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Magalhaes, A. P.

Publications and source records attributed to Magalhaes, A. P..

2 recordsLinked to original sources

3D neuroblastoma models expose divergent responses to magnetic hyperthermia and photothermal therapy

PurposeHyperthermia is emerging as an adjunct strategy in pediatric oncology, yet its translation is limited by poor understanding of how different modalities impact complex tumor microenvironments. Neuroblastoma (NB), the most common extracranial solid tumor in children, displays profound heterogeneity that hampers therapeutic predictability. Here, we performed the first systematic head-to-head comparison of photothermal therapy (PTT) and magnetic hyperthermia (MH) in tissue-engineered NB (TE-NB) models. MethodsTE-NB scaffolds incorporating five NB cell lines were loaded with magnetic nanoparticles (MNPs) and subjected to PTT (808-nm laser, 130 W/cm2, 10 min) or MH (285 kHz, 20 mT, 60 min). Constructs were analyzed at 24 h, 48 h, and 5 d post-treatment for DNA content, cell viability, proliferation (Ki67 immunohistochemistry), and apoptosis (caspase-3/7 staining). ResultsMH produced consistent MNP-dependent heating with minimal background, while PTT was dominated by nonspecific medium absorption. Both modalities modulated proliferation within 24 h, but effects varied sharply by cell line and scaffold region, reflecting microenvironmental heterogeneity. By 48 h, PTT often triggered paradoxical increases in proliferation, whereas MH disrupted scaffold integrity, reduced DNA content, and suppressed Ki67 expression. Notably, neither modality induced sustained caspase-3/7 activation, indicating that cytotoxicity proceeds via non-apoptotic pathways. ConclusionOur findings position MH as a superior modality for uniform heating and proliferation control in 3D NB models, but also highlight that hyperthermia should be considered a context-dependent modulator rather than a binary cytotoxic agent. By integrating patient-specific TE-NB platforms, "precision hyperthermia" could define individualized therapeutic windows, optimize combinations with pro-apoptotic or immunomodulatory agents, and accelerate translation of hyperthermia strategies for children with NB.

bioengineering↗

The critical role of spatio-temporal control in combinatorial chemo- and magnetic hyperthermia thermo-therapy: 'the where', 'the how' and 'the when'

Combinatorial treatments hold the key to the future of cancer treatment as they enhance therapeutic indexes by inducing synergistic effects and reducing resistance processes, while often providing a safer option for patients with fewer off-target effects. However, combinatorial treatments bring extra problems to cancer management not only derived from the actual compatibility of the treatments, but also from their hands-on administration. Operational parameters such as administration order and dosing (dose, spacing) have to be optimized in order to positively impact patient prognosis. Here we present a systematic study on the optimization and the importance of these parameters within the framework of a combinatorial chemo-/thermo-therapy. Parameters like where, how and when are investigated in detail. Furthermore, we delve into the underlying biochemical mechanisms driving the observed effects through transcriptome analysis.

biochemistry↗