Bioengineering for Global Health

Developing point-of-care devices for the detection of pathogenic bacteria is essential to prevent and treat infections and to provide food security. This Review highlights paper-based analytical devices with substantial point-of-care applicability for bacteria detection and discusses challenges and opportunities for future development.

Current HCV nucleic acid-based diagnosis is largely performed in centralised laboratories. Here, the authors present a pan-genotypic RNA assay, based on reverse transcriptase loop mediated isothermal amplification and develop a low-cost prototype paper-based lateral flow device for point-of-care use, providing a visually read result within 40 min.

CRISPR-based assays can be adopted as ultrasensitive molecular diagnostics in resource-limited settings, but point-of-care applications must address additional requirements. Here, we discuss the major obstacles for developing these assays and offer insights into how to surmount them.

In this work, the authors developed a multiplexed, minimally invasive, CRISPR-Cas13-based approach to detect Mycobacterium tuberculosis cell-free DNA in the plasma of active pulmonary tuberculosis patients.

The specific high-sensitivity enzymatic reporter unlocking (SHERLOCK) assay detected severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA with high sensitivity and specificity in hundreds of nasopharyngeal and throat swab samples collected at Siriraj Hospital in Thailand.

The optical detection of two virulence factors of Mycobacterium tuberculosis on extracellular vesicles in blood allowed for the diagnosis of tuberculosis in paediatric cases that were missed by clinical microbiological assays.

Multiplex detection of two interacting Mycobacterium tuberculosis biomarkers on the surface of circulating extracellular vesicles, using a nanoplasmon-enhanced immunoassay, improves the diagnosis of tuberculosis in immunosuppressed children living with HIV.

The feasibility of large-scale testing with lateral flow tests has been demonstrated in the COVID-19 pandemic. This Review examines lessons learned from the COVID-19 pandemic to inform the design and bioengineering of next-generation lateral flow tests to strengthen future diagnostic resilience.

A paper-based assay leveraging nucleic acid strand-displacement reactions and the enzymatic amplification of the recognition of viral RNA at the single-nucleotide level allows for the rapid colorimetric detection of SARS-CoV-2 variants.

SARS-CoV-2 and its variants can be visually detected via easy-to-use Cas13-based nucleic acid tests leveraging lyophilised reagents and fast sample inactivation at ambient temperature.

Point-of-care (POC) diagnostics are particularly important in resource-limited settings. To ensure their sustainability, deployment and uptake by underserved communities, systemic, infrastructural, operational and logistical limitations need to be addressed.

Double-blinded studies show that paper-based diagnostic tests and a companion portable device designed for use in low-resource settings perform well for the diagnosis of the Zika and chikungunya viruses in serum samples.

Biomarkers in breath can be related to certain diseases, which makes breath-based analysis a powerful diagnostic tool. Here we highlight milestones and remaining challenges for the broad clinical implementation of wearables for breath analysis.

Most conventional tuberculosis diagnostic tests rely on difficult to obtain sputum samples. In this proof-of-concept study, authors analyse whether pulmonary tuberculosis can be detected using exhaled breath condensate samples.

Open-source design of medical devices, following the concept of frugal engineering, provides unrestricted descriptions of technical details, allowing the low-cost and local fabrication of devices to reduce global inequities in healthcare.

The ability to detect precancer at the point of care is important to reduce global inequities in cancer outcomes. This Review outlines how low-cost optical imaging technologies, slide-free microscopy and machine learning can improve imaging performance and provide real-time interpretation in settings with limited resources.

The advent of portable, low-field MRI is transforming clinical brain imaging. This Review discusses the bioengineering advances that have enabled scanning outside the controlled environment of conventional MRI suites, enhancing access to neuroimaging. Ongoing development and innovation will increase the real-world application of MRI.

A low cost MRI scanner may have the potential to meet clinical needs at point of care or in low and middle income countries. Here the authors describe a low cost 0.055 Tesla MRI scanner that operates using a standard AC power outlet, and demonstrate its preliminary feasibility in diagnosing brain tumor and stroke.

A hand-powered centrifuge made of two paper discs, string and wooden handles is shown to achieve rotational speeds of 125,000 r.p.m., separate pure plasma from whole blood in less than 1.5 minutes and isolate malaria parasites in 15 minutes.

A hand-spun centrifuge made of paper and string can separate plasma from whole blood in less than two minutes, and be used to diagnose malaria and other infectious diseases in areas without laboratory resources or electricity.

Continuous monitoring of diverse biomolecular signatures has the potential to transform our understanding of personalized and preventative medicine. This Review Article discusses the emerging trends and pertinent considerations for the development of a new generation of body-based biomolecular sensors for in vivo measurement.

A point-of-care device that can run on a variety of power inputs enables isothermal nucleic acid quantification for the diagnosis of infectious diseases in resource-limited settings with unreliable electrical power supply.

A custom-made fidget spinner rapidly concentrates pathogens in 1-ml samples of undiluted urine by more than 100-fold for the on-device colorimetric detection of bacterial load and pathogen identification.

Circulating biomarkers can be detected and analysed in the form of liquid biopsies to improve disease diagnosis and monitoring. This Review discusses the integration of specific assay designs in miniaturized device platforms for the detection of circulating biomarkers, including whole cells, extracellular vesicles and cell-free factors.

An inexpensive knotted catheter-like device made of a piezoresistive elastic silicone–liquid-metal composite performs comparably to commercial manometry devices for the sensing of gastrointestinal motility in anaesthetized pigs.

Access to prosthetic and orthotic devices remains limited in low- and middle-income countries (LMICs) due to the lack of manufacturing and specialized healthcare facilities, and the limited access to skilled, certified medical personnel. Rise Bionics makes devices with digital fabrication and access-conscious engineering to increase accessibility and affordability.

A portable magnetic-resonance sensor accurately grades liver steatosis and fibrosis in living mice and human liver samples.

A low-cost probe for otoacoustic emissions made from off-the-shelf earbuds and microphones performs similarly to a clinical-grade device, as shown via a clinical study involving 201 paediatric ears screened for hearing loss.

Skin-interfaced wireless biosensors offer great opportunities for inexpensive, burdenless and continuous health monitoring of perinatal and paediatric patients in clinical and home settings. This Review highlights the latest technology developments and deployment activity in this rapidly expanding field.

Real-time sensing of biomarkers via the use of wearable devices is a major aim of personalised medicine. Here, authors demonstrate an on-line wearable microneedle patch for real-time capture and monitoring of universal cell-free DNA.

A portable device enables the automated manufacturing of therapeutic-grade biologics in a few hours and under current good-manufacturing-practice conditions.

Delivery of vaccines by nasal sprays may enable more robust, protective mucosal immune responses against infectious diseases, such as COVID-19, compared with intramuscular injection. In this Comment, we highlight how biomaterials can be designed to allow intranasal and inhaled vaccination.

A portable prototype scanner for brain MRI that uses a compact and lightweight permanent rare-earth magnet with a built-in readout field gradient generates clinically relevant images of the brain, as shown in adult volunteers.

Fast, low-cost and multiplexed nucleic acid detection is challenging. Here the authors report a strategy that couples microfluidic space coding, CRISPRCas12a, and multiplex RPA for the rapid detection of up to 30 targets with only one fluorescent probe.

A low-cost point-of-care device that uses contrast-enhanced microholography and deep learning accurately detects aggressive lymphomas in patients referred for aspiration and biopsy of enlarged lymph nodes.

Advances in digitizing human tissue slides and progress in artificial intelligence have boosted progress in the field of computational pathology. This Review consolidates recent methodological advances and provides future perspectives as the field expands to take on a broader range of clinical and research tasks.

The lateral flow assay (LFA) has been considered a rapid test tool but with low sensitivity hampering the precise diagnosis. Here, the authors report bioengineered enrichment tools for LFAs with enhanced sensitivity and specificity that can reinforce LFA’s clinical performance.

A cost-aware AI framework facilitates the development of predictive AI models that optimize the trade-off between prediction performance and feature cost.

Deep-learning models trained on retinal fundus images can be used to identify chronic kidney disease and type 2 diabetes and to predict the risk of the progression of these diseases.

Smartphone-based mobile health platforms have drawn increasing attention from researchers developing point-of-care testing devices. Here the authors summarize recent progress and future directions of approaches combining microfluidics and artificial intelligence.

Though wearable gloves are widely used for gesture associated applications (e.g. sign language recognition), sentence identification of sign language remains a challenge. Here, the authors report AI-enabled recognition system helps barrier-free communication between signers and non-signers.

What does global health equity mean? In bioengineering, ‘equity’ is often interpreted as global ‘access’ to technologies, thereby neglecting wider structural inequalities. Here we suggest that concepts of equity need to be expanded to incorporate principles of equitable representation and recognition within the innovation ecosystem.

Therapeutic nanoparticle and biomaterial systems can be specifically designed to deliver drugs for the treatment of women’s health-related conditions. This Review discusses the engineering and optimization of delivery technologies for women’s health applications, including vaginal infections, reproductive tract disorders, pregnancy conditions and congenital disorders.

Women’s health has long been overlooked in both fundamental and clinical research, which, sadly, also holds true for the bioengineering field — albeit things are slowly changing.

Anton Molina and colleagues demonstrate the fabrication of absorbent materials from the drought tolerant plant agave sisalana (sometimes known as sisal). The findings suggest a route toward local production of the absorbent component of menstrual pads in low- and middle-income countries, where there is more limited access to sanitary products.

Digital medicine tools, including medical AI, have been advocated as potential game-changers to solve long-standing healthcare access and treatment inequality issues in low and middle income countries. As these applications are increasingly becoming a reality, we connect here with researchers with experience in planning and deployment of these tools in under-resourced settings.

Engineers need to meaningfully engage in global health by developing solutions that work in the low-resource environments that are a reality for many health-care professionals and patients around the world. Engineering World Health, founded in 2001, aims to inspire, educate and empower the biomedical engineering community to improve health-care delivery around the world. 

Bioengineering has the power to improve health globally by engineering diagnostic, treatment and disease monitoring platforms that function in diverse settings, including resource-constrained contexts. In this Viewpoint, the authors highlight the pressing challenges that need to be addressed to make the field more equitable and to enable bioengineered solutions that can be implemented anywhere, anytime and by anyone.

Plant-based recombinant protein production has the power to ensure rapid and global-scale deployment of biopharmaceuticals. This Review discusses genetic tools and systems for the plant-based production and engineering of biopharmaceuticals, including vaccines and monoclonal antibodies.

Bioengineers need to adopt holistic and human-centred design principles in the development of technologies intended for applications in low-resource settings, to overcome infrastructural limitations and ensure functionality in all environments.

At the LV Prasad Eye Institute in India, we developed an ophthalmic electronic medical record and hospital management system, integrating clinical, surgical and operational functions in one platform to allow digital eye care services at the point of care.

Social connections are an important means for people to cope with adversity and illness. Thus, technologies, such as social network analysis, that can leverage close, face-to-face social networks could help optimize healthcare interventions and reduce healthcare-related costs, particularly in low-resource settings.

An article in Communications Engineering reports the development of menstrual pads made of a plant-based high-quality absorption material.