131I‐Labeled Multifunctional Polyphosphazene Nanospheres for SPECT Imaging‐Guided Radiotherapy of Tumors. Issue 23 (7th November 2019) - Zhu, Wei
Abstract: Design of theranostic nanoplatforms represents a major topic for current nanomedicine. Here, the preparation of multifunctional poly(cyclotriphosphazene‐ co ‐polyethylenimine) nanospheres (PNSs) labeled with radionuclide 131 I for single photon emission computed tomography (SPECT) imaging‐guided radiotherapy of tumors is reported. In this work, PNSs are prepared using hexachlorocyclotriphosphazene as a crosslinker to crosslink branched polyethylenimine (PEI) via a nucleophilic substitution reaction, modified with 3‐(4′‐hydroxyphenyl) propionic acid‐OSu (HPAO) for 131 I labeling, and reacted with 1, 3‐propane sulfonate (1, 3‐PS) to render the particles with antifouling property, followed by acetylation of the remaining surface amines and labeling with 131 I. The acquired PNS.NHAc‐HPAO( 131 I)‐PS particles are well characterized. It is shown that the multifunctional PNSs with an average size of 184 ± 29.3 nm exhibit favorable antifouling properties, high 131 I labeling efficiency (76.05 ± 3.75%), and excellent radiostability and colloidal stability. With these properties owned, the developed PNS.NHAc‐HPAO( 131 I)‐PS spheres enable much more efficient SPECT imaging and radiotherapy of a xenografted tumor model in vivo than the PEI counterpart material (PEI.NHAc‐HPAO( 131 I)‐PS). The developed PNSs may be used as a versatile platform for further development of different forms of nanomedicine for various biomedical applications. Abstract : Multifunctional monodisperse polyphosphazene nanospheres can be synthesized via one‐step precipitation polymerization to crosslink polyethylenimine by hexachlorocyclotriphosphazene, followed by different modifications to create an 131 I‐labeled platform with favorable antifouling properties, radiostability, and colloidal stability. The platform can maintain in the tumor region for a long time, thereby enabling effective single photon emission computed tomography imaging‐guided radiotherapy of tumors.