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

Another advantageous feature of using DNA as a surface scaffold is that the uniqueness of nucleotide sequences enables the independent control of loading multiple cargos on the same material surface (Fig 2d) . Polymer-DNA conjugates with three distinct DNA sequences (namely R, G, and B strand) that do not anneal with each other (Fig. Supplementary 2f) were synthesized and incorporated into particle emulsion with reaction mixtures at different ratios (3:1:1, 1:1:1 and 1:1:3). After surface hybridization with a mixture of their respective dye-labeled complementary strands (Fig. 2d) , we found that the ratios of hybridized DNA scaffolds of different sequences on PLGA microparticles were consistent with the polymer-DNA conjugate input, evidenced by both confocal fluorescence imaging (Fig. 2e) and a fluorescencebased quantification assay (Fig. 2f) . The ratiometric control of dye-labeled DNA strand loading was equally efficient for PLA microparticles (Fig. Supplementary 2g ,h). Based on this, we co-loaded three different proteins (GFP and two antibodies), each individually attached with one of the three complementary DNA strands, onto PLGA microparticles with varying ratios of the DNA surface scaffold sequences above. Similar distribution of each protein cargo compared with the scaffold population was observed (Fig. 2g) , demonstrating the robust ratiometric control of surface protein loading using this particle synthesis strategy.