fig2

Figure 2. Representative rapid assembly strategies for collagen microgel fabrication. (A) Schematic illustration of collagen microgel formation from acidic collagen solution under PEG-induced macromolecular crowding. The crowding effect accelerates collagen fibril nucleation and assembly, enabling rapid gelation within microfluidic droplets. Figure 2A is adapted in part from Ref.^[34]. Reused under the terms of the Creative Commons Attribution License (CC BY); (B) Microfluidic preparation of collagen microgels assisted by ultralong DNA strands. Electrostatic interactions between collagen and DNA, together with the interlocking of complementary ultralong single-stranded DNAs under shear force, markedly accelerate collagen gelation and enable growth factor loading. Figure 2B is newly drawn by the authors based on the fabrication principle reported by Ref.^[37]. No original figure elements were reused.