Fig. 2: Identification of key surface-attached protein species in relation to nanocarrier transcytosis.

a To understand the role of protein attachment on biodistribution, we gathered serum from KPC tumor-bearing mice. Subsequently, various particle variants, F1 to F3, were subjected to serum incubation, followed by mass spectrometry analysis, as outlined in the schematic (Created in BioRender. Meng, H. (2025) https://BioRender.com/ffbjjg3). b A heat map showed the most abundant proteins detected on the surfaces of the nanocarriers. We present the 46 proteins exhibiting high abundance. The lower panel is the Venn diagram of identified proteins across F1 ~ F3. The distinct protein species unique to the best-performing particle (F1) during the biodistribution study are highlighted by the α zone (in red). The β zone (in cyan) included protein types detected in F1, which also appeared in F2 and F3. c Using UniProt database, detailed protein functions for the most abundant proteins in zone α (upper part) and zone β (lower part) were provided. d Based on the findings from (c), we purchased ANX A2, ANX A3, ANX A5, ANX A7, and ANX A8. Pure VTN, albumin and GAPDH were also obtained. Following incubation of F1 particles with these protein types, an electrophoresis assay confirmed the efficient attachment of these proteins to F1 (n = 3 independent experiments). Source data are provided as a Source Data file.