Opportunities and challenges in biological soft matter research

bacterial suspension, bio-condensates, biomaterials, cells, extracellular matrix (ECM), extracellular polymeric substance (EPS), liquid-liquid phase separation (LLPS), subcellular granules Soft matter, a relatively new scientific field, encompasses the study of materials between traditional liquids and solids.Familiar examples include complex fluids, liquid crystals, colloidal suspensions, emulsions of immiscible fluids, polymeric networks in both aqueous and non-aqueous media, and gels that are often soft and permeable, just to name a few.One diverse subset of soft matter covers biological matter.Since most, if not all, biological entities consist of water and organic compounds, they are often soft and compliant.In essence, most biomaterials, including biological entities such as cells, tissues, and organs, may be viewed as biological soft matter.Therefore, Biological Soft Matter as a section of the new journal, Frontiers in Soft Matter, will naturally be both broad and interdisciplinary.It seeks to inspire dissemination of new findings made by physical and life scientists, as well as bioengineers and biomedical scientists who share a broader perspective rather than staying within the confines of traditional specialties.Biological soft matter deals with biological materials and systems.Thus, the work to be published in this new section naturally shall fall within a focused sub-field of materials science.Frontiers in Soft Matter encourages the publication of studies that focus on the physical and emergent properties of biomaterials ranging from the microscopic to the macroscopic scales.Examples of microscopic biomaterials may include DNA/RNA/ proteins, subcellular components (e.g.molecular motors, pumps, channels, membranes, cytoskeletons, granules, centrosomes, nucleolus, etc.), live cells as small as viruses and bacteria or as large as macrophages and neurons, and even tissues and organs of animals and plants.The physical properties include, but are not limited to, single molecule dynamics, self-assembly, phase transitions, viscoelasticity, complex fluids, liquids and gels, and all forms of active matter phenomena and processes.Our goal for the Biological Soft Matter section of Frontiers in Soft Matter is to serve as a nexus connecting physical and life scientists who share the interdisciplinary perspective of understanding physical properties of life and, more broadly, for the new journal to serve as a global hub for soft matter scientists to share original findings with unrestricted access to all.Although it goes beyond the goal of the journal to publish the development of future drugs, the basic research that this new specialty area seeks to publish will provide an interdisciplinary knowledge base to foster future advances in the life sciences and in medicine that are rooted in the principles of fundamental physics and materials science.