Reviews & Analysis

Cell engineering by synthetic biology typically relies on synthetic gene constructs that compete with the host cell for intracellular resources. This Review discusses how such resource competition can impact mammalian cell engineering and outlines strategies for how to mitigate cellular burden using circuit-centric and host-centric approaches.

Microbial nanowires are attractive materials for the fabrication of electronic devices because they are sustainably produced and can be genetically reengineered for a broad range of functionalities. Guberman-Pfeffer and colleagues describe novel devices and mass production strategies that have been demonstrated and outline the optimization strategies required for their commercialization.

Organoids and organs-on-chips aim to improve drug testing and disease modelling, but each has limitations. This Review discusses the integration of these systems to improve cellular hierarchy, structural fidelity, reproducibility, throughput, scale-up and efficiency to improve translational outcomes.

Photodynamic therapy allows the local destruction of diseased cells and tissues by light. This Review examines how photodynamic therapy and priming can be engineered for the treatment of localized, regional and distant cancer, from photosensitizer engineering to photonic devices and clinical translation.

Cells can be engineered to modify their function and behaviour for therapeutic and diagnostic applications. This Review discusses biological, genetic and materials-based engineering approaches for both mammalian and bacterial cells, outlining key design strategies and applications of engineered cell products.

Polysaccharides possess immune-activating or immune-regulatory functions and can thus be applied as immunomodulators. This Review discusses engineering approaches for the design of polysaccharides for vaccine, immunoadjuvant, immune-modulation and drug-delivery applications.

Soft bioelectronic devices are made from polymer-based and hybrid electronic materials that form natural interfaces with the human body. In this Review, the authors present recent developments in soft bioelectronic sensors and actuators, and discuss system-level integration for wearable and implantable medical applications.

Brain-on-a-chip models, mimicking brain physiology, hold promise for developing treatments for neurological disorders. This Review discusses the engineering challenges and opportunities for these devices, including the integration of 3D cell cultures and electrodes and scaffold engineering strategies.

Stimulation therapy for neuropsychiatric disorders is hindered by the complexity and inter-individual and intra-individual variability in symptom manifestations, neural representations and response to therapy. Brain–computer interfaces could model the brain response to stimulation and decode the symptom state of a patient from brain activity as feedback to personalize the stimulation therapy in closed loop.

Despite inspiring proof-of-concepts that are often widely covered by the media, only a few neurotechnologies have firmly established themselves as clinical solutions. In this Review, we discuss opportunities and shortcomings of this technology, and provide a framework to facilitate clinical and commercial translation.

University departments may benefit from guidelines not only to craft effective diversity, equity and inclusion plans, but also to measure progress towards achieving specific goals. This Perspective presents a framework for building, assessing and continuously improving strategic plans to improve recruitment and retention and make departments more inclusive.

The organic electrochemical transistor stands out as a tool for constructing powerful biosensors owing to its high signal transduction ability and adaptability to various geometrical forms. However, the performance of organic electrochemical transistors relies on stable and seamless interfaces with biological systems. This Review examines strategies to improve and optimize interfaces between organic electrochemical transistors and various biological components.

Using nanoparticles featuring anisotropic characteristics is a promising approach to developing multifunctional platforms for drug delivery and theranostics. This Review discusses methods to generate anisotropy in nanosystems and strategies to control particle transport, targeting and interaction with cells to overcome biological barriers.

Motion artefacts challenge the translational application of soft bioelectronics by distorting physiological monitoring. This Review introduces fundamental causes of motion artefacts and discusses various management strategies, including materials usage, bioelectronics design and algorithmic intervention.

Microfluidic 3D cell culture platforms may serve as tools for the modelling of human tissues. This Review discusses the design, standardization and automation of such systems for non-clinical drug evaluation and investigation of disease.

Ultrasound is an emerging tool for tissue engineering with the distinct advantages of cytocompatibility and deep tissue penetration. This Review discusses the integration of ultrasound for cellular assembly and tissue maturation with tissue-engineering techniques to advance regenerative medicine.

Hydrogels are being explored and clinically applied for a variety of biomedical and clinical applications. This Review outlines a model-based modular hydrogel design framework that is application-driven and considers clinical translation early in the design process, emphasizing the importance of fundamental modelling and standardized design.

The application of nanoscale drug delivery systems by subcutaneous (SC) administration may circumvent disadvantages of other injections routes, such as intramuscular and intravenous administration. This Review discusses the design and clinical translation of nanoscale drug delivery systems for SC administration for the treatment of various conditions.

Small-scale wireless soft robotic devices are promising tools for various medical applications. This Review outlines safety, navigation and functionality challenges, as well as the ethical and regulatory considerations that remain to be addressed for their clinical translation.

Traditional urinalysis relies on endogenous biomarkers, which have limited diagnostic sensitivity and specificity. This Review discusses molecular optical probes that interact with disease biomarkers in vivo and produce artificial urinary biomarkers, which are excreted into urine for remote urinalysis.