Fig. 5.

A) (a) SEM image of Fe₃O₄ nanoparticle-cross-linked hydrogels (scale bar: 200 nm); (b) TEM image of ultramicro-cut of a NP gel. (c) Study on the rheological properties of the hydrogels. Used with permission [48]. Copyright 2015, American Chemical Society. B) The preparation process and implementation of collagen-genipin-quantum dot (CGQ) composite hydrogels in cartilage defects. Used with permission [51]. Copyright 2020, Wiley-VCH GmbH. C) Fabrication process of SF@TA@HA hydrogel. Used with permission [52]. Copyright 2020, Wiley-VCH GmbH.