The High Stability and Selectivity of Electrochemical Sensor Using Low-Cost Diamond Nanoparticles for the Detection of Anti-Cancer Drug Flutamide in Environmental Samples.

In this study, a novel electrochemical sensor was created by fabricating a screen-printed carbon electrode with diamond nanoparticles (DNPs/SPCE). The successful development of the sensor enabled the specific detection of the anti-cancer drug flutamide (FLT). The DNPs/SPCE demonstrated excellent conductivity, remarkable electrocatalytic activity, and swift electron transfer, all of which contribute to the advantageous monitoring of FLT. These qualities are critical for monitoring FLT levels in environmental samples. Various structural and morphological characterization techniques were employed to validate the formation of the DNPs. Remarkably, the electrochemical sensor demonstrated a wide linear response range (0.025 to 606.65 µM). Additionally, it showed a low limit of detection (0.023 µM) and high sensitivity (0.403 µA µM-1 cm-2). Furthermore, the practicability of DNPs/SPCE can be successfully employed in FLT monitoring in water bodies (pond water and river water samples) with satisfactory recoveries.

Overcoming the yield challenge of mussel foot proteins: Enhancing adhesion through metal ion-incorporated nanoparticles.

Mussel foot proteins (MFPs) hold tremendous potential for various fields, but their low natural production yield presents a significant challenge for practical use. This study aims to explore possible solutions to overcome this limitation. While advanced recombinant technology can improve production efficiency, the resulting proteins lack the crucial chemical signature of mussel adhesion, 3,4-Dihydroxyphenylalanine (DOPA). Recent studies have shown that adhesives in nanoparticle form offer higher adhesion on solid surfaces, making them a promising alternative. Moreover, metal ions can enhance the cohesive forces between MFPs, leading to improved adhesion. In this study, we prepared MFP nanoparticles via spray-drying and tested their adhesion performance on surfaces with varying hydrophobicity using a universal testing machine. Our findings confirmed that MFP nanoparticles exhibit stronger adhesive performance than native MFPs, with metal ions contributing to even more robust adhesion. This study offers valuable insights into the adhesive behavior of MFPs in nanoparticle form with metal ions, presenting a potential solution to the challenge of low natural production yield of MFPs and the possibility of enhancing their adhesion properties in bio-adhesive materials.

Study of polymethylmethacrylate/tricalcium silicate composite cement for orthopedic application.

BACKGROUND: Among orthopedic surgery materials, poly (methyl methacrylate) (PMMA) is most commonly used for its excellent mechanical properties and rapid self-setting time. However, PMMA bone cement has been reported to cause thermal necrosis and to have poor bioactivity, which must be improved. In contrast, tricalcium silicate (TCS), the most significant component of Portland Cement and the most effective bone cement material, might not always meet the needs of the cement due to its poor mechanical properties and elevated pH levels during hydration. We hypothesize that the benefits of both PMMA and TCS can be harnessed by mixing them together in different proportions. This would represent a better solution for the issues faced when using them alone. METHODS: We, therefore, prepared a novel organic-inorganic PMMA/TCS composite bone cement mixing PMMA and different amounts of TCS and tested its effect on the biophysical properties. RESULTS: The addition of 30% TCS reduced the exothermic temperature and pH variation during cement setting and hydration processes. However, the mechanical and handling properties of the bioactive PMMA/TCS composite were not affected. The in vitro study also revealed that the composite materials had higher cell viability than pure PMMA and TCS. Also, the in vivo study on animals indicated that the composite materials were more capable of forming bone, which further reinforced the biocompatibility of the proposed PMMA/TCS bone cement. CONCLUSION: By combining the advantages of each component, it could be possible to construct a more effective composite bone cement material. This would meet the needs of implantation material for orthopedic surgeries or a possible bone filler.

Correlation between surface friction and the hydrophobicity of structure-related side-chain exposure of albumin on contact lens.

The management of contact lens discomfort remains a challenge leading to the increased contact lens dropout rates. Tear protein accumulates on the lens surfaces with different configurations observed are correlated to the lens friction, with the improved comfort experienced by reduced surface friction in the eye. However, protein adsorption is a complex process with the combined protein-protein interactions (PPI) and protein-surface interactions (PSI) involved, which is difficult to explain the complicated tribological behavior in terms of protein structural shifts alone on lens surfaces. On the other hand, the type of solvent-exposed side chains from specific protein conformations on lens surfaces should be more important to the lens friction involved. We aim to investigate the correlation between the structure-related side-chain exposure and corresponding lens friction of adsorbed tear proteins on lens surfaces under varied PPI and PSI. Albumin was the model protein adsorbed onto the conventional lens material. Such as polymethylmethacrylate (PMMA) or the poly-2-hydroxyethyl methacrylate (PHEMA) surfaces applied here. Adsorption was conducted under varying protein solution concentrations to saturate the model surface to change the PPI effects over a wide range. Our results indicate that PPI effects help stabilize protein structures on both surfaces. When PPI is minimized, a distinct correlation was observed between the surface friction and the hydrophobicity of structure-related side-chain exposure of albumin on lens surfaces depending on the different PSI involved. At a fundamental understanding, our results would provide insights for developing new lens materials or the lens care solution designs to reduce the lens discomfort.

Correction: Wei, Y.; et al. Quantify the Protein-Protein Interaction Effects on Adsorption Related Lubricating Behaviors of α-Amylase on a Glass Surface. Polymers 2020, 12, 1658.

The authors wish to make the following corrections to this paper [...].

Effect of varied hair protein fractions on the gel properties of keratin/chitosan hydrogels for the use in tissue engineering.

Keratin/chitosan composite is a readily available source for a hybrid hydrogel in tissue engineering. While human hair keratins could provide biological functions, chitosan could further enhance the mechanical strength of the hybrid hydrogels. However, hair keratin is a group of natural proteins, and the uncontrolled hair protein contents in a hydrogel may lead to the batch-to-batch inconsistent gel properties. The purpose of this study was to investigate the role of hair protein composition, including the keratin-associated proteins (KAPs, 6-30 kDa) and keratin intermediate filaments (KIFs, 45-60 kDa) on gel characteristics of the keratin/chitosan hydrogel. The various compressive and tensile modulus of the gel was observed based on the selection of different protein fractions as the significant gel components. These results thus suggest a straightforward method of preparing hair keratin/chitosan hydrogel with much more controllable gel properties by merely modulating the KAPs/KIFs ratios in a gel.

Quantify the Protein-Protein Interaction Effects on Adsorption Related Lubricating Behaviors of α-Amylase on a Glass Surface.

Dental ceramic material is one of the widely preferred restorative materials to mimic the natural tooth enamel surface. However, it has continuously been degraded because of low wear resistance during mastication in the oral cavity. The friction involved was reduced by introducing the lubricant saliva protein layers to improve the wear resistance of the dental materials. However, little is understood regarding how the protein-protein interactions (PPI) influence the adsorbed-state structures and lubricating behaviors of saliva proteins on the ceramic material surface. The objective of this study is to quantify the influences of PPI effects on the structural changes and corresponding oral lubrications of adsorbed α-amylase, one of the abundant proteins in the saliva, on the dental ceramic material with glass as a model surface. α-Amylase was first adsorbed to glass surface under varying protein solution concentrations to saturate the surface to vary the PPI effects over a wide range. The areal density of the adsorbed protein was measured as an indicator of the level of PPI effects within the layer, and these values were then correlated with the measurements of the adsorbed protein's secondary structure and corresponding friction coefficient. The decreased friction coefficient value was an indicator of the lubricated surfaces with higher wear resistance. Our results indicate that PPI effects help stabilize the structure of α-amylase adsorbed on glass, and the correlation observed between the friction coefficient and the conformational state of adsorbed α-amylase was apparent. This study thus provides new molecular-level insights into how PPI influences the structure and lubricating behaviors of adsorbed protein, which is critical for the innovations of dental ceramic material designs with improved wear resistance.

Sonochemical synthesis of perovskite-type barium titanate nanoparticles decorated on reduced graphene oxide nanosheets as an effective electrode material for the rapid determination of ractopamine in meat samples.

A simple and facile ultrasound based sonochemical method to incorporate Perovskite-type barium titanate (BaTiO3) nanoparticles inside the layered and reduced graphene oxide sheets (rGOs) is reported. BaTiO3@rGOs nanocomposite was characterized by FESEM, HRTEM, EDX, mapping, XRD, XPS and EIS. The results show that the decoration and also incorporation of BaTiO3 nanoparticles in the multi-layered and ultrasound reduced graphene oxide matrix. Non-enzymatic and differential pulse voltammetric sensor of ractopamine (food toxic) based on the BaTiO3@rGOs nanocomposite modified screen printed carbon electrode is developed. Compared with the original BaTiO3/SPCE and rGOs/SPCE, the BaTiO3@rGOs/SPCE displays excellent current response towards ractopamine and gives linearity in the range of 0.01-527.19 µM ractopamine in neutral phosphate buffer (pH 7.0). The BaTiO3@rGOs nanocomposite modified sensor also exhibits valuable ability of anti-interference to electroactive analytes. Furthermore, the as-prepared BaTiO3 NPs@rGOs/SPCE has been applied to the determination of ractopamine in pork and chicken samples.