This issue highlights a slide-free histology approach, and advances in local drug delivery to the heart, in nanoparticles for imaging metastases in multiple organs, in imaging probes for prostate cancer, and a cryptography-inspired approach for decoding movement from neural activity.

The cover illustrates a histology image obtained by a slide-free microscopy technique that is rapid, inexpensive and can be applied to fresh tissue (Levenson and co-authors).

This issue highlights the delivery of CRISPR components via nanoparticles, and advances in the precision of CRISPR/Cas9 gene editing, the modulation of global patterns in gene expression, the imaging of calcification in aortic valves, and the understanding of glial responses to implanted electrodes.

The cover illustrates the delivery of Cas9 ribonucleoprotein and donor DNA by gold nanoparticles, for the correction of a gene mutation (Article)

This issue highlights the analysis of tumour-heterogeneity patterns to stratify patient prognosis, growing paediatric implants, and advances in gastrointestinal motility sensing and in the discovery of peptides that rescue the misfolding of disease-associated proteins.

The cover illustrates patterns of vascular heterogeneity in cleared solid tumours identified through light-sheet microscopy (Article).

This issue highlights the design of localizable implantable magnetic microdevices, and also includes advances in cancer-cell detection via lasing, in tumour therapy with a non-toxic dendrimer, and in the amplification of rare DNA-sequence variants.

The cover illustrates the concept of implantable microdevices that broadcast their location when in a magnetic-field gradient by emitting a magnetic-field-dependent radiofrequency signal (Article).

This issue highlights the use of ultrasound for the on-demand delivery of an anaesthetic, and also includes advances in nanoparticle delivery to tumours, the biocompatibility of iron oxide nanoparticles, and technology for measuring local drug kinetics in small animals. The cover illustrates the concept of on-demand nerve block via ultrasound-triggered drug delivery of an anaesthetic (Article).

Arraying neutrophil swarms

This issue highlights technology for the characterization of human-neutrophil swarming, and also includes advances in non-destructive histopathology, the biophysics of ageing, oligonucleotide cloning probes and Matrigel substitutes.

The cover shows a snapshot of the swarming of human neutrophils on a microscale array (Article).

Long-lasting implanted biomaterials

This focus issue highlights strategies for increasing the functional durability of implanted biomaterials.

The cover illustrates a subcutaneously-implanted scaffold for the study and modulation of a pre-metastatic niche (Review Article).

Powerful optoacoustic imaging

The May issue highlights the potential of optoacoustic imaging for the diagnosis of skin diseases (Article; News & Views) and for whole-body pre-clinical tomography (Article; News & Views).

The cover shows an artistic rendering of a cross-section of human skin as imaged by optoacoustic mesoscopy (Article; News & Views).

Early cancer diagnosis

This focus issue highlights advances in the isolation of cancer biomarkers in blood and in diagnostic or imaging probes for the early detection of cancer.

The cover illustrates a lipid-based nanoprobe for the isolation of nanoscale extracellular vesicles (Article; News & Views).

Lasting bioelectronic devices

This focus issue highlights engineering advances that lengthen the lifespan of bioelectronics (Editorial, Comment): energy harvesting in the gastrointestinal tract (Article, News & Views), a conformal electromagnetic surface for powering an implanted device (Article, News & Views), and an ultrathin passivating layer for electronic arrays (Article, News & Views).

The cover illustrates an ingestible energy-harvesting electrochemical cell (Article, News & Views).

Machine learning in healthcare

This focus issue highlights the accelerating power of machine learning (Editorial) in diagnosing rare disease (Article, News & Views), classifying brain tumours (Article, News & Views), and categorizing the activity of spinal motor neurons (Article, News & Views).

The cover illustrates the concept of a cloud-based multihospital collaboration platform powered by artificial intelligence (Article, News & Views).

Discovery and technology for human health

This first issue includes the design and operation of a hand-spun paper centrifuge (Video, Article), neurocognitive barriers to technology embodiment (Comment), and Review Articles on biomedical imaging. Please also read our Editorial.

The cover shows an intravital microscopy image of the foreign-body response to an implanted biomaterial (Article, News & Views).