5. Innovative VFD Transformations
With its unique operating characteristics, vortex fluidic technology warrants consideration for preparing/transforming nanomaterial, as a paradigm shift for preparing material with unique properties, for niche innovative research and industrial applications. For instance, it has been shown that enzymatic reactions could be accelerated using a VFD, with pressure waves effective in accelerating enzymatic reactions24. Despite chemical transformations being catalyzed with outstanding regio- and stereo-specificities, extended reaction times limit numerous enzymes. However, Britton et al.found that the above pressure waves generated at specific rotational speeds allow an enzyme to respond, providing an acceleration landscape, Figure 8. Enzymatic efficiency (kcat/Km) and rate constants (kcat) have been increased, with an average 15-fold enhancement for deoxyribose-5-phosphate aldolase, an a seven-fold average acceleration displayed by four other enzymes. The VFD increase the mass transfer such that the chattering events for the enzyme are more likely to be successful, with negative pressure collapsing the transition, ie. mechanically changing the secondary structure of the enzyme. More recently, the fabrication of hybrid laccase-Cu3(PO4)2nanoflowers via an intermediate toroidal structure is dramatically accelerated in the VFD. This innovative approach leads to the formation of the composite material with enhanced catalytic activity (1.8 fold) compared to free laccase under diffusion control.25Following the fabrication process, the hybrid nanoflowers are subsequently integrated as a coating on the side wall of the reactor surface. The resulting coating exhibits exceptional stability and reusability. This remarkable durability enables a significant 16-fold enhancement in catalytic rates compared to the control conditions.
The VFD has also been utilized to procure a rapid protein refolding technique, with yields for proteins being increased for simple cell lines, not to mention lowering costs, reducing streams of waste, and significantly reducing the time associated with protein expression for an extensive range of research and industrial applications, as reported by Yuan et al. 27 The shear stresses from fluid films micrometer wide have been observed in refolding lysozyme in hen egg-whites, Figure 8. Recombinant lysozyme in hen egg-whites and caveolin-1, and a protein much larger in size, cAMP-dependent protein kinase A, all of which require only minutes for processing, thereby being much faster than overnight dialysis by conventional means. In recent advancements, the ability to manipulate the unfolding and refolding of β-lactoglobulin has been established using the technology, aided by the monitoring of aggregation-induced emission luminogen (AIEgen).50 The AIEgen have been intensively explored in the biomedical field51 and in this case they serve as a monitoring tool, enabling real-time observation of the folding behavior of the protein during the processes. Furthermore, solutions with larger volumes can be accommodated, with the VFD scaling up through multiple units for parallel processing or the continuous mode, consequently dramatically lowering financial costs and time for refolding inactive proteins on an industrial scale.