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Spheroids recapitulate the organization, heterogeneity and microenvironment of solid tumors. Herein, we targeted spatiotemporally the accelerated metabolism of proliferative cells located on the spheroid surface that ensure structure maintenance and/or growth. We demonstrate that phosphorylated carbohydrate amphiphile acts as a potent antimetabolite due to glycolysis inhibition and to in situ formation of supramolecular net around spheroid surface where alkaline phosphatase is overexpressed. The efficiency of the treatment is higher in spheroids as compared to the conventional 2D cultures because of the 2-fold higher expression of glucose transporter 1 (GLUT1). Moreover, treated spheroids do not undergo following relapse. 

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.

 

Anisotropic 3D tissue interfaces with functional gradients found in nature are replicated in vitro for drug development and tissue engineering. Even though different fabrication techniques, based on material science engineering and microfluidics, are used to generate such microenvironments, mimicking the native tissue gradient is still a challenge. Here, the fabrication of 3D structures are described with linear/random porosity and gradient distribution of hydroxyapatite microparticles which are combined with a gradient of growth factors generated by a dual chamber for the development of heterotypic‐like tissues. The hydroxyapatite gradient is formed by applying a thermal ramp from the first to the second gel layer, and the porous architecture is controlled through ice templating. A 3D osteochondral (OC) tissue model is developed by codifferentiating fat pad adipose‐derived stem cells. Osteogenic and chondrogenic markers expression is spatially controlled, as it occurs in the native osteochondral unit. Additionally, a prevasculature is spatially induced by the perfusion of proangiogenic medium in the bone‐like region, as observed in the native subchondral bone. Thus, in this study, precise spatial control is developed over cell/tissue phenotype and formation of prevasculature which opens up possibilities for the study of complex tissues interfaces, with broader applications in drug testing and regenerative medicine.