Identification of novel antioxidant collagen peptides for preventing and treating H2 O2 -induced oxidative stress in HepG2 cells through in vitro and in silico approaches.

BACKGROUND: Nowadays, the prevalence of oxidative stress-related chronic diseases is increasing. The identification of novel antioxidant collagen peptides to counteract oxidative stress for individuals' health has gained significant attention. RESULTS: In this study, collagen peptides with antioxidant activities were separated and identified by ion chromatography, reversed-phase high-performance liquid chromatography and liquid chromatography-tandem mass spectrometry. The identified antioxidant collagen peptides were further screened by molecular docking for Keap1-targeted peptide inhibitors and their theoretical interaction mechanisms were investigated. Four novel antioxidant collagen peptides, GPAGPIGPVG, GPAGPpGPIG, ISGPpGPpGPA and IDGRPGPIGPA, with high binding affinity to Keap1 were selected. Molecular docking results demonstrated that the putative antioxidant mechanism of the four antioxidant collagen peptides contributed to their blockage of Keap1-Nrf2 interactions. The results of antioxidant activity of the four antioxidant collagen peptides proved that IDGRPGPIGPA exerted a high scavenging capacity for DPPH and ABTS free radicals, while GPAGPpGPIG improved the resistance of cells to hydrogen peroxide-induced oxidative damage by promoting the activation of intracellular antioxidant enzymes and the production of reduced glutathione in human hepatoma (HepG2) cells. CONCLUSION: The antioxidant collagen peptides (GPAGPIGPVG, GPAGPpGPIG, ISGPpGPpGPA and IDGRPGPIGPA) will be developed as novel functional food for human health in the near future. © 2023 Society of Chemical Industry.

Functions and applications of emerging metal-organic-framework liquids and glasses.

Traditional metal-organic-frameworks (MOFs) have been extensively studied and applied in various fields across chemistry, biology and engineering in the past decades. Recently, a family of emerging MOF liquids and glasses have gained ever-growing research interests owing to their fascinating phase transitions and unique functions. To date, a growing number of MOF crystals have been found to be capable of transforming into liquid and glassy states under external stimuli, which overcomes the limitations of MOF crystals by introducing functional disorder in a controlled manner and offering some desirable properties. This review is dedicated to compiling recent advances in the fundamental understanding of the phase and structure evolution during crystal melting and glass formation in order to give insights into the underlying conversion mechanism. Benefiting from the disordered metal-ligand arrangement and free grain boundaries, various functional properties of liquid and glassy MOFs including porosity, ionic conductivity, and optical/mechanical properties are summarized and evaluated in detail, accompanied by the structure-property correlation. At the same time, their potential applications are further assessed from a developmental perspective according to their unique functions. Finally, we summarize the current progress in the development of liquid/glassy MOFs and point out the serious challenges as well as the potential solutions. This work provides perspectives on the functional applications of liquid/glassy MOFs and highlights the future research directions for the advancement of MOF liquids and glasses.

Trivalent Cations Detection of Magnetic-Sensitive Microcapsules by Controlled-Release Fluorescence Off-On Sensor.

A pyrene-based derivative, 2-((pyrene-1-ylmethylene)amino)ethanol (PE) nanoparticle, was encapsulated via water-in-oil-in-water (W/O/W) double emulsion with the solvent evaporation method by one-pot reaction and utilized as a fluorescence turn-on sensor for detecting Fe3+, Cr3+, and Al3+ ions. Magnetic nanoparticles (MNPs) embedded in polycaprolactone (PCL) were used as the magnetic-sensitive polyelectrolyte microcapsule-triggered elements in the construction of the polymer matrix. The microcapsules were characterized by ultraviolet-visible (UV-Vis) and photoluminescence (PL) titrations, quantum yield (Φf) calculations, 1H nuclear magnetic resonance (NMR), scanning electron microscopy (SEM), and superconducting quantum interference device magnetometry (SQUID) studies. This novel responsive release of the microcapsule fluorescence of the turn-on sensor for detecting trivalent cations was due to the compound PE and the MNPs being incorporated well within the whole system, and an effective thermal and kinetic energy transfer between the core and shell structure efficiently occurred in the externally oscillating magnetic field. The magnetic-sensitive fluorescence turn-on microcapsules show potential for effective metal ion sensing in environmental monitoring and even biomedical applications. Under the optimal controlled-release probe fluorescence conditions with high-frequency magnetic field treatment, the limit of detection (LOD) reached 1.574-2.860 µM and recoveries ranged from 94.7-99.4% for those metals in tap water.

The Multifunctionally Graded System for a Controlled Size Effect on Iron Oxide-Gold Based Core-Shell Nanoparticles.

We report that Fe3O4@Au core-shell nanoparticles (NPs) serve as a multifunctional molecule delivery platform. This platform is also suitable for sensing the doxorubicin (DOX) through DNA hybridization, and the amount of carried DOX molecules was determined by size-dependent Fe3O4@Au NPs. The limits of detection (LODs) for DOX was found to be 1.839 nM. In our approach, an Au nano-shell coating was coupled with a specially designed DNA sequence using thiol bonding. By means of a high-frequency magnetic field (HFMF), a high release percentage of such a molecule could be efficiently achieved in a relatively short period of time. Furthermore, the thickness increase of the Au nano-shell affords Fe3O4@Au NPs with a larger surface area and a smaller temperature increment due to shielding effects from magnetic field. The change of magnetic property may enable the developed Fe3O4@Au-dsDNA/DOX NPs to be used as future nanocarrier material. More importantly, the core-shell NP structures were demonstrated to act as a controllable and efficient factor for molecule delivery.

Use of curcumin-modified diamond nanoparticles in cellular imaging and the distinct ratiometric detection of Mg2+/Mn2+ ions.

An intrinsically luminescent curcumin-modified nanodiamond derivative (ND-Cur) has been synthesized as an effective probe for cell imaging and sensory applications. DLS data allowed the particle size of ND-Cur to be estimated (170.6 ± 46.8 nm) and the zeta potential to be determined. The photoluminescence signal of ND-Cur was observed at 536 nm, with diverse intensities at excitation wavelengths of 350 to 450 nm, producing yellow emission with a quantum yield (Φ) of 0.06. Notably, the results of the MTT assay and cell imaging experiments showed the low toxicity and biocompatibility of ND-Cur. Subsequently, investigations of the selectivity towards Mg2+ and Mn2+ ions were performed by measuring intense fluorescence peak shifts and "Turn-off" responses, respectively. In the presence of Mg2+, the fluorescence peak (536 nm) was shifted and then displayed two diverse peaks at 498 and 476 nm. On the other hand, for Mn2+ ions, ND-Cur revealed a fluorescence-quenching response at 536 nm. Fluorescence studies indicated that the nanomolar level detection limits (LODs) of Mg2+ and Mn2+ ions were approximately 423 and 367 nM, respectively. The sensing mechanism, ratiometric changes and binding site were established through PL, FTIR, Raman, SEM, TEM, DLS and zeta potential analyses. Furthermore, the effective determination of Mg2+ and Mn2+ ions by ND-Cur has been validated through cell imaging experiments.

Antioxidant cuttlefish collagen hydrolysate against ethyl carbamate-induced oxidative damage.

Ethyl carbamate (EC) has been associated with the generation of reactive oxygen species (ROS) and depletion of glutathione (GSH), leading to a decline in cell viability. In this study, we found that the cuttlefish collagen hydrolysate (CCH) exhibited high antioxidant activity in scavenging hydroxyl radicals (IC50 = 0.697 mg mL-1), which was also effective in combating EC-induced oxidative damage in liver hepatocellular carcinoma HepG2 cells. The expression of genes related to oxidative stress response could be regulated by CCH to mitigate EC-induced oxidative stress. Pathway analysis confirmed that the protective ability of CCH could be related to ferroptosis and glutathione metabolism. Therefore, CCH could reduce the decline in cell viability by alleviating GSH depletion, and prevent EC-induced oxidative damage. Moreover, protective effect of CCH could be realized by upregulating the heme oxygenase-1 to achieve the preventation of cell sensitization. Considering these effects, CCH has potential for use in food to prevent oxidative stress.

Isolation and identification of an antioxidant collagen peptide from skipjack tuna (Katsuwonus pelamis) bone.

To date, many researchers have developed active components that are derived from seafood processing for the purposes of healthcare. Here, an antioxidant collagen peptide was obtained from skipjack tuna (Katsuwonus pelamis) bone by using a combination of trypsin and chymotrypsin as the catalyst. The amino acid sequence of the peptide was identified as Ser-Ser-Gly-Pro-Pro-Val-Pro-Gly-Pro-Met-Gly-Pro-Met-Gly-Pro-Arg (SSGPPVPGPMGPMGPR) by liquid chromatography-electrospray ionization quadrupole time-of-flight mass spectrometry (LC-ESI-QTOF-MS) analysis. We found that the as-prepared collagen peptide can efficiently scavenge DPPH radical (IC50 3.149 mM), superoxide anion radical (IC50 3.803 mM) and ABTS radical (IC50 9.489 mM). In addition, it has been found that the methionine (Met) residue in the collagen peptide could provide a precise active site during the scavenging of DPPH radicals by Fourier transform infrared spectroscopy (FTIR) analysis and matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry analysis. These results suggest that the peptide can find wide uses in the food, cosmetic and pharmaceutical industries.

Eco-Friendly and Biodegradable Biopolymer Chitosan/Y2O3 Composite Materials in Flexible Organic Thin-Film Transistors.

The waste from semiconductor manufacturing processes causes serious pollution to the environment. In this work, a non-toxic material was developed under room temperature conditions for the fabrication of green electronics. Flexible organic thin-film transistors (OTFTs) on plastic substrates are increasingly in demand due to their high visible transmission and small size for use as displays and wearable devices. This work investigates and analyzes the structured formation of aqueous solutions of the non-toxic and biodegradable biopolymer, chitosan, blended with high-k-value, non-toxic, and biocompatible Y2O3 nanoparticles. Chitosan thin films blended with Y2O3 nanoparticles were adopted as the gate dielectric thin film in OTFTs, and an improvement in the dielectric properties and pinholes was observed. Meanwhile, the on/off current ratio was increased by 100 times, and a low leakage current was observed. In general, the blended chitosan/Y2O3 thin films used as the gate dielectric of OTFTs are non-toxic, environmentally friendly, and operate at low voltages. These OTFTs can be used on surfaces with different curvature radii because of their flexibility.