Fig. 3. Delivery of KGN via polymer microspheres. (A) Preparation of PLGA-KGN NPs (i). Hydrogels after addition of KGN showed no cytotoxicity (ii). This figure has been adapted from ref. 59 with permission from Elsevier, Copyright © 2021. (B) Scanning electron micrographs (SEM) of CS-KGN NPs and CS-KGN MPs (i). Release curves of KGN in CS-KGN NPs and CS-KGN MPs (ii). This figure has been adapted from ref. 60 with permission from Elsevier, Copyright © 2014. (C) Exosome-encapsulated KGN for cartilage repair. This figure has been adapted from ref. 61 with permission from Elsevier, Copyright © 2021.