Adaptive immune cell reactivity to polycaprolactone, alginate, chitosan, and zein nanofibers

This study explores how nanofiber chemical composition influences human immune cell responses, a key factor in the body's defense against foreign substances. Nanofiber mats composed of polycaprolactone (PCL), alginate (ALG), chitosan (CS), and zein were incubated with both unstimulated and phytohemagglutinin-L-stimulated peripheral blood mononuclear cells (PBMCs), as well as immature and mature monocyte-derived dendritic cells (MoDCs). We evaluated viability, metabolic activity, and cytokine release of PBMCs while in MoDCs, we assessed surface marker expression, phagocytic capacity, and allogeneic T-cell stimulatory function of MoDCs. Results demonstrate that nanofiber composition significantly influenced immune cell responses. While PCL and ALG nanofibers showed no significant effects on PBMCs, those made of CS, however, reduced their metabolic activity, warranting caution in their use. In contrast, zein nanofibers increased both metabolic activity and pro-inflammatory cytokine release of PBMCs, suggesting their potential immunogenicity. In MoDCs, PCL and CS nanofibers impaired both their phenotypic maturation and functional performance, including antigen uptake and presentation. Although zein nanofibers induced changes in MoDC surface marker expression, their overall functionality remained intact. In contrast, ALG nanofibers exhibited the highest biocompatibility, with minimal impact on both immature and mature MoDCs. This favorable profile of ALG nanofibers supports their suitability for biomedical applications, such as tissue engineering and drug delivery. Overall, our findings underscore the importance of thorough immunological safety assessment of nanofiber-based biomaterials prior to their clinical use.