Noninvasive imaging of nanoparticle-labeled transplant populations within polymer matrices for neural cell therapy.

Aim: To develop a 3D neural cell construct for encapsulated delivery of transplant cells; develop hydrogels seeded with magnetic nanoparticle (MNP)-labeled cells suitable for cell tracking by MRI.
Materials & Methods: Astrocytes were exogenously labeled with MRI-compatible iron-oxide MNPs prior to intra-construct incorporation within a 3D collagen hydrogel.
Results: A connective, complex cellular network was clearly observable within the 3D constructs, with high cellular viability. MNP accumulation in astrocytes provided a hypointense MRI signal at 24 h & 14 days.
Conclusion: Our findings support the concept of developing a 3D construct possessing the dual advantages of (i) support of long-term cell survival of neural populations with (ii) the potential for noninvasive MRI-tracking of intra-construct cells for neuroregenerative applications.