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The copyright holder for this preprint (which was not peer-reviewed) is the author/funder. Macrophage uptake assay Biotin-modified "self"-peptide (biotin-miniPEG-GNYTCEVTELTREGETIIELK[Lys(FITC)], LifeTein) was loaded onto streptavidincoated PLGA microparticles using the protocol described above. The streptavidin of the control particles without "self-peptide" were labeled with NHS-fluorescein (ThermoFisher #46409) at 6 μM/OD550 for 1 hour at room temperature, followed by three washes. Murine macrophage cell line J77A4.1 (ATCC) grown on glass bottom chamber slides (Thermo Scientific #154526) was treated with lipopolysaccharides (Sigma #L4391) at 100 ng/mL for overnight. On the next day, "self"-peptide loaded particles and control particles were added at 0.03 OD550 x 200 μL and incubated at 37 o C for 1 hour. Cells were then washed three times with PBS to remove uninternalized particles and fixed using 4% paraformaldehyde (Electron Microscopy Sciences #15710) for 20 minutes. After three washes, cells were imaged using the All rights reserved. No reuse allowed without permission.