3D Construction of Biologically Derived Materials

Current scaffold designs and materials do not provide all of the appropriate cues necessary to mimic in-vivo conditions for tissue engineering and stem cell engineering applications. It has been hypothesized that many biomaterials, such as bone, muscle, brain and heart tissue exhibit piezoelectric and ferroelectric properties. Typical cell seeding environments incorporate biochemical cues and more recently mechanical stimuli, however, electrical cues have just recently been incorporated in standard in-vitro examinations. In order to develop their potential further, novel scaffolds are required to provide adequate cues in the in-vitro environment to direct stem cells to differentiate down controlled pathways or develop novel tissue constructs. This invention is for a scaffold that provides for such cues by mimicking the native biological environment, including biochemical, topographical, mechanical and electrical cues.

NASA's new technique for generating recyclable feedstocks for on-demand additive manufacturing employs the high-yield reversibility of the Diels-Alder reaction between maleimide and furan functionalities, utilizing the exceedingly favorable interaction between specific chemical functionalities, often termed "click reactions" due to their rapid rate and high efficiency. Integration of these moieties within a polymer coating on epoxy microparticle enables reversible assembly into macroscopic, free-standing articles. This click chemistry can be activated and reversed through the application of heat. Monomer species can be used to incorporate these functionalities into polyimide materials, which provide excellent mechanical, thermal, and electrical properties for space applications. Copoly (carbonate urethane) has been shown to be a viable coating material in the generation of polymer-coated epoxy microparticle systems and is amenable to being processed through a variety of approaches (e.g., filaments and slurries for 3D printing, compression molding, etc.). The polymeric materials are grown from the surfaces of in-house fabricated epoxy microparticles. The thermal and mechanical properties of the microparticles can be readily tuned by changes in composition. There are a number of potential applications for this NASA technology ranging from use of these materials for recyclable/repurpose-able articles (structural, decorative, etc.) to simple children's toys. More demanding uses such as for replacement parts in complex industrial systems are also possible. For long term space missions, it is envisioned that these feedstocks would be integrated into secondary spacecraft structures such that no additional concerns would be introduced due to in-space chemical reactions and no additional mass would be required.

The technology is a method to increase automation of Additive Manufacturing (AM) through augmentation of the Fused Filament Fabrication (FFF) process. It can significantly increase the speed of 3D printing by automating the removal of printed components from the build platform without the need for additional hardware, which increases printing throughput. The method can also be leveraged to perform automated object testing and characterization. The method includes embedding into the manufacturing instructions methods to fabricate directly onto the build platform an actuator tool, such as a linear spring. The deposition head can be leveraged as a robotic manipulator of the actuator tool to bend, cock, and release the linear spring to strike the target manufactured object and move it off the build platform of the machine they were manufactured on. The ability for an object to 'fly off of the machine that made it' essentially enables automated clearing of the processed build volume. The technology can also be used for testing the AM machine or the feedstock material by successively fabricating prototypes of the manufactured object, and taking measurements from sensors as the actuator strikes the prototype. This provides automated testing for quality control, machine calibration, material origins, and counterfeit detection.

The miniature bioreactor system was developed to provide the capabilities for NASA to perform cell studies in space and then provide results back to investigators on Earth with minimal tools and cost. The miniature bioreactor system has the potential to also be used on Earth as a laboratory bench-top cell culturing system without the need for expensive equipment and reagents. The system can be operated under computer control to reduce the operator handling and to reduce result variations. The system includes a bioreactor, a fluid-handling subsystem, a chamber wherein the bioreactor is maintained in a controlled atmosphere and temperature, and control subsystems. The system can be used to culture both anchorage dependent and suspension cells (prokaryotic or eukaryotic cell types). Cells can be cultured for extended periods of time in this system, and samples of cells can be extracted and analyzed at specified intervals. The miniature bioreactor system for cell culturing has applications in pharmaceutical drug screening and cell culture studies.

Microorganisms are unique from the standpoint that they can be employed as self-replicating bio-factories to produce both native and engineered mission relevant bio-products. Methane (CH4) usage in In-Space Manufacturing (ISM) platforms has been discussed previously for human exploration and has been proposed to be used in physicochemical systems as a propulsion fuel, supply gas, and in fuel cells. Carbon Dioxide (CO2) is abundant on Mars and manned spacecraft. On the International Space Station (ISS), NASA reacts excess CO2 with Hydrogen (H2) to generate CH4 and Water (H2O) using the Sabatier System (Figure 1). The resulting water is recovered in the ISS, but the methane is vented to space. Recapturing this methane and using it for microbial manufacturing could provide a unique approach in development of in-space bio-manufacturing. Thus, there is a capability need for systems that convert methane into valuable materials. Methane (CH4) is a potential carbon substrate for methanotrophic microorganisms which are able to metabolize CH4 into biomass. The innovative technology from NASA Ames Research Center ports Soluble Methane Monooxygenase (sMMO) to Pichia, that is, it moves the methane metabolism into a robust microbial factory (Pichia pastoris) (Figure 2). The yeast Pichia pastoris is a refined microbial factory that is used widely by industry because it efficiently secretes products. Pichia could produce a variety of useful products in space. Pichia does not consume methane but robustly consumes methanol, which is one enzymatic step removed from methane. This novel innovation engineers Pichia to consume methane thereby creating a powerful methane-consuming microbial factory and utilizing methane in a robust and flexible synthetic biology platform.