Fibrin-based microsphere reservoirs for delivery of neurotrophic factors to the brain

Juhi Samal, Deirdre B Hoban, Carol Naughton, Ruth Concannon, Eilis Dowd, Abhay Pandit

The in vivo therapeutic potential of neurotrophic factors to modify neuronal dysfunctions is limited by their short half-life. A biomaterials-based intervention, which protects these factors and allows a controlled release, is required. Hollow fibrin microspheres were fabricated by charge manipulation using polystyrene templates and were loaded with NGF. Bioactivity of released NGF was demonstrated by neuronal outgrowth assay in PC-12 cells followed by in vivo assessment for NGF release and host response. Fibrin-based hollow spheres showed high loading efficiency (>80%). Neurotrophin encapsulation into the microspheres did not alter its bioactivity and controlled release of NGF was observed in the in vivo study. Fibrin hollow microspheres act as a suitable delivery platform for neurotrophic factors with tunable loading efficiency and maintaining their bioactive form after release in vivo.