Showing papers by "Balbir Singh Kaith published in 2022"

A review on chitosan-gelatin nanocomposites: Synthesis, characterization and biomedical applications

Abstract: In the wide range of materials available for variety of biomedical applications, the chitosan-gelatin nanocomposites are emerging rapidly. The chitosan-gelatin nanocomposites are generally synthesized by inclusion of nanoparticles into the chitosan-gelatin matrix using various cross-linking methods. Apart from acting as a matrix for dispersing nanoparticles, the chitosan-gelatin composite can work as a reducing as well as stabilizing agent for nanoparticles preventing their agglomeration. The chitosan-gelatin matrix provides a biocompatible, biodegradable, and bioactive base to synthesize the nanocomposites of biological importance. The chitosan and gelatin are usually blended to improve the biological properties of the resulting material by promoting cell adhesion and forming a polyelectrolyte complex. Apart from the chemical cross-linkages between chitosan and gelatin produced via suitable cross-linker, the functional groups of chitosan (-NH3+ and -OH) and gelatin (-NH2, -OH, -COOH/-COO−) interact through hydrogen bonding and electrostatic interactions which further improves their compatibility and chemistry. Depending upon the nature of the nanoparticles, the chitosan-gelatin nanocomposites offer numerous materials with diverse properties and a multitude of applications. The literature cited in this paper reveals that drug loading and release capacity for different drugs from chitosan-gelatin composites synthesized with different nanoparticles have been found to be more than 80%. The sustained delivery of different drugs ranging from cancer drugs-antibiotics-proteins from these nanocomposites has been observed for a time period in the range of 5–15 days. The cell adhesion efficiency and cell viability of different chitosan-gelatin nanocomposites has been observed to be more than 90% and 100%, respectively. The mechanical strength of these composites with different nanoparticles has been observed between 12.4 Pa and 16.6 MPa. In the present review paper, the authors present a critical review of the development of different types of chitosan-gelatin matrices with distinct nanoparticles (in the form of composites, films/membranes, hydrogels, scaffolds and nanospheres) and their utilization for biomedical applications such as bone tissue engineering, drug delivery, and wound healing. Subsequently, the structure-property relationship of chitosan-gelatin with nanocomposites is addressed and finally the correlation of properties of nanocomposites with their biological applications is discussed.

Malic acid cross-linked chitosan based hydrogel for highly effective removal of chromium (VI) ions from aqueous environment

Abstract: The acrylamide grafted chitosan hydrogel was synthesized through cross-linking of malic acid using a simple one pot synthesis method involving free radical polymerization. The hydrogel with porous infrastructure and diverse functionalities offered large surface area for adsorption. The synthesized hydrogel exhibited high adsorption capacity (427 mg/g) for Cr(VI) ions in an aqueous medium under optimized conditions and it was quite high in comparison to the previously reported literature. The process of adsorption of Cr(VI) as oxyanion at pH 2 was endothermic and driven by entropy. It demonstrated the suitability of Langmuir adsorption isotherm, specifying monolayer adsorption of the metal ions over the hydrogel. The kinetics of adsorption was well suited with pseudo-second-order kinetic model indicating chemisorption and dependence of adsorption rate upon the adsorption capacity of hydrogel. The adsorption mechanism studied using FTIR spectroscopy and XPS indicated the strong intermolecular interactions of the negatively charged Cr(VI) species (HCrO 4 − & CrO 4 2− at pH 2) to the various functional groups (hydroxyl, protonated amine and amide groups) of the hydrogel and further partial reduction of Cr(VI) to Cr(III) by the functionalities present on the hydrogel. The synthesized hydrogel with good mechanical and thermal characteristics and recycling potential can act as an efficient adsorbent for adsorption and removal of Cr(VI) ions in an aqueous environment. • Malic acid cross-linked chitosan hydrogel was synthesized using a one pot methodology involving free radical polymerization. • The synthesized hydrogel exhibited high adsorption capacity (427 mg/g) for Cr(VI) oxyanions at pH 2 in an aqueous medium. • The monolayer adsorption of Cr(VI) over the hydrogel involved both physisorption and chemisorption. • The adsorption mechanism indicated the strong interactions among Cr(VI) oxyanions and the functionalities on the hydrogel.

Synthesis of gelatin and green tea based stretchable self-healing material of biomedical importance

Abstract: Stimuli-responsive stretchable self-healing hydrogels of bio-based origin have gained extreme importance for the development of materials possessing numerous applications related to wound healing, preparation of electronic skin and many health monitoring issues. This paper highlights the synthesis of novel self-healing, stretchable hydrogel derived from gelatin and aqueous green tea extract (Gel- ox GT p-phen ). The hydrogel Gel- ox GT p-phen was found to be biodegradable in phosphate buffer, urea solution and solutions of different pH. The synthesized material exhibited viscoelastic and self-healing properties. Self-healing occurred in the material after 2 h. Lastly, the blood containing Gel- ox GT p-phen hydrogel sample exhibited 1.47% percentage hemolysis ratio indicating non-hemolytic nature of the synthesized hydrogel and practical utility in the biomedical field. • Facile preparation of self-healing hydrogels based on dextrin and green tea extract • Excellent stretching and compression features were obtained from the synthesized material • The self-healing hydrogel showed excellent degradability in phosphate buffer, urea solution and solution of different pH • The sample showed 1.47% percentage hemolysis ratio suggesting its practical utility in biomedical field

Biodegradation and water absorption studies of natural gum rosin-based hydrogel

Abstract: Hydrogels with high scientific interest and numerous applications have become the most important materials. Currently, natural polymer-based hydrogels are more preferred than synthetic ones because of their biocompatibility and ecofriendly nature. In 1960 first-time hydrogels were reported, and they are defined as three-dimensional high molecular weight materials with the capacity to hold water or biological fluids within its porous structure without getting disintegrated. Hydrogels based on 2-hydroxymethylmethacrylate and ethylene dimethacrylate are mostly used in ophthalmology. These can absorb water more than 90%; hence, they are also known as super absorbents. Functional groups like –OH, –COOH, –CONH2, and –SO3H are the main key feature of such properties. Hydrogels are similar to natural tissues in appearance, so these can be used to prepare biocompatible materials. They have high absorption capacity, smoothness, elasticity, and low interfacial tension with solutions, which make them highly attractive. They are more responsive to physiological pH, ionic strength, temperature, and electric currents, which make these smart materials. These three-dimensional hydrophilic networks have been widely studied and extensively used in various fields like biomedical, wastewater treatment, agriculture and horticulture. This chapter deals with the synthesis of hydrogels through grafting of poly(acrylamide) onto derivatized gum rosin through free radical graft copolymerization in the presence of KPS as an initiator and N,N-methylene bisacrylamide as a crosslinker. Different reaction parameters such as the amount of solvent, pH of the reaction medium, reaction time, concentration of crosslinker, initiator, monomer and reaction temperature were optimized for getting the candidate polymer with maximum fluid uptake capacity.