Shock wave impact on the viability of MDA-MB-231 cells

Extracorporeal shock waves effectively suppress colorectal cancer proliferation and growth

Shock waves are widely used to treat various diseases and have numerous medical applications. In particular, extracorporeal shock waves (ESV) can substantially inhibit tumour growth. However, the therapeutic efficacy of ESV in colorectal cancer and its underlying mechanisms are not well understood. To address this gap in our knowledge, colorectal cancer cell lines HT29 and SW620 were used to generate xenograft mouse models and examined the therapeutic effects of a stepwise increase in ESV energy on tumour growth. In vivo, 60 mJ ESV significantly delayed xenograft growth compared with 120 and 240 mJ ESV, with no impact on body weight or hepatic and renal function. Transcriptome analysis revealed that 60 mJ ESV suppressed colorectal cancer cell proliferation and induced apoptosis and ferroptosis; these findings were further confirmed by immunohistochemical staining and western blotting. The in vitro study showed that ESV mechanistically suppressed cell proliferation and induced apoptosis and ferroptosis by activating the p53 signaling pathway. In conclusion, 60 mJ ESV substantially inhibited colorectal cancer growth by activating p53 pathway-related proliferation inhibition and cell death. These findings indicate that ESV therapy is a promising therapeutic strategy for colorectal cancer.

In vitro effect of Er: YAG laser irradiation in caries cavity preparation on biobehaviors of adjacent human dental pulp cells in the pulp chamber

The erbium-doped yttrium aluminum garnet (Er: YAG) laser has been successfully applied in caries removal; however, little is known about proper parameters of Er: YAG laser on different conditions of caries removal, especially the influence of Er: YAG irradiation on human dental pulp cells (hDPCs). Here, we tested the effects of Er: YAG laser at different output energy levels (100, 200, 300, 400, and 500 mJ) on biobehaviors of hDPCs. To simulate clinical deep caries conditions, hDPCs were cultured on the pulpal side of 500-μm-thick dentin disks in an in vitro pulp chamber model. Temperature change, structural change, and ablation depth of dentin disk were also recorded. The findings suggested that the biological behaviors of hDPCs are strongly correlated with the energy output of the Er: YAG laser. Er: YAG laser irradiation at 100 mJ may be proper and safe for deep caries removal since it would not cause any adverse effect on hDPCs biobehaviors.

Enhanced Therapeutic Effects of an Antitumor Agent on Subcutaneous Tumors in Mice by Photomechanical Wave-based Transvascular Drug Delivery

Purpose: We previously developed a site-selective transvascular drug delivery system based on nanosecond pulsed laser-induced photomechanical waves (PMWs). In this study, we applied this method to the delivery of cisplatin (cis-diamminedichloroplatinum, CDDP) to a subcutaneous tumor in a mouse and examined its antitumor effects. Methods: A mouse tumor model with subcutaneous inoculation of human head and neck cancer cells (FaDu cells) was used. The mice were divided into four groups: control without any treatment (control), CDDP application only (CDDP only), PMW application only (PMW only) and combined application of PMWs and CDDP (PMW+CDDP). A PMW was generated by irradiating a laser target, which was placed on the skin over the tumor, with a ruby laser pulse (fluence, 1.6 J/cm²). A CDDP solution was intraperitoneally injected into the mice (2.5 mg/kg). Results: Until 7 days posttreatment, the tumor volume in the control group monotonically increased, while the tumor volumes in the CDDP-only group and PMW-only group did not change greatly and that in the PMW+CDDP group slightly decreased. Afterward, the tumors started to regrow in all treatment groups, but the tumor growth rate was considerably low in the PMW+CDDP group. There was a significant difference in the time courses of tumor volume between the PMW+CDDP group and the control group for up to 14 days posttreatment. The ratio of the Ki-67-positive (proliferative) areas to the whole tumor regions in the PMW+CDDP group was significantly smaller than that in the control group at 7 days posttreatment. These results are attributable to the synergistic effects of enhanced extravasation of CDDP and mechanical tumoricidal effect by PMWs. Conclusion: The combined application of CDDP and PMWs significantly improved the antitumor effects on mouse subcutaneous tumors.

Mechanotherapy in oncology: Targeting nuclear mechanics and mechanotransduction

Mechanotherapy is proposed as a new option for cancer treatment. Increasing evidence suggests that characteristic differences are present in the nuclear mechanics and mechanotransduction of cancer cells compared with those of normal cells. Recent advances in understanding nuclear mechanics and mechanotransduction provide not only further insights into the process of malignant transformation but also useful references for developing new therapeutic approaches. Herein, we present an overview of the alterations of nuclear mechanics and mechanotransduction in cancer cells and highlight their implications in cancer mechanotherapy.

Shockwaves Increase In Vitro Resilience of Rhizopus oryzae Biofilm under Amphotericin B Treatment

Acoustical biophysical therapies, including ultrasound, radial pressure waves, and shockwaves, have been shown to harbor both a destructive and regenerative potential depending on physical treatment parameters. Despite the clinical relevance of fungal biofilms, little work exits comparing the efficacy of these modalities on the destruction of fungal biofilms. This study evaluates the impact of acoustical low-frequency ultrasound, radial pressure waves, and shockwaves on the viability and proliferation of in vitro Rhizopus oryzae biofilm under Amphotericin B induced apoptosis. In addition, the impact of a fibrin substrate in comparison with a traditional polystyrene well-plate one is explored. We found consistent, mechanically promoted increased Amphotericin B efficacy when treating the biofilm in conjunction with low frequency ultrasound and radial pressure waves. In contrast, shockwave induced effects of mechanotransduction results in a stronger resilience of the biofilm, which was evident by a marked increase in cellular viability, and was not observed in the other types of acoustical pressure waves. Our findings suggest that fungal biofilms not only provide another model for mechanistical investigations of the regenerative properties of shockwave therapies, but warrant future investigations into the clinical viability of the therapy.

Extracorporeal Shock Wave Enhances the Cisplatin Efficacy by Improving Tissue Infiltration and Cellular Uptake in an Upper Urinary Tract Cancer Animal and Human-Derived Organoid Model

Upper urinary tract urothelial carcinoma (UTUC) is a relatively rare cancer with a poor prognosis if diagnosed at an advanced stage. Although cisplatin-based chemotherapy is a common treatment strategy, it has a limited response rate. Shock wave lithotripsy is a common treatment for upper urinary tract stones. Low-energy shock waves (LESWs) temporarily increase tissue permeability and enhance drug penetration to the targeted tissue. However, no study has investigated the efficacy of the combination of shock wave lithotripsy and chemotherapy in UTUC. Hence, in this study, we aimed to identify the potential application of the combination of LESW and chemotherapy in UTUC. We evaluated the synergistic effects of LESW and cisplatin in vitro, in vivo, and in patient-derived organoid (PDO) models. Compared with cisplatin alone, the combination treatment caused more significant tumour suppression in vitro and in animal models, without increased toxicity. Histological examination showed that compared with animals treated with cisplatin alone, those who received the combination treatment showed more deteriorated cell arrangement and cell oedema. Moreover, LESW improved the cytotoxicity of cisplatin in the preclinical PDO model of UTUC. Thus, LESW combined with cisplatin is a potential new antitumour strategy for improving the treatment response in locally advanced UTUC.

Evolution of Shock-Induced Pressure in Laser Bioprinting

Laser bioprinting with gel microdroplets that contain living cells is a promising method for use in microbiology, biotechnology, and medicine. Laser engineering of microbial systems (LEMS) technology by laser-induced forward transfer (LIFT) is highly effective in isolating difficult-to-cultivate and uncultured microorganisms, which are essential for modern bioscience. In LEMS the transfer of a microdroplet of a gel substrate containing living cell occurs due to the rapid heating under the tight focusing of a nanosecond infrared laser pulse onto thin metal film with the substrate layer. During laser transfer, living organisms are affected by temperature and pressure jumps, high dynamic loads, and several others. The study of these factors’ role is important both for improving laser printing technology itself and from a purely theoretical point of view in relation to understanding the mechanisms of LEMS action. This article presents the results of an experimental study of bubbles, gel jets, and shock waves arising in liquid media during nanosecond laser heating of a Ti film obtained using time-resolving shadow microscopy. Estimates of the pressure jumps experienced by microorganisms in the process of laser transfer are performed: in the operating range of laser energies for bioprinting LEMS technology, pressure jumps near the absorbing film of the donor plate is about 30 MPa. The efficiency of laser pulse energy conversion to mechanical post-effects is about 10%. The estimates obtained are of great importance for microbiology, biotechnology, and medicine, particularly for improving the technologies related to laser bioprinting and the laser engineering of microbial systems.