Polymeric Core-shell Architectures to Adapt Biocatalytically Active Enzymes in Non-aqueous Media with Enhanced Performance
Biological Process Engineering
Synthesis and Properties of Functional Materials
Final Report Abstract
The project clearly aimed at the development of polymeric core-shell architecture for biocatalysis in organic media. Based on these results, a rational approach should be developed to create the polymeric structure for efficient catalysis. As model systems, a block copolymer, PCL21-PEG45- PCL21, and enzyme-PNIPAAm were respectively applied. In the PCL21-PEG45-PCL21 stabilized core-shell emulsions, a rational polymer structure was synthesized by optimizing polymer structure and HLB value, achieving the best emulsion stability. Moreover, it was unexpected to find that the core-shell structure could be compartmentalized by just varying water to oil ratios, resulting in a much larger surface area. With these positive findings, two types of interesting enzymes, BAL and ADHA, were encapsulated into the core-shell structure. As compared to the control systems (e.g., biphasic system), enzymatic catalysis in the core-shell emulsions, particularly multiple emulsions, are enormously improved due to their interfacial area. Furthermore, the use of block-copolymers was found to improve enzyme stability, and the whole system could be reused for many times. Since the polymer and core-shell emulsion were easily prepared, the systems were scaled up to 2 L, where gram scale pure chiral products were achieved. Therefore, the project demonstrated a model system using block copolymers to create core-shell emulsions that could be applied for the efficient, reusable, and scalable biocatalysis. In addition to isolated enzymes, the block copolymer-stabilized emulsions were applied for whole cell biocatalysis. The system was found very successful to encapsulate living cells, in which high cell viability could be identified. After the encapsulation, the whole biocatalysis was substantially improved as compared to the biphasic system. These findings suggest that the block copolymers can be used for different biocatalyst sources, ranging from enzymes to whole cells. Following the design of block copolymer, an enzyme-polymer conjugate was synthesized for building up the core-shell emulsions. This was successfully demonstrated by the BAL-PNIPAAm, which behaved like the PCL21-PEG45-PCL21, creating stable core-shell emulsions. Differently, BAL, as enzymes, located in the shell, thus acting as both stabilizer and catalysts. With this design, excellent catalytic efficiency was observed. Likewise, the system could be reused and had better stability than native enzymes. Overall, these completed investigations strictly followed the project goal in the past, creating two types of polymeric systems, in which one used block copolymer and the other one designed enzymepolymer conjugates. Both enabled to constructed core-shell architecture (emulsions) for the improved catalytic performance.
Publications
- Polymeric nano-/micro-structured biocatalysts - 16th EPF Congress, Lyon, July 2-7, 2017
Wu C., Zhao Q.
- Compartmentalized aqueous‐organic emulsion for efficient biocatalysis. Chemistry - A European Journal 2018, 24, 10966-10970
Zhao Q., Ansorge-Schumacher M., Haag R., Wu C.
(See online at https://doi.org/10.1002/chem.201802458) - Enzyme-polymer conjugates as robust Pickering interfacial biocatalysts for efficient biotransformation and one-pot cascade reactions. Angewandte Chemie International Edition 2018, 57, 13810 – 13814
Sun Z., Glebe U., Charan H., Böker A., Wu C.
(See online at https://doi.org/10.1002/anie.201806049)
