Cultivating densely packed cells is crucial in trying to engineer ‘living’ implants, such as lab-grown tissue for replacing a patient’s damaged organ. However, when cells get too cramped, they will eventually need to compete for nutrients such as oxygen and end up suffocating each other. Pictured here is a new type of porous material that features many microscopic pores that are just the right size for cells to live comfortably inside of. The other key property of this material is that the network of solid walls exhibits rapid transport of oxygen. As a result, oxygen can be efficiently distributed to a greater number of cells throughout the entire structure. In other words, this engineered material offers cells a high-capacity tenement building with a modern central air system! I took this image to inspect the microscale structure of the material.