title: Nerve conduit scaffolds for discrete delivery of two neurotrophic factors.
abstract: Axonal repair and regeneration remain critical due to lack of appropriate delivery systems for efficient release of neurotrophic factors (NTFs). Recently, we have demonstrated the synergistic activity of nerve growth factor (NGF) and glial cell line-derived neurotrophic factor (GDNF) on axonal regeneration. Combined delivery of GDNF and NGF with individually controlled release kinetics may be crucial for exploiting their synergistic action on axonal elongation in animals. For engineering discrete NTF release kinetics, we have developed several nerve conduits (NCs) using collagen (Col) and silk fibroin (SF); the NC were made of Col or SF alone, or of Col and SF layers, or of Col/SF blends, all loaded with GDNF and NGF. All NC types provided sustained combined release of NGF and GDNF over 28 days. NC made of combinations of Col and SF showed reduced burst and more sustained dual release of GDNF and NGF. SF/Col-based NC scaffolds provide an adaptable delivery system for growth factors and hold potential for nerve regeneration and possibly for other tissue engineering applications.
authors: Institute of Pharmaceutical Sciences, ETH Zurich, Zurich, Switzerland.
authors: Stefan
authors: S
authors: Catrina
authors: Bruno
authors: B
authors: Gander
authors: Srinivas
authors: S
authors: Madduri
mesh_terms: D000818:Animals; D002417:Cattle; D003094:Collagen / Q000737:chemistry; D004339:Drug Compounding; D016503:Drug Delivery Systems; D004343:Drug Implants; D005349:Fibroins / Q000737:chemistry; D051100:Glial Cell Line-Derived Neurotrophic Factor / Q000008:administration & dosage / Q000737:chemistry / Q000235:genetics; D006133:Growth Substances / Q000008:administration & dosage / Q000737:chemistry* / Q000235:genetics; D048091:Guided Tissue Regeneration; D006801:Humans; D007700:Kinetics; D008422:Materials Testing; D020932:Nerve Growth Factor / Q000008:administration & dosage / Q000737:chemistry / Q000235:genetics; D009414:Nerve Growth Factors / Q000008:administration & dosage / Q000737:chemistry* / Q000235:genetics; D009416:Nerve Regeneration; D016062:Porosity; D011994:Recombinant Proteins / Q000008:administration & dosage / Q000737:chemistry; D012995:Solubility; D054457:Tissue Scaffolds / Q000737:chemistry*
chemical_list: D004343:Drug Implants; C495039:GDNF protein, human; D051100:Glial Cell Line-Derived Neurotrophic Factor; D006133:Growth Substances; C502240:NGF protein, human; D009414:Nerve Growth Factors; D011994:Recombinant Proteins; C482288:fibroin, silkworm; D003094:Collagen; D005349:Fibroins; D020932:Nerve Growth Factor
keywords: Axonal regeneration; Collagen; Controlled release; Delivery systems; Growth factors; Nerve conduits; Nerve repair; Silk fibroin