The purpose of this study was to evaluate the improved characteristics of catalase (CAE) when loaded in lipidic and bienzymatic nanosomes. Lipidic and bienzymatic nanosomes containing CAE and uricase (LSCU) were manufactured in two buffer solutions. Their micromorphologies, sizes, zeta potentials, enzymatic activities, kinetic characteristics, and hydrogen peroxide-lowering effects were compared with those of free CAE and lipidic nanosomes containing only CAE (LSC). The structural change and stability mechanism were investigated using fluorescent probes. Compared with free CAE and LSC, LSCU had better physiochemical characteristics and improved in vitro enzymatic activity under different temperatures and pH conditions. In vivo bioavailability and peroxidase activity were also improved. For example, the bioavailability of LSCU was ∼450% greater than that of free CAE, and the time required for LSCU to lower hydrogen peroxide concentrations to a physiologically normal level was almost one-third the time required for free CAE and one-half the time required for LSC. The increased catalytic activity and hydrogen peroxide-lowering capabilities of CAE loaded in LSCU could be ascribed to the favorable conformational changes of CAE and the protection offered by the lipidic and bienzymatic nanosomal biomembrane. Lipidic and bienzymatic nanosomes might be promising nanocarriers for the parenteral delivery of therapeutic enzymes such as CAE.
Keywords: Catalase; Enzymatic activity; Hydrogen peroxide-lowering effect; Lipidic and bienzymatic nanosome; Mechanism; Relative bioavailability.
Copyright © 2017. Published by Elsevier B.V.