Towards the development of a targeted albumin-binding radioligand: Synthesis, radiolabelling and preliminary in vivo studies.
Nucl Med Biol
; 94-95: 53-66, 2021.
Article
en En
| MEDLINE
| ID: mdl-33550011
ABSTRACT
INTRODUCTION:
The compound named 4-[10-(4-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)butanamido)decyl]-11-[10-(ß,d-glucopyranos-1-yl)-1-oxodecyl]-1,4,8,11-tetraazacyclotetradecane-1,8-diacetic acid is a newly synthesised molecule capable of binding in vivo to albumin to form a bioconjugate. This compound was given the name, GluCAB(glucose-chelator-albumin-binder)-maleimide-1. Radiolabelled GluCAB-maleimide-1 and subsequent bioconjugate is proposed for prospective oncological applications and works on the theoretical dual-targeting principle of tumour localization through the "enhanced permeability and retention (EPR) effect" and glucose metabolism.METHODS:
The precursor, GluCAB-amine-2, and subsequent GluCAB-maleimide-1 was synthesised via sequential regioselective, distal N-functionalisation of a cyclam template with a tether containing a synthetically-derived ß-glucoside followed by a second linker to incorporate a maleimide moiety for albumin-binding. GluCAB-amine-2 was radiolabelled with [64Cu]CuCl2 in 0.1â¯M NH4OAc (pHâ¯3.5, 90⯰C, 30â¯min), purified and converted post-labeling in 0.01â¯M PBS to [64Cu]Cu-GluCAB-maleimide-1. Serum stability and protein binding studies were completed according to described methods. Healthy BALB/c ice (three groups of nâ¯=â¯5) were injected intravenously with [64Cu]Cu-TETA, [64Cu]Cu-GluCAB-amine-2 or [64Cu]Cu-GluCAB-maleimide-1 and imaged using microPET/CT at 1, 2, 4, 8 and 24â¯h post-injection. Biodistribution of the compounds were determined ex vivo after 24â¯h using gamma counting.RESULTS:
GluCAB-maleimide-1 was synthesised in five consecutive steps with an overall yield of 11%. [64Cu]Cu-GluCAB-amine-2 (97% labelling efficiency) was converted to [64Cu]Cu-GluCAB-maleimide-1 (93% conversion; 90% radiochemical purity). Biodistribution analysis indicated that the control compounds were rapidly and almost completely excreted as compared to [64Cu]Cu-GluCAB-maleimide-1 that exhibited a prolonged biological half-life (6-8â¯h). Both, [64Cu]Cu-GluCAB-maleimide-1 and -amine-2 were excreted through the hepatobiliary system but a higher hepatic presence of the albumin-bound compound was noted. CONCLUSIONS, ADVANCES IN KNOWLEDGE AND IMPLICATIONS FOR PATIENT CARE This initial evaluation paves the way for further investigation into the tumour targeting potential of [64Cu]Cu-GluCAB-maleimide-1. An efficient targeted radioligand will allow for further development of a prospective theranostic agent for more personalized patient treatment which potentially improves overall patient prognosis, outcome and health care.Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Albúminas
Límite:
Animals
/
Humans
Idioma:
En
Revista:
Nucl Med Biol
Asunto de la revista:
BIOLOGIA
/
MEDICINA NUCLEAR
Año:
2021
Tipo del documento:
Article
País de afiliación:
Sudáfrica