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Biology subjects

Duraj-Thatte, A. M.

Publications and source records attributed to Duraj-Thatte, A. M..

4 recordsLinked to original sources

Intrinsic antifungal activity of curli nanofibers expands the design space for programmable antimicrobial biomaterials

The rise of antifungal resistance and limited antifungal drug classes creates an urgent need for biomaterials with localized, programmable activity. Here, we engineered curli nanofibers displaying the antifungal peptide heliomicin and unexpectedly discovered that wild-type CsgA itself exhibits intrinsic antifungal activity against Candida albicans, reducing fungal viability by approximately 2 log units. Heliomicin fusion enhanced this activity to a 3.5-log fungicidal reduction while preserving nanofiber self-assembly, hydrogel formation, mechanical properties, and 3D printability. Mechanistic analyses linked enhanced activity to membrane disruption and expansion of the cationic surface of CsgA. Heliomicin-CsgA hydrogels further reduced fungal burden and suppressed hyphal development in an ex vivo porcine skin infection model. These findings reveal that extracellular protein nanofibers can harbor intrinsic biological activities that can be uncovered and enhanced through protein engineering, establishing a strategy for developing intrinsically bioactive, programmable biomaterials for localized therapeutic applications against fungal pathogens and potentially other microbial infections.

bioengineering↗

De novo Autogenic Engineered Living Functional Materials

Autogenic engineered living materials (ELMs) involve in situ production and engineering of native extracellular matrix (ECM). However, the existing autogenic ELMs have limited scope and functionalities. Herein, we report a platform for de novo autogenic functional ELMs. By protein mining, we have discovered CsgA-like 33,564 homologs that can find potential utility as de novo ECM of protein nanofibers. By employing AlphaFold2 and molecular dynamics simulations, we shed insights into the CsgA-like {beta}-solenoid protein structures and stability. By hacking Escherichia coli curli machinery, we demonstrate the production of de novo autogenic ELMs from CsgA-like proteins ([≤]9-times the molecular weight and {beta}-sheet repeat units) of extremophilic non-model bacteria. Additionally, we biomanufacture macroscopic materials with tunable mechanical properties (enhancing storage modulus by 3-times) and programmable functionalities (3D printability, binding to nanoparticles/antibodies). This work showcases a versatile platform to discover, rationally design, and harness the sophisticated functionalities of natural systems for futuristic autogenic ELMs.

bioengineering↗

Programmable Microbial Ink for 3D Printing of Living Materials Produced from Genetically Engineered Protein Nanofibers

Living cells have the capability to synthesize molecular components and precisely assemble them from the nanoscale to build macroscopic living functional architectures under ambient conditions.1-3 The emerging field of living materials has leveraged microbial engineering to produce materials for various applications, but building 3D structures in arbitrary patterns and shapes has been a major challenge.1-14 We set out to develop a new bioink, termed as "microbial ink" that is produced entirely from genetically engineered microbial cells, programmed to perform a bottom-up, hierarchical self-assembly of protein monomers into nanofibers, and further into nanofiber networks that comprise extrudable hydrogels. We further demonstrate the 3D printing of functional living materials by embedding programmed Escherichia coli (E. coli) cells and nanofibers into microbial ink, which can sequester toxic moieties, release biologics and regulate its own cell growth through the chemical induction of rationally designed genetic circuits. This report showcases the advanced capabilities of nanobiotechnology and living materials technology to 3D-print functional living architectures.

synthetic biology↗

Probiotic Associated Therapeutic Curli Hybrids (PATCH)

There is an unmet need for new treatment methods for inflammatory bowel disease (IBD) that can reliably maintain remission without leading to detrimental side effects. Beneficial bacteria have been utilized as an alternative treatment for IBD albeit with low efficacy. We genetically engineered Escherichia coli Nissle 1917 (EcN) to create an anti-inflammatory fibrous matrix in situ. This matrix consists of EcN-produced curli nanofibers displaying trefoil factors (TFFs), known to promote intestinal barrier function and epithelial restitution. We confirmed that engineered EcN was able to secrete the curli-fused TFFs in vitro and in vivo, and was non-pathogenic. We observed an enhanced protective effect of engineered EcN against dextran sodium sulfate induced colitis in mice, associated with barrier function reinforcement and immunomodulation. This work sets the foundation for the development of a novel therapeutic platform in which the in situ production of a therapeutic protein matrix from beneficial bacteria can be exploited.

bioengineering↗