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bioRxiv · 10.1101/2025.06.19.660580

Two-Photon Lithography-Fabricated Deterministic Lateral Displacement Microfluidic System for Efficient Minicell Purification in Cancer Therapy

Sharavu, S. H.·Bhagwat, S.·Konak, B. M. K.·Di Ventura, B.·Pezeshkpour, P.·Rapp, B. E.
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Abstract

Chromosome-less minicells, derived from aberrant polar division events of bacterial cells, have emerged as promising nanocarriers for targeted cancer drug delivery due to their unique characteristics. A major challenge in their purification process lies in effectively isolating such spherical minicells (<1 {micro}m) from their rod-shaped parental cells (1-10 {micro}m). This study investigates the use of Deterministic Lateral Displacement (DLD) microfluidic systems for minicell purification, leveraging Two-Photon Lithography (TPL) for the rapid prototyping of high-resolution designs optimized for this purpose. Under laminar flow conditions, we investigated key DLD design parameters including symmetric and asymmetric post gaps, outlet widths, dual post arrays, fluidic-resistance-optimized design. To enhance separation efficiency, we developed a two-stage microfluidic separation system combining a spiral inertial chip and an optimized DLD chip in series. Utilizing high-resolution TPL for chip fabrication of an inertial chip with 12 spirals and an asymmetric DLD chip with a 2 {micro}m downstream post gap, we achieved a separation efficiency of 94%. This high efficiency achieved using microfluidics for the separation of cells differing in both shape and size, demonstrates the potential of advanced microfluidic systems in cell sorting. TOCThis study presents the use of Deterministic Lateral Displacement (DLD) microfluidic systems, fabricated via high-resolution 3D printing, Two-Photon Lithography, to isolate minicells for targeted cancer drug delivery. By optimizing post geometries, array designs, fluidic resistance, and integrating a spiral inertial stage, the system achieves 94% separation efficiency. These advancements ensure high throughput, operational stability, and continuous sorting of bacterial cells. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=182 SRC="FIGDIR/small/660580v1_ufig1.gif" ALT="Figure 1"> View larger version (75K): org.highwire.dtl.DTLVardef@696f37org.highwire.dtl.DTLVardef@4c2aaorg.highwire.dtl.DTLVardef@883752org.highwire.dtl.DTLVardef@e7f513_HPS_FORMAT_FIGEXP M_FIG C_FIG

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Sharavu, S. H., Bhagwat, S., Konak, B. M. K., Di Ventura, B., Pezeshkpour, P., Rapp, B. E.. 2025-06-25. Two-Photon Lithography-Fabricated Deterministic Lateral Displacement Microfluidic System for Efficient Minicell Purification in Cancer Therapy. https://doi.org/10.1101/2025.06.19.660580

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