Scalable Biofabrication of Functional 3D Scaffolds via Synergy of Autopilot Single-Jet Electrospun 3D PCL Fiber Scaffolds and Cell-Laden Hydrogels.

3D bioprinting enables cell-laden hydrogel construct fabrication in a layer-by-layer fashion but faces scalability challenges due to the mechanical weakness of hydrogels. Matrix reinforcement compromises cellular activity, creating a scalability-functionality trade-off that remains unresolved as sophisticated strategies including sequential and embedded printing fail to effectively overcome these limitations. This study presents an alternative approach by integrating autopilot single-jet electrospun (AJ-3D ES) 3D PCL fiber scaffolds with hydrogels, achieving anatomical precision, mechanical robustness, and enhanced cell function.

Enzyme-DNA chimeras: Construction, allostery, applications.

We describe the operational principle, synthesis, and applications of the enzyme-DNA chimeras. These are supramolecular constructions where a DNA spring is coupled to an enzyme and introduces artificial allosteric control of the enzyme. This method is universal and can be applied to various enzymes and proteins.

Dissipative dynamics of enzymes.

We explore enzyme conformational dynamics at sub-Å resolution, specifically, temperature effects. The ensemble-averaged mechanical response of the folded enzyme is viscoelastic in the whole temperature range between the warm and cold denaturation transitions. The dissipation parameter γ of the viscoelastic description decreases by a factor of 2 as the temperature is raised from 10 to 45 °C; the elastic parameter K shows a similar decrease.

Asymmetric effect of mechanical stress on the forward and reverse reaction catalyzed by an enzyme.

The concept of modulating enzymatic activity by exerting a mechanical stress on the enzyme has been established in previous work. Mechanical perturbation is also a tool for probing conformational motion accompanying the enzymatic cycle. Here we report measurements of the forward and reverse kinetics of the enzyme Guanylate Kinase from yeast (Saccharomyces cerevisiae).

Mechanical control of Renilla luciferase.

We report experiments where the activity of the enzyme luciferase from Renilla reniformis is controlled through a DNA spring attached to the enzyme. In the wake of previous work on kinases, these results establish that mechanical stress applied through the DNA springs is indeed a general method for the artificial control of enzymes, and for the quantitative study of mechano-chemical coupling in these molecules. We also show proof of concept of the luciferase construct as a sensitive molecular probe, detecting a specific DNA target sequence in an easy, one-step, homogeneous assay, as well as SNP detection without melting curve analysis.

Elastic energy of protein-DNA chimeras.

We present experimental measurements of the equilibrium elastic energy of protein-DNA chimeras, for two different sets of attachment points of the DNA "molecular spring" on the surface of the protein. Combining these with measurements of the enzyme's activity under stress and a mechanical model of the system, we determine how the elastic energy is partitioned between the DNA and the protein. The analysis shows that the protein is mechanically stiffer than the DNA spring.