RESEARCH ARTICLE Antimicrobial and antitumor activities of 1,2,4‐triazoles/ polypyrrole chitosan core shell nanoparticles Nehal Salahuddin 1 | Ahmed A. Elbarbary 1 | Mohamed L. Salem 2 | Samar Elksass 1 1 Department of Chemistry, Faculty of Science, Tanta University, Tanta, Egypt 2 Department of Zoology, Faculty of Science, Tanta University, Tanta, Egypt Correspondence N. Salahuddin, Department of Chemistry, Faculty of Science, Tanta University, Tanta 31527, Egypt. Email: nehal.attaf@science.tanta.edu.eg Funding information High Studies and Research Sector at Tanta University, Grant/Award Number: 03‐13‐02 Abstract Combination of natural biodegradable polymer with a synthetic polymer offers excel- lent properties for the support in drug delivery system. For this purpose, biodegradable conductive nanoparticle polypyrrole based on chitosan (PPC) has been prepared via oxidative polymerization of pyrrole in presence of chitosan using FeCl 3 as oxidant in acidic medium and used as a carrier for 1,2,4‐triazoles. The resultant nanoparticles were characterized by X‐ray diffraction, Fourier transform infrared analysis, transmission electron microscopy, scanning electron microscopy, and thermal gravimetric analysis. The results indicate that spherical nanoparticle of average diameter 52 Æ 8 nm was suc- cessfully prepared. The spherical particles were composed of dark sphere surrounded by grey shell. A circumferential dark ring is observed in the shell after loading 1,2,4‐ triazoles into PPC nanoparticles. The loaded triazoles were released almost linearly against time in a sustained fashion into different pH media. The mechanism of triazoles release was determined using different kinetics equations. The antibacterial activities against the gram‐negative and gram‐positive bacteria were examined. Furthermore, the antitumor activity of PPC nanoparticles loaded 1,2,4‐triazoles was also examined against Ehrlich ascites carcinoma cells and breast cancer cell line (MCF7). Polypyrrole chitosan loaded nanoparticles exhibited higher antitumor activity than 1,2,4‐triazoles. KEYWORDS antibacterial activity, antitumor activity, drug delivery, kinetics of triazole released, polypyrrole chitosan nanoparticles 1 | INTRODUCTION Nanotechnology is one of the most promising and growing technology today that shows an extremely high potential for applications in the field of medicine and biotechnology. [1] Nanostructured materials were found to be of great signifi- cance because of their inherent properties such as large surface area to volume ratio and stability. [1] Chitosan (CS) is a naturally occurring nontoxic, biocom- patible, biodegradable, cationic polysaccharide, so it has gained an increased attention in biomedical as well as pharmaceutical purposes. [2] Chitosan is very abundant, and its production is of low cost and ecologically interesting. [2] Chitosan was obtained by partial deacetylation of chitin, the major component of crustacean shells with multifunc- tional polysaccharide based on amino glycoside repeating unit. [3] Chitosan is a linear amino polysaccharide composed of randomly distributed (1 ! 4) linked D‐glucosamine and N‐acetyl‐D‐glucosamine units. [3] Due to its positive charges at physiological pH, CS is also bioadhesive, which increases retention at the site of application. [4] In addition, CS promotes wound healing, has bacteriostatic effects, and is a suitable candidate in the field of drug carrier, actuators, and tissue scaffolds. [5–7] However, the good solu- bility of CS in acidic media limits its application as drug delivery. [8] Received: 25 October 2016 Revised: 25 January 2017 Accepted: 24 February 2017 DOI: 10.1002/poc.3702 J Phys Org Chem. 2017;30:e3702. https://doi.org/10.1002/poc.3702 Copyright © 2017 John Wiley & Sons, Ltd. wileyonlinelibrary.com/journal/poc 1 of 13