Remediation of Organic Pollutants Using Biobased Nanomaterials
Vertika Shukla in Persistent Organic Pollutants in the Environment, 2021
Due to the ubiquity of organic pollutants, it is imperative to develop cost-effective remediants to treat persistent and emerging organic pollutants in the environment. Recently, the advent of nanotechnology has triggered the emergence of biobased nanometrials for sustainable removal of toxins from different environmental matrices. Most of these materials are renewable, with hybrid functions for efficient treatment of organic contaminants in different environmental matrices. In this chapter, we consider the preparation, characteristics, and application of important nanomaterials prepared from starch, cellulose, chitosan, biochar, polylactic acid, and other biopolymers for remediation of organic contaminants. Some perspectives on future research trends are also discussed.
Chitosan and Modified Chitosans for Drug Delivery Application
Akhilesh Vikram Singh, Bang-Jing Li in Polysaccharides in Advanced Drug Delivery, 2020
This chapter discusses the properties of Chitosan (CS) and modified CS as associated with drug delivery systems. CS is the most important derivative obtained from chitin. Chitin is the second most ubiquitous natural polysaccharide after cellulose on earth. The basicity of CS due to the presence of primary amino group resulted into some unique properties like polyoxysalt formation, ability to form films, chelate metal ions and specific structural characteristics. CS has been regarded as a source of potential bioactive material, but it also has several limitations to be utilized in biological system, including its poor solubility under physiological condition. The ability of CS to degrade within a biological system is based on the degree of de-acetylation that occurs in it during processing. The development of new delivery system for the control release of drug is one of the most interesting fields of research in pharmaceutical sciences.
Evaluation of PCL/Chitosan/Nanohydroxyapatite/Tetracycline Composite Scaffolds for Bone Tissue Engineering
Naznin Sultana, Sanchita Bandyopadhyay-Ghosh, Chin Fhong Soon in Tissue Engineering Strategies for Organ Regeneration, 2020
In bone tissue engineering, the biodegradable scaffolds will play a role as a temporary template for new bones tissues. Freezing freeze-drying technique involves creating a solution using polymers and solvent, quickly freezing the solution to lock liquid state structure and then remove the solvent by freeze drying. This chapter focuses on the fabrication and evaluation of polycaprolactone (PCL)/chitosan-based scaffolds using a freeze-drying technique. Bone is a complex and highly specialized form of connective tissues pertaining to the formation of the skeleton of the body. Mechanical properties of the scaffold should match the host bone properties and have proper load transferred to support the harboring of new bone tissues and support and also the mechanical integrity of the implanted area. Nano-sized hydroxyapatite and tetracycline HCL were incorporated into the scaffolds to study their characteristics, release and biocompatibility with human osteoblast cells via in vitro studies.
Chitosan Promoted the Corneal Epithelial Wound Healing via Activation of ERK Pathway
Published in Current Eye Research, 2017
Rui Cui, Qingjun Lu, Yufei Teng, Kun Li, Na Li
Purpose: To investigate the mechanism of chitosan promoting corneal wound healing though evaluating its effect on extracellular signal-regulated kinases (ERK) and p38 pathway activity in a rabbit animal model. Methods: Cell proliferation and migration assay were performed 24 hours after chitosan treatment. The activity of ERK and p38 pathways was detected by using immunofluorescence and Western blotting in the presence of chitosan and an ERK inhibitor. In vivo study of epithelial debridement wounds was performed on 8 mm rabbit corneas in the presence of chitosan and an ERK pathway inhibitor. Results: Immunostaining with Ki67 and migrating assay showed that chitosan could upregulate the cell proliferation and promote the cell migration. Chitosan activated the ERK pathway in 5 min to 30 min after treatment but did not affect the p38 pathway. ERK inhibitor PD98059 can inhibit the chitosan-stimulated ERK phosphorylation. Chitosan increased the corneal epithelial wound closure in organ culture and ERK inhibition with PD98059 blocked the effect of chitosan on wound healing. Conclusions: Chitosan promoted corneal epithelial proliferation and migration during the wound healing in rabbits’ eye. Chitosan-stimulated epithelial wound healing is partially mediated through the activation of the ERK pathway but not the p38 pathway.
Chitosan delaying human fibroblast senescence through downregulation of TGF-β signaling pathway
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2018
Ching-Wen Tsai, I-Ni Chiang, Jyh-Horng Wang, Tai-Horng Young
This study evaluated the effect of chitosan, poly vinyl alcohol (PVA) and poly (2-hydroxyethyl methacrylate) (pHEMA) on delaying the human fibroblast senescence. Cells could form suspending multicellular spheroids on these biomaterials, but only chitosan was capable of decreasing the SA β-gal activity and increasing the proliferation ability of senescent fibroblasts. Therefore, in addition to the structure of multicellular spheroids, chitosan itself should play an important role in delaying fibroblast senescence. The main difference of senescence-related protein expressions for cells cultured on chitosan, PVA and pHEMA occurred on the TGF-β signaling pathway. In addition to the intracellular TGF-β expression, the extracellular TGF-β expression was also downregulated. Chitosan with cationic amino structure was assumed to bind with anionic TGF-β by forming polyelectrolyte complexes. This assumption was demonstrated by directly adding chitosan into the medium to downregulate the cell TGF-β expression and further to delay cell senescence, indicating TGF-β signaling pathway was involved in the chitosan-mediating fibroblast senescence process. Finally, the delaying cell senescence ability of chitosan increased with increasing the amount of amino groups in chitosan and its ionization degree. In summary, these results provide important information for considering the application of chitosan in the future cell therapy and regeneration medicine.
Optimization of Chitosan Succinate and Chitosan Phthalate Microspheres for Oral Delivery of Insulin using Response Surface Methodology
Published in Pharmaceutical Development and Technology, 2009
Udhumansha Ubaidulla, R.K. Khar, F.J. Ahmad, Purnima Tripathi
In the present study, a Box-Behnken experimental design was employed to statistically optimize the formulation parameters of chitosan phthalate and chitosan succinate microspheres preparation. These microspheres can be useful for oral insulin delivery system. The effects of three parameters namely polymer concentration, stirring speed and cross linking agent were studied. The fitted mathematical model allowed us to plot response surfaces curves and to determine optimal preparation conditions. Results clearly indicated that the crosslinking agent was the main factor influencing the insulin loading and releasing. The in vitro results indicated that chitosan succinate microspheres need high amount of crosslinking agent to control initial burst release compared to chitosan phthalate microspheres. The reason may be attributed that chitosan succinate is more hydrophilic than chitosan phthalate. The relative pharmacological efficacy for chitosan phthalate and chitosan succinate microspheres (18.66 ± 3.84%, 16.24 ± 4%) was almost three-fold higher than the efficacy of the oral insulin administration (4.68 ± 1.52%). These findings suggest that these microspheres are promising carrier for oral insulin delivery system.
Related Knowledge Centers
- Chitin
- Exoskeleton
- Fungi
- Hydrogel
- Insects
- Acetylglucosamine
- Wounds