Evaluation of patterned substrates for directed and controlled Schwann cell and neurite outgrowth.

摘要

Peripheral nerve injuries affect hundreds of thousands of people every year, costing millions of dollars in hospital care and lost wages. Repair of these injuries almost always requires surgery yet does not always provide a functional recovery. Currently, the most effective method is to use an autograft where a section of nerve is removed from a donor site to repair the injury. Artificial nerve conduits made of degradable polymers are under investigation, but are not as effective as autografts because they lack directional cues and trophic support for the regenerating nerves.; Patterned substrates direct cellular attachment, growth, proliferation, as well as other processes. Using microcontact printing, a technique derived from photolithography, protein patterns can be printed onto polymeric substrates to provide chemical cues to direct attachment of Schwann cells, the cellular component of the mammalian peripheral nervous system which provides guidance to neurons during development and repair after injury. By organizing Schwann cell orientation and taking advantage of the natural repair process, neurons can be directed to their innervation targets to provide enhanced repair after injury.; Various substrates, organic and inorganic, were micropatterned using laminin, a protein component of the basal lamina of Schwann cells, and evaluated chemically by X-ray photoelectron spectroscopy and physically by near-field scanning optical microscopy, to determine the environments encountered by the cells on the substrates. Schwann cells were seeded onto the substrates and evaluated for pattern adherence and directionality. The substrates were evaluated for proliferative directional control as the cells formed a monolayer.; Control of cellular behavior by local substrate environment is possible through micropatterning surfaces. Understanding how microenvironments influence cellular functions such as adhesion and migration can be achieved through various physical and chemical techniques including near-field scanning optical microscopy, atomic force microscopy, water-contact angle and x-ray photoelectron spectroscopy. By manipulation of cellular environments through surface modification of substrates, Schwann cell orientation can be controlled and regeneration of peripheral nerves can be enhanced.