In the last few decades, electrical stimulation devices have been clinically used for a wide spectrum of applications, ranging from deep brain stimulation to drug and gene delivery. Despite such clinical relevance, the impact of electrical stimulation on the cellular biophysical processes has not been explored significantly. We report here the analytical results to develop quantitative biophysical insights into the influence of lateral electric field stimulation on bioelectric stresses in the intercellular/extracellular region and the membrane tension. In developing quantitative insights, we solved Laplace equation with appropriate boundary conditions in an azimuthally asymmetric system with a single cell. The magnitude of the stresses increases with the electric field strength in a parabolic manner. In case of cell without surface charges, the intracellular stress field is predicted to have both compressive and tensile regions with a maximum of 2 μPa, while a maximum tensile stress of 20 μPa in extracellular region could be predicted, at field strength of 300 V/m. While considering surface charges, the magnitude of extracellular normal and shear stresses at the cell membrane is an order of magnitude higher when compared to without surface charges. Based on the variation of shear stress tensors at cell membrane, the critical field strength for membrane rupture was found to be 5.3 kV/mm and 20 kV/mm for a cell without and with surface charges respectively. The impact of the bioelectric stresses on the mechanotransduction induced cytoskeletal reorganization and stress driven cellular signalling modulation were substantiated using quantitative results from the study.

This review aims to analyse the safety and clinical efficacy in terms of pain relief and local tumour control, in patients with metastatic epidural spinal cord compression undergoing electrochemotherapy (ECT). Moreover, a recommendation detailing optimal electrodes insertion is proposed with the intent of improving treatment planning. Clinical studies published between 2015 and 2023 were included since this time window is consistent with recent developments in the field of ECT of spinal metastases. In the whole, 3 articles were included. Results showed that percutaneous image-guided ECT provides effective pain relief with limited procedure-related morbidity, along with local tumour control (complete response 28.5%, 38% partial response, 24% stable disease) at 3-month follow-up in the largest published series so far. In conclusion, ECT should integrate the armamentarium of therapies that are currently being proposed to patients with painful metastatic epidural disease.

Electrochemotherapy (ECT) is a local treatment combining chemotherapy with electroporation. This prospective multicentre study aimed to evaluate the efficacy of ECT in the treatment of patients with skin metastases from breast cancer and confirm whether "luminal A-like" tumors are more responsive to treatment. One-hundred and ninety-five patients were included in the analysis. 55% achieved complete response, 27% partial response (objective response OR 82%); 12% stable disease and 5% experienced progressive disease. The analysis by tumor phenotype showed a significant better response rate in Luminal A-like (p = 0.0060) and Luminal B-like (p = 0.0271) groups compared to Triple-Negative. Patients were divided into 4 groups based on the number and size of cutaneous metastases. Higher response rate was observed in patients with small (≤ 3 cm), single or multiple, metastases (OR rate 95% and 90%, respectively); larger tumors (> 3 cm) showed an OR rate of 85%. Tumor response was not affected by the presence of distant metastases, whereas patients with large cutaneous lesions and distant metastases showed a OR rate of 58%. One-year local progression-free survival (LPFS) was 86% (C.I. 82-89%). In the multivariate analysis, patient age and response to ECT were significantly associated with longer LPFS. This study confirms the efficacy of ECT in small-volume cutaneous metastases from breast cancer regardless the presence of systemic disease and suggests higher efficacy in patients with luminal A- and luminal B-like tumors. ECT can be utilized not only as a palliative measure but also as an alternative treatment for patients not eligible for standard treatments, or in combination with them. Trial registered on https://clinicaltrials.gov/study/NCT06683404 (date of registration 11/11/2024) retrospectively registered.

Electroporation, a physical method that permeabilizes cell membranes, is increasingly used in cancer treatment. By enhancing the uptake of hydrophilic antitumor drugs, it boosts their cytotoxic effects and has proven effective in both human and veterinary medicine through electrochemotherapy. However, this treatment requires loco-regional or even general anesthesia, as electrical pulses cause muscle contractions and pain. Several clinical studies have demonstrated that application of high frequency pulses (above 5000 Hz) and short pulse duration (under 11 μs) causes much less discomfort to patients. In order to reduce the pain associated with contractions while maintaining the effectiveness of the treatment, we have developed new protocols using a high-frequency generator that delivers electric field pulses at a pulse repetition rate up to 2 MHz, associated to a multipolar electrode. In vitro tests on colorectal cancer cells were performed to assess the efficiency of cisplatin and bleomycin in inducing cell death. The efficiency obtained after one single treatment on both cell suspensions and on 3D multicellular spheroid models were similar to the ones obtained using ESOPE (European standard operating procedures for electrochemotherapy) protocol, which is currently used in clinics. In addition, as tumor cells die in an immunogenic cell death (ICD) mode and can release danger associated molecular patterns (DAMPs), major hallmarks of ICD were evaluated following the treatment by quantifying the apoptotic cell death, caspases 3/7 activation and key DAMPs. Subsequently, pilot studies on small number of conscious cats and horses under mild sedation confirmed that these protocols did not cause any noticeable muscle contractions and resulted in either partial or complete responses. New high-frequency electroporation protocols, described herein, show great promise in shifting electrochemotherapy into an effective and painless cancer treatment.

The rising prevalence of cutaneous and subcutaneous tumors has driven interest in electrochemotherapy (ECT) as a potential treatment. However, patient-reported outcomes remain underexplored. This study aims to assess the short-term impact of ECT on the quality of life (QoL) of patients, addressing a gap in the current literature. A prospective study evaluated 62 patients treated with ECT between 2015 and 2022. QoL was measured using the EQ-5D-3L questionnaire, calculating EQ-5D-index and assessing health state (EQ-VAS) and pain (pain-VAS). Subgroup analysis was conducted based on tumor histology, previous radiotherapy, and tumor size. Statistical analysis was performed using SPSS 29.0.0. The median age was 70 years, with a median follow-up of 47 days. Pre-treatment, 38.7% of patients reported pain/discomfort, and 24% had anxiety/depression. Post-treatment, these decreased to 32.2% and 19%, respectively. While the EQ-VAS and EQ-5D-3L scores showed a non-significant increase, pain-VAS decreased. Significant improvements were seen in patients with previous radiotherapy (EQ-VAS, p = 0.047; EQ-5D-index, p = 0.012) and smaller tumors (EQ-VAS, p = 0.035; pain-VAS, p = 0.029). ECT demonstrates a significant short-term benefit in maintaining or improving QoL in patients with cutaneous malignancies.

Electrochemotherapy (ECT) is a cancer treatment approach that utilizes the application of electroporation (EP) with standard chemotherapeutic drugs, resulting in a locally enhanced chemotherapy effect due to enhanced intracellular drug delivery. The aim of this study was to demonstrate (for the first time) that microsecond-range bleomycin electrochemotherapy (1.5 kV/cm × 100 μs × 8 pulses, 1 Hz), when combined with gold nanoparticles (AuNPs, 13 and 46 nm), can be efficiently utilized for in vivo carcinoma tumor treatment. It was anticipated that AuNPs would promote a better treatment response due to local electric field amplification within the tumor as predicted by available in vitro research. We focus the attenuation of tumor progression and reduction of the frequency of metastasis incl. the immune response in the murine BALB/C and 4T1 cancer model. It is shown that the application of 13 nm AuNPs hardly influenced the dynamics of tumor progression (when compared to ECT alone), the synergistic effects are not statistically significant by the end of experiment, which is not the case in vitro. However, the application of 46 nm AuNPs significantly potentiated the efficacy of ECT, which confirms the promising alliance of conductive nanoparticles for local intra-tumoral electric field amplification and ECT.

To study the electric field threshold of electroporation of real cell membrane structures under the action of the pulsed electric field, in this article, a finite element model of the real cell containing endoplasmic reticulum and nucleus was constructed in real cell staining images by cluster segmentation and edge extraction techniques. The electroporation equation was introduced into the real cell model to calculate the threshold value of different membrane structures for electroporation under a pulsed electric field. The results showed that the transmembrane potentials of the cell membrane, endoplasmic reticulum membrane, and nuclear membrane reached the electroporation thresholds at 1.2, 2.6, and 2.9 kV/cm, while the pore density thresholds were 1.7 × 1014/m2, 3.2 × 1014/m2, and 3.5 × 1014/m2, respectively. Under a single pulse with a pulse width of 100 μs and rise and fall times of 10 μs, the pore density reaches the electroporation threshold at 1.7, 3.2 and 3.5 kV/cm, respectively.

Colorectal cancer (CRC) remains a significant global health concern, with survival outcomes heavily dependent on the stage at diagnosis. Targeted therapies offer a promising approach to improve patient outcomes, particularly by addressing molecular drivers of tumor progression. One such target is the E2F1 transcription factor, a key regulator of the cell cycle and a contributor to proliferation, differentiation, apoptosis, metastasis, and chemoresistance in CRC. Previous studies have demonstrated the efficacy of E2F1 silencing via siRNA-loaded nanoliposomes in reducing tumor cell growth, but challenges such as immunogenicity and off-target effects have limited their in vivo application. In this study, we evaluated the potential of gene electrotransfer (GET) as a non-viral delivery system for delivery of therapeutic siRNA targeting E2F1 in the HT-29 CRC model. In vitro experiments showed effective silencing of E2F1 expression and a significant reduction in HT-29 cell survival. Subsequent in vivo studies confirmed the therapeutic potential of siE2F1 GET, with results demonstrating tumor growth delay, decreased proliferation, and increased necrosis in the tumors. This study establishes proof-of-principle for targeting E2F1 in CRC using GET, showcasing its versatility and therapeutic potential.

Kaposi sarcoma (KS) is a cancer of endothelial cells involving the skin and visceral organs. Electrochemotherapy (ECT) is an alternative treatment option for patients with cutaneous malignancies of skin and non-skin origin not suitable for conventional treatments. ECT exerts anti-tumour activity through enhanced drug delivery to tumour cells and cytotoxicity, inducing immunogenic tumour cell death and through a vascular-disrupting effect.

In this multi-institutional prospective, observational study, we aimed to evaluate the outcomes of using ECT as a treatment modality for cutaneous Kaposi's Sarcoma within the InspECT (International Network for Sharing Practice on ECT) registry. Patients with superficial lesions of Kaposi Sarcoma from 19 European centres were included. They underwent at least one ECT session with bleomycin performed following the European Standard Operating Procedures, between March 2011 and June 2024.

The analysis included 82 patients (mean age 71 years; median number of lesions/patient 2). Side effects were reported as mild and easily manageable. The response to treatment per patient was 80 % complete and 13 % partial. In the multivariate model, time since diagnosis to ECT and small tumour size showed a significant association with a complete response. One-year local progression-free survival (LPFS) in the whole population was 93 %, 2 years LPFS was 89 %.

In the present study, ECT showed antitumor activity and a favourable safety profile in patients with cutaneous Kaposi Sarcoma either not suitable for conventional treatments or that refused them. Better results were obtained in small tumours (<3 cm) using hexagonal electrodes.

In recent years, various gene therapy strategies have been developed for cancer treatment. One of these strategies is electroporation-based delivery of therapeutic transgenes - gene electrotransfer (GET). Electrochemotherapy and GET have been combined in several contemporary preclinical and veterinary studies. In most cases, two different pulse protocols are used, each for a specific treatment. The aim of our current study was to test whether the standard pulse protocol used in daily clinical practice for electrochemotherapy can also be used for effective GET.

Experiments were performed in vitro in a tumor (B16F10) and two normal tissue cell lines (C2C12 myoblasts and L929 fibroblasts). Four different GET protocols, three using monopolar electric pulses and one bipolar electric pulses, were tested for the GET of plasmid DNA, which codes for green fluorescent protein in vitro. In addition, two GET protocols were chosen for in vivo tumor and muscle transfection.

Two GET protocols using monopolar electric pulses of different voltages delivered at 1 Hz transfected B16F10 tumor cells significantly better than normal cells. GET4 protocol, which uses monopolar electric pulses at 5 kHz, again transfected the B16F10 tumor cells significantly better, but the difference to the C2C12 myoblast cells was not significant. Compared with other GET protocols, GET3 using bipolar electric pulses at 1 Hz was significantly less effective. Both the GET2 (1 Hz) and GET4 (5 kHz) protocols resulted in similar tumor transfection efficiencies, whereas only the GET4 protocol was effective for muscle transfection in vivo.

Our study demonstrated the efficient transfection of tumors and muscles with the GET4 pulse protocol, which is used clinically for electrochemotherapy. The use of this protocol could enable simultaneous electrochemotherapy and GET of the therapeutic gene in one session, which will significantly shorten the procedure and thus will be more tolerable for patients.

This study explores the combination of jasplakinolide with electroporation (JSP + EP), a method enhancing targeted molecule delivery. CHO-K1 (Chinese hamster ovarian), C2C12 (mouse myoblast), and RD (rhabdomyosarcoma) cells were treated with jasplakinolide (50 nM) in HEPES buffer and exposed to electrical pulses (0.8-1.2 kV/cm). Cell viability was measured via the MTS assay, cytoskeleton structure was assessed with confocal microscopy, and docking studies examined jasplakinolide-actin interactions. The combination of jasplakinolide and electric pulses synergistically affected RMS cells (Rhabdomyosarcoma), causing significant cytoskeletal changes and reduced viability. Docking studies revealed that jasplakinolide interacts with both monomeric and filamentous actin, highlighting a dual mechanism. Confocal imaging showed substantial actin cytoskeleton disruption in cancer cells, with minimal effects on normal cells. Jasplakinolide combined with electric pulses can specifically target cancer cells with less cytotoxicity to normal cells, potentially reducing side effects following the clinical procedure.

Electrochemotherapy (ECT) uses electroporation to enhance drug delivery into tumor cells, triggering bystander effects like immunogenicity and cell death. This study investigated bystander effects in vitro in 4T1 breast cancer cells following various electroporation treatments: reversible (1400 V/cm, 100 µs) bleomycin electrotransfer, irreversible (2800 V/cm, 100 µs) bleomycin electrotransfer, and calcium electroporation, including combinations. Conditioned media from treated cells (12-72 h incubation) were transferred to untreated cells, and viability was assessed via metabolic activity, cell count, and colony formation. A scratch assay evaluated wound healing. The bystander effect dramatically reduced colony formation, reaching 0% after bleomycin and calcium electrotransfer, and 2.37 ± 0.74% after irreversible electroporation (IRE). Metabolic activity decreased to 18.05 ± 6.77% and 11.62 ± 3.57% after bleomycin and calcium electrotransfer, respectively, and 56.21 ± 0.74% after IRE. Similarly, cell viability measured by flow cytometry was 10.00 ± 1.44%, 3.67 ± 0.32%, and 24.96 ± 1.37% after bleomycin electrotransfer, calcium electrotransfer, and IRE, respectively. Combined analysis of these effects yielded comparable results. Conditioned media, particularly from bleomycin electrotransfer and calcium electroporation, significantly reduced cell number, metabolic activity, and colony formation, demonstrating a strong bystander effect. Wound healing was also significantly delayed in groups exposed to conditioned media.

Electrochemotherapy (ECT) is a local nonsurgical effective tumor treatment in the hand of the clinician for the treatment of patients with liver tumors or metastases. The study aimed to test the technical feasibility and safety of intra-arterial (i.a.) bleomycin administration compared to the established intravenous (i.v.) administration in percutaneous electrochemotherapy (pECT). Furthermore, the equivalence hypothesis was tested between the 2 modalities in terms of local short-term response and progression-free survival.

Forty-four patients have been recruited and treated by pECT for hepatocellular carcinoma, cholangiocarcinoma and liver metastatic lesions from cancers of different origin: 18 were treated with standard i.v., 26 with bleomycin i.a. administration.

The 2 groups were similar for anagraphic and anamnestic data, as well as for most relevant disease specific characteristics. Technical success of the treatment was obtained in 95% and 100% of patients in i.v. and i.a. groups respectively. Short-term local response was similar in the 2 groups with a slightly higher complete remission (CR) rate in the i.a. group. There were 61.9% CR, 23.8% partial remission (PR), 4.8% stable disease (SD) in the i.v. group, and 80.6%, CR 12.9% PR, 3.2% PD (p = 0.3454). One-year progression free survival was 60% (C.I. 33%-88%) in the i.v. group and 67% (C.I. 42%-91%) in the i.a. group (p = 0.5849).

The results of this study confirmed the safety and feasibility of super-selective i.a. bleomycin administration. Analysis of local response and progression free survival confirmed the equivalence hypothesis of the new modality compared to standard i.v. administration in the treatment of primary and secondary liver malignancies by pECT.

Squamous cell carcinoma (SCC) is a malignant epidermal tumor. Biologic behavior and metastasis rate vary according to species and tumor location. The goal of this study was to report the occurrence and behavior of an oral SCC in a Tapirus terrestris treated with electrochemotherapy. The tapir was anesthetized for two electrochemotherapy sessions, six months apart, with intralesional cisplatin (0.25 mL/cm3) and VetCP 125TM electroporator. Side effects were minimal. Because of tumor relapse, onset of joint disorders, and poor prognosis, the animal was euthanized and submitted to necropsy, followed by histopathological and immunohistochemical analyses. Electrochemotherapy significantly improved the tapiŕs life quality. Tumor bleeding resolved, and food uptake was improved. Necropsy demonstrated tumor invasion in adjacent soft tissues and bones and submandibular lymph nodes with multiple areas of metastasis. Overall survival time of 35 months was achieved, with good life quality. Histopathologic characteristics were more aggressive in the relapsed tumor.

In addition to its direct cytotoxic effects, ablative therapies as electrochemotherapy (ECT) can elicit indirect antitumor effects by triggering immune system responses. Here, we comprehensively analyzed this dual effectiveness of intratumoral ECT with chemotherapeutic drugs bleomycin (BLM), oxaliplatin (OXA), and cisplatin (CDDP). Our aim was to determine if ECT can act as in situ vaccination and thereby induce an abscopal effect. By evaluating ECT's potential for in situ vaccination, our goal was to pave the way for future advancements for its combination with emerging (immuno)therapies, leading to enhanced responses and outcomes.

We employed two mouse tumor models, the immunologically cold B16F10 melanoma and 4T1 mammary carcinoma, to explore both local and systemic (i.e., abscopal) antitumor effects following equieffective intratumoral ECT with BLM, OXA, and CDDP. Through histological analyses and the use of immunodeficient and metastatic (for abscopal effect) mouse models, we identified and compared both the cytotoxic and immunological components of ECT's antitumor efficiency, such as immunologically recognizable cell deaths (immunogenic cell death and necrosis) and immune infiltrate (CD11+, CD4+, CD8+, GrB+).

Differences in immunological involvement after equieffective intratumoral ECT were highlighted by variable kinetics of immunologically recognizable cell deaths and immune infiltrate across the studied tumor models. Particularly, the 4T1 tumor model exhibited a more pronounced involvement of the immune component compared to the B16F10 tumor model. Variances in the antitumor (immune) response were also detected based on the chemotherapeutic drug used in ECT. Collectively, ECT demonstrated effectiveness in inducing in situ vaccination in both tumor models; however, an abscopal effect was observed in the 4T1 tumor model only.

This is the first preclinical study systematically comparing the immune involvement in intratumoral ECT's efficiency using three distinct chemotherapeutic drugs in mouse tumor models. The demonstrated variability in immune response to ECT across different tumor models and chemotherapeutic drugs provides a basis for future investigations aimed at enhancing the effectiveness of combined treatments.

Electroporation causes a temporal increase in cell membrane permeability and leads to prolonged changes in transmembrane voltage (TMV) in both excitable and non-excitable cells. However, the mechanisms of these TMV changes remain to be fully elucidated. To this end, we monitored TMV over 30 min after exposing two different cell lines to a single 100 µs electroporation pulse using the FLIPR Membrane Potential dye. In CHO-K1 cells, which express very low levels of endogenous ion channels, membrane depolarization following pulse exposure could be explained by nonselective leak current, which persists until the membrane reseals, enabling the cells to recover their resting TMV. In U-87 MG cells, which express many different ion channels, we unexpectedly observed membrane hyperpolarization following the initial depolarization phase, but only at 33 °C and not at 25 °C. We developed a theoretical model, supported by experiments with ion channel inhibitors, which indicated that hyperpolarization could largely be attributed to the activation of calcium-activated potassium channels. Ion channel activation, coupled with changes in TMV and intracellular calcium, participates in various physiological processes, including cell proliferation, differentiation, migration, and apoptosis. Therefore, our study suggests that ion channels could present a potential target for influencing the biological response after electroporation.

Pancreatic ductal adenocarcinoma (PDAC) is one of the most difficult cancers to treat, with a dismal 5-year survival rate of only 8-10%. This challenging prognosis highlights the urgent need for innovative therapeutic approaches to improve outcomes for patients with PDAC. Electrochemotherapy (ECT), which enhances intracellular chemotherapeutic uptake via electric pulses, has been explored for resectable, borderline resectable (BR), locally advanced (LA), recurrent, and metastatic PDAC, either as a complement to conventional treatments or as an alternative when these are not feasible or effective, offering possible benefits in symptomatic palliation and local tumor control.

A systematic review was performed in accordance with PRISMA guidelines for studies assessing the efficacy of ECT in PDAC. After searching Embase, PubMed/MEDLINE, Scopus, and Web of Science, five studies with a combined total of 43 patients in various disease stages were identified.

ECT showed promise in improving tumor control, alleviating cancer-related pain, and improving quality of life. One study noted a trend towards tumor size reduction of 8.3% at one-month and 16.1% at six-months follow-up (p = 0.211 and p = 0.315), although these findings were derived from studies conducted without specific comparative control groups. Severity of complication was mainly mild (Clavien-Dindo I-II), while severe complications occurred in only 2.3% of patients. Median overall survival was reported in two studies as 8 months (range 2-19) and 11.5 months (range 1-74). ECT showed efficacy for symptom management, with 60% of patients reporting reduced pain/discomfort and 40% showing enhanced quality of life in one study, while another reported pain scores as decreasing from 6 to 3 at one month and to 2 at six months.

ECT appears to be a new promising and safe adjunct treatment modality in PDAC management across different disease stages, with potential benefits in tumor control, cancer-related pain reduction, and quality of life. Further studies are warranted to validate these findings and identify patients who could benefit most.

Gelonin is a ribosome-inactivating protein with extreme intracellular toxicity but poor permeation into cells. Targeted disruption of cell membranes to facilitate gelonin entry is explored for cancer and tissue ablation. We demonstrate a hundreds- to thousands-fold enhancement of gelonin cytotoxicity by pulsed electric fields in the T24, U-87, and CT26 cell lines. The effective gelonin concentration to kill 50% of cells (EC50) after electroporation ranged from <1 nM to about 100 nM. For intact cells, the EC50 was unattainable even at the highest gelonin concentration of 1000 nM, which reduced cell survival by only 5-15%. For isoeffective electroporation treatments using 300 ns, 9 µs, and 100 µs pulses, longer pulses were more efficient at lowering gelonin EC50. Increasing the electric field strength of 8, 100 µs pulses from 0.65 to 1.25 kV/cm reduced gelonin EC50 from 128 nM to 0.72 nM. Conversely, the presence of 100 nM gelonin enabled a more than 20-fold reduction in the number of pulses required for equivalent cell killing. Pulsed electric field-mediated delivery of gelonin shows promise for hyperplasia ablation at concentrations sufficiently low to minimize or avoid systemic toxicity.

PurposeThis study aimed to investigate the efficacy of electrochemotherapy on the three common types of skin cancer, including basal cell carcinoma (BCC), cutaneous squamous cell carcinoma (cSCC), and melanoma.Methods26 patients with skin cancer were recruited from single cancer treatment centers from 2022 to 2024. Electrochemotherapy (ECT) was performed to treat the cancerous nodules; all nodules in a patient with multiple lesions were treated. However the biggest lesions were always pointed out (according to European Standard Operating Procedures on Electrochemotherapy protocol) and their clinical response and adverse effects were evaluated during the study.Resultstotally, 104 nodules of 26 patients were assessed. Clinical complete response was achieved in 53 lesions, while partial response was observed in 51 lesions after first month of treatment. The most common adverse effect was pain which was in 65% of cases.ConclusionBCC shows a notably higher clinical complete response rate. Because the research was conducted at a single center and given the novelty of this treatment in Iran, the number of patients included in the study was limited. Electrochemotherapy (ECT) has shown significant clinical effectiveness for superficial tumors, especially for patients who have health issues related to standard therapies or who are resistant to conventional treatments. It is generally well-tolerated, with side effects predominantly consisting of temporary pain. Ongoing research aims to expand its use in deep-seated tumors that are resistant to conventional therapies.

This Special Issue is dedicated to the memory of Professor Jolanta Saczko (1964-2023), a remarkable leader whose guidance and dedication were instrumental in advancing electroporation-based research in Poland [...].

Although the pulse electric field (PEF) has been used in electrochemotherapy (ECT) for many years, the kinetics and profile of extracellular particles (EPs) released as a result of reversible electroporation have yet to be studied. It also needs to be clarified whether and how the profile of released EPs depends on the parameters of the applied PEF. The presented studies investigated the effect of EPs released from human melanoma cells after various parameters of reversible electroporation on markers indicating EP-mediated transformation of normal fibroblasts into tumor-associated fibroblasts. The expression levels of the vascular cell adhesion molecule-1 (VCAM-1) and changes in the expression of phosphor-histone H3 (pHH3), a biomarker specific for cells in mitosis, cell viability, and the migration capacity of the studied fibroblast cells, were analyzed. EPs were isolated from two commercial malignant melanoma cell lines previously subjected to reversible electroporation. Human primary fibroblasts (HPFs) were selected for EPs exposure. It was observed that after incubation with melanoma-derived EPs, HPFs showed differences in cell viability, migration capacity, VCAM-1, pHH3, and N-cadherin expression, depending on PEF parameters and the grade of melanoma cells. This study highlights that small extracellular particles (sEPs) from cancer cells can promote metastasis by carrying specific signals that lead to the upregulation of molecules like FAK, MMP-9, and N-cadherin in recipient cells.

Calcium electroporation (CaEP) involves the combination of calcium ions with electroporation, which is induced by pulsed electric fields (PEFs). This study explores the application of high-frequency unipolar nanosecond pulsed electric fields (nsPEFs: 8-14 kV/cm, 200 ns, 10 kHz, 100 kHz, 1 MHz repetition frequency pulse bursts, n = 100) and their potential in inhibiting lung cancer cell growth. As a reference, standard microsecond range parametric protocols were used (100 µs x 8 pulses). Methods included cell permeability quantification through Yo-Pro-1 uptake, cell viability assays, immunofluorescence studies for apoptosis and EMT markers, analysis of cell death types depending on repetition frequency pulse bursts. We determined the susceptibility of human lung cancer to electric pulses, characterized the efficacy of CaEP, and investigated cell death types depending on repetition frequency pulse bursts. We have shown that adding calcium ions to the applied nsPEF protocol increases cytotoxicity. Additionally, the use of these electroporation parameters can modulate key cellular processes, such as the epithelial-mesenchymal transition and apoptosis, as indicated by changes in the expression of markers such as E-cadherin, N-cadherin, BCL-2, and p53. Changes in cell morphology over time were observed using holotomographic microscopy. The study provides insights into the modulation of key cellular processes, indicating that nsPEF technology could improve the outcomes of conventional cancer treatments through enhanced efficacy and potentially mitigating drug resistance mechanisms. The promising results advocate for further research to optimize nsPEF protocols for clinical application, highlighting the potential of electrical fields in advancing cancer therapy.

Calcium electroporation (CaEP) is an efficient approach for ovarian cancer treatment. It causes cell death by introducing elevated levels of calcium into cells. In this work, the research focused on two types of cell lines: CHO-K1, representing normal ovary cells, and OvBH-1, representing ovarian clear carcinoma cells. Those cell lines exhibited distinct reactions to calcium electroporation (CaEP). Also, we have evaluated the effects of 17β-estradiol following CaEP and electrochemotherapy (ECT) with cisplatin (CPP). The combination of ECT with CPP and CaEP with prior E2 preincubation resulted in approximately 23.55 % and 39 % decreases in cell survival compared to the control cells (exposed to CPP and CaCl2 alone) for ovarian cancer cells. The obtained results showed that ovarian cancer cells preincubated with 17β-estradiol after exposure to pulsed electric fields undergo primary necrosis. Additionally, preincubation of ovarian cancer cells with 17β-estradiol can significantly improve the effectiveness of both chemotherapy and electrochemotherapy involving cisplatin and calcium chloride.

This study aimed to describe the ultrasound, CT findings, and clinical manifestations of pathologically confirmed metastases involving the subcutaneous fat layer of the trunk and pelvis.

We included 30 patients with subcutaneous metastases in the trunk and pelvis, verified by ultrasound-guided biopsy. We comprehensively reviewed ultrasound findings of all 30 patients and contrast-enhanced CT findings of 25 patients obtained before biopsy. Medical records were reviewed, including primary malignancy type, presence of coexisting distant metastasis, and detection method leading to biopsy referral.

Most subcutaneous metastases were heterogeneously hypoechoic (86.7%) with well-defined margins (80.0%), lobulated (46.7%) or round-to-oval (40.0%) shape, and vascularity (96.7%). Metastases frequently exhibited no contact (53.3%) or focal contact with deep peripheral fascia, resulting in acute contact angle formation (30.0%). Common CT manifestations included central low attenuation with peripheral rim-like enhancement (60.0%) or well-circumscribed lesion with heterogeneous enhancement (32.0%). Lung cancer (46.7%) was the prevalent primary malignancy. CT was the predominant detection method (56.7%). Coexisting subcutaneous metastases were present in 50.0% of cases, and distant metastases (less subcutaneous metastases) were observed in 90.0% of patients.

This study describes typical imaging findings of subcutaneous metastases involving the trunk and pelvis. CT may play a crucial role in their early detection, and our results may assist radiologists in their diagnosis.

The global incidence of secondary liver cancer is rising due to multiple risk factors, presenting significant challenges in public health. Similarly, colorectal cancer (CRC) remains a leading cause of cancer-related mortality with the development of frequent liver metastases. Surgical resection of CRC liver metastases is only suitable for a limited subset of patients, necessitating alternative nonsurgical treatments such as electrochemotherapy (ECT); Methods: This review adhered to the S.P.I.D.E.R.

Systematic searches of PubMed, Cochrane, and Scopus databases were conducted for studies published between 2003 and 2023, following PRISMA guidelines. Inclusion criteria were full-text clinical studies in English focusing on ECT-treated CRC liver metastases, excluding reviews, editorials, and non-clinical papers. The GRADE approach was utilized to assess evidence quality, considering study limitations, consistency, and other factors; Results: From 38 identified articles, 4 met the inclusion criteria, encompassing 78 patients and 128 treated lesions. The studies demonstrated variability in design and follow-up duration (3-11 months). Complete response (CR) rates ranged from 33.3% to 63.0%, while progression disease (PD) rates were high, ranging from 23.0% to 55.6%. Median overall survival (OS) spanned 11.3 to 29.0 months. No severe ECT-related complications were reported.

ECT appears to be a safe and effective modality for the treatment of CRC liver metastases, especially for lesions unsuitable for other ablative techniques. Further prospective and randomized studies are essential to better define the role of ECT in managing CRC liver metastases and to compare its efficacy with other ablative methods.

Triple-negative breast cancer (TNBC), the most aggressive subtype of breast cancer lacks estrogen, progesterone, and HER2 receptors and hence, is therapeutically challenging. Towards this, we studied an alternate therapy by repurposing metformin (FDA-approved type-2 diabetic drug with anticancer properties) in a 3D-scaffold culture, with electrical pulses. 3D cell culture was used to simulate the tumor microenvironment more closely and MDA-MB-231, human TNBC cells, treated with both 5 mM metformin (Met) and 8 electrical pulses at 2500 V/cm, 10 µs (EP1) and 800 V/cm, 100 µs (EP2) at 1 Hz were studied in 3D and 2D. They were characterized using cell viability, reactive oxygen species (ROS), glucose uptake, and lactate production assays at 24 h. Cell viability, as low as 20 % was obtained with EP1 + 5 mM Met. They exhibited 1.65-fold lower cell viability than 2D with EP1 + 5 mM Met. ROS levels indicated a 2-fold increase in oxidative stress for EP1 + 5 mM Met, while the glucose uptake was limited to only 9 %. No significant change in the lactate production indicated glycolytic arrest and a non-conducive environment for MDA-MB-231 growth. Our results indicate that 3D cell culture, with a more realistic tumor environment that enhances cell death using metformin and electrical pulses could be a promising approach for TNBC therapeutic intervention studies.

Background/Objectives: Electrochemotherapy (ECT) is a safe and efficient method of targeted drug delivery using pulsed electric fields (PEF), one that is based on the phenomenon of electroporation. However, the problems of electric field homogeneity within a tumor can cause a diminishing of the treatment efficacy, resulting only in partial response to the procedure. This work used gold nano-particles for electric field amplification, introducing the capability to improve available elec-trochemotherapy methods and solve problems associated with field non-homogeneity. Methods: We characterized the potential use of gold nanoparticles of 13 nm diameter (AuNPs: 13 nm) in combination with microsecond (0.6-1.5 kV/cm × 100 μs × 8 (1 Hz)) and nanosecond (6 kV/cm × 300-700 ns × 100 (1, 10, 100 kHz and 1 MHz)) electric field pulses. Finally, we tested the most prominent protocols (microsecond and nanosecond) in the context of bleomycin-based electrochemotherapy (4T1 mammary cancer cell line). Results: In the nano-pulse range, the synergistic effects (improved permeabilization and electrotransfer) were profound, with increased pulse burst frequency. Addi-tionally, AuNPs not only reduced the permeabilization thresholds but also affected pore resealing. It was shown that a saturated cytotoxic response with AuNPs can be triggered at significantly lower electric fields and that the AuNPs themselves are non-toxic for the cells either separately or in combination with bleomycin. Conclusions: The used electric fields are considered sub-threshold and/or not applicable for electrochemotherapy, however, when combined with AuNPs results in successful ECT, indicating the methodology's prospective applicability as an anticancer treatment method.

Malignant melanoma is the most lethal form of skin cancer. As a promising anti-cancer agent, plasma-activated water (PAW) rich in reactive oxygen and nitrogen species (RONS) has shown significant potential for melanoma treatment. However, rapid decay of RONS and inefficient delivery of PAW in conventional injection methods limit its practical applications. To address this issue, here we report a new approach for the production of plasma-activated cryo-microneedles (PA-CMNs) patches using custom-designed plasma devices and processes. Our innovation is to incorporate PAW into the PA-CMNs that are fabricated using a fast cryogenic micro-molding method. It is demonstrated that PA-CMNs can be easily inserted into skin to release RONS and slow the decay of RONS thereby prolonging their bioactivity and effectiveness. The new insights into the effective melanoma treatment suggest that the rich mixture of RONS within PA-CMNs prepared by custom-developed hybrid plasma-assisted configuration induces both ferroptosis and apoptosis to selectively kill tumor cells. A significant inhibition of subcutaneous A375 melanoma growth was observed in PA-CMNs-treated tumor-bearing nude mice without any signs of systemic toxicity. The new approach based on PA-CMNs may potentially open new avenues for a broader range of disease treatments.

Electrochemotherapy (ECT) with intravenous (IV) and/or intratumoral (IT) bleomycin has shown considerable efficacy in the treatment of non-resectable feline cutaneous squamous cell carcinoma (cSCC), boasting response rates of up to 95%, but other chemotherapy protocols have not yet been investigated. The objective of this prospective multicentre study was to compare the overall response rate (ORR) and progression-free interval (PFI) between cats with cSCC treated with ECT using IT and IV carboplatin (IV + IT), IV carboplatin (IV) or IV bleomycin (IV). A total of 44 cats with unresectable cSCC across three centres were enrolled and treated with ECT using carboplatin IV + IT (n = 10), carboplatin IV (n = 11) or bleomycin IV (n = 23). Treatment response according to RECIST criteria was recorded at 2 and 4 weeks post-treatment, and patients were followed until disease progression and/or death. All three groups were comparable regarding age, sex, weight, and lesion size. Adverse events were generally mild, localised and similar between groups. ORRs were 90.0% (carboplatin IV + IT), 90.9% (carboplatin IV) and 95.6% (bleomycin IV) and were not significantly different (p = 0.79). Median PFI was not reached for carboplatin IV + IT or carboplatin IV and was 566 days for bleomycin IV, with no significant difference between the three groups (p = 0.81). This study suggests that ECT using IV or IV + IT carboplatin is a reasonable alternative therapeutic option for managing cSCC, and further studies are warranted to compare outcomes between treatment protocols.

The phenomenon known as bipolar cancellation is observed when biphasic nanosecond electric field pulses are used, which results in reduced electroporation efficiency when compared to unipolar pulses of the same parameters. Basically, the negative phase of the bipolar pulse diminishes the effect of the positive phase. Our study aimed to investigate how bipolar cancellation affects Ca2+ electrochemotherapy and cellular response under varying electric field intensities and pulse durations (3-7 kV/cm, 100, 300, and 500 ns bipolar 1 MHz repetition frequency pulse bursts, n = 100). As a reference, standard microsecond range parametric protocols were used (100 µs × 8 pulses). We have shown that the cancellation effect is extremely strong when the pulses are closely spaced (1 MHz frequency), which results in a lack of cell membrane permeabilization and consequent failure of electrochemotherapy in vitro. To validate the observations, we have performed a pilot in vivo study where we compared the efficacy of monophasic (5 kV/cm × ↑500 ns × 100) and biphasic sequences (5 kV/cm × ↑500 ns + ↓500 ns × 100) delivered at 1 MHz frequency in the context of Ca2+ electrochemotherapy (B16-F10 cell line, C57BL/6 mice, n = 24). Mice treated with bipolar pulses did not exhibit prolonged survival when compared to the untreated control (tumor-bearing mice); therefore, the bipolar cancellation phenomenon was also occurrent in vivo, significantly impairing electrochemotherapy. At the same time, the efficacy of monophasic nanosecond pulses was comparable to 1.4 kV/cm × 100 µs × 8 pulses sequence, resulting in tumor reduction following the treatment and prolonged survival of the animals.

Electrochemotherapy (ECT) combines the reversible electroporation (rEP) with intravenous (i.v.) or intratumoral (i.t.) administration of chemotherapeutic drugs. We conducted this study to compare the efficacy of i.v., i.t., and i.v. + i.t. injection of bleomycin (BLM) in ECT treatment of colorectal hepatic metastases in a rat model. WAG/Rij rats were randomized into three groups and underwent ECT with i.v., i.t., or i.v. + i.t. injection of BLM. Tumor volumes and oxygenation were measured by means of ultrasound and photoacoustic imaging. Moreover, liver and tumor tissue were analyzed by histology and immunohistochemistry. The i.v. and i.v. + i.t. groups exhibited a 44.0% and 46.6% reduction in oxygen saturation of the tumor tissue when compared to pretreatment values, whereas the i.t. group only showed a reduction of 35.2%. The extent of tumor tissue necrosis did not statistically differ between the groups. However, the i.t. group showed a tendency towards a lower necrosis rate. Cell proliferation, apoptotic cell death, vascularization, and immune cell infiltration were comparable in the treated tumors of the three groups. ECT with i.v. administration of BLM should be preferred in clinical practice, as the combined i.v. + i.t. therapy did not show superior oncological outcomes in the present study.

Uveal melanoma (UM) represents a rare tumor of the uveal tract and is associated with a poor prognosis due to the high risk of metastasis. Despite advances in the treatment of UM, the mortality rate remains high, dictating an urgent need for novel therapeutic strategies. The current study introduces the first in vivo analysis of the therapeutic potential of calcium electroporation (CaEP) compared with electrochemotherapy (ECT) with bleomycin in a patient-derived xenograft (PDX) model based on the chorioallantoic membrane (CAM) assay. The experiments were conducted as monotherapy with either 5 or 10 mM calcium chloride or 1 or 2.5 µg/mL bleomycin in combination with EP or EP alone. CaEP and ECT induced a similar reduction in proliferative activity, neovascularization, and melanocytic expansion. A dose-dependent effect of CaEP triggered a significant induction of necrosis, whereas ECT application of 1 µg/mL bleomycin resulted in a significantly increased apoptotic response compared with untreated tumor grafts. Our results outline the prospective use of CaEP and ECT with bleomycin as an adjuvant treatment of UM, facilitating adequate local tumor control and potentially an improvement in metastatic and overall survival rates.

Pulsed magnetic field treatment can enhance cell membrane permeability, allowing large molecular substances that normally cannot pass through the cell membrane to enter the cell. This research holds significant prospects for biomedical applications. However, the mechanism underlying pulsed magnetic field-induced cell permeabilization remains unclear, impeding further progress in research related to pulsed magnetic field. Currently, hypotheses about the mechanism are struggling to explain experimental results. Therefore, this study developed a parameter-adjustable pulsed magnetic field generator and designed experiments. Starting from the widely accepted hypothesis of "induced electric fields by pulsed magnetic field," we conducted a preliminary exploration of the biophysical mechanisms underlying pulsed magnetic field-induced cell permeabilization. Finally, we have arrived at an intriguing conclusion: under the current technical parameters, the impact of the pulsed magnetic field itself is the primary factor influencing changes in cell membrane permeability, rather than the induced electric field. This conclusion holds significant implications for understanding the biophysical mechanisms behind pulsed magnetic field therapy and its potential biomedical applications.

Cutaneous metastases are seen in up to 10% of all oncology patients and can occur in different locations depending on the entity. Cutaneous metastases are often associated with a high psychological burden and, especially in the case of exulceration, with shame and social withdrawal. This review discusses the diagnostic and therapeutic options. The most common tumor entities in which cutaneous metastases are observed are discussed, and local and systemic treatment options are presented according to the current state of research.

Electroporation is a method that shows great promise as a non-viral approach for delivering genes by using high-voltage electric pulses to introduce DNA into cells to induce transient gene expression. This research aimed to evaluate the interplay between electric pulse intensity and 100 µs-duration pulse numbers as an outcome of gene electrotransfer efficacy and cell viability. Our results indicated a close relationship between pulse number and electric field strength regarding gene electrotransfer efficacy; higher electric pulse intensity resulted in fewer pulses needed to achieve the same gene electrotransfer efficacy. Subsequently, an increase in pulse number had a more negative impact on overall gene electrotransfer by significantly reducing cell viability. Based on our data, the best pulse parameters to transfect CHO cells with the pMax-GFP plasmid were using 5 HV square wave pulses of 1000 V/cm and 2 HV of 1600 V/cm, correspondingly resulting in 55 and 71% of transfected cells and maintaining 79 and 54% proliferating cells. This shows ESOPE-like 100 µs-duration pulse protocols can be used simultaneously to deliver cytotoxic drugs as well as immune response regulating genetically encoded cytokines.

Paediatric Interventional Oncology (IO) lags behind adult IO due to a scarcity of specific outcome data. The suboptimal way to evolve this field is relying heavily on adult experiences. The distinct tumour types prevalent in children, such as extracranial germ cell tumours, sarcomas, and neuroblastoma, differ strongly from those found in adults, presenting a completely different biological behaviour. Compounding this challenge, paediatric interventional radiology often employs adapted or off-label techniques, potentially compromising optimal outcomes. This review outlines the present indications for interventional radiology in paediatric cancer, from biopsy to supportive care, including complication management. It emphasises the role of locoregional approaches, and explores the status of common paediatric oncological diseases, highlighting areas where IO has made progress identifying potential opportunities for future advancements in this evolving field.

Nanosecond pulsed electric field (nsPEF) has emerged as a promising approach for inducing cell death in melanoma, either as a standalone treatment or in combination with chemotherapeutics. However, to date, there has been a shortage of studies exploring the impact of nsPEF on the expression of cancer-specific molecules. In this investigation, we sought to assess the effects of nsPEF on melanoma-specific MAGE (Melanoma Antigen Gene Protein Family) expression. To achieve this, melanoma cells were exposed to nsPEF with parameters set at 8 kV/cm, 200 ns duration, 100 pulses, and a frequency of 10 kHz. We also aimed to comprehensively describe the consequences of this electric field on melanoma cells' invasion and proliferation potential. Our findings reveal that following exposure to nsPEF, melanoma cells release microvesicles containing MAGE antigens, leading to a simultaneous increase in the expression and mRNA content of membrane-associated antigens such as MAGE-A1. Notably, we observed an unexpected increase in the expression of PD-1 as well. While we did not observe significant differences in the cells' proliferation or invasion potential, a remarkable alteration in the cells' metabolomic and lipidomic profiles towards a less aggressive phenotype was evident. Furthermore, we validated these results using ex vivo tissue cultures and 3D melanoma culture models. Our study demonstrates that nsPEF can elevate the expression of membrane-associated proteins, including melanoma-specific antigens. The mechanism underlying the overexpression of MAGE antigens involves the initial release of microvesicles containing MAGE antigens, followed by a gradual increase in mRNA levels, ultimately resulting in elevated expression of MAGE antigens post-experiment. These findings shed light on a novel method for modulating cancer cells to overexpress cancer-specific molecules, thereby potentially enhancing their sensitivity to targeted anticancer therapy.