(a) Experimental and clinical delivery applications of fibrin in wound healing. Fibrin has been used to deliver cells, drugs, growth factors or gene vectors, and combinations thereof. GF: growth factor, Fbg: fibrinogen, FXIII: factor XIII, MSCs: mesenchymal stem cells, ESC: embryonic stem cell, iPSC: induced pluripotent stem cell, FGF: fibroblast growth factor, PDGF: platelet-derived growth factor, VEGF: vascular endothelial growth factor, IGF: insulin-like growth factor, EGF: epidermal growth factor, KGF: keratinocyte growth factor, NGF: nerve growth factor, BDNF: brain-derived neurotrophic factor, GDNF: glial-cell-line-derived growth factor, NT: neurotrophin, BMP: bone morphogenetic protein, GAM: gene-activated matrix, COPROG: copolymer protected gene vector. Reprinted/adapted with permission from Ref. [62], 2000, Elsevier. (b) Fibrin preparations useful in therapeutic delivery. Reprinted/adapted with permission from Ref. [60], 2001, Elsevier.