Electrospun polymer nanofibers with entrapped magneticnanoparticles(magnetic NP–NF) represent a novel scaffold substrate thatcan be functionalized for single-step isolation and activation ofspecific lymphocyte subsets. Using a surface-embedded T cell receptorligand/trigger (anti-CD3 monoclonal antibody), we demonstrate, asproof of principle, the use of magnetic NP–NF to specificallyisolate, enrich, and activate CD3+T cells from a heterogeneouscell mixture, leading to preferential expansion of CD8+CD3+T cells. The large surface area, adjustable antibodydensity, and embedded paramagnetic properties of the NP–NFpermitted enhanced activation and expansion; its use represents astrategy that is amenable to an efficient selection process for adoptivecellular therapy as well as for the isolation of other cellular subsetsfor downstream translational applications. [ABSTRACT FROM AUTHOR]