Focused ultrasound (FUS) has become an important non-invasive therapy for prostate tumor ablation
thermal effects in the clinic. The cavitation effect induced by FUS is applied for histotripsy, ...support drug delivery, and the induction of blood vessel destruction for cancer therapy. Numerous studies report that cavitation-induced sonoporation could provoke multiple anti-proliferative effects on cancer cells. Therefore, cavitation alone or in combination with thermal treatment is of great interest but research in this field is inadequate.
Human prostate cancer cells (LNCap and PC-3) were exposed to 40 s cavitation using a FUS system, followed by water bath hyperthermia (HT). The clonogenic assay, WST-1 assay, and Transwell
invasion assay, respectively, were used to assess cancer cell clonogenic survival, metabolic activity, and invasion potential. Fluorescence microscopy using propidium iodide (PI) as a probe of cell membrane integrity was used to identify sonoporation. The H2A.X assay and Nicoletti test were conducted in the mechanism investigation to detect DNA double-strand breaks (DSBs) and cell cycle arrest. Immunofluorescence microscopy and flow cytometry were performed to determine the distribution and expression of 5α-reductase (SRD5A).
Short FUS shots with cavitation
FUS-Cav) in combination with HT resulted in, respectively, a 2.2, 2.3, and 2.8-fold decrease (LNCap) and a 2.0, 1.5, and 1.6-fold decrease (PC-3) in the clonogenic survival, cell invasiveness and metabolic activity of prostate cancer cells when compared to HT alone. FUS-Cav immediately induced sonoporation in 61.7% of LNCap cells, and the combination treatment led to a 1.4 (LNCap) and 1.6-fold (PC-3) increase in the number of DSBs compared to HT alone. Meanwhile, the combination therapy resulted in 26.68% of LNCap and 31.70% of PC-3 with cell cycle arrest in the Sub-G1 phase and 35.37% of PC-3 with cell cycle arrest in the G2/M phase. Additionally, the treatment of FUS-Cav combined with HT block the androgen receptor (AR) signal pathway by reducing the relative Type I 5α-reductase (SRD5A1) level to 38.28 ± 3.76% in LNCap cells, and decreasing the relative Type III 5α-reductase 3 (SRD5A3) level to 22.87 ± 4.88% in PC-3 cells, in contrast, the relative SRD5A level in untreated groups was set to 100%.
FUS-induced cavitation increases the effects of HT by interrupting cancer cell membranes, inducing the DSBs and cell cycle arrest, and blocking the AR signal pathway of the prostate cancer cells, with the potential to be a promising adjuvant therapy in prostate cancer treatment.
Sonodynamic therapy (SDT) is currently on critical path for glioblastoma therapeutics. SDT is a non-invasive approach utilising focused ultrasound to activate photosensitisers like 5-ALA to impede ...tumour growth. Unfortunately, the molecular mechanisms underlying the therapeutic functions of SDT remain enigmatic. This is primarily due to the lack of intricately optimised instrumentation capable of modulating SDT delivery to glioma cells in vitro. Consequently, very little information is available on the effects of SDT on glioma stem cells which are key drivers of gliomagenesis and recurrence. To address this, the current study has developed and validated an automated in vitro SDT system to allow the application and mapping of focused ultrasound fields under varied exposure conditions and setup configurations. The study optimizes ultrasound frequency, intensity, plate base material, thermal effect, and the integration of live cells. Indeed, in the presence of 5-ALA, focused ultrasound induces apoptotic cell death in primary patient-derived glioma cells with concurrent upregulation of intracellular reactive oxygen species. Intriguingly, primary glioma stem neurospheres also exhibit remarkably reduced 3D growth upon SDT exposure. Taken together, the study reports an in vitro system for SDT applications on tissue culture-based disease models to potentially benchmark the novel approach to the current standard-of-care.
Focused ultrasound (FUS) has become an important non-invasive therapy for solid tumor ablation via thermal effects. The cavitation effect induced by FUS is thereby avoided but applied for ...lithotripsy, support drug delivery and the induction of blood vessel destruction for cancer therapy. In this study, head and neck cancer (FaDu), glioblastoma (T98G), and prostate cancer (PC-3) cells were exposed to FUS by using an in vitro FUS system followed by single-dose X-ray radiation therapy (RT) or water bath hyperthermia (HT). Sensitization effects of short FUS shots with cavitation (FUS-Cav) or without cavitation (FUS) to RT or HT (45 °C, 30 min) were evaluated. FUS-Cav significantly increases the sensitivity of cancer cells to RT and HT by reducing long-term clonogenic survival, short-term cell metabolic activity, cell invasion, and induction of sonoporation. Our results demonstrated that short FUS treatment with cavitation has good potential to sensitize cancer cells to RT and HT non-invasively.
Purpose
High-intensity focused ultrasound (HIFU/FUS) has expanded as a noninvasive quantifiable option for hyperthermia (HT). HT in a temperature range of 40–47 °C (thermal dose CEM43 ≥ 25) could ...work as a sensitizer to radiation therapy (RT). Here, we attempted to understand the tumor radiosensitization effect at the cellular level after a combination treatment of FUS+RT.
Methods
An in vitro FUS system was developed to induce HT at frequencies of 1.147 and 1.467 MHz. Human head and neck cancer (FaDU), glioblastoma (T98G), and prostate cancer (PC-3) cells were exposed to FUS in ultrasound-penetrable 96-well plates followed by single-dose X‑ray irradiation (10 Gy). Radiosensitizing effects of FUS were investigated by cell metabolic activity (WST‑1 assay), apoptosis (annexin V assay, sub-G1 assay), cell cycle phases (propidium iodide staining), and DNA double-strand breaks (γH2A.X assay).
Results
The FUS intensities of 213 (1.147 MHz) and 225 W/cm
2
(1.467 MHz) induced HT for 30 min at mean temperatures of 45.20 ± 2.29 °C (CEM43 = 436 ± 88) and 45.59 ± 1.65 °C (CEM43 = 447 ± 79), respectively. FUS improves the effect of RT significantly by reducing metabolic activity in T98G cells 48 h (RT: 96.47 ± 8.29%; FUS+RT: 79.38 ± 14.93%;
p
= 0.012) and in PC-3 cells 72 h (54.20 ± 10.85%; 41.01 ± 11.17%;
p
= 0.016) after therapy, but not in FaDu cells. Mechanistically, FUS+RT leads to increased apoptosis and enhancement of DNA double-strand breaks compared to RT alone in T98G and PC-3 cells.
Conclusion
Our in vitro findings demonstrate that FUS has good potential to sensitize glioblastoma and prostate cancer cells to RT by mainly enhancing DNA damage.
Focused ultrasound (FUS) is a non-invasive technique producing a variety of biological effects by either thermal or mechanical mechanisms of ultrasound interaction with the targeted tissue. FUS could ...bring benefits, e.g., tumour sensitisation, immune stimulation, and targeted drug delivery, but investigation of FUS effects at the cellular level is still missing. New techniques are commonly tested in vitro on two-dimensional (2D) monolayer cancer cell culture models. The 3D tumour model-spheroid-is mainly utilised to mimic solid tumours from an architectural standpoint. It is a promising method to simulate the characteristics of tumours in vitro and their various responses to therapeutic alternatives. This study aimed to evaluate the effects of FUS on human prostate and glioblastoma cancer tumour spheroids in vitro. The experimental follow-up enclosed the measurements of spheroid integrity and growth kinetics, DNA damage, and cellular metabolic activity by measuring intracellular ATP content in the spheroids. Our results showed that pulsed FUS treatment induced molecular effects in 3D tumour models. With the disruption of the spheroid integrity, we observed an increase in DNA double-strand breaks, leading to damage in the cancer cells depending on the cancer cell type.
The integration of surgical robotics into the operating room requires reliable and flexible communication with other medical devices. The IEEE 11073 SDC standard can provide the necessary ...requirements to deploy robotics for the application of focused ultrasound in radiation therapy. The aim of this work was to implement and evaluate an SDC compliant connection between two collaborative robots. For this purpose, the KUKA LBR iiwa 7 R800 was adapted and the connectivity modelled and then tested successfully with 42 transmittable properties. Latency measurements were conducted to evaluate the network stability, resulting in a median round trip time of 10.13 ms.
All over the world, different types of nanomaterials with a diversified spectrum of applications are designed and developed, especially in the field of nanomedicine. The great variety of ...nanoparticles (NPs), in vitro test systems and cell lines led to a vast amount of publications with conflicting data. To identify the decisive principles of these variabilities, we conducted an intercomparison study of collaborating laboratories within the German DFG Priority Program SPP1313, using well-defined experimental parameters and well-characterized NPs. The participants analyzed the in vitro biocompatibility of silica and polymer NPs on human hepatoma HepG2 cells. Nanoparticle mediated effects on cell metabolism, internalization, and inflammation were measured. All laboratories showed that both nanoparticle formulations were internalized and had a low cytotoxicity profile. Interestingly, small variations in nanoparticle preparation, cell handling and the type of culture slide influenced the nanoparticle stability and the outcomes of cell assays. The round robin test demonstrated the importance of the use of clearly defined and characterized NPs and parameters for reproducible results across laboratories. Comparative analyses of in vitro screening methods performed in multiple laboratories are absolutely essential to establish robust standard operation procedure as a prerequisite for sound hazard assessment of nanomaterials.
Focused ultrasound (FUS) can be used to physiologically change or destroy tissue in a non-invasive way. A few commercial systems have clinical approval for the thermal ablation of solid tumors for ...the treatment of neurological diseases and palliative pain management of bone metastases. However, the thermal effects of FUS are known to lead to various biological effects, such as inhibition of repair of DNA damage, reduction in tumor hypoxia, and induction of apoptosis. Here, we studied radiosensitization as a combination therapy of FUS and RT in a xenograft mouse model using newly developed MRI-compatible FUS equipment. Xenograft tumor-bearing mice were produced by subcutaneous injection of the human prostate cancer cell line PC-3. Animals were treated with FUS in 7 T MRI at 4.8 W/cm
to reach ~45 °C and held for 30 min. The temperature was controlled via fiber optics and proton resonance frequency shift (PRF) MR thermometry in parallel. In the combination group, animals were treated with FUS followed by X-ray at a single dose of 10 Gy. The effects of FUS and RT were assessed via hematoxylin-eosin (H&E) staining. Tumor proliferation was detected by the immunohistochemistry of Ki67 and apoptosis was measured by a TUNEL assay. At 40 days follow-up, the impact of RT on cancer cells was significantly improved by FUS as demonstrated by a reduction in cell nucleoli from 189 to 237 compared to RT alone. Inhibition of tumor growth by 4.6 times was observed in vivo in the FUS + RT group (85.3%) in contrast to the tumor volume of 393% in the untreated control. Our results demonstrated the feasibility of combined MRI-guided FUS and RT for the treatment of prostate cancer in a xenograft mouse model and may provide a chance for less invasive cancer therapy through radiosensitization.
Robotic assistance in clinical interventions provides high precision and performance. However, the acceptance of such systems is still very low. The idea of collaborative robotics promises practical ...solutions for this problem. To further promote these ideas in the medical domain, novel concepts for user interactions are needed. This work presents a preliminary study on the recognition accuracy of touch gesture interaction with a KUKA LBR iiwa robotic arm. A recognition application utilising a set of 4 different touch gestures was implemented and evaluated by eight participants. The overall recognition accuracy of the system is 89.8%.
In the research field of nanoparticles, many studies demonstrated a high impact of the shape, size and surface charge, which is determined by the functionalization, of nanoparticles on cell viability ...and internalization into cells. This work focused on the comparison of three different nanoparticle types to give a better insight into general rules determining the biocompatibility of gold, Janus and semiconductor (quantum dot) nanoparticles. Endothelial cells were subject of this study, since blood is the first barrier after intravenous nanoparticle application. In particular, stronger effects on the viability of endothelial cells were found for nanoparticles with an elongated shape in comparison to spherical ones. Furthermore, a positively charged nanoparticle surface (NH2, CyA) leads to the strongest reduction in cell viability, whereas neutral and negatively charged nanoparticles are highly biocompatible to endothelial cells. These findings are attributed to a rapid internalization of the NH2-functionalized nanoparticles in combination with the damage of intracellular membranes. Interestingly, the endocytotic pathway seems to be a size-dependent process whereas nanoparticles with a size of 20 nm are internalized by caveolae-mediated endocytosis and nanoparticles with a size of 40 nm are taken up by clathrin-mediated internalization and macropinocytosis. Our results can be summarized to formulate five general rules, which are further specified in the text and which determine the biocompatibility of nanoparticles on endothelial cells. Our findings will help to design new nanoparticles with optimized properties concerning biocompatibility and uptake behavior with respect to the respective intended application.
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