Comparison of the antioxidant properties of wound dressing materials–carboxymethylcellulose, hyaluronan benzyl ester and hyaluronan, towards polymorphonuclear leukocyte-derived reactive oxygen species

Abstract

In chronic wounds, factors are released which perpetuate inflammatory processes, including polymorphonuclear leukocyte (PMN)-derived reactive oxygen species (ROS), such as superoxide radical (O 2 − ) and hydroxyl radical ( OH) species. The glycosaminoglycan, hyaluronan, has established antioxidant properties towards ROS, although the antioxidant potential of wound dressing biomaterials, such as 75% benzyl esterified hyaluronan (BEHA) and carboxymethylcellulose (CMCH), are less characterised. This study compared the antioxidant properties of high and low molecular weight hyaluronan (HMWT HA and LMWT HA), BEHA and CMCH towards ROS, generated by stimulated PMN in vitro. The antioxidant capacities of each biomaterial were assessed by their inhibition of O 2 − -induced cytochrome C reduction, generated via PMN stimulation by phorbol myristyl acetate (PMA); and their inhibition of OH-induced 2-deoxy- d-ribose degradation, generated by PMA stimulated PMN in the presence of a ferric chloride-EDTA chelate. All biomaterials, except LMWT HA, possessed dose-dependent antioxidant properties against O 2 − , BEHA having greatest antioxidant potential, followed by HMWT HA and CMCH. HMWT HA exhibited the highest dose-dependent antioxidant properties towards OH, followed by BEHA and CMCH. LMWT HA demonstrated no antioxidant properties towards OH. These antioxidant activities, particularly towards O 2 − , may be beneficial in removing the initial source of ROS necessary for the secondary formation of OH, implicated as a causal factor for the extensive metabolic alterations observed in chronic wounds.