Poly(3-hydroxi-butyrate-co-3-hydroxy-valerate) (PHB-HV) microparticles loaded with holmium acetylacetonate as potential contrast agents for magnetic resonance images

Autor(es)

de Azevedo, Mariangela de Burgos M. ^[1] ; Melo, Vitor H. S. ^[1] ; Soares, Carlos R. J. ^[1] ; Gamarra, Lionel F. ^[2] ; Barros, Caio H. N. ^{[3, 4]} ; Tasic, Ljubica ^[3]

Afiliação do(s) autor(es)

^[1] IPEN CNEN SP, Ctr Biotecnol, BR-05508000 Sao Paulo - Brazil

^[2] Hosp Israelita Albert Einstein, Sao Paulo, SP - Brazil

^[3] Univ Estadual Campinas, Inst Quim, Campinas, SP - Brazil

^[4] Univ Coll Dublin, Sch Chem & Bioproc Engn, Dublin - Ireland

• Tipo de documento: Artigo Científico
• Fonte: INTERNATIONAL JOURNAL OF NANOMEDICINE; v. 14, p. 6869-6889, 2019.
• Citações Web of Science: 0

Resumo

Introduction: Biodegradable polymers that contain radioactive isotopes such as Holmium 166 have potential applications as beta particle emitters in tumor tissues. Also, Ho(III) is paramagnetic, which makes it suitable as a contrast agent for magnetic resonance (MR) images. Methods: Holmium acetylacetonate (Ho(acac)(3)) loaded poly(3-hydroxy-butyrate-co-3-hydroxy-valerate) micro spheres, with 5% or 8% of 3-hydroxy-valerate (HV), were prepared by emulsification/evaporation process within 20-53 mu m size. Microspheres characterization was done using scanning electron microscopy, energy-dispersive X-ray, and infrared spectroscopies. The release of holmium(III) in sodium phosphate buffer (pH 7.4) was followed for 9 days with inductively coupled plasma. Finally, T-2 and T-2{*} magnetic resonance images (MRI) were acquired and compared with the MRI of the inclusion complex of holmium acetylacetonate in some beta-cyclodextrins. Results: Holmium acetylacetonate loading, evaluated by thermogravimetry, was up to 20 times higher for copolymer with 5% of HV. It was shown that microspheres loaded with Ho(acac)(3) exhibited an accumulation of Ho(III) on their surfaces but were stable over time, as no expressive release of holmium(III) was detected in 9-day exposition to sodium phosphate buffer. Holmium acetylacetonate in both microspheres or inclusion complexes was very efficient in obtaining T-2 and T-2{*} weighted images in magnetic resonance, thus, might be used as contrast agents. Conclusion: This is the first description of the use of inclusion complexes of holmium acetylacetonate in biodegradable polymers as contrast agents. New investigations are underway to evaluate the resistance of PHB-HV polymer microparticles to nuclear activation to assess their potential for use as radiopharmaceuticals for the treatment of liver cancer. (AU)

• Processo FAPESP: 15/26058-0 - Estudo do perfil de N-glicosilação e dos sítios de ocupação em várias preparações de tireotropina humana (hTSH) hipofisária e recombinante
• Beneficiário: Carlos Roberto Jorge Soares
• Modalidade de apoio: Auxílio à Pesquisa - Regular