Chemical composition, structural features, surface morphology and bioactivities of chitosan derivatives from lobster (Thenus unimaculatus) shells

Incorporation of copper ion promoted adsorption of anionic dye (Acid Yellow 36) by acrolein-crosslinked polyethyleneimine/chitosan hydrogel: Adsorption, dynamics, and mechanisms

In this study, a novel adsorbent, A-PEI/CS-Cu2+, was developed by crosslinking polyethyleneimine/chitosan hydrogel with acrolein and loading it with copper ions. The adsorption process of A-PEI/CS-Cu2+ on the anionic dye acid yellow 36 (AY36) was investigated by kinetic, isothermal and thermodynamic modeling. It was noteworthy that A-PEI/CS-Cu2+ exhibited rapid adsorption with a 90 % removal rate achieved within just 5 min, which was much faster than the adsorption rate of A-PEI/CS without load of copper ions and showed its potential for rapid adsorption applications. The maximum adsorption capacity for AY36 could reach up to 3114 mg g-1. In addition, the high concentration of saline wastewater was found to have almost no effect on the adsorption reaction in the salt effect test experiment. In five desorption-regeneration cycle experiments, the sample exhibited good recyclability and regeneration performance. The driving force of the adsorption process mainly originated from the electrostatic interaction, hydrogen bonding, and intermolecular interaction, in which the addition of copper ions led to the enhancement of the electrostatic interaction and chelation between A-PEI/CS-Cu2+ and AY36. Overall, the findings suggest the excellent potential of A-PEI/CS-Cu2+ for rapid and efficient adsorption, as well as its suitability for practical applications in wastewater treatment.

Isolation and Free Radical Scavenging Ability of Linear Polysaccharides From Cuttlebone of Sepia prashadi

Background This study aimed to isolate linear polysaccharides from Sepia prashadi cuttlebone with the objective of evaluating their ability to scavenge free radicals. By providing new natural components for pharmaceutical and functional food uses, this research advances our understanding of the potential health benefits of polysaccharides originating from marine sources and their antioxidant properties. Objective The objective of the study is to isolate a linear polysaccharide chitosan from Sepia prashadi cuttlebone (produced by the partial deacetylation of chitin), characterize its structure using fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and X-ray diffraction (XRD), and explore the isolated polysaccharide's free radical scavenging potential. Material and methods Linear polysaccharide, chitosan was extracted chemically from Sepia prashadi from cuttlebone waste, by demineralization and deproteinization.Chemical characterization of chitosan was performed using Fourier transform infrared spectroscopy (FTIR) in the 400-4000 nm frequency range. The surface characteristics of chitosan, such as its texture, porosity, and roughness, are visible in scanning electron microscopy (SEM) images. X-ray diffraction (XRD) can be utilized to examine how chitosan interacts with other substances, such as medications or nanoparticles, by analyzing alterations in the diffraction pattern during complexation or formulation. Scavenging ability was demonstrated by 2,2-diphenyl-1-picrylhydrazyl (DPPH), superoxide radical, and chelating ability of ferrous ions assays. Results  Chitosan is formed from chitin. The extraction yields of chitosan and chitin were 78% and 39%, respectively. High levels of superoxide radical scavenging activity (76.1%), DPPH radical scavenging activity (62.1%) and chelating activity (127.5% at 100 g/mL) were observed in cuttlebone chitosan. Sepia prashadi showed an increased antioxidant activity in chitosan. Conclusion The goal of this study was to determine the effectiveness of various extraction techniques for preserving the antioxidant activity of chitosan derived from Sepia prashadi cuttlebone waste. The maximum scavenging activity was demonstrated by both the chelating ability and antioxidant activity. Considering that this raw material is derived from renewable resources and produces highly valued chemicals, it is a profitable endeavor.

Adsorption isotherm, kinetics and response surface methodology optimization of cadmium (Cd) removal from aqueous solution by chitosan biopolymers from cephalopod waste

The present investigation was aimed to explore the cadmium removal efficiency, mechanism and characterization of Chitosan biopolymers from cephalopods waste. The extracted chitosan has showed good yield of 32% and with high minerals, ash and moisture content. In the Fourier-transform infrared spectroscopy (FT-IR) analysis multiple active functional groups of Amine, Amine, Hydroxyl were found between 612 and 3424 cm^-1 and the sugar signals such as N-acetyl glucosamine (GlcNAc) and H-1 [GlcN (H-1D), GlcNAc (H-1A)] were identified in Chitosan by ¹H Nuclear Magnetic Resonance (NMR). The Crystalline, rough surface, micropores characters were observed in Chitosan surface by Scanning Electron Microscope (SEM) analysis and the pores played a key role in adsorption process. The Cd ions removal was performed by batch experiment and the results were revealed that the pH, temperature, time and dosage highly influenced the process and the optimum condition was discovered through RSM for pH 7, temperature 42.5 °C, time 220 min and dosage of sorbent 1 g/L respectively. The kinetics models of the Cd removal were carried out and the results revealed that the Pseudo-second order is more suitable and fit for removal than Pseudo-first order model. Chitosan surface characters and functional groups played a big role in adsorption process and Chitosan can be alternative eco-friendly, low cost and highly efficient sorbent for heavy metal removal in effluent treatment plants.

Optimization of the Extraction of Chitosan and Fish Gelatin from Fishery Waste and Their Antimicrobial Potential as Active Biopolymers

Fishery residues are abundant raw materials that also provide numerous metabolites with high added value. Their classic valorization includes energy recovery, composting, animal feed, and direct deposits in landfills or oceans along with the environmental impacts that this entails. However, through extraction processes, they can be transformed into new compounds with high added value, offering a more sustainable solution. The aim of this study was to optimize the extraction process of chitosan and fish gelatin from fishery waste and their revalorization as active biopolymers. We successfully optimized the chitosan extraction process, achieving a yield of 20.45% and a deacetylation degree of 69.25%. For the fish gelatin extraction process, yields of 11.82% for the skin and 2.31% for the bone residues were achieved. In addition, it was demonstrated that simple purification steps using activated carbon improve the gelatin's quality significantly. Finally, biopolymers based on fish gelatin and chitosan showed excellent bactericidal capabilities against Escherichia coli and Listeria innocua. For this reason, these active biopolymers can stop or decrease bacterial growth in their potential food packaging applications. In view of the low technological transfer and the lack of information about the revalorization of fishery waste, this work offers extraction conditions with good yields that can be easily implemented in the existing industrial fabric, reducing costs and supporting the economic development of the fish processing sector and the creation of value from its waste.

Chitosan electrospun nanofibers derived from Periplaneta americana residue for promoting infected wound healing

Periplaneta americana has been used medicinally for years to treat a wide variety of skin lesions or ulcers. However, a sizable portion of the drug residues that are retained after extraction are routinely thrown away, thus posing a hazard to the environment and depleting resources. In this study, low molecular weight Periplaneta americana chitosan (LPCS) and high molecular weight Periplaneta americana chitosan (HPCS) were extracted from Periplaneta americana residue (PAR) based on the conventional acid-base method and two deacetylation methods. Moreover, the physicochemical properties and structural differences between the above two chitosan and commercial chitosan (CS) were compared using different methods. Next, two nanofibers comprising different ratios of Periplaneta americana chitosan (LPCS or HPCS), polyvinyl alcohol (PVA), and polyethylene oxide (PEO) were prepared and optimized. The above nanofibers exhibited excellent mechanical properties, antibacterial properties, and biocompatibility while facilitating wound healing in an infected rat whole-layer wound model by promoting wound closure, epithelialization, collagen deposition, and inflammation reduction. In brief, this study produced an effective and affordable wound dressing and offered a suggestion for the comprehensive utilization of Periplaneta americana residue.

Chitosan and carboxymethyl cellulose-based 3D multifunctional bioactive hydrogels loaded with nano-curcumin for synergistic diabetic wound repair

Biopolymer-based thermoresponsive injectable hydrogels with multifunctional tunable characteristics containing anti-oxidative, biocompatibility, anti-infection, tissue regeneration, and/or anti-bacterial are of abundant interest to proficiently stimulate diabetic wound regeneration and are considered as a potential candidate for diversified biomedical application but the development of such hydrogels remains a challenge. In this study, the Chitosan-CMC-g-PF127 injectable hydrogels are developed using solvent casting. The Curcumin (Cur) Chitosan-CMC-g-PF127 injectable hydrogels possess viscoelastic behavior, good swelling properties, and a controlled release profile. The degree of substitution (% DS), thermal stability, morphological behavior, and crystalline characteristics of the developed injectable hydrogels is confirmed using nuclear magnetic resonance (¹H NMR), thermogravimetric analysis, scanning electron microscopy (SEM), and x-ray diffraction analysis (XRD), respectively. The controlled release of cur-micelles from the hydrogel is evaluated by drug release studies and pharmacokinetic profile (PK) using high-performance liquid chromatography (HPLC). Furthermore, compared to cur micelles the Cur-laden injectable hydrogel shows a significant increase in half-life (t_1/2) up to 5.92 ± 0.7 h, mean residence time (MRT) was 15.75 ± 0.76 h, and area under the first moment curve (AUMC) is 3195.62 ± 547.99 μg/mL*(h)² which reveals the controlled release behavior. Cytocompatibility analysis of Chitosan-CMC-g-PF127 hydrogels using 3T3-L1 fibroblasts cells and in vivo toxicity by subcutaneous injection followed by histological examination confirmed good biocompatibility of Cur-micelles loaded hydrogels. The histological results revealed the promising tissue regenerative ability and shows enhancement of fibroblasts, keratinocytes, and collagen deposition, which stimulates the epidermal junction. Interestingly, the Chitosan-CMC-g-PF127 injectable hydrogels ladened Cur exhibited a swift wound repair potential by up-surging the cell migration and proliferation at the site of injury and providing a sustained drug delivery platform for hydrophobic moieties.

Effects of Neutralization on the Physicochemical, Mechanical, and Biological Properties of Ammonium-Hydroxide-Crosslinked Chitosan Scaffolds

It has been reported that chitosan scaffolds, due to their physicochemical properties, stimulate cell proliferation in different tissues of the human body. This study aimed to determine the physicochemical, mechanical, and biological properties of chitosan scaffolds crosslinked with ammonium hydroxide, with different pH values, to better understand cell behavior depending on the pH of the biomaterial. Scaffolds were either neutralized with sodium hydroxide solution, washed with distilled water until reaching a neutral pH, or kept at alkaline pH. Physicochemical characterization included scanning electron microscopy (SEM), elemental composition (EDX), Fourier-transform infrared (FTIR) spectroscopy, Raman spectroscopy, thermogravimetric analysis (TGA), and mechanical testing. In vitro cytotoxicity was assessed via dental-pulp stem cells' (DPSCs') biocompatibility. The results revealed that the neutralized scaffolds exhibited better cell proliferation and morphology. It was concluded that the chitosan scaffolds' high pH (due to residual ammonium hydroxide) decreases DPSCs' cell viability.

Pt-Chitosan-TiO2 for Efficient Photocatalytic Hydrogen Evolution via Ligand-to-Metal Charge Transfer Mechanism under Visible Light

The Pt-chitosan-TiO2 charge transfer (CT) complex was synthesized via the sol-gel and impregnation method. The synthesized photocatalysts were thoroughly characterized, and their photocatalytic activity were evaluated toward H2 production through water reduction under visible-light irradiation. The effect of the preparation conditions of the photocatalysts (the degree of deacetylation of chitosan, addition amount of chitosan, and calcination temperature) on the photocatalytic activity was discussed. The optimal Pt-10%DD75-T200 showed a H2 generation rate of 280.4 μmol within 3 h. The remarkable visible-light photocatalytic activity of Pt-chitosan-TiO2 was due to the CT complex formation between chitosan and TiO2, which extended the visible-light absorption and induced the ligand-to-metal charge transfer (LMCT). The photocatalytic mechanism of Pt-chitosan-TiO2 was also investigated. This paper outlines a new and facile pathway for designing novel visible-light-driven photocatalysts that are based on TiO2 modified by polysaccharide biomass wastes that are widely found in nature.

The Impact of COVID-19 Pandemic on Seafood Safety and Human Health

The coronavirus disease (COVID-19) pandemic caused several negative impacts on global human health and the world’s economy. Food and seafood safety and security were among the principal challenges and causes of concern for the food industry and consumers during the spread of this global pandemic. This article focused on the effects of COVID-19 pandemic on potential safety issues with seafood products and their processing methods. Moreover, the potential impacts of coronavirus transmission through seafood on human health were evaluated. The role of authenticity, traceability, and antimicrobials from natural sources to preserve seafood and the possible interaction of functional foods on the human immune system are also discussed. Although seafood is not considered a principal vector of SARS-CoV-2 transmission, the possible infections through contaminated surfaces of such food products cannot be neglected. The positive effects of seafood consumption on possible immunity built up, and COVID-19 are also summarized.

Preparation of the porous carbon-based solid acid from starch for efficient degradation of chitosan to D-glucosamine

Effective degradation of chitosan to D-glucosamine is considered to make a great contribution for the development of the medical industry. To address this issue, a porous carbon-based solid acid catalyst (PCSA) functionalized with -OH, -COOH and -SO₃H groups was successfully prepared. Typically, the physicochemical properties of PCSA were deeply determined by a series of characterization technique including FT-IR, TGA, RM, NH₃-TPD, SEM and Element Analysis. Moreover, the catalytic performances of PCSA towards to D-glucosamine production from chitosan were evaluated. In particular, the effects of catalyst acid density, ratio of acidic groups, chitosan concentration, reaction temperature, reaction time and catalyst dosage on the yield of D-glucosamine were investigated in detail. Interestingly, the experimental results indicated that a yield of D-glucosamine as high as 90.5% was achieved, and no obvious deactivation occurred even after six consecutive cycles. In light of the advantages of superior activity/recyclability and low cost, the starch-derived solid acid developed in this work might possess the broad industrial application prospects.

The Ideal Donor Site Dressing: A Comparison of a Chitosan Based Gelling Dressing to Traditional Dressings

INTRODUCTION

Donor site wound management is critical in split-thickness skin graft surgeries. These sites typically recover in 7-14 days due to the dermal-imbedded keratinocytes that promote skin regeneration. An ideal donor site dressing can help to mitigate pain, reduce infection risk, promote hemostasis, and accelerate healing times. Additionally, this dressing would be easy to apply in the operating room, easily managed, and cost-effective. Chitosan-based gelling dressings (CBGD) possess many of these qualities that make an ideal donor site dressing.

METHODS

We conducted a retrospective chart review of patients who received CBGD as part of their post-operative wound care plan. We collected data on infections, hemostasis, dressing failure, and hospital course over a 14-month period where CBGD was used as the donor site dressing.

RESULTS

One hundred and fourteen patients were evaluated. We found an infection rate of 7%, a bleed-through rate of 1.8%, and a re-application rate of 9.6%. The average CBGD cost per patient was $75.15.

CONCLUSIONS

CBGD has acceptable infection rates, and pain scores as traditional donor site dressings. However, it possesses several qualities of a suitable donor site dressing notably swift healing rates, impressive hemostatic property, and low cost. Our study supports the idea that CBGD is a suitable donor site dressing for split-thickness skin graft surgeries.

Crustacean Waste-Derived Chitosan: Antioxidant Properties and Future Perspective

Chitosan is obtained from chitin that in turn is recovered from marine crustacean wastes. The recovery methods and their varying types and the advantages of the recovery methods are briefly discussed. The bioactive properties of chitosan, which emphasize the unequivocal deliverables contained by this biopolymer, have been concisely presented. The variations of chitosan and its derivatives and their unique properties are discussed. The antioxidant properties of chitosan have been presented and the need for more work targeted towards harnessing the antioxidant property of chitosan has been emphasized. Some portions of the crustacean waste are being converted to chitosan; the possibility that all of the waste can be used for harnessing this versatile multifaceted product chitosan is projected in this review. The future of chitosan recovery from marine crustacean wastes and the need to improve in this area of research, through the inclusion of nanotechnological inputs have been listed under future perspective.

Preparation of Antioxidant and Antibacterial Chitosan Film from Periplaneta americana

Simple Summary

The American cockroach (Periplaneta americana) is a kind of insect distributed worldwide. Commonly, it is considered as a pest. However, nowadays, it has been developed as a potential resource of protein, lipid, and antibacterial peptide. Besides, it also contains chitin, which could be used to produce chitosan by deacetylation. Chitosan is a valuable biomaterial containing amino groups, and has been applied in various fields. However, the researches focusing on the applications of P. americana chitosan are rare, which might hinder the exploration of the value of P. americana. In this paper, we prepared and characterized the chitosan film from P. americana. The performances relating to food packaging of the obtained film were also examined. As the results showed, P. americana chitosan film could resist UV light effectively. It could also keep scavenging 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals in 8 h, proving its ability of antioxidant. In addition, it exhibited antibacterial activity by resisting the growth of Serratia marcescens and Escherichia coli. The results showed that P. americana chitosan film could work as a potential food packaging material, which implicated the value of P. americana chitosan and provided a new clue for the exploration of the value of more insects, especially pests.

Abstract

Among different insects, the American cockroach (Periplaneta americana) has been bred in industrial scale successfully as a potential resource of protein, lipid, and antibacterial peptide. However, the application of its chitosan has not been studied widely, which has hindered the sufficient utilization of P. americana. In this paper, the chitosan from P. americana was separated, characterized, and processed into film (PaCSF) to examine its potential of being applied in food packaging. As the results of different characterizations showed, PaCSF was similar to shrimp chitosan film (SCSF). However, concerning the performances relating to food packaging, the two chitosan films were different. PaCSF contained more water (42.82%) than SCSF did, resulting in its larger thickness (0.08 mm). PaCSF could resist UV light more effectively than SCSF did. Concerning antioxidant activity, the DPPH radical scavenging ability of PaCSF increased linearly with time passing, reaching 72.46% after 8 h, which was better than that of SCSF. The antibacterial activity assay exhibited that PaCSF resisted the growth of Serratia marcescens and Escherichia coli more effectively than SCSF did. The results implied that P. americana chitosan could be a potential raw material for food packaging, providing a new way to develop P. americana.

Seafood Waste as Attractive Source of Chitin and Chitosan Production and Their Applications

Chitosan is a cationic polymer obtained by deacetylation of chitin, found abundantly in crustacean, insect, arthropod exoskeletons, and molluscs. The process of obtaining chitin by the chemical extraction method comprises the steps of deproteinization, demineralization, and discoloration. To obtain chitosan, the deacetylation of chitin is necessary. These polymers can also be extracted through the biological extraction method involving the use of microorganisms. Chitosan has biodegradable and biocompatible properties, being applied in the pharmaceutical, cosmetic, food, biomedical, chemical, and textile industries. Chitosan and its derivatives may be used in the form of gels, beads, membranes, films, and sponges, depending on their application. Polymer blending can also be performed to improve the mechanical properties of the bioproduct. This review aims to provide the latest information on existing methods for chitin and chitosan recovery from marine waste as well as their applications.

Extraction of chitosan from squid pen waste by high hydrostatic pressure: Effects on physicochemical properties and antioxidant activities of chitosan

Squid pen sample was treated by high hydrostatic pressure (HHP) prior to the extraction of chitosan. The physicochemical and antioxidant activities of the chitosan obtained with HHP (HHP-CS) were compared with chitosan of untreated squid pen sample (UT-CS). The chitosan extraction yield was optimized using response surface methodology, and the optimum condition was achieved at pressure of 500 MPa, extraction time of 10 min, and 1% (w/w) acetate concentration. The maximum yield of chitosan sample from the chitin of squid pens treated by HHP reached 81.9%. Among the process variables, the combined effects of pressure and acetate concentration significantly enhanced the extraction of chitosan from squid pens. The HHP-CS was found to be significantly effective in enhancing the fat binding capacity, water binding capacity, and water solubility index. SEM image analysis suggested that the HHP-CS had a rough surface with high porosity, while UT-CS exhibited a smooth surface. In vitro antioxidant assay suggested that HHP-CS had significantly higher DPPH radical scavenging activity, greater reducing power, and a stronger ferrous ion chelating effect than did UT-CS. Therefore, HHP can be an excellent alternative method for improving the physicochemical properties and antioxidant activities of chitosan from squid pens.

Insight on Extraction and Characterisation of Biopolymers as the Green Coagulants for Microalgae Harvesting

This review presents the extractions, characterisations, applications and economic analyses of natural coagulant in separating pollutants and microalgae from water medium, known as microalgae harvesting. The promising future of microalgae as a next-generation energy source is reviewed and the significant drawbacks of conventional microalgae harvesting using alum are evaluated. The performances of natural coagulant in microalgae harvesting are studied and proven to exceed the alum. In addition, the details of each processing stage in the extraction of natural coagulant (plant, microbial and animal) are comprehensively discussed with justifications. This information could contribute to future exploration of novel natural coagulants by providing description of optimised extraction steps for a number of natural coagulants. Besides, the characterisations of natural coagulants have garnered a great deal of attention, and the strategies to enhance the flocculating activity based on their characteristics are discussed. Several important characterisations have been tabulated in this review such as physical aspects, including surface morphology and surface charges; chemical aspects, including molecular weight, functional group and elemental properties; and thermal stability parameters including thermogravimetry analysis and differential scanning calorimetry. Furthermore, various applications of natural coagulant in the industries other than microalgae harvesting are revealed. The cost analysis of natural coagulant application in mass harvesting of microalgae is allowed to evaluate its feasibility towards commercialisation in the industrial. Last, the potentially new natural coagulants, which are yet to be exploited and applied, are listed as the additional information for future study.

Aquaculture and its by-products as a source of nutrients and bioactive compounds

Underutilized marine resources (e.g., algae, fish, and shellfish processing by-products), as sustainable alternatives to livestock protein and interesting sources of bioactive compounds, have attracted the attention of the researchers. Aquatic products processing industries are growing globally and producing huge amounts of by-products that often discarded as waste. However, recent studies pointed out that marine waste contains several valuable components including high-quality proteins, lipids, minerals, vitamins, enzymes, and bioactive compounds that can be used against cancer and some cardiovascular disorders. Besides, previously conducted studies on algae have shown the presence of some unique biologically active compounds and valuable proteins. Hence, this chapter points out recent advances in this area of research and discusses the importance of aquaculture and fish processing by-products as alternative sources of proteins and bioactive compounds.