Transferrin bioconjugation of conjugated polymer nanoparticles for selective photodynamic therapy of glioblastoma

PALACIOS R.E.; OLIVEDA P.M.; IBARRA L.E.; CAVERZAN M.D.; CHESTA C.A.

Mar del Plata

Congreso; Reunion Anual de Sociedades de Biociencias; 2022

SAIC

Glioblastoma (GBM) is the most aggressive brain tumor. New therapies are proposed such as Photodynamic Therapy (PDT) that combines light, oxygen and photosensitizers (PSs) to eradicate tumor cells through massive generation of ROS. We recently developed conjugated polymer nanoparticles (CPN) as new efficient PSs. The main objective of the present work was to decorate CPN surface with holo-transferrin (Holo-Tf) that recognize transferrin receptor 1 (TfR1) which is overexpress in GBM cells and endothelial cells from the blood-brain barrier. CPN were synthetized by nanoprecipitation method using conjugated polymer F8BT, two type of stabilizer polymers (poly(styrene-co-maleic anhydride) PSMA and polystyrene-polyethylene glycol-carboxyl PSPEG) and porphyrin PtOEP; and afterwards, protein bioconjugation was achieved by carbodiimide reaction using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC). Different proportions of coupling reagents, CPN and Holo-Tf were tested in order to determine the most optimal coupling reaction efficiency. Purification of unbound Holo-Tf was achieved by size exclusion centrifugation. Holo-Tf decorated CPN were characterized by DLS (size and Z potential) and gel-electrophoresis mobility. PSMA was able to contribute to the development of narrow size CPN (25 nm) with Holo-Tf. Using Human Protein Atlas, TfR1 expression was investigated in different cell lines including GBM to later validate receptor expression using flow cytometry immunophenotyping. Finally, cell uptake in GBM cell lines was evaluated comparing unconjugated CPN with Holo-Tf decorated CPN by flow cytometry and PDT efficacy by MTT assay. GBM U87MG and MO59K cells expressed more TfR1 than T98G and cell uptake was effective at low concentration (6,25 ug/mL) and different incubation times (30 min, 1 and 4 hs) using Holo-Tf decorated CPN. After PDT, Holo-Tf CPN improved cell death in TfR1-overexpressing GBM cells. CPN have risen as promising nanosystem platform to eradicate aggressive forms of cancers with selectivity of recognition of biomolecules.