Sara Salatin1,2,*
Research Center for Pharmaceutical Nanotechnology, Faculty of Pharmacy, Tabriz University of Medical Sciences, Tabriz, Iran
2 Student Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran
*Correspondence: Sara Salatin, Research Center for Pharmaceutical Nanotechnology, Faculty of Pharmacy, Tabriz University of Medical Sciences, Tabriz, Iran, E-mail: sarasalatin93@gmail.com, Tel: +98 (41) 3339-2585. Fax: +98 (41) 3334-4798
Oxygen is an essential element for life. When oxygen is used by cells to produce energy, free radicals are created in the mitochondria as an outcome of adenosine triphosphate (ATP) production. Oxidation is a chemical reaction in which, electrons or hydrogens from a substance are transferred to an oxidizing agent, leading to the production of free radicals.
In vivo, the oxidized by-products are usually consisting of reactive nitrogen species (RNS) as well as reactive oxygen species (ROS) that are provided from the process of cellular redox [1]. They are naturally generated from normal cell metabolisms in situ or from external sources such as cigarette, pollution, radiation, and medication. Free radicals and oxidants are well known for playing a dual role in human as both toxic and beneficial compounds, since they are sometimes helpful and sometimes harmful to the body. The accumulation of free radicals in the body that cannot gradually be destroyed gives rise to a process called oxidative stress. Oxidative stress plays a major role in causing many chronic-degenerative diseases such as cancer, autoimmune disorders, aging, cataract, rheumatoid arthritis, cardiovascular and neurodegenerative diseases. However, the human body has developed multiple strategies for protecting itself against oxidative stress. These strategies include the production of antioxidants that are either naturally generated, or externally provided via foods or supplements. Antioxidants are defined as molecules that inhibit or slow the oxidation of other molecules by scavenge ring of free radicals [2, 3].
Antioxidants are classified into two main divisions: enzymatic and non-enzymatic antioxidants.
Antioxidant enzymes are specific, with high potential, affinity, and rates of reaction that decompose ROS with high efficacy, but they are not consumed in reaction with ROS, whereas non-enzymatic antioxidants are represented by molecules characterized by the ability to rapidly inactivate free radicals [4].
Recently, antioxidant enzymes have exhibited promise as a potent strategy in the inhibition of numerous reactive free radicals. However, their efficiency of antioxidant enzymes for use in protecting against oxidative stress is related to their ability to achieve of active enzymes at the target site at the therapeutically adequate levels [5, 6].
The encapsulation of antioxidants enzyme in nanoparticles, as colloidal delivery systems with a sub cellular size, has been reported as promising carriers enabling both guided delivery to the target site due to improve their biodistribution, bioavailability as well as to protect against drastic conditions. Recently, a group of researchers showed that superoxide dismutase incorporated into nanoparticles had neuroprotective efficacy against the oxidative challenge in a cell culture model. Another study by the same group exhibited that intracarotid injection of oxidant-loaded nanoparticles meaningfully enhanced the result of secondary injury in a rat stroke model [7-9].
The encapsulation of antioxidants enzyme in liposomes shows enhanced bioavailability and improves protective effects in animal models. Besides, polymeric nanocarriers especially the polymers based on PEG-copolymers protect encapsulated antioxidants enzyme from proteolysis and progress delivery to the target cells. Targeted advanced nanoparticles deliver antioxidants enzyme to locations of vascular oxidative stress in the cardiovascular, pulmonary and nervous systems. More developments in nanocarriers for antioxidants enzyme delivery will offer the clinical use of these materials [8-10].
Conflict of interests
The author declare that there are no conflicts of interest associated with this work.
References