Ammonium salts of microcrystalline cellulose-g-poly (acrylonitrile): toxicity, antioxidant and anti-inflammatory properties

Abstract

Cellulose is an excellent starting material for the construction of bioactive polymers. In the present work, we have synthesized quaternized graft copolymers of cellulose and tested their biological properties. Cellulose was grafted with acrylonitrile in a cerium ion catalyzed reaction. High yield of the grafting reaction, 89%, was achieved. Next, the poly (acrylonitrile) chains were aminated using three different amines and finally, the amino functions were quaternized using methyl iodide. In addition to chemical and physical characterization of the polymers, several tests on their bioactive properties have been conducted. The polymers turned out to have good antioxidant properties, as assessed studying how they scavenge ABTS radicals. Anti-inflammatory properties were investigated by a membrane stabilization method. The results showed that the quaternized polymers had anti-inflammatory effects and the one aminated with tris(2-aminoethyl)amine was the most significant compared with indomethacin. The cytotoxicity was evaluated in vitro against HepG2 and WI-38 cell lines. All quaternized polymers showed moderate effects against the cancerous cell line HEPG2. On the other hand, their effect against normal fibroblast WI-38 was weak. The acute toxicity in vivo was evaluated for one of the polymers, for which the LD50 was 6606 mg/kg. The high LD50 indicates the polymer is relatively non-toxic, and will be considered in future for in vivo studies.Graphical abstract