Proteome analysis of secretions from human monocyte-derived macrophages post-exposure to biomaterials and the effect of secretions on cardiac fibroblast fibrotic character

The use of exogenous biomolecules (BM) for the purpose of repairing and regenerating damaged cardiac tissue can yield serious side effects if used for prolonged periods. As well, such strategies can be cost prohibitive depending on the regiment and period of time applied. Alternatively, autologous monocytes/monocyte-derived macrophages (MDM) can provide a viable path towards generating an endogenous source of stimulatory BM. Biomaterials are often considered as delivery vehicles to generate unique profiles of such BM in tissues or to deliver autologous cells, that can influence the nature of BM produced by the cells. MDM cultured on a degradable polar hydrophobic ionic (D-PHI) polyurethane has previously demonstrated a propensity to increase select anti-inflammatory cytokines, and therefore there is good rationale to further investigate a broader spectrum of the cells’ BM in order to provide a more complete proteomic analysis of human MDM secretions induced by D-PHI. Further, it is of interest to assess the potential of such BM to influence cells involved in the reparative state of vital tissues such as those that affect cardiac cell function. Hence, this current study examines the proteomic profile of MDM secretions using mass spectrometry for the first time, along with ELISA, following their culture on D-PHI, and compares them to two important reference materials, poly(lactic-co-glycolic acid) (PLGA) and tissue culture polystyrene (TCPS). Secretions collected from D-PHI cultured MDM led to higher levels of regenerative BM, AGRN, TGFBI and ANXA5, but lower levels of pro-fibrotic BM, MMP7, IL-1β, IL-6 and TNFα, when compared to MDM secretions collected from PLGA and TCPS. In the application to cardiac cell function, the secretion collected from D-PHI cultured MDM led to more human cardiac fibroblast (HCFs) migration. A lower collagen gel contraction induced by MDM secretions collected from D-PHI was supported by gene array analysis for human fibrosis-related genes. The implication of these findings is that more tailored biomaterials such as D-PHI, may lead to a lower pro-inflammatory phenotype of macrophages when used in cardiac tissue constructs, thereby enabling the development of vehicles for the delivery of interventional therapies, or be applied as coatings for sensor implants in cardiac tissue that minimize fibrosis. The general approach of using synthetic biomaterials in order to induce MDM secretions in a manner that will guide favorable regenerat