Synthesis, Drug Release, and Antibacterial Properties of Novel Dendritic CHX-SrCl2 and CHX-ZnCl2 Particles

Rui Sun; Jiaxin Zhang; Robert A Whiley; Gleb B Sukhorukov; Michael J Cattell

doi:10.3390/pharmaceutics13111799

Synthesis, Drug Release, and Antibacterial Properties of Novel Dendritic CHX-SrCl₂ and CHX-ZnCl₂ Particles

Pharmaceutics. 2021 Oct 27;13(11):1799. doi: 10.3390/pharmaceutics13111799.

Authors

Rui Sun¹, Jiaxin Zhang², Robert A Whiley³, Gleb B Sukhorukov², Michael J Cattell¹

Affiliations

¹ Centre for Oral Bioengineering, Bart's and the London, School of Medicine and Dentistry, Queen Mary University of London, Turner Street, London E1 2AD, UK.
² School of Engineering and Materials Science, Queen Mary University of London, Mile End Road, London E1 4NS, UK.
³ Centre for Oral Immunobiology and Regenerative Medicine, Bart's and the London, School of Medicine and Dentistry, Queen Mary University of London, Blizzard Building, 4 Newark Street, London E1 2AT, UK.

Abstract

This work demonstrated for the first time the synthesis of novel chlorhexidine particles containing strontium and zinc, to provide an effective, affordable, and safe intervention in the treatment of recurrent infections found in Medicine and Dentistry. The CHX-SrCl₂ and CHX-ZnCl₂ particles were synthesized by co-precipitation of chlorhexidine diacetate (CHXD) and zinc chloride or strontium chloride, where particle size was manipulated by controlling processing time and temperature. The CHX-ZnCl₂ and CHX-SrCl₂ particles were characterized using SEM, FTIR, and XRD. UV-Vis using artificial saliva (pH 4 and pH 7) was used to measure the drug release and ICP-OES ion release. The antibacterial properties were examined against P. gingivalis, A. actinomycetemcomitans, and F. nucleatum subsp. Polymorphum, and cytotoxicity was evaluated using mouse fibroblast L929 cells. The novel particles were as safe as commercial CHXD, with antibacterial activity against a range of oral pathogens. UV-Vis results run in artificial saliva (pH 4 and pH 7) indicated a higher release rate in acidic rather than neutral conditions. The CHX-ZnCl₂ particles provided the functionality of a smart Zinc and CHX release, with respect to environmental pH, allowing responsive antibacterial applications in the field of medicine and dentistry.

Keywords: antibacterial; chlorhexidine; controlled release; drug delivery; particulate delivery systems.