Antagonist biocompatibilities of Zn-based materials functionalized with physiological active metal oxides

Zinc coated with nanostructured ZnO flowers has received increasing attention as a versatile biomaterial for medical applications. Whatsoever, the potential of these materials to meet specific medical requirements must be explored. Despite in its infancy, surface functionalization is the key strategy to achieve this goal. The functionalization, successfully achieved with cooper (Cu), iron (Fe) or manganese (Mn) oxides (Ox), was highly dependent on the presence of the flowered structures, with the deep physicochemical characterization of these new surfaces revealing specific metal oxide distributions. The functionalization with these metal oxides resulted in distinct biological and in vitro behaviours. The biological response, assessed by fibroblast viability, hemocompatibility, and chick chorioallantoic membrane (CAM), further supported by the in vitro degradation studies, evaluated by immersion and electrochemical techniques, revealed that the deleterious role of CuOx functionalization brought potential for anti-cancer applications; with an antagonist behaviour, the functionalization with MnOx, and in a less extent with FeOx, can be used to favour wound healing in traumatic processes. Despite the possible correlation between biocompatibility and hydroxyapatite precipitation, no correlation could be drawn with the corrosion activity of these surfaces. Overall, the minor addition of relevant physiological as Cu, Fe or Mn oxides resulted in antagonist in vitro responses that can be used as expedite strategies to modulate the behaviour of Zn-based materials, contributing in this way for the design of anti-cancer or wound healing therapies.