This month, we celebrate — albeit from our socially-distanced home offices — our fifth anniversary. As editors, our experiences have been truly amazing and we wish to thank those in the materials science community who have written articles, given their valuable time as referees and (we hope!) enjoyed reading our pages. Alongside our authors, we have shared enthusiasm for their chosen topics as well as shared their satisfaction of providing high-quality articles outlining the developments in their field to the wider community.

Five years on, we wish to reflect on some of these topics in the primary literature, that together with conversations with researchers at conferences (now virtually) and laboratory visits, have led the journal down certain paths.

First, take the way that immunotherapy has revolutionized how we treat disease, providing a new treatment modality for cancer. The rapidly growing insight into the role of the immune system in health and disease has also enhanced our understanding of tissue repair and regeneration, and sparked the development of immunoengineering. As a result, in 2019, we dedicated a focus issue to the topic. Since, the field has progressed at speed — ranging from biomaterial-based cancer vaccines to delivery vehicles targeting specific lymph node compartments — and we are excited about the future contributions of materials science to immunoengineering.

Nanomedicine has recently gained renewed attention owing to the importance of nanomaterials for the delivery of nucleic acid-based vaccines, which are among the most prominent candidates currently in clinical trials against SARS-CoV-2 (NCT04405076). In addition, nanomaterials enable the in vivo delivery of genome-editing machineries, such as the CRISPR/Cas platform. In our first volume, we published an analysis which concluded that only 0.7% of administered nanoparticles find their way into a solid tumour. This conclusion initiated discussions about the importance of nanoparticle dose (as pharmacological parameters, such as peak drug concentration and elimination half-life, can be considered equally important) and caused a renaissance of fundamental investigations into nanoparticle-tissue interactions, including clearance routes, interactions in the kidneys and liver, and cell-specific delivery. Many of these advances have already been overviewed in Review articles in Nature Reviews Materials, and we look forward to learning about the knowledge gained from these studies and how the findings will translate into clinical applications.

Research on topological materials and phenomena — ranging from skyrmions to Majorana quasiparticles — has also grabbed our attention. Skyrmions, with their whirling spin textures, may be used to carry information using the electron spin, whereas Majorana quasiparticles, with their fractional spin and topological properties, may find applications in topological quantum computing. The recent direct measurement of the properties of a type of quasiparticle with fractional spin (an anyon) is a step forward in the understanding needed to fabricate a topological quantum bit.

Fields have also taken us by surprise; five years ago some may have argued that the most groundbreaking research on 2D materials was behind us. Instead, reports of magnetism in Cr-based 2D layers and of superconductivity in twisted bilayer graphene — a highly tuneable system — have propelled the field forward. These findings complete the toolbox of 2D materials to include a wide range of materials: namely, metals, semimetals, topological insulators, trivial insulators, magnets and superconductors. Moreover, these properties can be combined in heterostructures in endless combinations. We have featured the modelling and synthesis, characterization and applications of 2D materials ranging from energy storage to quantum information. Looking forward, we anticipate the rich phenomena that may be uncovered in twisted heterostructures of 2D materials.

Also in our pages, we aim to cover themes that are of societal importance and seek to provide a platform for material scientists to give their opinions and calls-to-action. The aim is to establish a diverse, equal and inclusive research environment, which enables opportunities for everyone who wishes to work and thrive in the community. This is an important message that we hope grows in the Comment articles we will publish in 2021 and beyond.

While the world is, quite rightly, reflecting on other issues as 2020 draws to a close, taking a moment to reflect that scientists and science are capable of such awesome advances, we hope encourages optimism and your drive to research, report and write Review articles!