Synthesis and characterization of 159Gd-doped hydroxyapatite nanorods for bioapplications as theranostic systems

Gadolinium-doped hydroxyapatite (HA-Gd) nanorods have become promisor theranostic nanoparticles for early stage cancers as radioisotope carriers able to act in the treatment and multi-imaging diagnosis by single photon emission computed tomography and magnetic resonance imaging systems. In this work, gadolinium-doped HA nanorods were synthesized aiming the use as theranostic system for osteosarcomas. The as-prepared HA-Gd nanorods were characterized by XRD with Rietveld refinement method, FTIR, XPS, ICP-AES, TEM, SEM, BET and VSM in order to investigate the physical-chemical, morphology, pore size distribution and magnetic properties. Moreover, phosphorous and gadolinium in the HA-Gd sample were activated by neutron capture, in a nuclear reactor, producing 32P and 159Gd radioisotopes, and the surfaces of these nanorods were functionalized with folic acid. The results indicate that Gd3+ are trapped in the HA nanorods crystal net showing great stability of the HA-Gd interaction. Gadolinium provide paramagnetic properties on HA nanorods and structural phosphorous and gadolinium can be activated to induced gamma and beta activity. The well succeeded production of 159Gd-32P-HA makes this material a promisor agent to act as a theranostic system.