Search

Nanofibers show promise for wound healing by facilitating active agent delivery, moisture retention, and tissue regeneration. However, selecting suitable dressings for diverse wound types and managing varying exudate levels remains challenging. This study synthesized carbon quantum dots (CQDs) from citrate salt and thiourea using a hydrothermal method. The CQDs displayed antibacterial activity against Staphylococcus aureus and Escherichia coli. A nanoscaffold comprising gelatin, chitosan, and polycaprolactone (GCP) was synthesized and enhanced with silver nanoparticle-coated CQDs (Ag-CQDs) to form GCP-Q, while citrate addition yielded GCP-QC. Multiple analytical techniques, including electron microscopy, FT-IR spectroscopy, dynamic light scattering, UV-Vis, photoluminescence, X-ray diffraction, porosity, degradability, contact angle, and histopathology assessments characterized the CQDs and nanofibers. Integration of CQDs and citrate into the GCP nanofibers increased porosity, hydrophilicity, and degradability-properties favorable for wound healing. Hematoxylin and eosin staining showed accelerated wound closure with GCP-Q and GCP-QC compared to GCP alone. Overall, GCP-Q and GCP-QC nanofibers exhibit significant potential for skin tissue engineering applications., (© 2024. The Author(s).)

Cold atmospheric pressure plasma (CAP) has been described as a novel technology with expanding applications in biomedicine and biotechnology. In the present study, we provide a mildly stressful condition using non-lethal doses of CAP (120, 180, and 240 s) and evaluate its potential benefits on the recombinant production of a model protein (enhanced green fluorescent protein (eGFP)) in yeast Pichia pastoris. The measured eGFP fluorescence augmented proportional to CAP exposure time. After 240 s treatment with CAP, the measured fluorescent intensity of culture supernatant (after 72 h) and results of real-time PCR (after 24 h) indicated an 84% and 76% increase in activity and related RNA concentration, respectively. Real-time analysis of a list of genes involved in oxidative stress response revealed a significant and durable improvement in their expression at five h and 24 h following CAP exposure. The improvement of the recombinant model protein production may be partly explained by the impact of the RONS on cellular constituents and altering the expression of specific stress genes. In conclusion, using CAP strategy may be considered a valuable strategy to improve recombinant protein production, and deciphering the molecular background mechanism could be inspiring in the reverse metabolic engineering of host cells., (© 2023. The Author(s).)

Cellulases are hydrolytic enzymes with wide scientific and industrial applications. We described a novel cellulase, CelC307, from the thermophilic indigenous Cohnella sp. A01. The 3-D structure of the CelC307 was predicted by comparative modeling. Docking of CelC307 with specific inhibitors and molecular dynamic (MD) simulation revealed that these ligands bound in a non-competitive manner. The CelC307 protein was purified and characterized after recombinant expression in Escherichia coli (E. coli) BL21. Using CMC 1% as the substrate, the thermodynamic values were determined as K m 0.46 mM, k cat 104.30 × 10 -3 (S -1 ), and k cat /K m 226.73 (M -1  S -1 ). The CelC307 was optimally active at 40 °C and pH 7.0. The culture condition was optimized for improved CelC307 expression using Plackett-Burman and Box-Behnken design as follows: temperature 20 °C, pH 7.5, and inoculation concentration with an OD 600  = 1. The endoglucanase activity was positively modulated in the presence of Na + , Li + , Ca 2+ , 2-mercaptoethanol (2-ME), and glycerol. The thermodynamic parameters calculated for CelC307 confirmed its inherent thermostability. The characterized CelC307 may be a suitable candidate for various biotechnological applications., (© 2022. The Author(s).)

Atmospheric pressure cold plasma (ACP) is introduced as a useful tool in a variety of biological applications. Proteins are the most abundant macromolecules in living systems with a central role in all biological processes. These organic molecules are modified by ACP exposure that is responsible for many of ACP's biological effects. This study evaluated the effect of ACP on the production of recombinant phytase in yeast Pichia pastoris (P. pastoris) as well as the structure and function of the phytase enzyme. The results indicated that yeast cells treated with ACP, directly or indirectly, produced higher amounts of recombinant phytase, which was associated with the time of ACP treatment. The exposure of commercial phytase solution with ACP caused a significant increase in the enzyme activity (125%) after 4 hours. Evaluation of the phytase solution by far- and near-UV circular dichroism (CD) and fluorescence analysis indicated that this protein maintained its secondary structure when exposed to ACP while the tertiary structure was slightly unfolded. The effects of heat and H 2 O 2 on the phytase structure and function were compared with the effect of ACP treatment. The modification of Cys, Tyr and Trp amino acids upon reactive oxygen/nitrogen spices was simulated using a molecular dynamics approach. RMSF and RMSD analysis suggested that this structural alteration occurs owing to changes made by reactive species in accessible amino acids.