Preparation of Curdlan sulphate - Chitosan nanoparticles as a drug carrier to target Mycobacterium smegmatis infected macrophages

• Published in: Carbohydrate polymers Vol. 258; p. 117686
• Main Authors: Ravindran, Radhika, Mitra, Kartik, Arumugam, Senthil Kumar, Doble, Mukesh
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 15.04.2021
• Subjects: Cellular uptake; Chitosan; Curdlan sulphate; Endocytotic inhibitors; Gene expression; Macrophages; Polyelectrolyte complex; Cellular uptake; Curdlan sulphate; Chitosan; Endocytotic inhibitors; Macrophages; Gene expression; Polyelectrolyte complex
• ISSN: 0144-8617; 1879-1344
• DOI: 10.1016/j.carbpol.2021.117686

Graphical Representation: Curdlan produced from Agrobacterium is sulphated to produce curdlan sulphate (polyanionic) and it is mixed with chitosan solution (polycationic) to form curdlan sulphate - chitosan nanoparticles (CSC NP). d-Pinitol and Rifampicin are encapsulated into CSC NPs to form encapsulated CSC NPs and the cellular uptake is inhibited by adding different endocytosis inhibitors indicating that encapsulated CSC nanoparticles enter through multiple pathways like caveolae and clathrin-mediated pathways and macropinocytosis. [Display omitted] •Drug encapsulated nanoparticles were prepared for targeting infected macrophages.•Drug release follows a Weibull model with Initial burst followed by sustained release.•CSC NPs enter through multiple pathways like, caveolae, clathrin, macropinocytosis.•They have superior intracellular bactericidal activity when compared to free drug. In this study, curdlan sulphate - chitosan nanoparticles were prepared through polyelectrolyte complexing at a mass ratio of 2:1 respectively. The curdlan was produced by fermentation with Agrobacterium sp. ATCC 31750, which was then sulphated to form the polyanionic polymer. A first-line tuberculosis drug, Rifampicin and a phytochemical, DdPinitol, were encapsulated into Curdlan Sulphate (CS) - Chitosan Nanoparticles (C) (CSC NPs) of size 205.41 ± 7.24 nm. The drug release kinetics followed a Weibull model with initial burst release (48 % Rifampicin and 27 % d-Pinitol within 6 h), followed by a sustained release. The prepared CSC: d-PIN + RIF NPs was cytocompatible and entered the M.smegmatis infected macrophages through multiple endocytic pathways including clathrin, caveolae and macropinocytosis. They showed superior bactericidal activity (2.4–2.7 fold) within 4 h when compared to free drug Rifampicin (1.6 fold). The drug encapsulated CSC: RIF suppressed the pro-inflammatory gene (TNF-α by 3.66 ± 0.19 fold) and CSC: d-PIN + RIF increased expression of the anti-inflammatory gene (IL-10 by 13.09 ± 0.47 fold). Expression of TGF- β1 gene also increased when treated with CSC: d-PIN + RIF (13.00 ± 0.19 fold) which provided the immunomodulatory activity of the encapsulated CSC NPs. Thus, curdlan sulphate - chitosan polyelectrolyte complex can be a potential nanocarrier matrix for intracellular delivery of multiple drugs.