Three-Dimensional Printable Enzymatically Active Plastics

Abstract

Here, we describe a facile route to the synthesis of enzymatically active highly fabricable plastics, where the enzyme is an intrinsic component of the material. This is facilitated by the formation of an electrostatically stabilized enzyme−polymer surfactant nanoconstruct, which, after lyophilization and melting, affords stable macromolecular dispersions in a wide range of organic solvents. A selection of plastics can then be co-dissolved in the dispersions, which provides a route to bespoke 3D enzyme plastic nanocomposite structures using a wide range of fabrication techniques, including melt electrowriting, casting, and pistondriven 3D printing. The resulting constructs comprising active phosphotriesterase (arPTE) readily detoxify organophosphates with persistent activity over repeated cycles and for long time periods. Moreover, we show that the protein guest molecules, such as arPTE or sfGFP, increase the compressive Young's modulus of the plastics and that the identity of the biomolecule influences the nanomorphology and mechanical properties of the resulting materials. Overall, we demonstrate that these biologically active nanocomposite plastics are compatible with state-of-the-art 3D fabrication techniques and that the methodology could be readily applied to produce robust and on-demand smart nanomaterial structures.

Carrier Variety Used in Immobilization of His6-OPH Extends Its Application Areas

“…is based that fast and highly effective immobilization, and then isolation and purification of the enzyme itself occurs. The emerging coordination bonds between metal atoms in the carrier and nitrogen atoms in the imidazole rings of the polyhistidine sequence in the protein molecule make it possible to anchor the enzyme on the carrier quite firmly [ 2 , 22 , 23 ] and use it for a long time, in such an immobilized form, for the destruction of OPCs ( Table 1 , [ 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 ]). Of particular interest are such immobilization variants for the stabilization and repeated use of the enzyme in the degradation of OPC-polluting water systems [ 22 , 23 ].…”

“…A fundamentally different approach, based on the use of polyelectrolyte interactions of the surface of the His-tagged enzyme with variously charged surfactants, was used by researchers for the creation of various bioconjugates to improve the stability and catalytic characteristics of the enzyme [ 33 , 34 , 35 ]. At the same time, the expediency of using such coatings for the enzyme, including forming a capsule in the form of a so-called corona, was noted.…”

Advances in 3D Gel Printing for Enzyme Immobilization

“…Examples of novel technological variations also exist for non-aqueous systems. Perriman and co-workers [ 81 ] stabilized enzymes electrostatically through sequential addition of a pair of surfactants to the enzyme solution and retrieved organic solvent-soluble and melt-processable solid stabilized enzymes through dialysis and lyophilization. Then, they went on to use this stabilized enzyme in solvent casting, organic solvent-based solution extrusion, thermal molding, and, most interestingly, melt electrowriting.…”

“…The success of 3D printed immobilized enzymes for biocatalysis hinges heavily on minimizing diffusion limitations that limit catalytic rates, which could partially be overcome by improving the printing resolution of popular economical techniques, namely hydrogel-based direct ink writing. There are already a number of developments, such as 3D jet writing [ 80 ] and melt electrowriting [ 81 ] for creating micro-sized enzyme-entrapped polymer fibers with well-defined 3D patterns with fine structural features to mitigate diffusion limitations and aid mixing. General progress in 3D printing technology development, i.e., higher resolution and speed, and lowering of the cost of the most advanced 3D printing technologies will also provide advances for enzyme immobilization.…”

“…( B ) Melt electrowriting of PCL with entrapped electrostatically stabilized enzymes/proteins: ( a ) photo of the fabric with area of 3 cm 2 ; ( b ) widefield microscopy view of the fine structures of the printed fabric with fiber thickness <5 μm; ( c ) enzymatic activity after the melt electrowriting process as shown by the fluorescent emission from the enzyme catalyzed hydrolysis reaction; ( d ) fluorescent plastics created by entrapping superfolder green fluorescent protein into PCL; ( e ) printed ordered grid structure with fluorescent PCL; and ( f ) the fluorescent plastics were used to print fabrics with repetitive tangles (reproduced with permission from Ref. [ 81 ]).…”