The complexity of biological tissue presents a challenge for engineering of mechanically compatible materials. Guimarães and colleagues discuss how understanding tissue stiffness, from extracellular matrix and single cell components to bulk tissue, facilitates the engineering of materials with life-like properties.

KRAS is one of the most frequently mutated oncogenes in cancer, being a potent initiator of tumorigenesis, a strong inductor of malignancy, and a predictive biomarker of response to therapy. Despite the large investment to understand the effects of KRAS activation in cancer cells, pharmacologic targeting of KRAS or its downstream effectors has not yet been successful at the clinical level. Recent studies are now describing new mechanisms of KRAS-induced tumorigenesis by analyzing its effects on the components of the tumor microenvironment. These studies revealed that the activation of KRAS on cancer cells extends to the surrounding microenvironment, affecting the properties and functions of its constituents. Herein, we discuss the most emergent perspectives on the relationship between KRAS-mutant cancer cells and their microenvironment components. .

High-throughput screening (HTS) methods based on topography gradients or arrays have been extensively used to investigate cell–material interactions. However, it is a huge technological challenge to cost efficiently prepare topographical gradients of inorganic biomaterials due to their inherent material properties. Here, we developed a novel strategy translating PDMS-based wrinkled topography gradients with amplitudes from 49 to 2561 nm and wavelengths between 464 and 7121 nm to inorganic biomaterials (SiO2, Ti/TiO2, Cr/CrO3, and Al2O3) which are frequently used clinical materials. Optimal substratum conditions promoted human bone-marrow derived mesenchymal stem cell alignment, elongation, cytoskeleton arrangement, filopodia development as well as cell adhesion in vitro, which depended both on topography and interface material. This study displays a positive correlation between cell alignment and the orientation of cytoskeleton, filopodia, and focal adhesions. This platform vastly minimizes the experimental efforts both for inorganic material interface engineering and cell biological assessments in a facile and effective approach. The practical application of the HTS technology is expected to aid in the acceleration of developments of inorganic clinical biomaterials.

Light guiding and manipulation in photonics have become ubiquitous in events ranging from everyday communications to complex robotics and nanomedicine. The speed and sensitivity of light–matter interactions offer unprecedented advantages in biomedical optics, data transmission, photomedicine, and detection of multi‐scale phenomena. Recently, hydrogels have emerged as a promising candidate for interfacing photonics and bioengineering by combining their light‐guiding properties with live tissue compatibility in optical, chemical, physiological, and mechanical dimensions. Herein, the latest progress over hydrogel photonics and its applications in guidance and manipulation of light is reviewed. Physics of guiding light through hydrogels and living tissues, and existing technical challenges in translating these tools into biomedical settings are discussed. A comprehensive and thorough overview of materials, fabrication protocols, and design architectures used in hydrogel photonics is provided. Finally, recent examples of applying structures such as hydrogel optical fibers, living photonic constructs, and their use as light‐driven hydrogel robots, photomedicine tools, and organ‐on‐a‐chip models are described. By providing a critical and selective evaluation of the field's status, this work sets a foundation for the next generation of hydrogel photonic research.