Biocompatibility of methylcellulose-based constructs designed for intracerebral gelation following experimental traumatic brain injury

Tissue engineering in the post-injury brain represents a promising option f or cellular replacement and rescue, providing a cell scaffold for either tr ansplanted or resident cells. We have characterized the use of methylcellul ose (MC) as a scaffolding material, whose concentration and solvent were va ried to manipulate its physical properties. MC solutions were produced to e xhibit low viscosity at 23 degreesC and form a soft gel at 37 degreesC, the reby making MC attractive for minimally invasive procedures in vivo. Degrad ation and swelling studies in vitro demonstrated a small amount of initial polymer erosion followed by relative polymer stability over the 2-week peri od tested as well as increased hydrogel mass due to solvent uptake. Concent rations up to 8% did not elicit cell death in primary rat astrocytes or neu rons at 1 or 7 days. Acellular 2% MC (30 mul) was microinjected into the br ains of rats 1 week after cortical impact injury (velocity = 3 m/s, depth = 2 mm) and examined at 2 days (n = 8; n = 3, vehicle injected) and 2 weeks (n = 5; n = 3, vehicle injected). The presence of MC did not alter the size of the injury cavity or change the patterns of gliosis as compared to inju red, vehicle-injected rats (detected using antibodies against GFAP and ED1) . Collectively, these data indicate that MC is well suited as a biocompatib le injectable scaffold for the repair of defects in the brain. (C) 2001 Els evier Science Ltd. All rights reserved.