An Enzyme‐Coated Metal–Organic Framework Shell for Synthetically Adaptive Cell Survival

Abstract

A bioactive synthetic porous shell was engineered to enable cells to survive in an oligotrophic environment. Eukaryotic cells (yeast) were firstly coated with a β-galactosidase (β-gal), then a metalorganic framework (MOF) film was crystallized on the enzyme coating producing a bioactive porous synthetic shell. The β-gal was an essential component of the bioactive shell as it generated nutrients (i.e. glucose and galactose) required for cell viability from nutrient deficient media (lactose-based). In addition the porous MOF coating carried out other vital functions, such as: 1) shielding the cells from cytotoxic compounds and radiation, 2) protecting the non-native enzymes (β-gal in this instance) from degradation and internalization, 3) allowing for the diffusion of molecules essential for the survival of the cells. Indeed, this bioactive porous shell enabled the survival of cells in simulated extreme oligotrophic environments for more than 7 days, leading to a decrease in cell viability less than 30%, versus a 99% decrease for naked yeast. When returned to optimal growth conditions and the bioactive porous exoskeleton could be removed and the cells regained full growth immediately. Alternative to synthetic biology or genetic modification, the construction of bioactive coatings represents a conceptually new and promising approach for the nextgeneration of cell-based research and application.Living organisms are sensitive to their environment and subtle changes in nutrient level, temperature, pressure, moisture, salinity, and pH can disrupt their biological functions, thereby leading to cell death. [1][2][3] To address this challenge, primary

Nano‐Biohybrids: In Vivo Synthesis of Metal–Organic Frameworks inside Living Plants

“…After MOF formation, SEM images demonstrated the presence of particles primarily inside the xylem, with few MOFs in the phloem (Figure ; Figures S1 and S2, Supporting Information). Fluorescence imaging at the cellular level revealed that the MOFs were primarily in the xylem and located on the cell walls, similar to our previous experiments on growing MOFs on unicellular organisms (Figure S3, Supporting Information) . Additionally, MOFs were found on the outside of the plant below the precursor waterline, which is also expected as the precursors can easily grow around the polysaccharides on the plant surface .…”

“…A recent promising innovation in bioaugmentation is the growth of metal–organic frameworks (MOFs) around bioentities, including biomolecules, viruses, and even living prokaryotic and eukaryotic cells . MOFs are a class of synthetic and natural nanoporous materials with potential for a wide variety of applications, including gas capture, catalysis, separation, proton conductivity, and biomedicine .…”

Protein surface functionalisation as a general strategy for facilitating biomimetic mineralisation of ZIF-8

“…proteins and enzymes, via a one-pot synthetic approach termed ‘biomimetic mineralisation’. 11 – 16 This strategy has also been extended to the synthesis of MOF-based biocomposites composed of viruses, 17 and cells, 18 , 19 and more recently to the co-encapsulation of gene-editing system CRISPR/CAS9. 20 A salient feature of the MOF coating is that it can protect an encapsulated enzyme from inhospitable external environments ( e.g.…”

Single‐Cell Nanometric Coating Towards Whole‐Cell‐Based Biodevices and Biosensors

“…Hence, Falcaro and coworkers firstly coated the anionic yeast cell surface using cationic β‐gal by electrostatic interaction in phosphate buffered saline (PBS), followed by the crystallization of a metal‐organic framework (MOF) film on the enzyme coating, thus leading to the formation of a bioactive porous synthetic shell. These MOF coatings can protect the cells from cytotoxic compounds/radiation or the degradation of the bio‐interface and endow the cells a high viability in simulated extreme oligotrophic environments . Similarly, PEI was employed for the fabrication of the bio‐interface for the following silicification, that is, the silica formation caused by the interaction between polyamines and silicic acid under mild conditions, but PEI was more toxic compared with other biomaterials, like we discussed before .…”