Synthetic actinobacteria for tailored supply of therapeutics
Leading PIs: Andriy Luzhetskyy and Christoph Wittmann
Patrick Oberhäuser / PhD student, started 08-2020
Dr. Sara‐Lisa Hoffmann / PostDoc (50%) started 10‐2020
This subproject aims at the creation of actinobacterial cell factories with synthetic pathways for relevant therapeutics and integrated sensing and control circuits for signal transduction, communication and streamlined output. Joint efforts of all partners will couple synthetic and control properties into cells of higher functionality. In addition, possibilities to combine cells with different performance into synthetic consortia will be explored. Within the consortium, collaboration with other LSC partners aim to combine the cell factories with polymers into living materials and test them for medical applications.
Safe bacterial hosts for antibiotic production in living materials
Leading PI: Rolf Müller
Timo Risch / PhD student, started 02-2021
We will basically generate an artificial biosynthetic gene cluster for odilorhabdin and transfer it into a heterologous host. As next steps in the development chain the optimisation of the production of darobactin, the integration of regulatory elements, and the transfer into safe host organisms will follow. Analytical procedures for darobactin and odilorhabdin to analyze the release from living materials have to be established in in vitro as well as in vivo experiments. Also the odilorhabdin production hast be optimized. Genetic engineering of the respective producer strains and modifications of the compound class will be performed. The project will conclude with the testing and adaptation of the living material composite into application-relevant conditions.
Temperature-sensitive bioswitches for control of bacterial activity in living therapeutic materials
Leading PI: Shrikrishnan Sankaran
Sourik Dey / PhD student, started 11-2020
We will start with the engineering of thermal switches for the production of IL-1Ra and IL-2, Darobactin, and Ectoine. Then we are going to transfer genetic modules including genetic switches and modules for drug production into the bacterial chromosome. Finally we will perform the encapsulation of thermally responsive drug-producing bacteria as living therapeutic materials for periodontitis and immunotherapy and improve the photothermal conversion efficiency using gold nanorods.
Bacteria encapsulation in miniaturized living devices for therapies in the biliary duct and the lung
Leading PI: Aránzazu del Campo
Syuzanna Hambardzumyan / PhD student, started 09-2020
Hydrogels and nanofibrillar meshes will be designed to encapsulate bacteria in the form of drug eluting living aerosols for the lung, or living drug eluting implants for the bile duct. Beyond supporting viability and functionality of the embedded biofactories, material selection and processing techniques will be oriented to address the particular geometrical, delivery and stability features characteristic for these scenarios. We will use approved or well established medical polymers for an encapsulation in form of hydrogels – such as polyurethanes, PVA, PEG, Pluronic and others – or porous or fibrillar meshes consisting e. g. of PTFE or PP. Processing techniques based on microfluidic encapsulation and bioprinting will be established. Structure-properties-performance correlations will be elaborated for the different combinations of composition, processing, and bacteria. Bacteria viability, drug production, stability, robustness and reproducibility of the devices will be assessed in the following. Coreshell devices will be targeted in order to incorporate different functionalities (drug production, mucoadhesive properties and so on) into the devices. Upscaling up to implantable prototype level will be attempted for the animal experiments up to the preclinical level.
Infrared-activatable antibiotic-producing living materials
Leading PI: Tobias Krauss
Selim Basaran / PhD student, started 08-2020
Here, we introduce a hybrid concept that combines inorganic nanostructures with genetically engineered cells to release an active compound upon optical irradiation. Gold nanorods (AuNRs) – exceptionally efficient and easily tunable photothermal IR converters – are compatibilized with thermally responsive bacteria. They will be tested in mixed suspensions and then encapsulated within a polymeric matrix in a defined geometrical relation to each other. We will evaluate the achievable temperature gradients, response of the bacteria, release profiles of the drug, and applicability in relevant environments, for example, simulated oral conditions.
Characterization of immune response to living therapeutic materials in vitro
Leading PI: Bin Qu
Dr. Zhao Renping / PostDoc (50%) started 10‐2020
Therapeutic bacteria have to be encapsulated in synthetic materials to construct implantable living therapeutic devices. For a realistic potential to become medical products the evaluation of the immune response to such devices in vitro and in vivo is critical for the selection of engineered strains and designs. In this context, we will develop assays, tests and quantify the response of immune cells to therapeutic bacteria and living devices.
Living Therapeutic for Chronic Cholangitis
Leading PI: Frank Lammert
Irina Nowak / Technical staff, started 09-2020
In this project we combine the development of an antimicrobial-releasing device with in vitro and in vivo experiments to demonstrate the feasibility and a mode of action. As a first step we will design light-regulated or pH-regulated threads containing E. coli that could release darobactin or colistin. An alternative to this is the use of carbapenem or a natural compound. The detection and quantification of antimicrobials in bile fluid by LC-MS/MS an in vitro tests of the LTM in artifical model bile systems will follow. Concluding the development process we will perform in vivo tests of the miniaturized implantable threads releasing darobactin in bile ducts of Abcb4 deficient mice and light activation by narrow band imaging (NBI).