a, SEM image of mesoporous SiMPs. b, Surface chemistry to functionalize SiMP surface with heparin. c, The efficiency of heparin-conjugation on SiMPs with various initial amounts of heparin in the reaction mixture. d, In vitro degradation of heparin-functionalized SiMPs over time. e-f, Cumulative release of IL-4 (e) and TGF-β
(f) from heparin-functionalized SiMPs at 37°C. The data are presented as mean ± SD (n = 5).