The effect of surface modification of mesoporous silica micro-rod scaffold on immune cell activation and infiltration

Biomaterial scaffold based vaccines show significant potential in generating potent antigen -specific immunity. However, the role of the scaffold surface chemistry in initiating and modulating the immune response is not well understood. In this study, a mesoporous silica micro -rod (MSR) scaffold was modified with PEG, PEG-RGD and PEG-RDG groups. PEG modification significantly enhanced BMDC activation marker up-regulation and IL-113 production in vitro, and innate immune cell infiltration in vivo. PEG-RGD MSRs and PEG-RDG MSRs displayed decreased inflammation compared to PEG MSRs, and the effect was not RGD specific. Finally, the NIrp3 inflammasome was found to be necessary for MSR stimulated IL-113 production in vitro and played a key role in regulating immune cell infiltration in vivo. These findings suggest that simply modulating the surface chemistry of a scaffold can regulate its immune cell infiltration profile and have implications for the design and development of new material based vaccines. (C) 2016 Elsevier Ltd. All rights reserved.