Characterization on co-delivery of Superoxide Dismutase and Glutathione Peroxidase by Using Nanoparticles

Mesoporous silica nanoparticle (MSN) was used as a multifunctional material because of its characteristics, such as high surface area, uniform pore size and easy functionalization. Besides, MSN is very suitable for biological applications such as controlled drug release, cell labeling and enzyme delivery due to the properties of biocompatibility and degradability.
As well known, ROS played a crucial role in many diseases and was defensed by superoxide dismutase (SOD) and glutathione peroxidase (GPx) which are two major antioxidant enzymes in physiological condition. The SOD scavenges superoxide radicals into hydrogen peroxide and GPx can convert hydrogen peroxide into water. In this study, we designed a catalytic MSN as a nanoreactor for scavenging ROS to reduce oxidative damages. The nanoreactor consists of three parts; namely, MSN, tether and enzymes. MSN was first synthesized with FITC and then modified by conjugating silane tether (NTA-Ni) to form FMSN-NTA-Ni. The fusion proteins of His-tagged TAT-hSOD and His-tagged TAT-hGPx were constructed and expressed by using genetic engineering method. Finally, the two fusion proteins are conjugated on the MSN surface respectively through the nickel and His-tagged interaction to compose sequential ROS scavengers. HIV transactivator protein (TAT) containing MSN was considered as an effective method in order to increasing the transmembrane permeability of nanoparticles.
We finally demonstrated a two different functionalized-MSNs co-delivery into cells which can decline ROS efficiently. This study becomes a novel and promising tool for future therapeutic approach.