Chitosan Nanocomposites

**97**

**Chapter 5**

**Abstract**

**1. Introduction**

Wound Dressing Application of

In this work, carbon dots (CDs), obtained through microwave assisted synthesis from butane tetra carboxylic acid (BTCA), was introduced into chitosan film via simple solvent casting approach. The CDs had an average diameter of 40 to 60 nm as determined by Transmission Electron Microscopy (TEM) analysis. They possessed a zeta potential of −20.2 mV. The X-ray photon spectroscopy (XPS) confirmed presence of carboxylate groups on the surface of carbon dots. The XRD of both the plain sample Ch/CD (0) and carbon dots loaded sample Ch/CD(2) showed two crystalline sharp peaks at 14.6 and 18.1 degree, along with presence of amorphous region also. The moisture absorption data was well fitted on GAB isotherm and the profiles obtained were sigmoidal. The water vapor permeation rates for the

/day respec-

conjugated core

Ch/CD Nanocomposite Film

sample Ch/CD(0) and Ch/CD(2) were found to be 1758 and 956 g/m2

**Keywords:** chitosan film, carbon dots, biocompatible, percent hemolysis

material formultiple applications [1, 2]. Usually they possess a sp2

In recent past, carbon dots have gained considerable importance as a versatile

with various oxygencontaining functionalities such as carboxyl, hydroxyl, aldehyde groups etc. [3, 4]., ease of functionalization, and production of fluorescence on UV exposure,carbon dots (CDs) find a number of biomedical applications like bioimaging [5–7], targeteddrug delivery [8, 9], wound dressings [10], cancer theranostics [11], screening the purinemetabolic disorders in human fluid etc. [12]. Carbon dots (luminescent) nanoparticles can be usedto track biological processes inside cells. A thorough literature survey reveals that there has not been even a single study which discussesthe changes in physico-chemical properties of chitosan film due to impregnation of carbon dotsinto film matrix. With this objective, we have previously reported synthesis and characterizationof carbon dots from butane tetra carboxylic acid (BTCA) and preliminary investigation of waterabsorption behavior of chitosan/carbon dots nanocomposite film [13]. In continuation, we hereby report a detailed investigation of physico-chemical properties and biocompatibility of

"0", suggesting their non-cell cytotoxic nature.

tively. The film samples Ch/CD(0) and Ch/CD(20 expanded 2.8 and 103 times when immersed in 4% gelatin solution for 4 h. The % hemolysis for the samples Ch/ CD(0) and Ch/CD(2) was 2.12 and 1.11 respectively, thus indicating biocompatible nature of the films. In the ex-vivo mucoadhesion study, the maximum detachment force (Fmax) was 88.22 and 46.28 mN for the samples Ch/CD(0) and Ch/CD(2) respectively. Finally, both of the samples, namely Ch/CD (0) and Ch/CD(2) scored

*Ranju Kandra and Sunil Bajpai*
