A chinrest-based approach to measure eye movements and experimental task engagement in macaques with minimal restraint.

BACKGROUND: The use of Rhesus macaques in vision research is crucial due to their visual system's similarity to humans. While invasive techniques have been the norm, there has been a shift towards non-invasive methods, such as facemasks and head molds, to enhance animal welfare and address ethical concerns. NEW METHOD: We present a non-invasive, 3D-printed chinrest with infrared sensors, adapted from canine research, allowing for accurate eye movement measurements and voluntary animal participation in experiments. RESULTS: The chinrest method showed a 16% and 28% increase in average trial numbers for Monkey 1 and Monkey 2, respectively, compared to the traditional headpost method. The engagement was high, with monkeys performing over 500 trials per session and initiating a new trial after an average intertrial interval of approximately 1 second. The hit rate improved by about 10% for Monkey 1 in the chinrest condition, and the fixation precision, measured by the standard deviation of gaze positions, was significantly better in the chinrest condition, with Monkey 1 showing a reduction in fixation imprecision from 0.26° to 0.17° in the X-axis. COMPARISON WITH EXISTING METHODS: The chinrest approach showed significant improvements in trial engagement and reduction in aborted trials due to fixation breaks, indicating less stress and potentially improved data quality compared to previous non-invasive methods. CONCLUSIONS: The chinrest method offers a significant advancement in primate cognitive testing by allowing for precise data collection while addressing animal welfare concerns, possibly leading to better scientific outcomes and a paradigm shift in primate research methodologies.

Ultrasound boosts doxorubicin efficacy against sensitive and resistant ovarian cancer cells.

Ovarian cancer (OC) is characterised by the highest mortality of all gynaecological malignancies, frequent relapses, and the development of resistance to drug therapy. Sonodynamic therapy (SDT) is an innovative anticancer approach that combines a chemical/drug (sonosensitizer) with low-intensity ultrasound (US), which are both harmless per sé, with the sonosensitizer being acoustically activated, thus yielding localized cytotoxicity often via reactive oxygen species (ROS) generation. Doxorubicin (Doxo) is a potent chemotherapeutic drug that has also been recommended as a first-line treatment against OC. This research work aims to investigate whether Doxo can be used at very low concentrations, in order to avoid its significant side effects, as a sonosensitiser under US exposure to promote cancer cell death in Doxo non-resistant (A2780/WT) and Doxo resistant (A2780/ADR) human OC cell lines. Moreover, since recurrence is an important issue in OC, we have also investigated whether the proposed SDT with Doxo induces immunogenic cell death (ICD) and thus hinders OC recurrence. Our results show that the sonodynamic anticancer approach with Doxo is effective in both A2780/WT and A2780/ADR cell lines, and that it proceeds via a ROS-dependent mechanism of action and immune sensitization that is based on the activation of the ICD pathway.

5-Aminolevulinic Acid Triggered by Ultrasound Halts Tumor Proliferation in a Syngeneic Model of Breast Cancer.

Sonodynamic therapy is a bimodal therapeutic approach in which a chemical compound and ultrasound (US) synergistically act to elicit oxidative damage, triggering cancer cell death. Despite encouraging results, mainly for anticancer treatment, sonodynamics is still far from having a clinical application. Therefore, to close the gap between the bench and bedside, more in vivo studies are needed. In this investigation, the combined effect of 5-aminolevulinic acid (Ala), a natural porphyrin precursor, plus exposure to US, was investigated in vivo on a syngeneic breast cancer model. Real-time RT-PCR, Western blotting, and immunohistochemistry assays were performed to evaluate the effect of sonodynamic treatment on the main cancer hallmarks. The sonodynamic-treated group had a significant reduction (p ≤ 0.0001) in tumor size compared to the untreated group, and the Ala- and US-only treated groups, where a strong decrease (p ≤ 0.0001) in Ki67 protein expression was the most relevant feature of sonodynamic-treated cancer tissues. Moreover, oxidative stress was confirmed as the pivotal driver of the anticancer effect through cell cycle arrest, apoptosis, and autophagy; thus, sonodynamics should be explored further for cancer treatment.

The bright side of sound: perspectives on the biomedical application of sonoluminescence.

Light is a physical phenomenon that is very important to human life, and has been investigated in its nature, behaviour and properties throughout human history although the most impressive improvements in the use of light in human activities, and of course in medicine, began just two centuries ago. However, despite the enormous progress in diagnosis, therapy and surgery to assess health and treat diseases, the delivery of light sources in vivo remains a challenge. In this regard, several strategies have been developed to overcome this drawback, the most interesting of which is the involvement of ultrasound. In this review, the authors examine how ultrasound may improve light delivery in vivo with a special emphasis on one of the most intriguing ultrasound-mediated phenomena called sonoluminescence, which is the conversion of mechanical ultrasound energy into light.

Sonodynamic treatment as an innovative bimodal anticancer approach: shock wave-mediated tumor growth inhibition in a syngeneic breast cancer model.

Despite the great advances in fighting cancer, many therapies still have serious side effects, thus urging the development of highly selective and safe treatments with a wide range of applicability. Sonodynamic therapy (SDT) is an innovative bimodal anticancer approach in which two normally non-toxic components -- one chemical, a sonosensitizer, and one physical, ultrasound -- selectively combine to cause oxidative damage and subsequent cancer cell death. In this study, we investigate the anticancer effect of SDT using shock waves (SWs) to activate protoporphyrin IX (PpIX) cytotoxicity on a Mat B-III syngeneic rat breast cancer model. The SDT-treated group saw a significant decrease (p<0.001) in magnetic resonance imaging (MRI) tumor size measurements 72 hours after treatment with PpIX precursor 5-aminolevulinic acid (ALA) and SWs. This occurred together with significant increase (p<0.01) in apparent diffusion coefficients between pre- and post-treatment MR tumor maps and strong increase in necrotic and apoptotic histological features 72 hours post-treatment. Moreover, significant HIF1A mRNA expression up-regulation was observed along with the prominent selective cleavage of poly (ADP-ribose) polymerase (PARP) and increased autophagy related protein LC3A/B expression in SDT-treated tumors, as compared to untreated tumors 72 hours post-treatment. Thus, the anticancer effect of SDT can be boosted by SWs, making them a valid technology for furthering investigations into this innovative anticancer approach.

Polymeric nanoparticles enhance the sonodynamic activity of meso-tetrakis (4-sulfonatophenyl) porphyrin in an in vitro neuroblastoma model.

PURPOSE: Sonodynamic therapy is a developing noninvasive modality for cancer treatment, based on the selective activation of a sonosensitizer agent by acoustic cavitation. The activated sonosensitizer agent might generate reactive oxygen species leading to cancer cell death. We investigated the potential poly-methyl methacrylate core-shell nanoparticles (NPs) loaded with meso-tetrakis (4-sulfonatophenyl) porphyrin (TPPS) have to function as an innovative sonosensitizing system, ie, TPPS-NPs. METHODS: Shockwaves (SWs) generated by a piezoelectric device were used to induce acoustic cavitation. The cytotoxic effect of the sonodynamic treatment with TPPS-NPs and SWs was investigated on the human neuroblastoma cell line, SH-SY5Y. Cells were exposed for 12 hours to TPPS-NPs (100 µg/mL) and then to SWs (0.43 mJ/mm(2) for 500 impulses, 4 impulses/second). Treatment with SWs, TPPS, and NPs alone or in combination was carried out as control. RESULTS: There was a statistically significant decrease in SH-SY5Y cell proliferation after the sonodynamic treatment with TPPS-NPs and SWs. Indeed, there was a significant increase in necrotic (16.91% ± 3.89%) and apoptotic (27.45% ± 3.03%) cells at 48 hours. Moreover, a 15-fold increase in reactive oxygen species production for cells exposed to TPPS-NPs and SWs was observed at 1 hour compared with untreated cells. A statistically significant enhanced mRNA (messenger ribonucleic acid) expression of NRF2 (P<0.001) and a significant downregulation of TIGAR (P<0.05) and MAP3K5 (P<0.05) genes was observed in cells exposed to TPPS-NPs and SWs at 24 hours, along with a statistically significant release of cytochrome c (P<0.01) at 48 hours. Lastly, the sonosensitizing system was also investigated in an in vitro three-dimensional model, and the sonodynamic treatment significantly decreased the neuroblastoma spheroid growth. CONCLUSION: The sonosensitizing properties of TPPS were significantly enhanced once loaded onto NPs, thus enhancing the sonodynamic treatment's efficacy in an in vitro neuroblastoma model.