A Mesoporous Silica Nanosphere-Based Nerve Growh Factor Delivery System Using an Electrically Conducting Polymer
Y.N. Cho, R. Shi, R.B. Borgens
Purdue university, US
Keywords: nerve growth factor, mesoporous silica nanoparticle, polypyrrol, drug delivery
Abstract:In this study, a mesoporous silica nanoparticle (MSN)-based nerve growth factor (NGF) delivery system has been successfully embedded within electroactive polypyrrol (Ppy). The spherical particles with ~ 100 nm in a diameter have revealed large surface-to-volume ratio for entrapment of NGF into the pores of MSNs while retaining its bioactivity. Direct incorporation of MSN-NGF within Ppy was achieved during electrochemical polymerization. The loading amount and released profile of NGF from composite was investigated by sandwich ELISA. The NGF incorporation can be controllable by varying particle concentration or by extending electrodeposition time. The morphology and chemical composition of Ppy/MSN-NGF composite was evaluated by Atomic Force Microscopy (AFM), Transmission Electron Microscope (TEM), Scanning Electron Microscope (SEM), and X-ray Photoelectron Spectroscopy (XPS). Optical and electron microscopy have revealed a characteristic adherence and neurite outgrowth of PC 12 cells grown on Ppy/MSN-NGF composite as a result of a sustained and controlled release of NGF. In order to observe the effectiveness of electrical stimulation, neurite extension of cells cultured on unstimulated and stimulated Ppy/MSN-NGF was compared. The NGF release in the presence of electrical stimulation had promoted neurite extension at a great rate. These electrically functional composite shows a potential for the development of neural implants to promote nerve protection and regeneration.