime of DOX molecules at a specific point in the cell is a reliable indicator of the discrimination of the different states of the drug in the internalization path, i.e., released versus loaded, the kinetics of AuNPs@gelatin-hyd-DOX cellular uptake and DOX release was compared to that of free DOX, resulting in two different drug internalization pathways. Finally, cell viability tests were conducted against NIH:OVCAR-3 cell line to prove the efficiency of our chemotherapeutic nanosystem. TPE-FLIM technique could be considered promising for noninvasive, high-resolution imaging of cells with improved capabilities over current one-photon-excited FLIM.

Interaction of copper nanoparticles and an endophytic growth promoter Piriformospora indica with Cajanus cajan

BACKGROUND

In recent years, agro-bionanotechnology has paved the way towards revolutionizing current practices in the food and agricultural fields. In the present study, the effect of copper nanoparticles (CuNPs) alone and in combination with the growth-promoting fungus Piriformospora indica on 2-week-old seedlings of Cajanus cajan was evaluated. Gelatin-coated stable CuNPs were synthesized by the chemical reduction method using hydrazine hydrate as a reducing agent.

RESULTS

CuNPs were characterized by using UV-visible spectroscopy, zeta potential measurement and transmission electron microscopy. The nanoparticles were found to be quite spherical with a diameter within the range 40 ± 10 nm. After the application of CuNPs and P. indica to the host plant C. cajan, the vitality of plants was determined using a Handy-PEA (plant efficiency analyzer) instrument. Handy-PEA analysis (which measures chlorophyll a fluorescence) indicated that seedlings inoculated with a combination of CuNPs and P. indica were the healthiest and also showed maximum vitality as compared to seedlings inoculated with CuNPs or P. indica alone.

CONCLUSION

These results suggest that CuNPs in combination with P. indica can serve as a nanobiofertilizer for enhancement of the growth and productivity of C. cajan. © 2017 Society of Chemical Industry.