Polymeric Hydrogel Coating for Modulating the Shape of Keratin Fiber

Tannic acid modified keratin/sodium alginate/carboxymethyl chitosan biocomposite hydrogels with good mechanical properties and swelling behavior

Natural polymer-based hydrogels have demonstrated great potential as wound-healing dressings. They help to maintain a moist wound environment as well as promote faster healing. In this work, a multifunctional hydrogel was prepared using keratin, sodium alginate, and carboxymethyl chitosan with tannic acid modification. Micro-morphology of hydrogels has been performed by scanning electron microscopy. Fourier Transform Infrared Spectroscopy reveals the presence of hydrogen bonding. The mechanical properties of the hydrogels were examined using a universal testing machine. Furthermore, we investigated several properties of the modified hydrogel. These properties include swelling rate, water retention, anti-freezing properties, antimicrobial and antioxidant properties, hemocompatibility evaluation and cell viability test in vitro. The modified hydrogel has a three-dimensional microporous structure, the swelling rate was 1541.7%, the elastic modulus was 589.74 kPa, the toughness was 211.74 kJ/m3, and the elongation at break was 75.39%, which was similar to the human skin modulus. The modified hydrogel also showed inhibition of S. aureus and E. coli, as well as a DPPH scavenging rate of 95%. In addition, the modified hydrogels have good biological characteristics. Based on these findings, the K/SA/CCS hydrogel holds promise for applications in biomedical engineering.

An innovative aluminium foil electrode modified with Al nanoparticles and EDTA for lead detection in biological samples

This study presents a novel Aluminium foil-based electrode characterized by its affordability, flexibility, and ease of modification with carboxylic moiety-containing organic molecules. Upon foil modification with Aluminium nanoparticles and EDTA (AlNP-EDTA/AlE), the modified electrode exhibits remarkable activity in the oxidation of lead at potentials around -0.4 V. The lead signal is derived from the oxidation of lead deposited on the electrode surface using anodic stripping voltammetry (ASV). The addition of EDTA to AlNP/AlE increased the anodic peak current of lead by more than 500 %. The surface characterization of the electrode was performed by scanning electron microscopy (SEM) and infrared spectroscopy (IR), while its electroactive properties were evaluated by cyclic voltammetry (CV) and electrical impedance spectroscopy (EIS). Optimal operating parameters include pH 2.1, square-wave voltammetry (SWV) with an accumulation time of 60 s and an accumulation potential of -0.8 V. A low detection limit of 0.20 µmol/L and a relative standard deviation (RSD) of 3.0 % were achieved using five different electrodes. The effectiveness of AlNP-EDTA/AlE was further demonstrated with consistent results in biological samples spiked with Pb.

Morphological Evaluation of Supramolecular Soft Materials Obtained through Co-Assembly Processes

Low-molecular-weight gelators (LMWGs) are compounds with an intrinsic tendency to self-assemble forming various supramolecular architectures via non-covalent interactions. Considering that the development of supramolecular assemblies through the synergy of molecules is not entirely understood at the molecular level, this study introduced a Fmoc-short peptide and four Fmoc-amino acids as building blocks for the self-assembly/co-assembly process. Hence, we investigated the formation of supramolecular gels starting from the molecular aggregation following two triggering approaches: solvent/co-solvent method and pH switch. The complex morphological analysis (POM, AFM, and STEM) offered an insight into the spontaneous formation of well-ordered nanoaggregates. Briefly, POM and AFM images demonstrated that self-assembled gels present various morphologies like dendrimer, spherulite, and vesicle, whereas all co-assembled supramolecular systems exhibit fibrillar morphologies as a result of the interaction between co-partners of each system. STEM study has confirmed that the molecules interact and join together, finally forming a fibrous network, an aspect seen in both self-assembled and co-assembled gels. XRD allowed the determination of the molecular arrangement. The study emphasized that the Fmoc motif protected the amino groups and facilitated gelation through additional π-π interactions.

Exploring Biomolecular Self-Assembly with Far-Infrared Radiation

Physical engineering technology using far-infrared radiation has been gathering attention in chemical, biological, and material research fields. In particular, the high-power radiation at the terahertz region can give remarkable effects on biological materials distinct from a simple thermal treatment. Self-assembly of biological molecules such as amyloid proteins and cellulose fiber plays various roles in medical and biomaterials fields. A common characteristic of those biomolecular aggregates is a sheet-like fibrous structure that is rigid and insoluble in water, and it is often hard to manipulate the stacking conformation without heating, organic solvents, or chemical reagents. We discovered that those fibrous formats can be conformationally regulated by means of intense far-infrared radiations from a free-electron laser and gyrotron. In this review, we would like to show the latest and the past studies on the effects of far-infrared radiation on the fibrous biomaterials and to suggest the potential use of the far-infrared radiation for regulation of the biomolecular self-assembly.