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

The direct incorporation of polymer-DNA reaction mixtures with different DNA:polymer ratios into the particle fabrication protocol yielded a significant increase of surface payload-attachable DNA scaffold density, as determined by a fluorescence-based hybridization analysis (Fig. 1d) . Strikingly, the highest average surface loading density on particles (~5 million DNA duplexes per particle, Fig. Supplementary 1e-g) was roughly analogous to the theoretical limit (at ~4 million by footprint calculation, based on ~2 nm diameter of DNA duplex) of a spherical particle with a 2 μm diameter. In particular, this hybridization-guided loading was about 27fold more efficient than that from the traditional method 33 , in which thiol-modified DNA molecules were conjugated to surface-exposed Mal groups after particle fabrication using equal input amount of PLGA10k-PEG5k-Mal (Fig. 1d) . The hybridization-guided biomolecule assembly protocol was optimized to a 30-minute incubation at 37 o C ( Fig. Supplementary 1h) , and functionalized particles can be further lyophilized for storage and transportation (Fig. Supplementary 1i) .