Chitosan Shell Research Articles

Synthesis and comprehensive characterization with anticancer activity assessment of salicylaldehyde and 2-acetylphenol based chitosan thiosemicarbazones and their copper(II) complexes

Synthesis and comprehensive characterization with anticancer activity assessment of salicylaldehyde and 2-acetylphenol based chitosan thiosemicarbazones and their copper(II) complexes

Precise Engineering of Growth Factor Presentation Using Extracellular Microenvironment-Mimicking Microfluidic Microparticles.

One of the main challenges in tissue engineering is finding a way to deliver specific growth factors (GFs) with precise spatiotemporal control over their presentation. Here, we report a novel strategy for generating microscale carriers with enhanced affinity for high content loading suitable for the sustained and localized delivery of GFs. Our developed microparticles can be injected locally and sustainably release encapsulated growth factors for up to 28 days. Fine-tuning of particles' size, affinity, microstructures, and release kinetics is achieved using a microfluidic system along with bioconjugation techniques. We also describe an innovative 3D micromixer platform to control the formation of core-shell particles based on superaffinity using a polymer-peptide conjugate for further tuning of release kinetics and delayed degradation. Chitosan shells block the burst release of encapsulated GFs and enable their sustained delivery for up to 10 days. The matched release profiles and degradation provide the local tissues with biomimetic, developmental-biologic-compatible signals to maximize regenerative effects. The versatility of this approach is verified using three different therapeutic proteins, including human bone morphogenetic protein-2 (rhBMP-2), vascular endothelial growth factor (VEGF), and stromal cell-derived factor 1 (SDF-1α). As in vivo morphogenesis is typically driven by the combined action of several growth factors, the proposed technique can be developed to generate a library of GF-loaded particles with designated release profiles.

In-situ magnetic alginate coated chitosan core@shell beads with excellent performance in simulated and real wastewater treatment: Behavior, mechanisms, and new perspectives

Herein, a new hybrid magnetic core@shell biocomposite was prepared based on an alginate-bentonite core and a chitosan shell layer (mAB@Cs) where magnetic Fe3O4 NPs (50.7nm) were in-situ generated on the surface via a simple non-thermal co-precipitation approach. The biocomposite has a high ability to magnetically separate and remove organic (ciprofloxacin (CPX)) and seven toxic inorganic (Cu2+, Cd2+, Co2+, Ni2+, Pb2+, Zn2+, and Hg2+) contaminants from simulated wastewater. Experimental results showed a CPX monolayer chemisorption with a Langmuir maximum adsorption capacity of 264.7mg/g, maintained effectiveness up to the fifth cycle, and high removal rates of heavy metals ranging from 74.89% to 99.86% corresponding to adsorption capacities ranging from 12 to 20mg/g. For a more accurate evaluation, the biocomposite was tested on a real urban wastewater sample (RWW) and it has manifested a noteworthy efficiency in removing a mixture of inorganic pollutants in terms of potassium K+ and orthophosphate phosphorous P-PO43-, and organic matter in terms of biological oxygen demand (BOD) and chemical oxygen demand (COD) with 46%, 90%, 84%, and 64% removal efficiencies, respectively. On top of this, a high inactivation rate of E. coli of the order of 96% was recorded, making the prepared magnetic biocomposite adept for the simultaneous removal of emergent wastewater pollutants, from organic, inorganic, to pathogen microorganisms.

β-Glycosidase sensitive oral nanoparticles for combined photothermal and chemo treatment of colorectal cancer.

Colorectal cancer is one of the most common malignant tumors in the world, and its treatment strategies mainly include surgical resection, chemotherapy, adjuvant radiotherapy, and immunotherapy. Among them, chemotherapy inevitably produces systemic toxicity due to the lack of tumor targeting properties and drug resistance caused by long-term medication frequently occurs, immensely constraining the efficacy of chemotherapy alone. To solve the above-mentioned problems, rhamnolipid was used to encapsulate the chemotherapeutic drug 5-FU and photothermal agent bismuthene nanosheets (BiNS), chitosan was applied as the shell of the nanoparticle, and BiNS@RHL-CS/5-FU NPs for oral administration was successfully prepared. When transported in the stomach and small intestine, the double protection of rhamnolipid and chitosan shell prevented the early release of BiNS and 5-FU. When transported to the colon, β-glycosidase existing in the microenvironment along with elevated pH degraded the chitosan shell, and the reduction in particle size was beneficial for tumor tissue to uptake nanoparticles, thus greatly improving the tumor targeting ability of 5-FU and reducing the systemic toxicity. Due to the presence of BiNS, 1.0 W cm-2 808 nm laser irradiation significantly increased the temperature of the tumor site, not only killing tumor cells directly but also promoting cell uptake and penetration of nanoparticles in the tumor tissue, accelerating the release of 5-FU and improving the sensitivity of tumor cells to chemotherapy, eventually solving the shortcomings of traditional chemotherapy alone. Excellent anti-tumor efficacy has been achieved in both in vitro and in vivo experiments.

CrabCare: Innovative Chitosan Biopolymer-Based Ointment from Crab Shell Waste by Utiling

Wounds are a common problem that requires effective care to prevent infection and accelerate the healing process. The use of conventional antiseptics is often unsatisfactory due to the long time required. Therefore, the innovation of using chitosan from crab shell waste as a base material for ointment becomes the focus of this research. This study aims to develop a chitosan-based ointment that can accelerate the wound healing process more efficiently. The research results show that the ointment developed from crab shells through the deproteinization process can significantly accelerate wound healing. Chitosan extracted from crab shells has unique properties such as bioactivity, biodegradability, and biocompatibility, which are effective in inhibiting bacterial and pathogen growth, as well as stimulating granulation tissue formation. Thus, the CrabCare ointment made from crab shell chitosan offers a promising alternative as a therapeutic agent for more effective and environmentally friendly wound care. In conclusion, the development of CrabCare provides new opportunities in wound therapy through innovative and sustainable means.

Modeling of the adsorption of acidic dyes by chitosan using both kinetic and thermodynamic comparisons

Two chitosans from two different sources crab shell chitosan (CC) and deep-pink shrimp chitosan (CP) were used in a batch system to test the adsorption of two acidic dyes, Acid Red 183 (AR183) and Acid Red 114 (AR114), and the results were compared with those of acid-washed powdered activated carbon (PAC). The effects of temperature, contact time, and starting dye concentration on the removal of AR114 and AR183 dye were investigated in a series of batch adsorption studies. The two chitosans had the highest dye absorption capacity for each AR dye-adsorbent system at 45 °C. The capacity of each adsorbent to adsorb increased when the initial dye concentration was increased up to 500 mg L−1. Chitosan CP was the most efficient of the three adsorbents, with maximum AR114 and AR183 absorption of 440 and 447 mg g−1, respectively, at 45 °C. At all concentrations and temperatures examined, the pseudo-second-order kinetic model accurately represented the adsorption kinetics, and the rate constants of second-order adsorption (k2) at these temperatures were calculated, respectively. The thermodynamic study revealed that the adsorption of dyes on chitosans was feasible, spontaneous, and endothermic process, and the adsorption of the dyes on each adsorbent may be chemical in nature. Results indicated that the synthesized chitosans were shown to be a promising adsorbent for the removal of dyes from aqueous solutions.

Formation Kinetics and Antimicrobial Activity of Silver Nanoparticle Dispersions Based on N-Reacetylated Oligochitosan Solutions for Biomedical Applications.

The paper presents the results of the synthesis, a detailed kinetics study, and an investigation of the biological activity of silver nanoparticles (AgNPs) in aqueous solutions of N-reacetylated oligochitosan hydrochloride. UV-visible spectrophotometry and dynamic light scattering were employed to control silver ion reduction. The process was observed to follow a pseudo-first-order law. Transmission and scanning electron microscopy demonstrated that AgNPs ranging in size from 10 to 25 nm formed aggregates measuring 60 to 90 nm, with the aggregate surface coated by a 2-4 nm chitosan shell. X-ray microanalysis and powder X-ray diffractometry were used to study the phase composition, identifying two crystalline phases, nanocrystalline silver and AgCl, present in the dispersions. The antibacterial effect was assessed using the serial dilution method for dispersions with varying degrees of Ag+ conversion. Nanodispersions exhibited significant activity against Escherichia coli, Pseudomonas aeruginosa, Bacillus cereus, and Staphylococcus aureus. Interestingly, the activity did not appear to be heavily influenced by the presence of the AgCl phase or the concentration of Ag+ ions. These synthesized dispersions hold promise for the development of materials tailored for biomedical applications.

Isolation and Toxicity Test of Chitosan from Green Mussels (Perna viridis L.) With Brine Shrimp Lethality Test (BSLT) Method

Green Mussels (Perna viridis L.) is one of Indonesia's fishery resources. The purpose of this study was to determine the toxicity level of chitosan from green clam shells (Perna viridis L.) by looking at the LC50 value tested on the BSLT method. This study included isolation of chitin and chitosan: deproteination, demineralization, depigmentation and deacetylation of chitin into chitosan, chitosan characterization, FTIR, and chitosan Toxicity Test using the BSLT method to see the number of deaths of Artemia salina L larvae obtained data (LC50). The results showed that the Chitosan Green Clam Shell (Perna viridis L.) had an LC50 of 4369.1806 ?g/mL. The results showed that green clam shell chitosan (Perna viridis L.) was non-toxic (LC50 > 1000 ?g/mL) in the BSLT test. Keywords: BSLT, Chitosan, Shellfish, Toxicity Test

Removal of diclofenac from aqueous solution by chitosan-encapsulated Aliquat-336 capsules: Optimization of preparation conditions and adsorption mechanism

Removal of diclofenac from aqueous solution by chitosan-encapsulated Aliquat-336 capsules: Optimization of preparation conditions and adsorption mechanism

Mangiferin loaded carrageenan/chitosan core-shell hydrogel beads: Preparation, characterization and proposed application

Mangiferin loaded carrageenan/chitosan core-shell hydrogel beads: Preparation, characterization and proposed application

Changes of physicochemical properties and bioactivities of resveratrol-loaded core-shell biopolymer nanoparticles during in vitro gastrointestinal digestion.

Resveratrol loaded nanoparticles (nano-resveratrol) containing a zein core surrounded by surfactant (Tween-NPs) or carboxymethyl chitosan (CMCS-NPs) shell were fabricated with different particle sizes, surface charges and colloidal stabilities. Changes of physicochemical properties for the two nano-resveratrols, as well as their antioxidant potentials and cytotoxicity were investigated during a static in vitro gastrointestinal tract (GIT) digestion. Results showed that the Tween-NPs had a much higher bioaccessibility (84.1±19.2%) than that of CMCS-NPs (36.6±4.2%) after the GIT digestion, which was expected due to the steric barrier of the CMCS coating. Both nano-resveratrols could sustained their antioxidant activities after digestion. However, the Tween-NPs had a significantly higher cytotoxicity against MCF-7 cells than CMCS-NPs and free resveratrol, while a reduction in cytotoxicity of Tween-NPs was observed after the digestion. The bioactivities results were well correlated with the physicochemical properties and dissolution of resveratrol under environmental stress.

Enhanced Anti-Herpetic Activity of Valacyclovir Loaded in Sulfobutyl-ether-β-cyclodextrin-decorated Chitosan Nanodroplets.

Valacyclovir (VACV) was developed as a prodrug of the most common anti-herpetic drug Acyclovir (ACV), aiming to enhance its bioavailability. Nevertheless, prolonged VACV oral treatment may lead to the development of important side effects. Nanotechnology-based formulations for vaginal administration represent a promising approach to increase the concentration of the drug at the site of infection, limiting systemic drug exposure and reducing systemic toxicity. In this study, VACV-loaded nanodroplet (ND) formulations, optimized for vaginal delivery, were designed. Cell-based assays were then carried out to evaluate the antiviral activity of VACV loaded in the ND system. The chitosan-shelled ND exhibited an average diameter of about 400 nm and a VACV encapsulation efficiency of approximately 91% and was characterized by a prolonged and sustained release of VACV. Moreover, a modification of chitosan shell with an anionic cyclodextrin, sulfobutyl ether β-cyclodextrin (SBEβCD), as a physical cross-linker, increased the stability and mucoadhesion capability of the nanosystem. Biological experiments showed that SBEβCD-chitosan NDs enhanced VACV antiviral activity against the herpes simplex viruses type 1 and 2, most likely due to the long-term controlled release of VACV loaded in the ND and an improved delivery of the drug in sub-cellular compartments.

The Potential of Crab Chitosan Polymer as EOR Injection Fluid

The abundant availability of crab shell waste in Indonesia is still not optimally utilized. Crab shell contains chitin that can be processed into chitosan. Chitosan polymer can be developed to be utilized on Enhanced Oil Recovery. The objective of this study is to measure the amount of biopolymer adsorption potential of crab shell on sandstone both statically and dynamically, in order to obtain oil recovery potential by using crab shell chitosan as injection fluid. Method of this study is categorized as experimental research through direct observation inside a laboratory. The utilized biopolymer in this research was chitosan made from crab shell. Biopolymer solution concentrations in this research are 5,000, 10,000, and 15,000 mg/L and the formation water salinity levels were at 10,000 and 20,000 mg/L. The research was conducted by using variations of formation water compounds namely NaCl and MgCl2. The research conducted consists of viscosity, transmittance, and adsorption measurements on biopolymer and water formation salinity concentrations. The sand pack flooding was conducted to observe oil displacement by selected formation water and chitosan solution. After conducted viscosity test, solution with the highest viscosity levels were chosen as driving fluid in sand pack flooding. The solutions are N2R3 samples which are crab shell chitosan solution with formation water containing NaCl with salinity level 20,000 mg/L and chitosan concentration of 15,000 mg/L. The viscosity value of the sample was at 1728.67 cP. Conclusion: Crab chitosan with 15,000 mg/L concentration, 20,000 mg/L salinity, and viscosity value of 1728.67 cp can be optimally utilized in sand pack flooding by providing incremental recovery factor of 10.27%.

Synthesis and Performance Study of pH/Magnetic Dual Response Chitosan Based Emulsifiers

Recently, stimuli-responsive emulsions have been widely applied due to their excellent structural stability, biocompatibility, and environmental friendliness. For this application, the emulsion needs to be able to respond quickly to environmental stimuli with controlled stabilization and destabilization. This paper reports a novel composite Pickering emulsifier using Fe3O4 as the core, silica as the intermediate layer, and chitosan as the outer shell, which possesses a pH/magnetic dual responsive feature when deionized water is used as the water phase, and liquid paraffin is used as the oil phase to form an emulsion. Fe3O4@SiO2@chitosan has good paramagnetism and pH responsiveness to realize controlled magnetic and pH-responsive breaking of an emulsion when needed. The size of the composite emulsifiers ranged from 90 nm to 120 nm. The strong magnetic responsiveness enables rapid emulsion breaking at pH=3-11. When used as stabilizer particles, the chitosan shell behaves differently depending on pH. At pH≤2, fully protonated chitosan as the free chain segment and Fe3O4@SiO2 stabilized emulsions together. The overall stabilization of the emulsion (Fe3O4@SiO2@chitosan as emulsifier) can be obtained at pH>2, and emulsion breaking is achieved at pH≈pKa condition.

Toward flame-retardant and toughened poly(lactic acid)/cross-linked polyurethane blends via the interfacial reaction with the modified bio-based flame retardants

Incorporating bio-based flame retardants into polylactic acid (PLLA) to improve flame retardancy has always been the focus of research, but the improvement of flame retardancy is usually at the expense of mechanical properties. How to successfully balanced the material's mechanical and combustion properties has puzzled many scholars. Herein, ammonium polyphosphate (APP) and chitosan (CS) were used as acid source and carbon source respectively. Biological flame retardant APP@CS was designed and synthesized by electrostatic self-assembly method. In addition, toughened PLLA composites were prepared by reactive blending with the in-situ formed polyurethane (PU) as toughening phase. The results show that the CS shell not only reduces the hydrophilicity of the flame retardant, but also has good flame retardant property because of its excellent char forming property. The addition of 10 phr APP@CS can endow PLLA/crosslinked PU (CPU) with UL-94V-2 rating and a LOI value of 24.9%. Interestingly, CS shell participates in the in-situ reaction, which improves the mechanical properties of the composite with elongation at break of 74%, which is higher than that of sample doped with the same amount of APP. This work provides guidance for the high performance modification of PLLA and is expected to expand the practical application range.

Influence of the complex of chitosan-ß-cyclodextrin with levofloxacin on the wounds’ microflora and the Sturgeon’s colon intestine

The authors in the article presented the results of determining the effectiveness of using the chitosan-ß-cyclodextrin complex with levofloxacin in the healing of mechanical wounds of valuable commercial fish sturgeons and their feeding. The experiment was conducted based on the “Progressive biotechnologies in aquaculture” research laboratory of the Saratov State University of Genetics, Biotechnology and Engineering. N.I. Vavilov. The microflora of incised wounds and the large intestine of sturgeon fingerlings under the influence of fluoroquinolone, represented by levofloxacin based on cyclodextrin, included in the shell of high-molecular chitosan, was studied. The studied microbiological indicators were chosen to determine that changes in the total number of microorganisms show the nature of the course of the inflammatory/pathological process, which contributes to the development of microorganisms (including opportunistic pathogens) and lactic acid bacteria in the intestine. Therefore, they are essential physiological indicators of the formation of “ intestinal immunity. It was found that the use of cyclodextrin with levofloxacin in the treatment of incised wounds in sturgeons leads to a significant decrease in the total microbial number (TMC) on their surface (by 10 thousand times compared to the group without treatment). It has been shown that using cyclodextrin with levofloxacin in feeding sturgeons reduces the total microbial number in the large intestine. This complex is characterised by good solubility and bioavailability for fish. The future study results can be used in aquaculture to treat mechanical injuries received during transportation and sorting in the rearing process in fish.

Chitooligosaccharide from Pacific White Shrimp Shell Chitosan Ameliorates Inflammation and Oxidative Stress via NF-κB, Erk1/2, Akt and Nrf2/HO-1 Pathways in LPS-Induced RAW264.7 Macrophage Cells.

Chitooligosaccharide (COS), found in both insects and marine sources, has several bioactivities, such as anti-inflammation and antioxidant activities. However, the mechanism of shrimp shell COS on retardation of inflammatory and antioxidant effects is limited. Therefore, the aim of this study is to examine the mechanism of the aforementioned activities of COS in LPS-activated RAW264.7 macrophage cells. COS significantly improved cell viability in LPS-activated cells. COS at the level of 500 µg/mL could reduce the TNF-α, NO and IL-6 generations in LPS-activated cells (p < 0.05). Furthermore, COS could reduce ROS formation, NF-κB overactivation, phosphorylation of Erk1/2 and Akt and Nrf2/HO-1 in LPS-exposed cells. These results indicate that COS manifests anti-inflammatory activity and antioxidant action via NF-κB, Erk1/2, Akt and Nrf2/HO-1 signaling with an increasing relevance for inflammatory disorders.

Formulation and optimization of theophylline-loaded enteric-coated spanlastic nanovesicles for colon delivery; Ameliorate acetic acid-induced ulcerative colitis

Treatment of colon diseases presents one of the most significant obstacles to drug delivery due to the inability to deliver sufficient drug concentration selectively to the colon. The goal of the proposed study was to develop, optimize, and assess an effective colon target delivery system of theophylline-based nanovesicles (TP-NVs) surrounded by a biodegradable polymeric shell of chitosan (CS) and Eudragit L100 (EL100) for the treatment of ulcerative colitis (UC). TP-loaded nanovesicles were fabricated using the ethanol injection method and coated with CS and EL100, respectively. We used a 32-factorial design approach to optimize the concentration of CS and EL100 to minimize particle size (PS) and maximize the cumulative amount of theophylline released (CTR) after 24 h. The optimized formulation was described using transmission electron microscopy (TEM), differential scanning calorimetry (DSC), and in vitro release. In-vivo quantification of theophylline in the gastrointestinal tract and in-vivo targeting potential in a rat model of acetic acid-induced colitis were also thoroughly evaluated. The characteristics of the optimal formula predicted by the 32-factorial design approach corresponded exceptionally well with the measured PS of 271.3 nm, the zeta potential of -39.9 mV, 3.95, and a 99.93% CTR after 5 and 24 hours, respectively. Notably, the in vivo results in the rat model of colitis showed that the formulation with an optimized coat significantly improved theophylline distribution to the colon and markedly decreased the expression of interleukin-6 and ulcerative lesions compared to a pure theophylline solution. These outcomes elucidated the feasibility of a 32-factorial design to detect the crucial interactions between the study's components. Our findings suggested that enteric-coated nanovesicles formulations with optimal coat compositions of 0.2693% (w/v) and 0.75% (w/v) of CS and EL100, respectively, were promising carriers for colonic delivery of theophylline, a rate-limiting step in the treatment of UC.

Bringing pathology to nanomedicine: a comparison of in vivo toxicity of polymeric nanoparticle carriers with and without chitosan coating

Over the last years, there has been an increasing number of proposals for the use of nanomaterials in medicine. The safety of novel technologies must be verified, prior to their clinical application. Pathology has much to contribute towards this end. In this study, we compared the in vivo toxicity effects of poly- (lactic-co-glycolic acid) nanoparticles with and without chitosan shell. Both nanoparticle types were loaded with curcumin. The nanoparticles were assessed in vitro for potential cytotoxicity with cell viability studies. For the in vivo test, 36 adult Wistar rats were used, four of which were the control group. The remaining 32 were divided into 2 groups, each of which was administered differentially coated drug carriers: (A) nanoparticles without chitosan coating and (B) nanoparticles with chitosan coating. For both groups, the subcutaneous route was used for administration. Each group was further divided into 2 sub-groups of 8 animals each. The animals of the first sub-groups were sacrificed 24 h after the injection and those of the second on the 7th day. The control group was also divided into 2 subgroups of 2 animals each. At the appointed post-administrative date, the rats were sacrificed, and specimens from the brain, liver, kidneys, heart, stomach, lungs, and from the skin at the injection site were collected and studied histopathologically. The evaluation of both in vitro and in vivo testing shows that nanoparticles with chitosan have significantly less, if any, toxic effects compared to those without chitosan.

Multi-stimuli-responsive chitosan-functionalized magnetite/poly(ε-caprolactone) nanoparticles as theranostic platforms for combined tumor magnetic resonance imaging and chemotherapy

Chitosan-functionalized magnetite/poly(ε-caprolactone) nanoparticles were formulated by interfacial polymer disposition plus coacervation, and loaded with gemcitabine. That (core/shell)/shell nanostructure was confirmed by electron microscopy, elemental analysis, electrophoretic, and Fourier transform infrared characterizations. A short-term stability study proved the protection against particle aggregation provided by the chitosan shell. Superparamagnetic properties of the nanoparticles were characterized in vitro, while the definition of the longitudinal and transverse relaxivities was an initial indication of their capacity as T2 contrast agents. Safety of the particles was demonstrated in vitro on HFF-1 human fibroblasts, and ex vivo on SCID mice. The nanoparticles demonstrated in vitro pH- and heat-responsive gemcitabine release capabilities. In vivo magnetic resonance imaging studies and Prussian blue visualization of iron deposits in tissue samples defined the improvement in nanoparticle targeting into the tumor when using a magnetic field. This tri-stimuli (magnetite/poly(ε-caprolactone))/chitosan nanostructure could find theranostic applications (biomedical imaging & chemotherapy) against tumors.