Precision oncology is an approach that tailors therapies to the genetic and molecular characteristics of each patient’s tumor. Functional precision oncology expands on this idea by identifying optimal treatment strategies based on the specific responses of individual tumors to experimental drug testing. Drug Sensitivity and Resistance Testing (DSRT) involves exposing cancer cells from patient biopsies to various anticancer drugs in vitro to determine the most effective therapy for each patient. However, this strategy often faces a number of challenges, including limited tumor cell availability, in particular from solid tumors, high costs, and long timelines for generating actionable data. These challenges are particularly significant for patients with advanced, inoperable cancers, where core needle biopsies yield small cell samples that must be shared across multiple diagnostic tests, leaving little material for DSRT. Furthermore, traditional DSRT methods, which typically rely on microtiter plates to test multiple drugs, require large amounts of cellular material and costly reagents, making them inaccessible to many patients.
In response to these challenges, miniaturization has emerged as a promising solution, enabling the development of advanced high-throughput screening platforms such as the Droplet Microarray (DMA). ... mehrThe DMA platform uses patterned hydrophilic and superhydrophobic surfaces to confine nanoliter-scale liquid droplets without the need for physical barriers. By reducing assay volumes by several orders of magnitude compared to traditional microtiter plates, the DMA platform significantly lowers cell and reagent consumption, offering a cost-effective approach to DSRT. This study presents the integration of the DMA platform into multiple functional precision oncology studies, demonstrating its application and efficacy in this field. The first project focuses on developing a miniaturized DSRT platform on primary cancer cells derived from patients’ Lung cancer tumors. The second project investigates the use of decitabine to sensitize glioblastoma cells and identifies drugs that, when paired with decitabine, demonstrate enhanced efficacy against glioblastoma. The third project introduces a hydrogel-based culture system on DMA platform, capable of incorporating cells or cell spheroids while maintaining stability during washing and medium immersion.
Lung cancer remains a leading cause of cancer mortality worldwide. Current treatment strategies rely on standardized approaches such as surgery, radiotherapy and systemic therapy. In the first project, a miniaturized DSRT platform is developed using DMA technology to advance therapeutic options for this type of cancer toward functional precision oncology. Tumor samples from patients with stage I to III Non-small cell lung carcinoma (NSCLC) were dissociated into single-cell suspensions using manual and semi-automated methods and dispensed onto DMA slides pre-printed with a panel of 12 chemotherapy drugs at five different concentrations. The DMA platform demonstrated reproducible drug sensitivity results with as few as 300 cells per spot, revealing patient-specific responses. Sensitivity to vinorelbine and carboplatin varied across patients and tumor regions, emphasizing the platform’s ability to capture both inter- and intra-patient variability. Furthermore, the DMA system successfully conducted DSRT on artificial needle biopsy samples, highlighting its potential for application in patients with limited tumor material.
The second project is focused on glioblastoma (GBM), which is highly resistant to standard therapies due to epigenetic dysregulation. This study investigates a therapeutic strategy that uses decitabine (DAC), a DNA methyltransferase inhibitor, to sensitize glioblastoma cells and enhance their response to treatment, followed by high-throughput screening (HTS) of CNS-penetrating drugs. Using the DMA platform, GBM cells pre-treated with DAC were screened under miniaturized conditions (200 nL per spot) against 722 CNS-penetrating drugs. This high-throughput approach identified several promising drugs including Obatoclax Mesylate, GNE-317, Vorinostat, Trametinib, and Flavopiridol which showed significantly enhanced efficacy in DAC-pretreated cells compared to DAC-untreated cells. These findings highlight the potential of combining epigenetic sensitization, such as with decitabine, and high-throughput drug testing to overcome therapeutic resistance in GBM.
In the third project, to further enhance the physiological relevance of in vitro models, the integration of hydrogel-based 3D cell cultures into the DMA platform was investigated. Dextran-PEG hydrogels were used to create stable nanoliter-volume arrays, supporting individual cells or spheroids. Two methods were developed to generate hydrogel pads on DMA platform. In the first method cells were pre-mixed with hydrogel precursors and dispensed on the spots and the second method includes on-chip gelation of cell-laden droplets. The hydrogel arrays demonstrated high structural integrity and cell viability, maintaining spheroid stability during washing and medium immersion. The selective gelation of individual spheroids inside of nanoliter droplets enables sorting of different spheroids and their patterning in a simple way, while gelation-degelation cycles provided advanced cell manipulation capabilities. This platform offers a robust tool for high-throughput screening in 3D microenvironments with application in cancer drug screening and precision medicine.
The integration of miniaturized DSRT and 3D culture systems on the DMA platform represents a significant advancement in precision oncology. By reducing the amount of cellular material and reagents required, these technologies make comprehensive drug sensitivity testing accessible to a broader range of patients, including those with minimal biopsy samples. Moreover, the platform enables rapid and cost-effective drug screening, facilitating more personalized and effective cancer therapies. This study highlights the potential of miniaturized HTS platforms in overcoming key limitations in current workflows therefore, advancing research in different fields such as drug screening and functional precision oncology.
