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The experiment was designed to examine the microsphere of the chitin-glucan complex. We formed a chitin-glucan microsphere (ChGMS) from the spray dryer technique. SEM images observed that shape of ChGMS was spherical. From particle size analyzer and SEM analysis both showed that the size of particles was in the range of 1.5 to 3.5 µm. It showed amorphous nature after the formation of microsphere particles of chitin-glucan. The effect of chitin-glucan complex and ciprofloxacin loaded chitin-glucan microsphere on Bacillus subtilis and Escherichia coli were also tested. Antibacterial analysis was indicating that the ciprofloxacin loaded chitinglucan microsphere strongly inhibited the growth of bacteria in comparison to the chitin-glucan solution. From the analysis, we can conclude that the antibacterial property was also dependent on the size of the chitin-glucan microsphere. Complexation of the chitin-glucan microsphere with ciprofloxacin improved the antibacterial activity of the chitin-glucan microsphere. [ABSTRACT FROM AUTHOR]

In this investigation we have shown the preparation of carboxylic acid containing new chromophore : 4-(3-(4-nitrophenyl) thioureido) benzoic acid and its use. The chemical modification of chitosan, e.g., chitosan- acid salt complexes is done under mild conditions. The synthesis of chromophore was carried out by conventional methods and the novel polymer complex was soluble in most of the organic solvents. The modified chitosan was analyzed by various techniques like optical properties by UV and SHG spectroscopy which showed red shift. The antibacterial activity showed obvious effect against food pathogenic bacteria. [ABSTRACT FROM AUTHOR]

The present investigation deals with the preparation of carboxylic acid containing new chromophore : 4-2-(2-hydroxy-5-(4-nitrophenyl) diazenyl) benzylidene) hydrazinyl) benzoic acid and its use for chemical modification of chitosan, e.g., chitosan-acid salt complexes under mild conditions. Optical properties of chitosan acid complexes were evaluated by UV and SHG spectroscopy which showed red shift. Antibacterial activity of prepared chitosan acid complexes showed obvious effect against food pathogenic bacteria. The novel polymer complex was soluble in most of the organic solvents. [ABSTRACT FROM AUTHOR]

Polyoxometalates are a class of stable metal-oxide clusters with great molecular diversity having significant biological applications. Firstly, europium substituted polyoxometalate K4H[Eu(α -SiW11O39)-(H2O)2].17H2O (Eu-Si-POM) was synthesized and Eu-Si-POM was encapsulated into biocompatible chitosan (CS), through ionotropic gelation technique thus synthesizing a nano-hybrid (CS-Eu-Si-POM). CS-Eu-Si-POM retained the fluorescence property even after encapsulation. The nano-hybrid CS-Eu-Si-POM was characterized using FT-IR, UV-Vis spectra, fluorescence spectra, scanning electron microscopy (SEM), atomic force microscopy (AFM) and dynamic light scattering (DLS). Eu-Si-POM was further characterized by inductively coupled plasma (ICP) technique. These characterization techniques reveal the successful encapsulation of Eu-Si-POM within CS matrix by electrostatic interaction between cationic CS and anionic Eu-Si-POM. CS-Eu-Si-POM was applied as a fluorescent probe in A549 cell lines fluorescence imaging. The antibacterial activity of (CS-Eu-Si-POM), CS and Eu-Si-POM have been tested against bacterial strains of B. subtilis gram (+) ve and P. aeruginosa gram (-) ve. The (CS-Eu-Si-POM) showed enhanced antibacterial activity as compared to bare POM and CS. [ABSTRACT FROM AUTHOR]

Designing theranostic agents that are responsive to mildly acidic and reducing tumor microenvironments for optimized imaging and chemotherapeutic effects, is of huge interest in nanomedicine. In this context, we have prepared mesoporous manganese silicate NPs and a biocompatible coating of carboxymethyl chitosan (CMC) was introduced on the surface of manganese silicate nanoparticles. In order to confer multifunctionality to the prepared nanovehicle, it was treated hydrothermally which resulted in formation of fluorescent C-dots on the surface of nanovehicle. The nanoarchitecture CD@CMC@MnSiO3 was characterized by FTIR, XRD, UV-visible and PL spectroscopy. A hydrophobic drug curcumin was loaded on the prepared nanoarchitecture and very high drug loading capacity was obtained. Drug release profile was observed at physiological pH (pH 7.4), acidic pH (pH 6.4 and 5.0) and acidic pH with reducing environment (pH 5.0 and glutathione). The prepared nanoarchitecture demonstrated exceptional pH-modulated drug release which was further enhanced in the presence of glutathione. Cellular imaging experiments conducted on SW480 cell lines confirmed potential applicability of the prepared nanoarchitecture for live cellular imaging which may also be applied for tracking of drug. [ABSTRACT FROM AUTHOR]

The present investigation deals with the anion sensing studies of prepared chitosan/methyl red dye: chitosan/hydroxy nitro azobenzaldehyde (CHNAB) and chitosan/hydroxy methyl azobenzaldehyde (CHMAB) derivatives under mild conditions. These derivatives were synthesized by 79% and ≥ 90% deacetylated chitosan, in isopropyl alcohol/water mixture and dimethyl sulfoxide. The polymers were well characterized by thermal analysis (differential scanning calorimetry, DSC and thermogravimetric analysis,TGA), FTIR, 1H-NMR, ESI-Mass spectra, birefringence and antibacterial activity and reported elsewhere. The optical property of the derivatives is an advantageous property prompted us to evaluate its anion sensing properties by UV-titrimetric method. UV-visible titration was carried out in DMSO to evaluate the binding affinities toward a set of anions (F-, Cl-, Br-, I-, CN-, AcO-, HSO4 -and H2PO4 -). In the present study, it is observed that cyanide is mainly operating as a nucleophile. These cyanide anion sensing phenomena were analyzed by UV-vis titration in dimethyl sulfoxide. The plausible sensing mechanism of the chitosan derivative for CN-recognition was established. The study on the novel design strategy may be used for sensing anions. [ABSTRACT FROM AUTHOR]

To develop a biodegradable antimicrobial composite film lignin was incorporated into chitosan in different compositions. The films were characterized by UV-visible, FT-IR and XRD techniques and evaluated for their potential antimicrobial activities against two food pathogens, namely, Gram (+) ve (Bacillus subtilis) and Gram (-) ve (Pseudomonas aeruginosa) bacteria. FT-IR results showed that an interaction among chitosan polymer matrix and lignin had occurred, absorbance band of chitosan at 3280 cm-1 for hydroxyl is shifted to ~ 3000 cm-1 with the weak intensity (in lignin, 200 µg), 1666 cm-1 for amide bond and it is shifted to 1644 cm-1; 1023 cm-1 for assigned to C-O stretching and shifted to 1066 cm-1. XRD peaks of lignin containing films were more intense, indicating that the interaction of lignin into the film matrix which induces an increase in crystallinity nature. It has been observed that there are no major changes in the thickness of chitosan films after mixing of lignin. Addition of lignin in chitosan films resulted in the decrease in water content and solubility of the composite films. Lignin (200 µg) could be well dispersed and showed strong tensile strength (TS) and ductility in the films. The composite films have shown significant antimicrobial activity against Gram (+) ve and Gram (-) ve bacteria. This study revealed that an antimicrobial chitosan film could be obtained by addition of lignin, which may give a new idea for the development of an active food packaging material. [ABSTRACT FROM AUTHOR]

Chitin-glucan complex (ChGC) was extracted from Agaricus bisporus (White Button Mushroom) biomass using a hot alkaline treatment for several times and washed with distilled water. The prepared material was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Scanning Electron Microscope (SEM), Energy-dispersive X-ray spectroscopy (EDX) and biological activity of ChGC was tested against Staphylococcus aureus, Pseudomonas aeruginosa and Bacillus subtilis, Escherichia coli. ChGC shows better antibacterial activity in comparison to native chitin. Hence, antibacterial study of ChGC may find better application opportunity in cosmetics, food packaging and medicinal fields. [ABSTRACT FROM AUTHOR]

Hydrogels have drawn great attention to researchers for its versatile kinds of properties, particularly in biomedical fields of research. The present hydrogels prepared by using chitosan as base material and acetic acid (aq) and propylene glycol as solvents for wound healing application. The durability of the hydrogels were lasted for prolong duration and its physico-chemical and biological properties were evaluated in a systematic manner. The microbiological screening has demonstrated the positive cellular mouse skin fibroblast activity against cell line (NIH 3T3). Viability was measured based on the esterase enzyme activity and plasma membrane integrity by FDA assay. The assays for cell proliferation and viability showed that prepared hydrogel was biocompatible. The studies of swelling and drug delivery were conducted with impressive results. Overall, this finding indicates the suitability of prepared hydrogel for wound healing application. [ABSTRACT FROM AUTHOR]

In our present investigation we have used chitosan-stearic acid derivative for both antibacterial screening and drug delivery applications. Stearic acid being the fatty acid with aliphatic chain homologue -CH2 - (n=16) enhanced the chemical properties of chitosan which becomes beneficial for antibacterial activity and drug delivery applications. Ciprofloxacin antibiotic was taken as a model drug for the release study. Stearic acid readily improved the permeability of incorporated ciprofloxacin drug. The prepared chitosan-stearic derivative was characterized using FTIR, XRD and DSC techniques while drug release screening was performed using UV spectrophotometer. The prepared chitosan-stearic acid derivative showed good antibacterial activity against S. aureus and E. coli bacterial strains. The drug release screening results indicated a brust release at first hour; nearly 17% in case of non crosslinked film whereas neary 19% release in stearic acid crosslinked conjugate. At later stage, the drug release becomes steady and slow in both the cases. Nearly 88% of the total drug loaded released within 48 h and later on it do not show more release probably due to interaction with chitosan and stearic acid. [ABSTRACT FROM AUTHOR]

The present study focussed on chitosan-lauric acid derivatized matrix for drug delivery. Lauric acid being the fatty acid with aliphatic chain homologue -CH2- (n=10) enhances the chemical properties of chitosan in drug delivery. Ciprofloxacin has been taken as a model drug for the release study. Lauric improved the permeability of the incorporated drug compounds. The chitosan derivative was characterized by FTIR, XRD and DSC measurement techniques and drug release study was performed by UV spectrophotometrically. The chitosan derivative shows good antibacterial activity. The release study of drug at first two hours was maximum (about 30%) and then it releases slowly. The initial burst release of drug may be due to the drug which exists on the surface of the film without being entrapped efficiently. CS-LA drug composite shows 80.2% drug release at 48 h while CS-CF composite (control) shows 83.26% drug release at 48 h. [ABSTRACT FROM AUTHOR]

In our present investigation, chitosan based prednisolone succinate prodrug conjugate (Cs - PS) has been successfully synthesized by using isopropyl alcohol/water and glacial acetic acid mixture and the film was made by solution casting method. The FTIR spectrum result confirmed the synthesis of Cs - PS. The physical parameters were analyzed by X- ray diffraction (XRD) pattern, thermal stability by differential scanning calorimetry (DSC) and morphology by scanning electron microscopy (SEM). The antimicrobial activity of the synthesized Cs/Cs - PS against various microorganisms viz. Escherichia coli, Pseudomonas aerugunosa, Bacillus subtilis and Staphylococcus aureus was evaluated by agar disc diffusion method. [ABSTRACT FROM AUTHOR]

Chitosan-methoxycinnamaldehyde derivative was prepared with crosslinker 4-methoxycinnamaldehyde by solution casting method. The prepared chitosan derivative was confirmed by Fourier transform infrared spectroscopy (FTIR). The film was evaluated by UV, XRD, thermal analysis, surface morphology and circular dichroism (CD) spectroscopy study. The CD spectrum of chitosan derivative, not shown a positive cotton effect at λ=323 nm, instead of it a broad negative signal around λ=320 nm with a decreased intensity was observed. [ABSTRACT FROM AUTHOR]

Chitosan based ciprofloxacin prodrug conjugate has been successfully synthesized using isopropyl alcohol/water and glacial acetic acid mixture and the film was made by solution casting method. The FTIR spectrum result showed that chitosan-ciprofloxacin (CH-CFX) complex exhibits an electrostatic interaction between NH3+ group of chitosan and COO- group of ciprofloxacin. The physical parameters of CH-CFX complex were analyzed by X- ray diffraction (XRD) and scanning electron microscopy (SEM). The thermal stability of chitosan and CH-CFX complex was checked by DSC. The antibacterial activity of the complex against various micro-organisms viz. Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Bacillus subtilis were evaluated and found that the antibacterial activity of CH-CFX complex was several times greater than that of parent drug ciprofloxacin. This may be due to the favourable pharmacokinetics, pharmacodynamics, excellent bacterial susceptibility and good stability of the drug conjugate. [ABSTRACT FROM AUTHOR]