International Journal of Nanomedicine (Aug 2021)
Biodistribution of 68/67Ga-Radiolabeled Sphingolipid Nanoemulsions by PET and SPECT Imaging
Abstract
Sandra Díez-Villares,1– 3 Juan Pellico,4,5 Noemí Gómez-Lado,6 Santiago Grijalvo,7,8 Sandra Alijas,1 Ramon Eritja,7,8 Fernando Herranz,5,9 Pablo Aguiar,6 María de la Fuente1,2 1Nano-Oncology and Translational Therapeutics group, Health Research Institute of Santiago de Compostela (IDIS), SERGAS, Santiago de Compostela, 15706, Spain; 2Biomedical Research Networking Center on Oncology (CIBERONC), Madrid, 28029, Spain; 3University of Santiago de Compostela (USC), Santiago de Compostela, 15782, Spain; 4School of Biomedical Engineering & Imaging Sciences, King’s College London, St. Thomas’ Hospital, London, SE1 7EH, UK; 5Biomedical Research Networking Center on Respiratory Diseases (CIBERES), Madrid, 28029, Spain; 6Nuclear Medicine Department and Molecular Imaging Group, Health Research Institute of Santiago de Compostela (IDIS), SERGAS, Santiago de Compostela, 15706, Spain; 7Institute for Advanced Chemistry of Catalonia (IQAC), Consejo Superior de Investigaciones Científicas (CSIC), Barcelona, E-08034, Spain; 8Biomedical Research Networking Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Madrid, 28029, Spain; 9NanoMedMol Group, Instituto de Química Medica (IQM),Consejo Superior de Investigaciones Científicas (CSIC), Madrid, 28006, SpainCorrespondence: María de la FuenteNano-Oncology Unit and Translational Therapeutics Unit, Health Research Institute of Santiago de Compostela (IDIS), Clinical University Hospital (CHUS), Building C, Floor − 2, Lab 18, Travesía da Choupana s/n, Santiago de Compostela, ES15706, SpainTel +34 981 955 704Email [email protected] and Purpose: Non-invasive imaging methodologies, especially nuclear imaging techniques, have undergone an extraordinary development over the last years. Interest in the development of innovative tracers has prompted the emergence of new nanomaterials with a focus on nuclear imaging and therapeutical applications. Among others, organic nanoparticles are of the highest interest due to their translational potential related to their biocompatibility and biodegradability. Our group has developed a promising new type of biocompatible nanomaterials, sphingomyelin nanoemulsions (SNs). The aim of this study is to explore the potential of SNs for nuclear imaging applications.Methods: Ready-to-label SNs were prepared by a one-step method using lipid derivative chelators and characterized in terms of their physicochemical properties. Stability was assessed under storage and after incubation with human serum. Chelator-functionalized SNs were radiolabeled with 67Ga and 68Ga, and the radiochemical yield (RCY), radiochemical purity (RCP) and radiochemical stability (RCS) were determined. Finally, the biodistribution of 67/68Ga-SNs was evaluated in vivo and ex vivo.Results: Here, we describe a simple and mild one-step method for fast and efficient radiolabeling of SNs with 68Ga and 67Ga radioisotopes. In vivo experiments showed that 67/68Ga-SNs can efficiently and indistinctly be followed up by PET and SPECT. Additionally, we proved that the biodistribution of the 67/68Ga-SNs can be conveniently modulated by modifying the surface properties of different hydrophilic polymers, and therefore the formulation can be further adapted to the specific requirements of different biomedical applications.Conclusion: This work supports 67/68Ga-SNs as a novel probe for nuclear imaging with tunable biodistribution and with great potential for the future development of nanotheranostics.Keywords: sphingomyelin nanoemulsions, biodistribution, gallium-68/67, nuclear imaging, nanotheranostics
