Targeting Glioblastoma-Associated Macrophages for Photodynamic Therapy Using AGuIX®-Design Nanoparticles

Abstract

Glioblastoma (GBM) is the most difficult brain cancer to treat, and photodynamic therapy (PDT) is emerging as a complementary approach to improve tumor eradication. Neuropilin-1 (NRP-1) protein expression plays a critical role in GBM progression and immune response. Moreover, various clinical databases highlight a relationship between NRP-1 and M2 macrophage infiltration. In order to induce a photodynamic effect, multifunctional AGuIX®-design nanoparticles were used in combination with a magnetic resonance imaging (MRI) contrast agent, as well as a porphyrin as the photosensitizer molecule and KDKPPR peptide ligand for targeting the NRP-1 receptor. The main objective of this study was to characterize the impact of macrophage NRP-1 protein expression on the uptake of functionalized AGuIX®-design nanoparticles in vitro and to describe the influence of GBM cell secretome post-PDT on the polarization of macrophages into M1 or M2 phenotypes. By using THP-1 human monocytes, successful polarization into the macrophage phenotypes was argued via specific morphological traits, discriminant nucleocytoplasmic ratio values, and different adhesion abilities based on real-time cell impedance measurements. In addition, macrophage polarization was confirmed via the transcript-level expression of TNFα, CXCL10, CD-80, CD-163, CD-206, and CCL22 markers. In relation to NRP-1 protein over-expression, we demonstrated a three-fold increase in functionalized nanoparticle uptake for the M2 macrophages compared to the M1 phenotype. The secretome of the post-PDT GBM cells led to nearly a three-fold increase in the over-expression of TNFα transcripts, confirming the polarization to the M1 phenotype. The in vivo relationship between post-PDT efficiency and the inflammatory effects points to the extensive involvement of macrophages in the tumor zone.

Photodynamic Therapy for Glioblastoma: Illuminating the Path toward Clinical Applicability

“…Other in vitro PDT approaches have seen success utilizing nanoparticles. One recent study published in March 2023 utilized AGuIX ® -design nanoparticles with an MRI contrast agent, porphyrin photosensitizer, and KDKPPR peptide ligand to investigate the influence of macrophage neuropilin-1 (NRP-1) protein expression, a protein known to impact GBM immune response and progression, on the uptake of nanoparticles [ 64 ]. Medium secreted by U87-MG tumor cells with or without PDT was incubated with THP-1 macrophages.…”

Metronomic Photodynamic Therapy with Conjugated Polymer Nanoparticles in Glioblastoma Tumor Microenvironment

“…Both in vitro and in vivo studies have shown that TAMs accumulate within GBM and that they are educated to adopt tumor-friendly phenotypes [68]. In order to evaluate the TAM population phenotype in co-culture conditions with GBM cells, a phenotype characterization by gene markers was performed to evaluate the transcript expression of relevant markers, such as TNF-a and CCR7 for M1 and MCR-1 and VEGFA for M2 profiles, after GBM CM exposure in THP-1-derived macrophages.…”

“…For instance, Soyama T. et al synthesized a mannose-conjugated chlorin e6 to decrease the proportion of M2-TAMs and increase that of M1-like TAMs [71]. A recent study of Lerouge L. et al demonstrated that the secretome of post-PDT GBM cells treated with AGuIX ® nanoparticles polarized macrophages to an M1-like phenotype [68]. Our results were in agreement with this finding, and, in our case, the mPDT irradiation modality increased the overexpression of M1 marker transcripts significantly compared to the conventional modality.…”

New Crystal Form of Human Neuropilin-1 b1 Fragment with Six Electrostatic Mutations Complexed with KDKPPR Peptide Ligand

“…Research has shown that NRP1 plays a significant role in the development and progression of various cancer types [ 4 ] and also more recently in the infectivity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) [ 5 ]. In particular, this transmembrane receptor has been suggested as a molecular therapeutic target for glioblastoma, with overexpression mainly due to endothelial cells of angiogenic phenotype and associated pro-tumor macrophages, both of which are linked to an unfavorable prognosis [ 6 ]. A recent review outlines the various functions of NRP1 in the context of cancer treatments [ 7 ].…”

“…Recently, a nanoparticle was designed that combines KDKPPR motif as a targeting peptide, porphyrin as photosensitizer and gadolinium chelate as contrast agent. This nanoparticle, called AGuIX@PS@KDKPPR, enables the detection of tumor tissue by magnetic resonance imaging and treatment by PDT [ 6 , 17 , 18 ]. The affinity of the nanoparticle for human NRP1 was validated, and it was found to be ten times lower than that of the free peptide ( K D of 4.7 µM for AGuIX@PS@KDKPPR and K D of 0.5 µM for KDKPPR) [ 17 ].…”