To overcome chondrosarcoma’s (CHS) high chemo- and radioresistance, we used polyethylene glycol-encapsulated iron oxide nanoparticles (IONPs) for the controlled delivery of the chemotherapeutic doxorubicin (IONP_DOX) to amplify the cytotoxicity of proton radiation therapy. Human 2D CHS SW1353 cells were treated with protons (linear energy transfer (LET): 1.6 and 12.6 keV/µm) with and without IONP_DOX. Cell survival was assayed using a clonogenic test, and genotoxicity was tested through the formation of micronuclei (MN) and γH2AX foci, respectively. Morphology together with spectral fingerprints of nuclei were measured using enhanced dark-field microscopy (EDFM) assembled with a hyperspectral imaging (HI) module and an axial scanning fluorescence module, as well as scanning electron microscopy (SEM) coupled with energy-dispersive X-Ray spectroscopy (EDX). Cell survival was also determined in 3D SW3153 spheroids following treatment with low-LET protons with/without the IONP_DOX compound. IONP_DOX increased radiosensitivity following proton irradiation at both LETs in correlation with DNA damage expressed as MN or γH2AX. The IONP_DOX–low-LET proton combination caused a more lethal effect compared to IONP_DOX–high-LET protons. CHS cell biological alterations were reflected by the modifications in the hyperspectral images and spectral profiles, emphasizing new possible spectroscopic markers of cancer therapy effects. Our findings show that the proposed treatment combination has the potential to improve the management of CHS.

Chondrosarcoma (CHS), the second most common primary malignant cartilage tumor, is largely resistant to conventional therapies, making surgical resection the standard treatment. Proton therapy offers a physical advantage through the Bragg peak, enabling targeted irradiation while sparing surrounding tissues. However, differential biological responses between malignant and normal cartilage cells remain poorly understood. In this study, CHS SW1353 cells and normal chondrocytes (MC615) were exposed to proton irradiation. Biological responses were assessed via clonogenic survival, cell viability, apoptosis (caspase 3/7), micronucleus formation, cell cycle profiling, and oxidative stress markers. Proteomic changes were analyzed using mass spectrometry and bioinformatics. CHS cells exhibited higher radioresistance (D₁₀ = 6.45 Gy) than normal chondrocytes (D₁₀ = 5.08 Gy), oxidative stress adaptation, G1 arrest and proteomic plasticity, whereas normal chondrocytes displayed increased oxidative stress, extracellular matrix fragility and impaired integrin signaling. Notably, the tumor-specific increased levels of Tyrosine-protein kinase Fyn and Yes1-associated transcriptional regulator (YAP1) signaling suggest molecular drivers of radioresistance. Overall, proton irradiation elicits distinct biological and proteomic responses in malignant versus normal cartilage cells. These findings highlight potential radiosensitization targets, including Fyn/Src and YAP1/Hippo pathways, while underscoring the need to optimize proton therapy to enhance tumor control while minimizing damage to healthy cartilage.

At the Radiopharmaceutical Research Center (CCR) of the Horia Hulubei National Institute for R&D in Physics and Nuclear Engineering (IFIN-HH), we operate a TR-19 cyclotron for radio isotope production. To broaden our spectrum of radioisotopes with applications in nuclear medicine, we add a new external beam line towards a state-of-the-art solid target station. Besides practical experience with the implementation of the Comecer ALCEO metal solid targetry system, a new, more efficient way of tuning the beam onto the target and the design of a dedicated neutron local layered shielding are presented.