Affiliations: Department of Orthopaedic Surgery, Keio University 35
Shinanomachi, Shinjuku, Tokyo 160-8582, Japan | Department of Physiology, Keio University 35
Shinanomachi, Shinjuku, Tokyo 160-8582, Japan | Core Research for Evolutional Science and Technology
(CREST), Japan Science and Technology Corporation, Saitama 332-0012,
Japan
Note: [] Corresponding author: Masaya Nakamura, Department of Orthopaedic
Surgery, Keio University, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan.
Tel.: +81 3 5363 3747; Fax: +81 3 3357 5445; E-mail: masa@sc.itc.keio.ac.jp
Abstract: Purpose: Recent studies demonstrated that transplanting neural
stem/precursor cells (NSPCs) into an injured spinal cord of adult rat promotes
functional recovery. The functional recovery from spinal cord injury might be
enhanced by transplanting NSPCs with a scaffold that fills the cavity, entraps
the NSPCs in the cavity, and acts as an attachment for neurite extension. We
recently focused on collagen type-1 as a scaffold for NSPC transplantation into
the injured spinal cord. In the present study, we determined the optimal
conditions for culturing NSPCs in 3D collagen type-1 gel with respect to cell
survival and cell migration. We, then, evaluated the ability of NSPCs to
differentiate under the optimal condition. Methods: NSPCs were derived
from the striatum of rat embryos. To determine the optimal cell density and
collagen concentration for 3D collagen gel culture for NSPC, we performed
viability assay and migration assay. Then, we examined the proportion of
phenotypes differentiated from NSPC in that optimal condition. Results:
In viability assay, the viability rate increased as the NSPC density increased,
and peaked at 1 × 10^{7} to 5 × 10^{7} cell/ml. For collagen
concentration, the viability rate increased as the collagen concentration
decreased. In migration assay, cell migration was most extensive at collagen
concentrations between 0.3 and 0.75 mg/ml. Migration distances gradually
declined as collagen concentrations increased. In the optimal condition, NSPCs
differentiated into neurons (40.1%), astrocytes (53.1%), and
oligodendrocytes (5.3%) in 3D collagen gel culture. Conclusion: The
optimal conditions for NSPC culture in 3D collagen gel was a cell density
between 1 × 10^{7} and 5 × 10^{7} cells/ml and a collagen
concentration between 0.5 and 0.75 mg/ml. Under the condition, NSPCs could
differentiate into neurons, astrocytes, and oligodendrocytes.
