A novel biointerface that suppresses cell morphological changes by scavenging excess reactive oxygen species

Antioxidative biointerface: biocompatible materials scavenging reactive oxygen species

Oxidative stress caused by reactive oxygen species (ROS) occurs as events in which living tissues contact certain materials. These events include cell cultures and implantation of materials. Because of the high reactivity of ROS, they damage cells by oxidizing DNA, lipids, and proteins. Conversely, ROS also act as signaling molecules regulating cellular morphology. In particular, mitochondrial ROS are involved in the regulation of cellular physiology, including differentiation, autophagy, metabolic adaptation, apoptosis, and immunity. The balance between generation and elimination of ROS is essential for signaling pathways and proper cell function, and redox imbalance leads to cellular dysfunction and disturbs cellular homeostasis. To reduce oxidative stress, versatile antioxidants, including natural compounds, have been used; however, their poor bioavailability and pro-oxidant effects have limited the versatility of these antioxidants. Recent developments of antioxidative biointerfaces may represent a potent solution to this issue. Designed biointerfaces composed of polymer antioxidants eliminate excessive ROS at the interface between living tissues and materials, and do not disturb regulated redox balance inside cells, thus eliminating unexpected cell responses, such as inflammation and dysfunction.

Nitroxide radical polymers – a versatile material class for high-tech applications

A comprehensive summary of synthetic strategies for the preparation of nitroxide radical polymer materials and a state-of-the-art perspective on their latest and most exciting applications.

Direct access to biocompatible nitroxide containing polymers

Ring-opening copolymerization of a nitroxide containing cyclic carbonate and d/l-lactide was used to directly access well-defined biocompatible polymers.

Design of antioxidative biointerface for separation of hematopoietic stem cells with high maintenance of undifferentiated phenotype

During cell cultivation, excessively generated reactive oxygen species (ROS) affect cellular properties and functions. Although cell cultivation media contain several types of low-molecular-weight antioxidants, these small antioxidants are internalized into the mitochondria and they disrupt regulated redox balance. Here, we developed a novel biointerface that effectively eliminates ROS on a cell culture surface. Poly(ethylene glycol)-b-poly[4-(2,2,6,6-tetramethylpiperidine-1-oxyl)aminomethylstyrene] (PEG-b-PMNT) was synthesized and covalently coated on a carboxyl group-activated culture dish using sec-amino groups on a PMNT segment followed by immobilization of anti-CD34 antibodies. CD34-positive hematopoietic stem progenitor cells (HSPCs) were separated from mice fetal liver cells using our polymer-coated cell culture dish. The separated HSPCs possessed intact mitochondrial membrane potential compared with those in the conventional cell cultivation system. In addition, the expression level of CD34 was maintained for an extended period on our culture dish with the antioxidative biointerface. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2080-2085, 2016.