The therapeutic half of this pairing rests on a simple but powerful physical idea. Ultrasound waves, unlike light, penetrate deeply into tissue, and they can be focused with high spatial precision while remaining non-invasive and biologically safe. When ultrasound interacts with engineered nanomaterials, it triggers a repertoire of effects: cavitation, in which microscopic bubbles oscillate and collapse; acoustic droplet vaporization, in which liquid phase-change droplets flash into gas; localized heating; mechanical forces; and the generation of reactive oxygen species. Each of these mechanisms can be harnessed to rupture cell membranes, enhance drug uptake, release payloads on demand or kill tumor cells outright. Sonodynamic therapy, the most prominent of these approaches, uses low-intensity ultrasound to activate so-called sonosensitizers accumulated at tumor sites, producing reactive oxygen species such as singlet oxygen that attack lipids, proteins and DNA, damage mitochondria and induce programmed cell death.

The review details a diverse toolbox of ultrasound-responsive carriers. Microbubbles and nanobubbles act primarily through inertial or stable cavitation, doubling as contrast agents for ultrasound imaging while generating potent mechanical forces. Inorganic nanomaterials such as titanium dioxide and molybdenum disulfide catalytically generate reactive oxygen species under ultrasound excitation, with stable physicochemical properties that ensure consistent performance. Acoustic-thermal conversion materials, including gold nanorods and carbon-based structures, transform sound energy into heat, enabling precisely controlled localized hyperthermia. Polymeric nanoparticles, built from natural polymers such as albumin, gelatin and chitosan or from synthetic polymers that self-assemble, can be engineered for conditional release, co-delivery of multiple drugs and recognition of tumor markers. At the most sophisticated end sit multifunctional hybrid materials that combine cavitation, thermoacoustic effects and controlled drug release within a single polymer or lipid matrix.

What makes the organoid side of the equation equally transformative is fidelity. Patient-derived tumor organoids are grown by culturing tumor cells from an individual patient within a three-dimensional extracellular matrix, where they self-organize into miniature versions of the original tumor. Unlike conventional two-dimensional cell lines, which undergo genetic drift during passaging and lack stromal context, organoids preserve the genomic landscape, histopathological architecture, cellular heterogeneity and key components of the tumor microenvironment of the parent tumor. Animal models, meanwhile, suffer from interspecies differences and translational limitations. The review traces the field’s history from the isolation of the first human embryonic stem cell line in 1998, through Yoshiki Sasai’s pioneering concept of simulating embryonic development in three dimensions and Hans Clevers’ definition of the organoid, to the derivation of patient-derived tumor organoids from colorectal, breast and pancreatic cancers between 2013 and 2015, and on to today’s era of high-throughput automation, multi-omics integration and artificial intelligence.

The synergy between the two technologies is where the review’s central argument takes shape. Organoids provide a clinically relevant human biological context for evaluating behaviors of ultrasound nanomaterials that flat cultures simply cannot capture: how deeply nanoparticles penetrate a three-dimensional extracellular matrix, how efficiently they target heterogeneous cell populations, and how they modulate an immune microenvironment. Conversely, ultrasound nanotechnology transforms the organoid from a static drug-testing model into a dynamic platform capable of physical intervention and mechanistic investigation. In a three-dimensional environment, the distribution of the acoustic field, cavitation effects and thermal effects differ significantly from those in a two-dimensional plane, meaning that results generated in organoids carry substantially greater clinical predictive value.

Concrete experimental capabilities illustrate the point. By co-incubating organoids with fluorescently labeled or dye-loaded ultrasound-responsive nanomaterials and then applying ultrasound, researchers can use confocal laser scanning microscopy to quantify penetration depth, spatial distribution uniformity and accumulation differences between core and peripheral cells. Cavitation from microbubbles can physically loosen the extracellular matrix and transiently reduce interstitial pressure, and changes in nanoparticle penetration before and after sonication can be measured directly, validating acoustically enhanced delivery. In advanced vascularized organoid models, the entire delivery pathway, from extravasation across endothelial networks to diffusion through tumor parenchyma, can be simulated in vitro. Real-time imaging adds a theranostic dimension: microbubbles serve as excellent ultrasound contrast agents, while phase-change nanodroplets transition from liquid to gas under ultrasonic excitation, generating intense nonlinear signals, and lanthanide-doped materials can function simultaneously as contrast agents for ultrasound, photoacoustic and magnetic resonance imaging.

The platform also opens a window onto therapeutic heterogeneity and resistance, two of the most stubborn problems in oncology. Single-cell sequencing or flow cytometry of treated organoids can identify sensitive and resistant cell clusters, revealing, for example, whether sonodynamic therapy preferentially eliminates highly metabolic proliferating cells while sparing quiescent cancer stem cells. Long-term treatment-relapse experiments, in which multiple rounds of ultrasound-nanotherapy are applied, allow researchers to observe clonal evolution and identify gene and pathway changes associated with acquired resistance. On the immunotherapy front, co-culturing immune cells with patient-derived organoids creates so-called immuno-organoids in which sonodynamic therapy’s induction of immunogenic cell death can be watched directly: dendritic cell maturation, antigen presentation and the activation and tumor-infiltrating capacity of cytotoxic T lymphocytes can all be quantified, providing evidence of an in situ vaccine effect. Ultrasound-responsive materials can further remodel the immune microenvironment by depleting regulatory T cells, reprogramming tumor-associated macrophages and disrupting physical barriers to enhance T cell infiltration, converting immunologically cold tumors into hot ones.

The review catalogs recent exemplars of the underlying nanomaterial science. Tin monosulfide nanoparticles have been developed as highly efficient nano-ultrasound sensitizers for fibroproliferative triple-negative breast cancer, overcoming stromal barriers. A holo-transferrin platform with in-situ-grown manganese dioxide, coupled to the sonosensitizer protoporphyrin, crosses the blood-brain barrier for high-specificity magnetic resonance imaging and sonodynamic therapy of glioblastoma. Functionalized graphene nanoribbons have been used to block ovarian cancer spheroid adhesion and enable sonodynamic ablation. A tumor microenvironment-responsive calcium carbonate-platinum-titanium dioxide nanocomposite combines calcium ion overload with sonodynamic immunotherapy, while a multifunctional hydrogel delivering Prussian blue nanozyme and the sonosensitizer Ce6 achieves combined photothermal and sonodynamic therapy. A porphyrin-based copper sensitizer exploits tumor glutathione to restore sonosensitivity, and an ultrasound-responsive, in-situ-gelling hydrogel nanocomposite normalizes the extracellular matrix while delivering tranilast to potentiate immune checkpoint blockade. In organoid-relevant work, a bimetallic copper nitroprusside nanosystem showed low toxicity toward normal liver organoids but potent antitumor effects in high-grade serous ovarian cancer organoids regardless of platinum resistance, and silver nitroprusside proved biocompatible toward normal mouse organoids while toxic toward patient-derived tumor organoids by altering redox balance.

Technological integration is accelerating on several fronts. Organoid-on-a-chip platforms use microfluidics to replicate organ structure and function, applying fluid shear stress to simulate blood-borne drug delivery and enabling real-time, high-content imaging; one multilayer chip co-culturing mesenchymal stem cells and peripheral blood mononuclear cells successfully predicted immunotherapy responses in hepatocellular carcinoma patients. Artificial intelligence is entering the workflow as well: a convolutional neural network called DenseNet 121 can predict the differentiation of kidney organoids from simple bright-field images non-invasively, and hybrid physics-based and deep-learning frameworks can reproduce tumor organoid morphogenesis across culture conditions. The clinical infrastructure is maturing too. As of September 2023, 159 organoid-related cancer projects were registered on ClinicalTrials.gov, organoid drug sensitivity data have been shown to correlate with patient outcomes in bladder and breast cancer, and in July 2022 the U.S. FDA for the first time approved preclinical data from organoid models to support initiation of a clinical trial. In 2024, Chinese experts published the first consensus on organoid drug sensitivity testing in Theranostics.

The authors are candid about the obstacles standing between this vision and routine practice. Ultrasound attenuation, scattering and focusing behave differently in three-dimensional organoids than in homogeneous solutions, so standardized exposure protocols are needed for reproducibility. Organoid platforms face batch-to-batch variability, a lack of standardized culture protocols, unstable long-term immune co-cultures and an inability to fully recapitulate systemic factors such as vascularization and neural innervation. Organ-on-a-chip materials like polydimethylsiloxane suffer from nonspecific drug adsorption, and scaling laboratory prototypes into industrially manufacturable products remains expensive. Ethical frameworks governing organoid establishment and data ownership, along with construction costs and the two-to-three-week turnaround for organoid generation, also constrain adoption. Yet the trajectory the review sketches is unmistakable: a closed-loop translational cycle running from patient to organoid to personalized treatment optimization and back to clinical decision-making, with artificial intelligence generating automated drug response scores and repeat biopsies spawning fresh organoids whenever resistance emerges. If standardization, automation and interdisciplinary integration continue on their current course, the authors conclude, this convergence could finally deliver on the long-promised vision of testing drugs on a patient’s avatar in vitro before a single dose is given.

Subject of Research: Ultrasound-responsive nanomaterials evaluated in patient-derived tumor organoids for precision cancer therapy

Article Title: Ultrasound-responsive nanomaterials for precision therapy in tumor organoids

Article References: Bai, X., Zhao, H., Zhao, Y., Zhou, W., Pang, L., Cheng, W., Yang, K., & Wu, B. (2026). Ultrasound-responsive nanomaterials for precision therapy in tumor organoids. Holistic Integrative Oncology, 5(1), Article 45. https://doi.org/10.1007/s44178-026-00266-9

Image Credits: AI Generated

DOI: 10.1007/s44178-026-00266-9

Keywords: ultrasound, nanomaterials, tumor organoids, sonodynamic therapy, precision oncology, drug delivery, tumor microenvironment, immunotherapy, organ-on-a-chip, artificial intelligence, personalized medicine, reactive oxygen species