Background

Primary tumors are known to shed circulating tumor cells (CTCs), promoting systemic dissemination and increasing the risk of metastasis to distant organs. Approximately 90% of cancer-related deaths are directly associated with metastasis. Several studies in animal models suggest improved overall survival following reduction in the number of CTCs in circulation. In this study, we demonstrate the capture of CTCs using a continuous blood-flow device incorporating three-dimensional glass substrates (3D GS) conjugated with affinity ligands, including anti-epithelial cell adhesion molecule (EpCAM) antibody and transferrin (Tf), in cancer patients.

Methods

A bi-spiral, plano-horizontal, optically transparent device fabricated from biocompatible resin with multiple channels for continuous blood flow was designed using a 3D printer. The circulation device comprised 14 loops capable of holding 17.5 mL of blood and containing 680 glass substrates (2 mm diameter) conjugated with anti-EpCAM antibody and transferrin. The system was mechanized for functional circulation using three pumps. Pyrogenicity resulting from blood passage through the device was evaluated in three New Zealand White rabbits according to ISO:10993-11 guidelines for systemic toxicity assessment.

Additionally, 27 blood samples from patients with early- and late-stage cancers across nine cancer types, including colorectal, lung, breast, and ovarian cancers, were processed using the OncoDialysis assay. The cohort consisted of 48.15% male and 51.85% female patients. CTCs were captured using five glass substrates from 1.5–5 mL of blood and validated using CK18 and CD45 markers through fluorescence microscopy. Samples were also analyzed using the Drug Controller, India–approved OncoDiscover technology for comparative evaluation.

Results

No hemolysis was observed as a result of the device. Continuous circulation of up to 5 mL of blood successfully demonstrated CTC capture within the flow system. All rabbits remained healthy during testing, and none exhibited an individual temperature increase of 0.5°C or more compared with controls, indicating no systemic toxicity.

The OncoDialysis assay detected CTCs in 48.15% of patients (n = 13/27), yielding a total of 14 CTCs (12 single CTCs and 2 clusters), with a mean CTC distribution of 0.51 per 1–5 mL of blood. The OncoDiscover platform isolated 23 CTCs (18 single CTCs and 5 clusters), with a mean CTC distribution of 0.8. A concurrence rate of 74.07% was observed between the two platforms. In 40.74% of cases (n = 11/27), CTCs were detected by both systems.

Conclusions

We developed a dynamic in vitro blood circulation device with demonstrated safety in animal studies, capable of selectively capturing circulating tumor cells from patient blood. Reduction of CTC burden may hold significant therapeutic potential in limiting metastatic spread and improving overall survival in epithelial-origin cancers, both in treated and untreated settings.