The process of human islet isolation triggers a cascade of stressful events in the islets of Langerhans involving activation of apoptosis and necrosis and the production of proinflammatory molecules that negatively influence islet yield and function and may produce detrimental effects after islet transplantation. In this study, we showed that activation of nuclear factor-κB (NF-κB) and poly(ADP-ribose) polymerase (PARP), two of the major pathways responsible for cellular responses to stress, already occurs in pancreatic cells during the isolation procedure. NF-κB−dependent reactions, such as production and release of interleukin-6 and -8 and macrophage chemoattractant protein 1, were observed days after the isolation procedure in isolated purified islets. Under culture conditions specially designed to mimic isolation stress, islet proinflammatory responses were even more pronounced and correlated with higher islet cell loss and impaired secretory function. Here we present novel evidence that early interventions aimed at reducing oxidative stress of pancreatic cells and islets through the use of the catalytic antioxidant probe AEOL10150 (manganese [III] 5,10,15,20-tetrakis [1,3,-diethyl-2imidazoyl] manganese-porphyrin pentachloride [TDE-2,5-IP]) effectively reduces NF-κB binding to DNA, the release of cytokines and chemokines, and PARP activation in islet cells, resulting in higher survival and better insulin release. These findings support the concept that the isolation process predisposes islets to subsequent damage and functional impairment. Blocking oxidative stress can be beneficial in reducing islet vulnerability and can potentially have a significant impact on transplantation outcome.

Despite zinc oxide nanoparticles (ZnONPs) being increasingly used as carriers in biomedical fields due to their multifaceted properties and therapeutic importance, better understanding of the mechanisms and cellular consequences resulting from their interaction with cells and cellular components has been warranted. In the present study, we investigate the size-dependent interaction of ZnONPs on RBCs, and its impact on cell viability, DNA damage, ROS generation and morphological changes, employing cellular and analytical methods. Size, charge, stability and solubility were confirmed by DLS, zeta potential, ICP-AES and TEM analysis. Further ICP-AES, TEM, spectroscopic observations and cell based assays showed that ZnONPs exhibited a size dependent impact on RBCs and haemoglobin (Hb), particularly size <50 nm. Conversely, ferulic acid (FA) conjugates and serum albumin significantly reduced the adverse effects exhibited by ZnONPs. The extent of DNA damage and ROS generation is comparatively low in ZnONPs-FA than in ZnONPs alone treated cells. Thus our study documents a novel conceptualization delineating the influence of size on the material properties and therapeutic potential of nanoparticle.