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Ann Biomed Eng ; 48(4): 1230-1240, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31916125


Irreversible electroporation (IRE) is an emerging technology for non-thermal ablation of solid tumors. This study sought to integrate electrodes into microporous poly(caprolactone) (PCL) scaffolds previously shown to recruit metastasizing cancer cells in vivo in order to facilitate application of IRE to disseminating cancer cells. As the ideal parallel plate geometry would render much of the porous scaffold surface inaccessible to infiltrating cells, numerical modeling was utilized to predict the spatial profile of electric field strength within the scaffold for alternative electrode designs. Metal mesh electrodes with 0.35 mm aperture and 0.16 mm wire diameter established electric fields with similar spatial uniformity as the parallel plate geometry. Composite PCL-IRE scaffolds were fabricated by placing cylindrical porous PCL scaffolds between two PCL dip-coated stainless steel wire meshes. PCL-IRE scaffolds exhibited no difference in cell infiltration in vivo compared to PCL scaffolds. In addition, upon application of IRE in vivo, cells infiltrating the PCL-IRE scaffolds were successfully ablated, as determined by histological analysis 3 days post-treatment. The ability to establish homogeneous electric fields within a biomaterial that can recruit metastatic cancer cells, especially when combined with immunotherapy, may further advance IRE technology beyond solid tumors to the treatment of systemic cancer.

Int J Hyperthermia ; 36(1): 130-138, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30676126


Focal thermal therapy (Heat), cryosurgery (Cryo) and irreversible electroporation (IRE) are increasingly used to treat cancer. However, local recurrence and systemic spread are persistent negative outcomes. Nevertheless, emerging work with immunotherapies (i.e., checkpoint blockade or dendritic cell (DC) vaccination) in concert with focal therapies may improve outcomes. To understand the role of focal therapy in priming the immune system for immunotherapy, an in vitro model of T cell response after exposure to B16 melanoma cell lysates after lethal exposures was designed. Exposure included: Heat (50 °C, 30 min), Cryo (-80 °C, 30 min) and IRE (1250 V/cm, 99 pulses, 50 µs pulses with 1 Hz intervals). After viability assessment (CCK-8 assay), cell lysates were collected and assessed for protein release (BCA assay), protein denaturation (FTIR-spectroscopy), TRP-2 antigen release (western blot), and T cell activation (antigen-specific CD8 T cell proliferation). Results showed IRE released the most protein and antigen (TRP-2), followed by Cryo and Heat. In contrast, Cryo released the most native (not denatured) protein, compared to IRE and Heat. Finally, IRE dramatically outperformed both Cryo and Heat in T cell activation while Cryo modestly outperformed Heat. This study demonstrates that despite all focal therapies ability to destroy cells, the 'quantity' (i.e., amount) and 'quality' (i.e., molecular state) of tumor protein (including antigen) released can dramatically change the ensuing priming of the immune system. This suggests protein-based metrics whereby focal therapies can be designed to prime the immune system in concert with immunotherapies to eventually achieve improved and durable cancer treatment in vivo.

Antígenos de Neoplasias/metabolismo , Linfócitos T CD8-Positivos/imunologia , Neoplasias/imunologia , Animais , Humanos , Camundongos , Camundongos Transgênicos