Medium Molecular Weight Chitosan Research Articles

An Investigation into the Effects of Processing Factors on the Properties and Scaling-Up Potential of Propranolol-Loaded Chitosan Nanogels.

Chitosan-triphosphate (TPP) nanogels are widely studied drug delivery carrier systems, typically prepared via a simple mixing process. However, the effects of the processing factors on nanogel production have not been extensively explored, despite the importance of understanding and standardising such factors to allow upscaling and commercial usage. This study aims to systematically evaluate the effects of various fabrication and processing factors on the properties of nanogels using a Design of Experiment approach. Hydrodynamic size, polydispersity index (PDI), zeta potential, and encapsulation efficiency were determined as the dependent factors. The temperature, stirring rate, chitosan grade, crosslinker choice, and the interaction term between temperature and chitosan grade were found to have a significant effect on the particle size, whereas the effect of temperature and the addition rate of crosslinker on the PDI was also noteworthy. Moreover, the addition rate of the crosslinker and the volume of the reaction vessel were found to impact the encapsulation efficiency. The zeta potential of the nanogels was found to be governed by the chitosan grade. The optimal fabrication conditions for the development of medium molecular weight chitosan and TPP nanogels included the following: the addition rate for TPP solution was set at 2 mL/min, while the solution was then stirred at a temperature of 50 °C and a stirring speed of 600 rpm. The volume of the glass vial used was 28 mL, while the stirrer size was 20 mm. The second aim of the study was to evaluate the potential for scaling up the nanogels. Size and PDI were found to increase from 128 nm to 151 nm and from 0.232 to 0.267, respectively, when the volume of the reaction mixture was increased from 4 to 20 mL and other processing factors were kept unchanged. These results indicate that caution is required when scaling up as the nanogel properties may be significantly altered with an increasing production scale.

Antibacterial wound coating based on chitosan and povidone, obtained by 3D printing

The objective of this study was to develop a method for forming an antimicrobial wound coating based on chitosan and polyvinylpyrrolidone using 3D printing technology.
 The properties of the coating were then studied in vitro and in vivo to improve the treatment outcomes of deep burns. The resulting coating was a 4% hydrogel of medium molecular weight chitosan with the addition of 1% povidone iodine and dermal fibroblasts. After transplantation, the coating was covered with “Foliderm” film. The coating was formed using an extrusion 3D bioprinter, with printing parameters determined experimentally. The samples were first studied in vitro. Scanning electron microscopy was used to evaluate the coating’s microarchitecture and its interaction with dermal fibroblasts. A colorimetric test was conducted to assess cell metabolic activity and cytotoxicity, and antimicrobial activity against reference strains of Staphylococcus aureus was analyzed. An experiment was conducted to evaluate the in vivo properties of the coating. Nineteen male Wistar rats were used in the study. An injury was inflicted that resulted in a deep thermal contact burn, affecting all layers of skin and subcutaneous fatty tissue, with an area of approximately 20 cm2. The animals were divided into three groups: experimental (with the application of the developed coating), comparative (using the traditional and widespread method of treatment with Levomekol ointment) and control (without treatment).
 The study lasted for 38 days and found that the developed coating is highly biocompatible, atraumatic, elastic, and adheres well to wounds. Chitosan was used to create a porous structure with channels running parallel to each other. The coating cells are evenly distributed on the surface of the matrix, specifically on the walls of the pores. The inclusion of 1% povidone iodine in the polymer resulted in high antimicrobial activity without significantly affecting the activity of the cells in the composition. The experiment on applying a coating for treating deep thermal burns demonstrated that the developed coating had a positive effect on the wound healing process. This effect was characterized by a higher rate of epithelization and a significantly lower incidence of infectious complications compared to other experimental groups. In the histological study, the experimental group outperformed the control and comparison groups in the quality of the formed granulation tissue, the number of newly formed capillaries, and the severity of the local inflammatory process.

The Potential of Chitosan-Based Composites for Adsorption of Diarrheic Shellfish Toxins.

Okadaic acid (OA) is one of the most potent marine biotoxins, causing diarrheal shellfish poisoning (DSP). The proliferation of microalgae that produce OA and its analogues is frequent, threatening human health and socioeconomic development. Several methods have been tested to remove this biotoxin from aquatic systems, yet none has proven enough efficacy to solve the problem. In this work, we synthesized and characterized low-cost composites and tested their efficacy for OA adsorption in saltwater. For the synthesis of the composites, the following starting materials were considered: chitosan of low and medium molecular weight (CH-LW and CH-MW, respectively), activated carbon (AC), and montmorillonite (MMT). Characterization by vibrational spectroscopy (FTIR), X-ray diffraction (XRD), and microscopy revealed differences in the mode of interaction of CH-LW and CH-MW with AC and MMT, suggesting that the interaction of CH-MW with MMT has mainly occurred on the surface of the clay particles and no sufficient intercalation of CH-MW into the MMT interlayers took place. Among the composites tested (CH-LW/AC, CH-MW/AC, CH-MW/AC/MMT, and CH-MW/MMT), CH-MW/MMT was the one that revealed lower OA adsorption efficiency, given the findings evidenced by the structural characterization. On the contrary, the CH-MW/AC composite revealed the highest average percentage of OA adsorption (53 ± 11%). Although preliminary, the results obtained in this work open up good perspectives for the use of this type of composite material as an adsorbent in the removal of OA from marine environments.

The Effect of Chitosan Incorporation on Physico-Mechanical and Biological Characteristics of a Calcium Silicate Filling Material.

A tricalcium silicate-based cement, Biodentine™, has displayed antibiofilm activity when mixed with chitosan powder. This study aimed to assess the effect of chitosan incorporation on the physico-mechanical and biological properties of Biodentine™. In this study, medium molecular weight chitosan powder was incorporated into Biodentine™ in varying proportions (2.5 wt%, 5 wt%, 10 wt%, and 20 wt%). The setting time was determined using a Vicat apparatus, solubility was assessed by calculating weight variation after water immersion, radiopacity was evaluated and expressed in millimeters of aluminum, the compressive strength was evaluated using an Instron testing machine, and the microhardness was measured with a Vickers microhardness tester. In addition, surface topography of specimens was analyzed using scanning electron microscopy, and the effect of chitosan on the viability of human embryonic kidney (HEK 293) cells was measured by a colorimetric MTT assay. Incorporation of 2.5 wt% and 5 wt% chitosan powder delivered an advantage by speeding up the setting time of Biodentine material. However, the incorporation of chitosan compromised all other material properties and the crystalline structure in a dose-dependent manner. The chitosan-modified material also showed significant decreases in the proliferation of the HEK 293 cells, signifying decreased biocompatibility. Chitosan incorporation into calcium silicate materials adversely affects the physical and biological properties of the material. Despite the increased antimicrobial activity of the modified material, the diminution in these properties is likely to reduce its clinical value.

Thermosensitive composite based on agarose and chitosan saturated with carbon dioxide. Preliminary study of requirements for production of new CSAG bioink

This study introduces a method for producing printable, thermosensitive bioink formulated from agarose (AG) and carbon dioxide-saturated chitosan (CS) hydrogels. The research identified medium molecular weight chitosan as optimal for bioink production, with a preferred chitosan hydrogel content of 40–60 %. Rheological analysis reveals the bioink's pseudoplastic behavior and a sol-gel phase transition between 27.0 and 31.5 °C. The MMW chitosan-based bioink showed also the most stable extrusion characteristic. The choice of chitosan for the production of bioink was also based on the assessment of the antimicrobial activity of the polymer as a function of its molecular weight and the degree of deacetylation, noting significant cell reduction rates for E. coli and S. aureus of 1.72 and 0.54 for optimal bioink composition, respectively. Cytotoxicity assessments via MTT and LDH tests confirm the bioink's safety for L929, HaCaT, and 46BR.1 N cell lines. Additionally, XTT proliferation assay proved the stimulating effect of the bioink on the proliferation of 46BR.1 N fibroblasts, comparable to that observed with Fetal Bovine Serum (FBS). FTIR spectroscopy confirms the bioink as a physical polymer blend. In conclusion, the CS/AG bioink demonstrates the promising potential for advanced spatial cell cultures in tissue engineering applications including skin regeneration.

Comparative study of the effect of cross‐linking degree on chitosan hydrogels synthesized with low and medium molecular weight chitosan

AbstractChitosan (CS) is often used in hydrogels due to its natural origin, sustainability, non‐toxicity, and biodegradability. However, the physicochemical properties of CS hydrogels generated via physical cross‐linking are relatively poor. CS hydrogels were prepared by cross‐linking with glutaraldehyde (GA) at different ratios ranging from 1% to 10% (w/w), using two different molecular weight CS. The swelling degree of hydrogels was investigated at pH 2.0, 5.6, and 7.4. The structure, morphology, and thermal characteristics of hydrogels were examined using Fourier transform infrared, scanning electron microscopy, differential scanning calorimetry, and thermogravimetric analysis, respectively. Compression tests were conducted using Zwick/Roell universal testing equipment following ASTM D695. In vitro degradation studies were performed in enzyme and enzyme‐free mediums at pH 7.4. The study demonstrated that low molecular weight CS (L‐CS) hydrogels have a lower sol content and higher swelling values than medium molecular weight CS (M‐CS) hydrogels. Both L‐CS and M‐CS hydrogels cross‐linked with 1% GA showed maximum swelling degrees at pH 2.0. Thermal analysis concluded that M‐CS hydrogels have higher thermal stability than L‐CS hydrogels. It was also found that the M‐CS hydrogels have higher compressive moduli. The degradation experiments in both enzyme and enzyme‐free media showed that L‐CS hydrogels have higher degradation rates.Highlights Chemically cross‐linked hydrogels synthesized using low and medium molecular weight chitosan. The mechanical and physical properties of medium and low molecular weight chitosan hydrogels were compared. Degradation experiments were performed in both enzyme and enzyme‐free media. Swelling values decreased noticeably with the increasing molecular weight. Low molecular weight chitosan improved the biodegradability of hydrogels.

Effects of chitosan with different molecular weights on storage quality and fungi inhibition of mini-cucumber

The effect of low (LWC, 30 kD), medium (MWC, 150 kD) and high molecular weight chitosan (HWC, 300 kD) coatings on storage quality and fungi inhibition of mini-cucumber was evaluated. Chitosan coatings significantly reduced the weight loss, and delayed the color change and sensory score of mini-cucumber when compared with the control. Chitosan coatings significantly retarded the decrease of DPPH free radical scavenging rate and total phenol content, and inhibited the total number of bacterial colonies and the viable numbers of yeast and molds in mini-cucumber. Chitosan coatings also significantly reduced the disease incidence and disease severity of mini-cucumber artificial inoculated with Botrytis cinerea. LWC coating showed superior preservation effectiveness and antifungal activity to MWC and HWC coating. Compared with the control, LWC coating prolonged the shelf life by 6 days which was evaluated by sensory score, and reduced the total number of bacterial colonies and viable numbers of yeast and molds in mini-cucumber by 4.20 log10 CFU/g and 2.72 log10 CFU/g, respectively. These results suggested that chitosan molecular weights affected preservation effectiveness and antifungal activity against B. cinerea and LWC could be used to prolong the shelf life of mini-cucumber and maintain its quality after harvest.

Characterization of alginate from Antarctic Himantothallus grandifolius (Phaeophyceae) and preparation of polyelectrolyte complexes with chitosan

AbstractHydrogels are three‐dimensional polymeric materials with applications in various areas such as biomedicine, tissue engineering, pollutant capture systems, and so forth. However, its application is limited due to the reproducibility of its properties. Factors such as the composition of the constituents, the type of union between the polymer chains, and the crosslinking time play a crucial role in ensuring its reproducibility. In this study, the objective is to prepare a matrix with well‐defined properties that ensure controlled release processes. Treatment of Himantothallus grandifolius with Na2CO3 aqueous solution afforded in 18.9% yield alkaline extract. Hydrogels were prepared by ionic complexation of alginate from H. grandifolius, and polyguluronate enriched alginate from Desmarestia ligulata with chitosan stabilized by immersion in 0.1 M CaCl2 solution; better swelling ratio in water was found for hydrogels with low molecular weight chitosan (MW 125,000 g/mol) than those with medium molecular weight chitosan (MW450,000–500,000 g/mol). Liberation of the model drug metformin hydrochloride from alginates: chitosan complexes (3:1) at pH 1.5 was especially low for hydrogel from H. grandifolius during the first 2 h; 70% of metformin was released at pH 6.5 after 24 h. This polyelectrolyte complex constitutes a good material for potential application in biomedicine considering its cationic and anionic characteristics.

Application of low-, and medium-molecular weight chitosan for preparation of spray-dried microparticles loaded with Ferulago angulata essential oil: Physicochemical, antioxidant, antibacterial and in-vitro release properties

The present work aimed at spray-drying encapsulation of Chavir (Ferulago angulata) essential oil (EO) using low-, and medium-molecular weight chitosan. The obtained EO was observed to be mainly composed of β-ocimene, α-pinene, and bornyl acetate with antioxidant, and antimicrobial activity. The results indicated that stable emulsions with uniform particle size distribution and encapsulation efficiencies higher than 93 % could be prepared using chitosan as feed for spray-drying. In addition, spray-drying resulted in fabricating stable microspheres with yields higher than 50 %, uniform particle size, and encapsulation efficiency exceeding 70 %. The microspheres were fairly soluble and hygroscopic, and exhibited antioxidant and bacteriostatic activities with a biphasic release pattern. FTIR characterisation confirmed successful encapsulation of EO and thermal properties of microspheres indicated enhanced stability of EO after microencapsulation. Overall, it was revealed that molecular weight of chitosan and EO:chitosan ratio affects some physicochemical properties of obtained chitosan microspheres.

Synthesized carboxymethyl-chitosan variant composites for cyclic adsorption-desorption based removal of Fe, Pb, and Cu

The global issue of environmental contamination from industrial wastewater comprising Cu, Fe and Pb demands effective treatment strategies. In this article, a functional composite sorbent was devised to selectively remove copper, iron, and lead from a real-world mimicking wastewater system. For the purpose, high, medium, and low molecular weight chitosan with amine and hydroxyl functional groups were used as a substrate, and glutaraldehyde was used to anchor the organic compound with carboxymethyl groups. Characterization with X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetric analysis, X-ray analyzer accompanied by field emission scanning electron microscope, and Brunauer-Emmett-Teller were conducted for the synthesized adsorbent. Accordingly, the properties of the adsorbent were evaluated to infer that the synthesis assured a purified and functionalized system. The surface area of the medium carboxymethyl chitosan derivative was analyzed as 31.43 m2 g−1. Various adsorption parameters were examined methodically to assess upon optimal removal requirements. The effect of adsorbent dosage, contact time and concentration on the adsorption of the studied metal ions were conducted and the optimum values were achieved at pH 3.82, 540 min contact duration and 1.2 g L−1 sorbent dose. Maximum adsorbent capacities of 344.83 mg g−1, 9.59 mg g−1, and 90.09 mg g−1 were realized for Cu, Pb, and Fe, respectively. The experimental measurements of the studied heavy metal ions inferred the best fitness of Langmuir isotherm equilibrium and pseudo second order kinetic models. Further, elution studies with easy-to-deploy low-cost acidic and basic eluents (HCl, HNO3, H2SO4, KOH, and NaOH) were conducted with cyclic adsorption-desorption strategies. These investigations confirmed the adsorbent's good reusability up to 3 cycles of adsorption and its proximity to serve as a potential material for multi-heavy metal ions elimination from complex adsorbate systems.

Chitosan: Properties and Its Application in Agriculture in Context of Molecular Weight.

Chitosan is a naturally occurring compound that can be obtained from deacetylated chitin, which is obtained from various sources such as fungi, crustaceans, and insects. Commercially, chitosan is produced from crustaceans. Based on the range of its molecular weight, chitosan can be classified into three different types, namely, high molecular weight chitosan (HMWC, >700 kDa), medium molecular weight chitosan (MMWC, 150-700 kDa), and low molecular weight chitosan (LMWC, less than 150 kDa). Chitosan shows several properties that can be applied in horticultural crops, such as plant root growth enhancer, antimicrobial, antifungal, and antiviral activities. Nevertheless, these properties depend on its molecular weight (MW) and acetylation degree (DD). Therefore, this article seeks to extensively review the properties of chitosan applied in the agricultural sector, classifying them in relation to chitosan's MW, and its use as a material for sustainable agriculture.

Comparison of shrimp waste-derived chitosan produced through conventional and microwave-assisted extraction processes: Physicochemical properties and antibacterial activity assessment

Depending on its physicochemical properties and antibacterial activities, chitosan can have a wide range of applications in food, pharmaceutical, medicine, cosmetics, agriculture, and aquaculture. In this experimental study, chitosan was extracted from shrimp waste through conventional extraction, microwave-assisted extraction, and conventional extraction under microwave process conditions. The effects of the heating source on the physicochemical properties and antibacterial activity were investigated. The results showed that the heating process parameters affected the physicochemical properties considerably. The conventional procedure yielded high molecular weight chitosan with a 12.7 % yield, while the microwave extraction procedure yielded a porous medium molecular weight chitosan at 11.8 %. The conventional extraction under microwave process conditions led to medium molecular weight chitosan with the lowest yield (10.8 %) and crystallinity index (79 %). Antibacterial assessment findings revealed that the chitosan extracted using the conventional method had the best antibacterial activity in the agar disk diffusion assay against Listeria monocytogenes (9.48 mm), Escherichia coli. (8.79 mm), and Salmonella Typhimurium (8.57 mm). While the chitosan obtained by microwave-assisted extraction possessed the highest activity against E. coli. (8.37 mm), and Staphylococcus aureus (8.05 mm), with comparable antibacterial activity against S. Typhimurium (7.34 mm) and L. monocytogenes (6.52 mm). Moreover, the minimal inhibitory concentration and minimal bactericidal concentration assays demonstrated that among the chitosan samples investigated, the conventionally-extracted chitosan, followed by the chitosan extracted by microwave, had the best antibacterial activity against the target bacteria.

Evaluation of antifungal efficacy of chitosan against Aspergillus fumigatus of stored rice (Oryza sativa)

Contamination of stored rice with fungal pathogens results in rice of poor quality and economic value, and may also have harmful effects on human and animal health. This study aimed at evaluating the antifungal efficacy of chitosan against Aspergillus fumigatus of stored rice (Oryza sativa). Four forms of chitosan were used in this study viz; Purchased Low, Medium and high molecular weight chitosan and chitosan synthesized from Crab Shell using deproteinization, demineralization, decolouration and deacetylation. Degree of deacetylation of the synthesized chitosan was determined using Fourier transform infrared (FTIR) analysis. The in vitro antifungal activity of all forms of chitosan were determined using food poisoning method against Aspergillus fumigatus isolated from stored rice seeds using agar plate methods. The percentage inhibition of mycelial radial growth Aspergillus fumigatus by the different forms of chitosan was determined. Fourier Transfrom InfraRed Spectra of synthesized chitosan showed major absorption bands from 3444.72, 2966.17, 2512.60, 2144.84, 1429.74, 1258.12, 1160.05, 1025.2, 869.92, 710.50, 608.40 to 559.36. Absorption peak at 559 was assigned to glucopyranose ring in the chitosan matrix. Degree of deacetylation of synthesized chitosan was at 98.6% degree. Highest mycelia radial growth of 8.00 cm was recorded in control, while 2.00, 0.00, 5.23, and 1.33cm were recorded in 2.0% concentration of High Molecular Weight Chitosan (HMWC), Medium Molecular Weight Chitosan (MMWC), Low Molecular Weight Chitosan (LMWC) and Chitosan synthesized from Crab shell (CSCS) treatment respectively. The result of the percentage inhibition reveals that A. fumigatus had 100% inhibition in 1.5% HMWC and 2.0% MMWC while 85% inhibition in 2.0% CSCS which were significantly different from 2.0% LMWC with 36.5% inhibitions. Results obtained from this study has shown the effectiveness of chitosan as an effective antifungal agent which can improve and maintain the quality of stored rice and ensure a safer environment due to its nontoxic and environmental friendly properties.

Cultivar-Specific Effect of Chitosan on Chitinase and Glucanase Activity in the Roots of Garlic Allium sativum L.

Chitosan is a natural polysaccharide and, when applied externally, is able to stimulate both growth and defense of the plant, enhancing its resistance to abiotic stresses and suppressing the development of many phytopathogens. Immune response includes the activation of defense proteins, carbohydrases such as chitinases and glucanases, which are also known to participate in the regulation of morphogenesis. In this study, for the first time, the effect of treatment with unfractionated (hydrolysate) chitosan of low (CH1) and medium (CH2) molecular weight on chitinase and glucanase activities, as well as on the expression of chitinase and -1,3-glucanase genes in the roots of two cultivars of garlic Allium sativum L. differing by resistance to Fusarium rot was examined. It was shown that the effect of chitosans on the enzymatic activity and expression of the genes encoding -1,3-glucanases (AsPR2a, AsPR2b, and AsPR2c) and chitinases (AsCHI1, AsCHI3, AsCHI7, AsCHI17, and AsCHI23) is cultivar-specific, which may be due to different susceptibility of the cultivars to Fusarium. The expression pattern of chitinase genes AsCHI10, AsCHI27, and AsCHI34, similar between varieties, suggested their involvement in root tissue morphogenesis. The results indicated a greater stimulatory effect of CH2 in comparison with CH1 on chitinase and glucanase activity. The stronger inhibitory influence of CH2 (as compared with CH1) on the expression of chitinase and -1,3-glucanase genes correlated with the lower fungicidal effect of CH2 on Fusarium proliferatum. The findings may be used in breeding biotechnology to increase the resistance of garlic to Fusarium.

Chitosan-Based Edible Coatings Containing Essential Oils to Preserve the Shelf Life and Postharvest Quality Parameters of Organic Strawberries and Apples during Cold Storage.

Edible coatings and films have been researched for more than three decades due to their ability to be incorporated with different functional ingredients or compounds as an option to maintain the postharvest quality of fruits and vegetables. The aim of this study was to evaluate the effect of three types of chitosan-based (CH) edible coatings obtained from medium and high molecular weight chitosan, containing ascorbic or acetic acid and sea buckthorn or grape seed essential oils on the physical-chemical and microbiological properties of organic strawberries and apple slices during cold storage at 4 °C and 8 °C. Scanning electron microscope images showed both a smooth structure and a fracture and pore structure on strawberry coatings and a dense and smooth structure on the apple slices coatings. Further, the edible coatings managed to reduce the microbial load of yeasts and molds of the coated strawberries during the storage period. Overall, the treatments preserved the ascorbic acid, total polyphenol content, and antioxidant activity for all the tested samples compared to the control sample, throughout the storage period. In addition, the water activity (aw) of the coated samples presented lower values (0.96-0.98) than the control samples. The obtained results indicate that the developed chitosan-based edible coatings could maintain the postharvest parameters of the tested samples, also leading to their shelf-life prolongation.

Eco-design and tunable structure-properties of chitosan-epoxy-glycerol-silicate biohybrids using integrated crosslinking

Tunable structure-properties were achieved for chitosan-epoxy-glycerol-silicate (CHTGP) biohybrids, eco-designed via integrated amine-epoxy and waterborne sol-gel crosslinking reactions. Medium molecular weight chitosan (CHT), with 83 % degree of deacetylation was prepared by microwave-assisted alkaline deacetylation of chitin. The amine group of chitosan was covalently bonded to the epoxide of 3-glycidoxypropyltrimethoxysilane (G) for further crosslinking with a sol-gel derived glycerol-silicate precursor (P) from 0.5 % to 5 %. The impact of crosslinking density on the structural morphology, thermal, mechanical, moisture-retention and antimicrobial properties of the biohybrids were characterized by FTIR, NMR, SEM, swelling and bacterial inhibition studies and contrasted with a corresponding series (CHTP) without epoxy silane. Water uptake was significantly reduced in all biohybrids with a 12 % window of variation between the two series. Properties observed in biohybrids with only epoxy-amine (CHTG) or sol-gel crosslinking reactions (CHTP), were reversed in the integrated biohybrids (CHTGP) to impart improved thermal and mechanical stability and antibacterial activity.

Antifungal activity of chitosan and its combination with the yeast Debaryomyces hansenii F9D for the control of Penicillium expansum in apples and pears stored at low temperatures

Penicillium expansum is an important pathogen of cold-stored fruit, currently controlled by chemical fungicides. In this work chitosan combined with the biocontrol yeast Debaryomyces hansenii F9D was tested as a safer alternative for its control on cold-stored apples and pears. When medium molecular weight chitosan was applied on fruit a reduction of rot incidence of 62% and 53% was achieved in apples and pears. respectively. When chitosan was combined with the yeast, disease reduction was 76% and 90%. The combination of biological control with chitosan appears as a feasible strategy for the control of phytopathogenic fungi.

Sustainable Synthesis of FITC Chitosan-Capped Gold Nanoparticles for Biomedical Applications

The quest for novel nanoscale materials for different applications necessitates that they are easy to obtain and have excellent physical properties and low toxicity. Moreover, considering the ongoing environmental impact of noxious chemical waste products, it is important to adopt eco-friendly approaches for nanoparticle synthesis. In this work, a natural polymer (medium molecular weight chitosan) derived from chitin was employed as a reducing agent to obtain gold nanoparticles (AuNPs) with a chitosan shell (AuNPs@CS) by a microwave oven. The chitosan is economically viable and cost-competitive in the market showing also nontoxic behavior in the environment and living organisms. The synthesized AuNPs@CS-FITC NPs were fully characterized by spectroscopic and microscopic characterization techniques. The size distribution of NPs was about 15 nm, which is a suitable dimension to use in biomedical applications due to their high tissue penetration, great circulation in blood, and optimal clearance as well as low toxicity. The prepared polymer-capped NPs were further functionalized with a fluorescent molecule, i.e., Fluorescein-5-isothiocyanate (FITC), to perform imaging in the cell. The results highlighted the goodness of the synthesis procedure, as well as the high internalization rate that resulted in an optimal fluorescence intensity. Thus, this work presents a good sustainable/green approach-mediated polymer nanocomposite for various applications in the field of diagnostic imaging.

Removal of Copper metal from Industrial wastewater using GCC adsorbent

Abstract: An Activated carbon has been employed as a adsorbent in adsorption methods, which are widely now used by numerous researcher to remove major heavy metals from waste streams. Activated carbon are still a pricy commodity even though it is majorly use in the water and wastewater treatments industries. The demand for economically technology to remove major heavy metal from contaminated waters has recently sparked research into the development of affordable alternatives to commercial available activated carbon. The ability of glutaraldehyde cross link chitosan (GCC) co polymer to remove and recover copper (Cu (II)) from electroplating solution is examined in this study, along with the impacts of solutions chemistry on adsorption and desorption character of Cu (II) using chitosan-based resins. A GCC co polymer adsorbent was made with the help grafting medium molecular weight chitosan with glutaraldehyde at a specific weight ratio (1/17). (25 percent in H2O). within the parameters of 4–9 pH, 30–150 min of contact time, 25–200 mg/L of dosage, 30–150 mg/L of starting Cu (II) concentration (conc.). Batch tests were done to determine which settings were ideal for copper. Additionally, the effects of factors like adsorbent dosage, pH, contact time, and initial metal ions con were examined. For copper, the ideal conditions were 120 minute of contacts time, 150 gL-1 of adsorbent, 30 mgL-1 of starting Cu (II) conc. and pH 5. The relation between the conc. and the amount that adsorbent absorbed is shown by the adsorption isotherms. To elaborate adsorption kinetics we define pseudo first order and, the pseudo second orders kinetic models could be utilize.

FORMULATION AND OPTIMIZATION OF CERITINIB LOADED NANOBUBBLES BY BOX-BEHNKEN DESIGN

Objective: Ceritinib is an anaplastic lymphoma kinase (ALK) inhibitor used to treat lung cancer. In the current research, the ceritinib-loaded nanobubbles were prepared by using perfluorobutane for inner core and medium molecular weight chitosan for the shell. Methods: A 33Box-Behnken design was used to determine the influence of L-α-Phosphatidylcholine (A), the concentration of chitosan (B) and concentration of palmitic acid (C) factors affecting particle size, and polydispersity index. The individual effects of these factors on particle size and polydispersity index were depicted in perturbation plot, response surfaces and counterplots based on Derringer’s desirability approach. Results: The extreme desirability function value was obtained at A: 1.31 % w/v, B: 3.00 % w/v, C: 1.5 % W/V. Three batches of formulation were prepared in accordance to the desirability function and evaluated. TEM images revealed the superficial morphology and core-shell structure of nanobubbles in the size range of 150-200 nm. Nanobubbles were able to load ceritinib with an encapsulation efficiency of 79.12 % and a loading capacity of 19.2 %. The nanobubbles released about 95.67 % drug in 24h. The in vitro cellular uptake study results show the enhanced cellular uptake of ceritinib with ultrasound from nanobubbles. In vitro cytotoxicity study results indicated that ultrasound-assisted nanobubbles can effectively release in the cells with high sensitivity. Conclusion: Chitosan-based ceritinib nanobubbles, therefore, offer a remarkable tool for the development of ultrasound-responsive formulations that deliver drugs to the target.