Digital printing of shape-morphing natural materials.

We demonstrate how programmable shape evolution and deformation can be induced in plant-based natural materials through standard digital printing technologies. With nonallergenic pollen paper as the substrate material, we show how specific geometrical features and architectures can be custom designed through digital printing of patterns to modulate hygrophobicity, geometry, and complex shapes. These autonomously hygromorphing configurations can be "frozen" by postprocessing coatings to meet the needs of a wide spectrum of uses and applications.

Transformation of hard pollen into soft matter.

Pollen's practically-indestructible shell structure has long inspired the biomimetic design of organic materials. However, there is limited understanding of how the mechanical, chemical, and adhesion properties of pollen are biologically controlled and whether strategies can be devised to manipulate pollen beyond natural performance limits. Here, we report a facile approach to transform pollen grains into soft microgel by remodeling pollen shells.

The performance of primary human renal cells in hollow fiber bioreactors for bioartificial kidneys.

Bioartificial kidneys (BAKs) containing human primary renal proximal tubule cells (HPTCs) have been applied in clinical trials. The results were encouraging, but also showed that more research is required. Animal cells or cell lines are not suitable for clinical applications, but have been mainly used in studies on BAK development as large numbers of such cells could be easily obtained.

Effects of bone morphogenetic proteins on primary human renal cells and the generation of bone morphogenetic protein-7-expressing cells for application in bioartificial kidneys.

Bioartificial kidneys (BAKs) contain renal cells, and primary human renal proximal tubule cells (HPTCs) have been applied in clinical trials with BAKs. Cell performance within the device is critical. HPTC performance is often compromised under in vitro conditions because of dedifferentiation, transdifferentiation, and tubule formation on substrate surfaces.

Characterization of membrane materials and membrane coatings for bioreactor units of bioartificial kidneys.

The bioreactor unit of bioartificial kidneys contains porous membranes seeded with renal cells. For clinical applications, it is mandatory that human primary renal proximal tubule cells (HPTCs) form differentiated epithelia on the membranes. Here, we show that HPTCs do not grow and survive on a variety of polymeric membrane materials.