P.K. Dutta

Evaluation of chitosan nano dressing for wound healing: characterization, in vitro and in vivo studies.

In our present investigation, a ternary nano dressing consists of titanium dioxide nano particle loaded chitosan-pectin was prepared to evaluate biocompatibility, antimicrobial and in vivo wound healing properties. The photoactive property of TiO₂ based materials makes it important candidate for numerous medical applications. Chitosan can be easily processed into membranes, gels, nanofibers, beads, nanoparticles, scaffolds, and sponge forms that can be used in wound healing applications. Pectin acts as a natural prophylactic substance against poisoning with toxic cations and its styptic and curing effects are well documented in healing ointments. The characterizations of prepared nano dressing were made by FTIR, TGA, DSC, SEM and TEM. The physicochemical parameters of nano dressing were evaluated by various techniques, namely, the Whole blood clotting test, haemolysis ratio measurement, cytotoxicity test using NIH3T3 and L929 fibroblast cells. The in vivo open excision-type wound healing efficiency of prepared nano dressing and its comparison with conventional gauze were evaluated by measuring wound contraction and histological examinations in adult male albino rats. The synergistic effects of nano dressing such as good antibacterial ability, high swelling properties, high water vapour transmission rate (WVTR), excellent hydrophilic nature, biocompatibility, wound appearance, wound closure rate and histological study through in vivo test makes it a suitable candidate for wound healing applications.

In vivo evaluation of chitosan–PVP–titanium dioxide nanocomposite as wound dressing material

In our present study, the blends of chitosan, poly(N-vinylpyrrolidone) (PVP) and titanium dioxide (TiO2) were investigated by Fourier transform infrared (FTIR) spectroscopy and thermogravimetric analysis (TGA). The size distribution of the TiO2 nanoparticles was measured using transmission electron microscope and scanning electron microscope. The studies on the mechanical properties of composite material indicate that the addition of TiO2 nanoparticles increases its strength. The prepared nanocomposite dressing has excellent antimicrobial efficacy and good biocompatibility against NIH3T3 and L929 fibroblast cells. Compared to conventional gauze, soframycin skin ointment and chitosan treated groups, the prepared nano dressing caused an accelerated healing of open excision type wounds in albino rat model. The synergistic effects of nanocomposite dressing material like good antibacterial ability, high swelling properties, high WVTR, excellent hydrophilic nature, biocompatibility, wound appearance and wound closure rate through in vivo test makes it a suitable candidate for wound healing applications.

Chitosan-PVP-nano silver oxide wound dressing: in vitro and in vivo evaluation.

The main aim of this work was to prepare wound healing material with chitosan, poly vinyl pyrrolidone (PVP), silver oxide nanoparticles. The prepared chitosan, chitosan-PVP-nano silver oxide (CPS) films were characterized for their thermal behaviour, morphological properties, mechanical properties, antibacterial properties and wound healing properties. The CPS film found higher antibacterial activity because the materials both chitosan as well as silver oxide poses good antibacterial activity. L929 cell lines were for cytotoxicity study and Adult male albino rats (140-180 g) were used for wound healing study. The prepared film has more wound healing property than of cotton gauge, 100% chitosan and other reported chitosan based dressings.

Progress in antimicrobial activities of chitin, chitosan and its oligosaccharides: a systematic study needs for food applications

In recent years, active biomolecules such as chitosan and its derivatives are undergoing a significant and very fast development in food application area. Due to recent outbreaks of contaminations associated with food products, there have been growing concerns regarding the negative environmental impact of packaging materials of antimicrobial biofilms, which have been studied. Chitosan has a great potential for a wide range of applications due to its biodegradability, biocompatibility, antimicrobial activity, nontoxicity and versatile chemical and physical properties. It can be formed into fibers, films, gels, sponges, beads or nanoparticles. Chitosan films have been used as a packaging material for the quality preservation of a variety of foods. Chitosan has high antimicrobial activities against a wide variety of pathogenic and spoilage microorganisms, including fungi, and Gram-positive and Gram-negative bacteria. A tremendous effort has been made over the past decade to develop and test films with antimicrobial properties to improve food safety and shelf-life. This review highlights the preparation, mechanism, antimicrobial activity, optimization of biocide properties of chitosan films and applications including biocatalysts for the improvement of quality and shelf-life of foods.

Preparation and characterization of N-heterocyclic chitosan derivative based gels for biomedical applications

The novel N-heterocyclic chitosan aerogel derivatives were prepared by reacting 79% deacetylated chitosan separately with 4-pyridinecarboxaldehyde and 2,6-pyridinedicarboxaldehyde followed by subsequent solvent exchange into acetone, filteration and lyophilization. The identity of the Schiff bases was confirmed by UV-vis absorption spectroscopy and Fourier transform infrared (FTIR) spectroscopy. The N-heterocyclic chitosan derivatives were evaluated by X-ray diffraction (XRD), thermo-gravimetric analysis (TGA), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), rheological studies and biological activity. Overall, the N-heterocyclic chitosan derivative based gels open new perspectives in biomedical applications.

Preparation and properties of hybrid monodispersed magnetic α-Fe2O3 based chitosan nanocomposite film for industrial and biomedical applications

In this study, hydrothermally prepared magnetic α-Fe2O3 nanoparticles were dispersed in chitosan (CH) solution to fabricate nanocomposite film. X-ray diffraction (XRD) patterns indicated that the α-Fe2O3 nanoparticles were pure α-Fe2O3 with rhombohedral structures, and the fabrication of CH did not result in a phase change. The scanning electron microscopy (SEM) and transmission electron microscope (TEM) results showed that the hexagonal and spherical monodispersed α-Fe2O3 nanoparticles were encapsulated into the spherical dumb shaped CH-α-Fe2O3 nanocomposite film with a mean diameter of ∼87 and ∼110 nm respectively. The α-Fe2O3 nanoparticles and CH-α-Fe2O3 nanocomposite film were also characterized by Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and vibrating sample magnetometer (VSM). Magnetic measurements revealed that the saturated magnetization (Ms) and remanent magnetization (Mr) of the pure α-Fe2O3 nanoparticles reached 0.573 emu/g and 0.100 emu/g respectively and the nanoparticles showed the characteristics of weak ferromagnetic before and after coating with CH.

Chitosan based antimicrobial films for food packaging applications

Abstract Antimicrobial packaging is one of the most promising active packaging systems. Antimicrobial packaging is the packaging system that is able to kill or inhibit spoilage and pathogenic microorganisms that are contaminating foods. A tremendous effort has been made over the last decade to develop and test films with antimicrobial properties to improve food safety and shelf life. For food preservation, chitosan films are very effective. Chitosan has widely been used in antimicrobial films, to provide edible protective coating, dipping and spraying for the food products due to its antimicrobial properties. Chitosan can be formed into fibers, films, gels, sponges, beads or nanoparticles. Chitosan films have been used as a packaging material for the quality preservation of a variety of food. Chitosan has great potential for a wide range of applications due to its biodegradability, biocompatibility, antimicrobial activity, non-toxicity and versatile chemical and physical properties. The present review outlines the preparation and antimicrobial activity of chitosan based films.

A new chitosan-thymine conjugate: Synthesis, characterization and biological activity

Conjugation of chitosan with nucleobases is expected to expand its not only antimicrobial activity but also anti-cancer activity. Here, we report the synthesis of a novel chitosan-thymine conjugate by the reaction between chitosan and thymine-1-yl-acetic acid followed by acylation. The synthesized conjugate was characterized by FTIR, XRD, (1)H NMR, TGA and SEM. The microbiological screening results demonstrated the antimicrobial activity of the conjugate against bacteria viz., Escherichia coli, Staphylococcus aureus, and fungi viz., Aspergillus niger. The chitosan-thymine conjugate also inhibited (p<0.05) the proliferation of human liver cancer cells (HepG2) in a dose-dependent manner but had no cellular toxicity in non-cancerous mouse embryonal fibroblast cells (NIH 3T3). Thus, the chitosan-nucleobase conjugate may open a new perspective in biomedical applications.

Highly luminescent chitosan-L-cysteine functionalized CdTe quantum dots film: synthesis and characterization.

The present work describes synthesis of water soluble L-cysteine-functionalized CdTe quantum dots (QDs) with size tunable emission at different time intervals for chitosan based film. The characterization of the synthesized CdTe QDs-chitosan film was made by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), differential scanning calorimetry (DSC), thermo gravimetric analysis (TGA) and scanning electron microscope (SEM). The optical property of CdTe QDs-chitosan film was determined by UV-vis and photo-luminescence (PL) spectroscopy whereas their antibacterial activity was screened for Gram positive (Staphylococcus aureus) as well as Gram negative (Pseudomonas aurigionasa and Escherichia coli) bacteria by disc diffusion method. The loss of tunable light emission effect of QDs as well as the positive result of antibacterial study reveals that the synthesized QDs based chitosan film is a promising candidate for wide range of biomedical applications.

Preparation, Characterization and Optical Property of Chitosan-Phenothiazine Derivative by Microwave Assisted Synthesis

In this article, we have described microwave assisted synthesis of 3-formyl-10H phenothiazine and preparation of chitosan-phenothiazine derivative film with potential for optical properties in biomedical applications, vis-à-vis it is also important to ensure that chemical processes used in converting biopolymer to useful material through green chemistry approach. From optical properties and biomedical application point of views, it is a benign technique. Chitosan-derivative film was prepared from hydrogel by solution casting method. The prepared chitosan-phenothiazine derivative was confirmed by Fourier transform infrared spectroscopy (FTIR). The film was evaluated by XRD, thermal analysis, surface morphology, photoluminescence (PL) spectrscopy and second harmonic generation (SHG) study. Overall, the chitosan-phenothiazine derivative film opens new perspectives to optical material for biomedical applications.