Protection Of Self-assembled Trolox-chitosan Nanoparticles On Caenorhabditis Elegans In Oxidative Stress

Chitosan nanoparticles, because of their excellent loading capacity, have beenextensively studied for delivery of genes, proteins, and drugs with low molecularweight. Because some drawbacks are associated with preparation of chitosannanoparticles, the sizes of chitosan nanoparticles, which are used to load drugs,are almost above100nm. Nowadays, there are scarcely chitosan nanoparticlesexemplified, which are less than50nm. However, it is demonstrated that theabsorbance and availability of chitosan nanoparticles are all closely related to thesizes of them. Small nano-sized chitosan nanoparticles could probably promote cellsor tissues to absorb active biomoleculars. Therefore, we prepared small nano-sizedTrolox-chitosan nanoparticles and studied their protection effects on oxidativedamage to Caenorhabditis elegans, just as followings:1、 Studies on preparation, characterization and biocompatibility of smallnano-sized chitosan nanoparticlesChitosan with low molecular weight was got through the methods of oxidativedegradation. And then, Epoxy ethane was added into chitosan solution to modifychitosan with hydroxyethyl group. Finally, small nano-sized chitosan nanoparticleswere formed through self-assembling method. The results of Transmission ElectronMicroscope (TEM) and Atom Force Microscope (AFM) indicated that the sizes ofuniform sized chitosan nanoparticles were about30nm. MTT [3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay, further showed that chitosannanoparticles were characteristic of no toxicity and excellent biocompatibility.Moreover, Although Trolox is called water-soluble vitamin E, the solubility of Troloxis still very low, which directly restricts the biological availability of Trolox. In thisstudy, Trolox was encapsulated into chitosan nanoparticles by means ofself-assembling. The solubility of Trolox in solution of chitosan nanoparticles washigher27times than Trolox alone, which also indicated that chitosan nanoparticlesprepared in our study had the excellent ability of loading capacity of small moleculars.2、Establishing the model of Paraquat’s oxidative damage on Caenorhabditiselegans.To verify antioxidant activity of Trolox-chitosan nanoparticles, it was in the firstplace to establish the experiment model which1mmol/L Parauat stressed onCaenorhabditis elegans.When Caenorhabditis elegans were in a state of oxidative stress, the content of freevadicals in their body has been higher than normal physiological level.Therefore itwas happened that antioxidant balance has been broken, the production of oxidativestress has been prompted, the damage of biological macromolecules (such asproteins、lipids and DNA) has been induced, moreover cells have been dead andfinally it has leaded to a series of oxidative stress related pathological process.3、The protection of self-assembled Trolox-chitosan nanoparticles onCaenorhabditis elegans in stress.(1) The experiment results that elegans longevity and the number of its offsprings wasaffected displayed that Trolox-chitosan nanoparticles had better protection on theelegans than Trolox-monomer and further extension on elegans’ lifespan inoxidative stress. Whether in regular growth or in oxidative stress, Trolox-chitosannanoparticles could increase the number of elegans’ offsprings.(2) The experiment results that the exercise and taking food capacity of elegans wasaffected showed that it was the fourth day that Trolox-chitosan nanoparticles hadthe best protection on exercise and taking food capacity of elegans, which wasseparately increased by42.64%and345%than blank Group CTRL on eachcapacity, similarly which was separately increased by22.67%and50.85%thanGroup Trolox in oxidative stress.(3) The experiment results that the scavenging activities of ROS and lipofuscin inelegans was affected showed that Trolox-chitosan nanoparticles had betterscavenging activities of ROS and lipofuscin than Trolox monomer in oxidativestress so elegans were given more protection.(4) The experiment results that the location of protein DAT-16was affected showed that Trolox-chitosan nanoparticles could promote protein DAT-16moving to cellnucleus further and enhance the rate of distribution of it in nucleus by observingthe distribution in cytoplasm、nucleus and something between them of proteinDAT-16in mutant elegans TJ356.