Bacterial biofilms can be programmed to produce living materials with self-healing and evolvable functionalities. However, the wider use of artificial biofilms has been hindered by limitations on processability and functional protein secretion capacity. We describe a highly flexible and tunable living functional materials platform based on the TasA amyloid machinery of the bacterium Bacillus subtilis. We demonstrate that genetically programmable TasA fusion proteins harboring diverse functional proteins or domains can be secreted and can assemble into diverse extracellular nano-architectures with tunable physicochemical properties. Our engineered biofilms have the viscoelastic behaviors of hydrogels and can be precisely fabricated into microstructures having a diversity of three-dimensional (3D) shapes using 3D printing and microencapsulation techniques. Notably, these long-lasting and environmentally responsive fabricated living materials remain alive, self-regenerative, and functional. This new tunable platform offers previously unattainable properties for a variety of living functional materials having potential applications in biomaterials, biotechnology, and biomedicine.

With the increasingly dominant role of smartphones in our lives, mobile health care systems integrating advanced point-of-care technologies to manage chronic diseases are gaining attention. Using a multidisciplinary design principle coupling electrical engineering, software development, and synthetic biology, we have engineered a technological infrastructure enabling the smartphone-assisted semiautomatic treatment of diabetes in mice. A custom-designed home server SmartController was programmed to process wireless signals, enabling a smartphone to regulate hormone production by optically engineered cells implanted in diabetic mice via a far-red light (FRL)-responsive optogenetic interface. To develop this wireless controller network, we designed and implanted hydrogel capsules carrying both engineered cells and wirelessly powered FRL LEDs (light-emitting diodes). In vivo production of a short variant of human glucagon-like peptide 1 (shGLP-1) or mouse insulin by the engineered cells in the hydrogel could be remotely controlled by smartphone programs or a custom-engineered Bluetooth-active glucometer in a semiautomatic, glucose-dependent manner. By combining electronic device-generated digital signals with optogenetically engineered cells, this study provides a step toward translating cell-based therapies into the clinic.

Sophisticated devices for remote-controlled medical interventions require an electrogenetic interface that uses digital electronic input to directly program cellular behavior. We present a cofactor-free bioelectronic interface that directly links wireless-powered electrical stimulation of human cells to either synthetic promoter–driven transgene expression or rapid secretion of constitutively expressed protein therapeutics from vesicular stores. Electrogenetic control was achieved by coupling ectopic expression of the L-type voltage-gated channel CaV1.2 and the inwardly rectifying potassium channel Kir2.1 to the desired output through endogenous calcium signaling. Focusing on type 1 diabetes, we engineered electrosensitive human β cells (Electroβ cells). Wireless electrical stimulation of Electroβ cells inside a custom-built bioelectronic device provided real-time control of vesicular insulin release; insulin levels peaked within 10 minutes. When subcutaneously implanted, this electrotriggered vesicular release system restored normoglycemia in type 1 diabetic mice.

By using tools from synthetic biology, sophisticated genetic devices can be assembled to reprogram mammalian cell activities. Here, we demonstrate that a self-adjusting synthetic gene circuit can be designed to sense and reverse the insulin-resistance syndrome in different mouse models. By functionally rewiring the mitogen-activated protein kinase (MAPK) signalling pathway to produce MAPK-mediated activation of the hybrid transcription factor TetR-ELK1, we assembled a synthetic insulin-sensitive transcription-control device that self-sufficiently distinguished between physiological and increased blood insulin levels and correspondingly fine-tuned the reversible expression of therapeutic transgenes from synthetic TetR-ELK1-specific promoters. In acute experimental hyperinsulinemia, the synthetic insulin-sensing designer circuit reversed the insulin-resistance syndrome by coordinating expression of the insulin-sensitizing compound adiponectin. Engineering synthetic gene circuits to sense pathologic markers and coordinate the expression of therapeutic transgenes may provide opportunities for future gene- and cell-based treatments of multifactorial metabolic disorders.

The ability to safely control transgene expression with simple synthetic gene switches is critical for effective gene-and cell-based therapies. Here, we harness the signaling pathway controlled by human transient receptor potential melastatin 8 (hTRPM8), a TRP channel family member 1 , to control transgene expression. hTRPM8 signaling is stimulated by menthol, an innocuous natural cooling compound, or by exposure to a cool environment (15-18°C). By functionally linking hTRPM8-induced signaling to a synthetic promoter containing nuclear factor of activated T cells (NFAT) binding elements, we designed a synthetic gene circuit that is adjustable by exposure to a cool environment or to menthol. We show that this gene switch is functional in various cell types, and in human primary cells, as well as in mice implanted with engineered cells. In response to transdermal delivery of menthol, microencapsulated cell implants harboring this gene circuit coupled to expression of either of two therapeutic proteins, insulin or a modified activin type IIB receptor ligand trap protein (mActRIIB ECD -hFc), were able to alleviate hyperglycemia in alloxan-treated mice (a model of type 1 diabetes) or to reverse muscle atrophy in dexamethasone-treated mice (a model of muscle wasting), respectively. This fully human-derived orthogonal transgene switch should be amenable to a wide range of clinical applications. MainTo develop synthetic biology-inspired treatment strategies, many gene switches have been built to respond to various signal inputs and transduce them into controlled outputs 2 .

The precise manipulation, localization, and assembly of biological and bioinspired molecules into organized structures have greatly promoted material science and bionanotechnology. Further technological innovation calls for new patternable soft materials with the long-sought qualities of environmental tolerance and functional flexibility. Here, we report a patterned amyloid material (PAM) platform for producing hierarchically ordered structures that integrate these material attributes. This platform, combining soft lithography with generic amyloid monomer inks (consisting of genetically engineered biofilm proteins dissolved in hexafluoroisopropanol), along with methanol-assisted curing, enables the spatially controlled deposition and in situ reassembly of amyloid monomers. The resulting patterned structures exhibit spectacular chemical and thermal stability and mechanical robustness under harsh conditions. The PAMs can be programmed for a vast array of multilevel functionalities, including anchoring nanoparticles, enabling diverse fluorescent protein arrays, and serving as self-supporting porous sheets for cellular growth. This PAM platform will not only drive innovation in biomanufacturing but also broaden the applications of patterned soft architectures in optics, electronics, biocatalysis, analytical regents, cell engineering, medicine, and other areas.

Cell-based therapies are recognized as the next frontier in medicine, but the translation of many promising technologies into the clinic is currently limited by a lack of remote-control inducers that are safe and can be tightly regulated. Here, we developed therapeutically active engineered cells regulated by a control system that is responsive to protocatechuic acid (PCA), a metabolite found in green tea. We constructed multiple genetic control technologies that could toggle a PCA-responsive ON/OFF switch based on a transcriptional repressor from Streptomyces coelicolor. We demonstrated that PCA-controlled switches can be used for guide RNA expression–mediated control of the CRISPR-Cas9 systems for gene editing and epigenetic remodeling. We showed how these technologies could be used as implantable biocomputers in live mice to perform complex logic computations that integrated signals from multiple food metabolites. Last, we used our system to treat type 1 and type 2 diabetes in mice and cynomolgus monkeys. This biocompatible and versatile food phenolic acid–controlled transgenic device opens opportunities for dynamic interventions in gene- and cell-based precision medicine.

Emerging digital assessment of biomarkers by linking health‐related data obtained from wearable electronic devices and embedded health and fitness sensors in smartphones is opening up the possibility of creating a continuous remote‐monitoring platform for disease management. It is considered that the built‐in flashlight of smartphones may be utilized to remotely program genetically engineered designer cells for on‐demand delivery of protein‐based therapeutics. Here, the authors present smartphone‐induced insulin release in β‐cell line (iβ‐cell) technology for traceless light‐triggered rapid insulin secretion, employing the light‐activatable receptor melanopsin to induce calcium influx and membrane depolarization upon illumination. This iβ‐cell‐based system enables repeated, reversible secretion of insulin within 15 min in response to light stimulation, with a high induction fold both in vitro and in vivo. It is shown that programmable percutaneous remote control of implanted microencapsulated iβ‐cells with a smartphone's flashlight rapidly reverses hyperglycemia in a mouse model of type‐1 diabetes.