The extracellular matrix (ECM) modulates cell behavior, shape, and viability as well as mechanical properties. In recent years, ECM disregulation and aberrant remodeling has gained considerable attention in cancer targeting and prevention since it may stimulate tumorigenesis and metastasis. Here, we developed an in vitro model that aims at mimicking the in vivo tumor microenvironment by recapitulating the interactions between osteosarcoma (OS) cells and ECM with respect to cancer progression. We long-term cultured 3D OS spheroids made of metastatic or non-metastatic OS cells mixed with mesenchymal stromal cells (MSCs); confirmed the deposition of ECM proteins such as Type I collagen, Type III collagen, and fibronectin by the stromal component at the interface between tumor cells and MSCs; and found that ECM secretion is inhibited by a neutralizing anti-IL-6 antibody, suggesting a new role of this cytokine in OS ECM deposition. Most importantly, we showed that the cytotoxic effect of doxorubicin is reduced by the presence of Type I collagen. We thus conclude that ECM protein deposition is crucial for modelling and studying drug response. Our results also suggest that targeting ECM proteins might improve the outcome of a subset of chemoresistant tumors.

The high failure rate of anticancer drugs in clinical trials highlights the need for preclinical models that accurately reproduce the structural, biochemical, and mechanical complexity of human tumors. Conventional two-dimensional cultures and animal models often lack the physiological complexity required to predict clinical outcomes, driving the development of three-dimensional systems that better emulate the tumor microenvironment. Among these, microfluidic-based spheroid models have emerged as powerful tools for cancer research and drug screening. By integrating 3D spheroids with microfluidics, these platforms allow precise control of nutrient flow, oxygen gradients, shear stress, and interstitial pressure, while supporting co-culture with stromal, immune, and endothelial cells. Such systems enable the investigation of drug response, angiogenesis, metastasis, and immune interactions under dynamic and physiologically relevant conditions. This review summarizes recent advances in microfluidic spheroid models for cancer, covering both carcinomas and sarcomas, with an emphasis on device design, biomaterial integration, and translational validation. Key challenges remain, including technical complexity, scalability constraints, and the absence of standardized protocols. Overall, the merger of microfluidic technology with 3D spheroid culture provides a promising pathway toward predictive, ethical, and personalized preclinical testing, bridging the gap between in vitro modeling and clinical oncology.

As life expectancy increases, the population experiences progressive ageing. Ageing, in turn, is connected to an increase in bone-related diseases (i.e., osteoporosis and increased risk of fractures). Hence, the search for new approaches to study the occurrence of bone-related diseases and to develop new drugs for their prevention and treatment becomes more pressing. However, to date, a reliable in vitro model that can fully recapitulate the characteristics of bone tissue, either in physiological or altered conditions, is not available. Indeed, current methods for modelling normal and pathological bone are poor predictors of treatment outcomes in humans, as they fail to mimic the in vivo cellular microenvironment and tissue complexity. Bone, in fact, is a dynamic network including differently specialized cells and the extracellular matrix, constantly subjected to external and internal stimuli. To this regard, perfused vascularized models are a novel field of investigation that can offer a new technological approach to overcome the limitations of traditional cell culture methods. It allows the combination of perfusion, mechanical and biochemical stimuli, biological cues, biomaterials (mimicking the extracellular matrix of bone), and multiple cell types. This review will discuss macro, milli, and microscale perfused devices designed to model bone structure and microenvironment, focusing on the role of perfusion and encompassing different degrees of complexity. These devices are a very first, though promising, step for the development of 3D in vitro platforms for preclinical screening of novel anabolic or anti-catabolic therapeutic approaches to improve bone health.

Background: Angiogenesis, the process of new blood vessel formation, is critically regulated by a balance of pro- and anti-angiogenic factors. This process plays a central role in tumor progression and is modulated by tumor cells. Sphingosine-1-phosphate (S1P), a bioactive lipid signaling molecule acting via G-protein-coupled receptors (S1PR1–5), has emerged as a key mediator of vascular development and pathological angiogenesis in cancer. Consequently, targeting the S1P-S1PRs axis represents a promising strategy for antiangiogenic therapies. This study explores S1PR3 as a potential therapeutic target in osteosarcoma, the most common primary bone malignancy, which we have previously demonstrated to secrete S1P within the acidic tumor microenvironment. Methods: The effects of KRX-725-II and its derivatives, Tic-4-KRX-725-II and [D-Tic]4-KRX-725-II—pepducins acting as S1PR3 antagonists as allosteric modulators of GPCR activity—were tested on metastatic osteosarcoma cells (143B) for proliferation and migration inhibition. Anti-angiogenic activity was assessed using endothelial cells (HUVEC) through proliferation and tubulogenesis assays in 2D, alongside sprouting and migration analyses in a 3D passively perfused microfluidic chip. Results: S1PR3 inhibition did not alter osteosarcoma cell growth or migration. However, it impaired endothelial cell tubulogenesis up to 75% and sprouting up to 30% in respect to controls. Conventional 2D assays revealed reduced tubule nodes and length, while 3D microfluidic models demonstrated diminished sprouting area and maximum migration distance, indicating S1PR3’s role in driving endothelial cell differentiation. Conclusions: These findings highlight S1PR3 as a critical regulator of angiogenesis and posit its targeting as a novel anti-angiogenic strategy, particularly for aggressive, S1P-secreting tumors with pronounced metastatic potential and an acidic microenvironment.

The advancement of personalized treatments in oncology has garnered increasing attention, particularly for rare and aggressive cancer with low survival rates like the bone tumors osteosarcoma and chondrosarcoma. This study introduces a novel PDMS–agarose microfluidic device tailored for generating patient-derived tumor spheroids and serving as a reliable tool for personalized drug screening. Using this platform in tandem with a custom imaging index, we evaluated the impact of the anticancer agent doxorubicin on spheroids from both tumor types. The device produces 20 spheroids, each around 300 µm in diameter, within a 24 h timeframe, facilitating assessments of characteristics and reproducibility. Following spheroid generation, we measured patient-derived spheroid diameters in bright-field images, calcein AM-positive areas/volume, and the binary fraction area, a metric analyzing fluorescence intensity. By employing a specially developed equation that combines viability signal extension and intensity, we observed a substantial decrease in spheroid viability of around 75% for both sarcomas at the highest dosage (10 µM). Osteosarcoma spheroids exhibited greater sensitivity to doxorubicin than chondrosarcoma spheroids within 48 h. This approach provides a reliable in vitro model for aggressive sarcomas, representing a personalized approach for drug screening that could lead to more effective cancer treatments tailored to individual patients, despite some implementation challenges.

Spheroids are three-dimensional cell clusters that serve as reliable in vitro models for cancer drug screening, mimicking tumor microarchitecture and chemoresistance. Despite their potential, current spheroid culture systems lack essential but highly challenging features, such as automatic real-time imaging, treatment response assessment, and detailed live image capturing without disturbing the spheroid structure. To address these challenges, we developed a custom culture dish with a micro-patterned agarose structure, fabricated from a 3D-printed mold. This innovative tool facilitates spheroid growth and immobilization, enabling automated high-throughput imaging and data collection. It allows the microscope objective to approach the spheroid closely (within micrometers) while it floats in the culture medium, in a mapped position. Furthermore, the platform is compatible with several imaging systems, including standard, confocal and dual-photon microscopy. We successfully demonstrated the effectiveness of our platform by culturing and treating osteosarcoma spheroids with different concentrations of a standard chemotherapeutic agent and by capturing confocal images of extracellular matrix antigens in live spheroids. Additionally, we showed that the platform is compatible with viability and metabolic assays (e.g. Alamar blue and acid phosphatase), with minimal reagent consumption and cost-effective, simultaneous imaging-based assays. In conclusion, we propose an innovative platform for the study of tumor spheroids and other three-dimensional cellular structures, which allows tracking of size, shape, antigen expression, viability, and indirect monitoring of cell count over time. This advancement enhances our capacity to conduct in-depth investigations of cell behavior and therapeutic responses, contributing significantly to cancer research and drug development.