DNA-scaffolded biomaterials enable modular and tunable control of cell-based cancer immunotherapies

Xiao Huang; Jasper Z. Williams; Ryan Chang; Zhongbo Li; Eric Gai; David M. Patterson; Yu Wei; Wendell A. Lim; Tejal A. Desai

Biomolecules can be loaded on the surface of DNA-scaffolded particles using one of two strategies: a) linking functional groups of the scaffolds to biomolecules through the surface step-by-step conjugation via a bifunctional linker; and b) through the direct hybridization of complementary DNA-biomolecule conjugates to the scaffold ( Fig. 2a) . In the case of a fluorescently labeled human IgG, the surface conjugation strategy resulted in saturated protein loading even with increased densities of available DNA linkers on surface (Fig 2b, Fig 1d and Fig. Supplementary 2a) . In contrast, the hybridization-guided assembly strategy showed a dramatically higher level of IgG loading for particles with denser DNA linkers, and the increase in IgG loading corresponded to the scaffold density (Fig. 2b) . The highest level of IgG loading achieved (at ~0.6 million per particle) was again comparable to the theoretical footprint limit of a spherical particle at 2 μm in diameter (~0.64 million per particle, based on ~5 nm diameter of IgG) (Fig. 2b) . For generating DNA-antibody conjugates with the minimum damage to the antibody activity, different chemistries ( Fig. Supplementary 2b,c) were attempted and the "TCEP" strategy 6 was identified as optimal, whereby the antibody hinge region was selectively reduced to expose the thiol group for 3'NH 2 -modified complimentary DNA to attach through a MAL-dPEG4-NHS linker (Quanta Biodesign). For example, anti-PD-L1 antibody All rights reserved. No reuse allowed without permission.