Current developments in medical technology have focused on therapeutic treatments that selectively and effectively address specific pathological areas, minimizing side effects on healthy tissues. In this regard, many procedures have been developed to provide non-invasive therapy, for example therapeutic ultrasound (US). In the medical field, in particular in cancer research, it has been observed how ultrasounds can cause cell death and inhibit cell proliferation of cancer cells, while preserving healthy ones with almost negligible side effects. Various studies have shown that low intensity pulse ultrasound (LIPUS) and low intensity continuous ultrasound (LICUS) regulate the proliferation, cell differentiation and cavitation phenomena. Nowadays, there are poorly known aspects of low intensity US treatment, in terms of biophysical and biomechanical effects on target cells. The aim of this study is to set up an innovative apparatus for US treatment of pancreatic ductal adenocarcinoma (PDAC) cells, monitoring parameters such as acoustic intensity, acoustic pressure, stimulation frequency and treatment protocol. To this purpose, we have developed a custom-made set up for the US stimulation at 1.2 and 3 MHz of tridimensional (3D) cultures of PDAC cells (PANC-1, Mia Paca-2 and BxPc3 cells). Images of the 3D cultures were acquired, and the Calcein/PI assay was applied to detect US-induced cell death. Overall, the setup we have presented paves the way to an innovative protocol for tumor treatment. The system can be used either alone or in combination with small molecules or recombinant antibodies in order to propose a novel combined therapeutic approach.
Sonoporation has garnered significant attention for its potential to temporarily permeabilize cell membranes through the application of ultrasound waves, thus enabling an efficient cellular uptake of molecules. Despite its promising applications, the precise control of sonoporation remains a complex and evolving challenge in the field of cellular and molecular biology. This review aims to address two key aspects central to advancing our understanding of sonoporation. Firstly, it underscores the necessity for the establishment of a standardized methodology to validate and quantify the successful entry of molecules into target cells. This entails a critical examination of existing techniques and the identification of best practices to ensure accurate, reliable, and reproducible results. By establishing a common framework for assessing sonoporation outcomes, researchers can enhance the reliability and comparability of their experiments, paving the way for more robust findings. Secondly, the review places particular emphasis on the detailed analysis of various acoustic parameters as reported in the papers selected from the literature. Among these parameters, acoustic intensity (specifically, ISPTA) emerges as a pivotal factor in sonoporation studies. Furthermore, this review delves into the exploration of the elastic modulus and its significance in sonoporation mechanisms and associated challenges. This knowledge can inform the development of more effective strategies to optimize sonoporation protocols. In summary, this review not only highlights the pressing need for a standardized approach to verify molecule entry into cells but also delves into the search for an effective frequency and acoustic intensity for in vivo and in vitro applications.
This study investigates the impact of low-intensity continuous ultrasound (LICU) on pancreatic adenocarcinoma (PANC-1) spheroids, emphasizing morphological and volumetric transformations. PANC-1 spheroids were cultured and treated with LICU across frequencies from 1 to 5 MHz. Cell viability and mortality were analyzed through Calcein AM/PI staining, while volumetric and morphological changes were quantified across frequencies from 2 to 4 MHz using advanced imaging techniques and computational tools, including a custom Python OpenCv Library, AnaSP 3.0, a MATLAB based open source tool. Notably, a frequency of 3.5 MHz yielded optimal outcomes, also achieving a reduction in spheroid volume and mortality while minimizing disgregation, a factor linked to metastasis risk. These findings underscore LICU’s potential as an effective therapeutic strategy, balancing tumor reduction with the preservation of structural cohesion. The study establishes a methodological framework for optimizing LICU parameters, presenting a less invasive avenue for improving therapeutic outcomes in pancreatic cancer treatment.
Microwave (MW) ablation is a minimally invasive technique used to destroy pathological tissues through localized heating generated by a needle applicator. Internally cooled applicators using water circulation have long been the standard for high-power applications; however, water cooling introduces significant mechanical complexity. This work investigates the feasibility of a novel air-cooled coaxial thermal-ablation needle operating at 2.45 GHz up to 70 W. The system uses two concentric metal tubes—an outer 14 G stainless steel shaft (OD 2.1 mm) and an inner copper capillary (OD 1 mm, ID 0.7 mm)—serving simultaneously as the MW transmission line and cooling conduit, with dry air at room temperature (25 °C) flowing at 11 L/min under 5 bar input pressure. Experimental cooling efficiency tests demonstrated 78% efficiency for the shaft section in air and 32% for the section embedded in tissue. Electromagnetic and thermal simulations predicted ablation dimensions in a non-perfused liver of 35 mm short axis with ellipticity of 0.65 for the basic applicator, improving to 0.88 with an advanced PEEK-shaft design featuring a cancelling slot. A prototype was built and tested on exvivo bovine liver, achieving input matching better than −24 dB at 2.44 GHz and ablation dimensions (average of 5 tests) of 31 mm short axis and 45 mm long axis. Results confirm the feasibility of air cooling as a simpler, safer, and lower-cost alternative to water cooling for medium-power MW ablation.