Microfluidic EV Isolation for Breast Cancer Diagnosis

The patent replaces the mechanical ultracentrifugation system with a microfluidic system that uses controlled flow dynamics and affinity-based capture. The microfluidic chip creates specific flow patterns that enable efficient EV isolation without requiring high-speed rotation, thereby reducing isolation time while maintaining or improving efficiency.

The patent changes the isolation parameters by using affinity-based capture mechanisms (such as antibody-coated surfaces or aptamer-functionalized materials) within the microfluidic device. This approach shifts from physics-based separation (centrifugal force) to chemistry-based specific binding, enabling faster and more efficient EV isolation with higher selectivity.

The patent introduces affinity-based intermediaries (antibodies, aptamers, or other ligands) that specifically recognize cancer-related EV surface markers. These intermediaries are incorporated into the microfluidic device structure, enabling selective capture of tumor-derived EVs while allowing other EVs to pass through, thus achieving high selectivity without compromising isolation efficiency.

The patent applies local quality by creating regions within the microfluidic device with different functional properties. Specific zones are functionalized with cancer-marker-specific ligands to selectively capture target EVs, while other regions maintain general EV passage capabilities. This spatial differentiation of functional properties enables high selectivity while maintaining overall isolation efficiency.

The patent merges multiple separate purification steps (binding, washing, and concentrating) into a single integrated microfluidic device. The continuous flow system performs all these operations simultaneously as the plasma sample passes through the device, eliminating the need for discrete manual steps and reducing overall process complexity while maintaining high selectivity.

The patent implements continuous flow processing where the plasma sample continuously passes through the affinity-based capture zones. This continuous action enables binding, washing, and concentrating to occur simultaneously in different regions of the device, rather than requiring sequential batch processing. The continuous flow maintains constant selective capture while automatically washing away non-specifically bound materials and concentrating the target EVs in real-time.