Neurite outgrowth from chick dorsal root ganglia entrapped in isotropic and magnetically aligned fibrin gels was studied, and the dependence on the diameter of the fibrin fibrils was characterized. The fibrin fibril diameter was varied, as inferred from turbidity measurements, by using different Ca2+ concentrations in the fibrin-forming solution, but this variation was accomplished without affecting the degree of magnetic-induced alignment, as directly visualized in fluorescently spiked gels. Magnetically aligned fibrin gels possessing different fibril diameters but similar alignment resulted in drastic changes in the contact guidance response of neurites, with no response in gels formed in 1.2mM Ca2+ (having smaller fibril diameter, ca. 150nm), but a strong response in gels formed in 12 and 30mM Ca2+ (having larger fibril diameter, ca. 510nm) with an attendant two-fold increase in neurite length. These changes are attributed to variation of the mechano-structural properties of the network of aligned fibrils as the fibril diameter is varied.
Bibliographical noteFunding Information:
This work has been supported by NSF/BES-9522758 (R.T.T.). NIH HD19950 (P.C.L.) is also gratefully acknowledged.
- Aligned fibrin
- Contact guidance
- Fibrin gel
- Magnetic alignment
- Nerve regeneration