One of the biggest challenges to the clinical success of allogeneic transplants is the interaction between the host immune system and foreign transplanted cells. The human immune system consists of the innate and adaptive immune systems, both highly potent, in which each branch plays a particular role in combating disease and infection. In the context of biomaterials, poorly biocompatible implants result in an aggressive foreign body reaction that is mediated largely by innate immunity. For tissue engineered implants containing cells, however, both innate and adaptive immunity play large roles. Innate provides a generalized response to the material and trauma associated with implantation, while adapative immunity is triggered by the foreign antigens presented by the cells. Further, the role of adapative immunity in biomaterials has recently been of interest, as antibodies to materials themselves has been uncovered.
As such, for implants containing cells and biomaterials, controlling immunological response to the implant is of utmost importance to permit healthy acceptance of the foreign implant. While biomaterials may be able to shield direct antigen recognition of the foreign cells, indirect antigen presentation still occurs. The use of biologically active agents that can combat immunological responses to the graft could serve to promote cell survival. These agents could be injected systemically or localized via the use of biomaterials. Biomaterials may release these agents in a drug-delivery platform or present these agents on their surface. In our laboratory, we are exploring both the capacity of local release of agents capable of directing tolerance, as well as the surface presentations of agents, such as antibodies, proteins, and/or nanoparticles, on coated surfaces. This provides a unique platform to explore the generation of immunomodulatory biomaterials that are capable of directing the host response towards tolerance of the foreign graft.
Check out our recent reviews for an overview on this topic:
Engineering immunomodulatory biomaterials for type 1 diabetes, published in Nature Reviews Materials
Nanotechnology Approaches to Modulate Immune Responses to Cell-based Therapies for Type 1 Diabetes published in the Journal of Diabetes Science and Technology
Biomedical applications of cerium oxide nanoparticles: a potent redox modulator and drug delivery agent published in the book Nanoparticles for Biomedical Applications
Our research publications on this topic are listed here
These efforts are currently being supported by an NIH R01 and JDRF