Methyl Chitosan Research Articles

Biochemical, Histopathological, and Immunological Effects of Mannan and/or Chitosan Oligosaccharides in Broilers intoxicated with Aflatoxins

Food additive such as carboxy methyl chitosan (CMC) and mannan (MOS) may have detoxification effect on aflatoxins (AFs). The current study aimed to investigate the role of chitosan and/or mannan in reducing the toxicity of AFs in broiler chickens (cobb500), through improving biochemical, hematological, oxidative stress, and antioxidant parameters. Furthermore, we investigated the impact on histopathological parameters and immune gene expression analysis (caspase 3 and interleukin 1-β). Five equal groups of 50 broilers each were selected (n=10); (G1) given the basal diet, (G2) basal diet intoxicated with 100 ppb AFs kg-1diet; (G3) given as basal diet intoxicated with 100 ppb AFs kg-1diet and supplemented with MAN (1 g kg-1 diet); (G4) given basal diet intoxicated with 100 ppb AFs kg-1diet and supplemented with CMC (0.5 g kg-1 diet) ; and (G5) given basal diet intoxicated with 100 ppb AFs kg-1diet and supplemented with MAN (1 g kg-1 diet)and CMC (0.5 g kg-1 diet). The current study's findings showed that the administration of both MAN and CMC brought hematological parameters back to the level of control. Chicks treated with MAN and/or CMC after being intoxicated with aflatoxins showed a considerable improvement in both renal and hepatic indicators with a notable improvement in antioxidant indicators in the groups receiving CMC and MAN supplements after being exposed to aflatoxicosis. Additionally, chicks treated with MAN and/or COS after being intoxicated with aflatoxins showed a considerable improvement in the gene expression of Caspase-3 and IL-1β. Furthermore, supplemental MAN and/or CMC decreased aflatoxin accumulation in the tissues of the muscles, liver, and kidneys. The groups G3, G4, and G5 showed notable improvements in the hepatic parenchymal architecture in their liver sections. The results of this study confirmed the hypothesis that adding natural additives such mannan and chitosan might enhance the antioxidant capacity and vital parameters of broilers exposed to 100 ppb aflatoxins.

A comparative and comprehensive study on robust silver-immobilized chitosan/carboxy methyl chitosan macromolecules for elimination of dyes

This study explores the potential of modified chitosan (CH) resulting from carboxy methyl (CM) group substitution in the chitosan skeleton, producing carboxy methyl chitosan (CMCH). Silver (Ag) was loaded to chitosan and modified chitosan (carboxy methyl substituted chitosan) supported on cellulose filter paper (FP) to tailor organic–inorganic macromolecule composites “Ag-Chi/CFP and Ag-CMCH/CFP” further applied as substantial composite for the reductive removal of methyl orange (MO) and rhodamine B (RB) dyes from wastewater. The synthesized catalyst was characterized via FTIR, 1H NMR, XRD, and SEM analysis. The degree of substitution was also measured, which was approximately 0.85. The reductive elimination efficiency of Ag-CMCH/CFP and Ag-Chi/CFP for MO dye was 95.31% and 88.85 %. In comparison, the elimination of RB was 98.28 and 94.04 %, respectively, in 16 min time, 0.6 mM Ag concentration, 40 mg/L, dye concentration and 0.3 M NaBH4 concentration. The synthesized catalysts were recycled three times. The degradation of MO and RB dyes using Ag-CMCH/CFP and Ag-Chi/CFP catalysts can be described by the first-order kinetic model. The determination coefficients (R2) and rate constants (k) values for MO degradation were found to be 0.9934 and 0.1736 s−1 for Ag-CMCH/CFP, and 0.9242 and 0.1001 s−1 for Ag-Chi/CFP, respectively. Similarly, for RB degradation, the R2 values were 0.9866 for Ag-CMCH/CFP and 0.9803 for Ag-Chi/CFP, with corresponding k values of 0.219 s−1 and 0.1548 s−1, respectively. The degradation process was optimized using response surface methodology (RSM) to determine the optimal conditions for maximum dye removal efficiency. The RSM models were statistically significant, as validated by ANOVA and correlation coefficient values. The F values of MO and RB models are significant as they have 2450.15 and 21999.37, respectively. The P value for both was <0.0001.

A self-healing nanocomposite double network bacterial nanocellulose/gelatin hydrogel for three dimensional printing

Extrusion-based three-dimensional (3D) printing of gelatin is important for additive manufactured tissue engineering scaffolds, but gelatin's thermal instability has remained an ongoing challenge. The gelatin tends to suddenly collapse at mild temperatures, which is a significant limitation for using it at physiological temperature of 37 °C. Hence, fabrication of a thermo-processable gelatin hydrogel adapted for extrusion-based additive manufacturing is still a challenge. To achieve this, a self-healing nanocomposite double-network (ncDN) gelatin hydrogel was fabricated with high thermo-processability, shear-thinning, mechanical strength, self-healing, self-recovery, and biocompatibility. To do this, amino group-rich gelatin was first created by combining gelatin with carboxyl methyl chitosan. Afterwards, a self-healing ncDN gelatin hydrogel was formed via an in-situ formation of imine bonds between the blend of gelatin/carboxyl methyl chitosan (Gel/CMCh) and dialdehyde-functionalized bacterial nanocellulose (dBNC). dBNC plays as nanofiber cross-linkers capable of simultaneously crosslinking and reinforcing the double networks of Gel/CMCh through formation of dynamic 3D imine bonds. Based on our findings, our self-healing ncDA gelatin hydrogel displayed great potential as a promising ink for additive manufactured tissue engineering scaffolds.

Comparative robustness and sustainability of in-situ prepared antimony nanoarchitectonics in chitosan/synthesized carboxymethyl chitosan in environmental remediation perspective

Due to the rapid race of industrialization natural assets like fresh water has been deteriorated causing lethal effects in living organisms. In the current study robust and sustainable composite of in-situ antimony nanoarchitectonics in chitosan/synthesized carboxymethyl chitosan matrix were synthesized. To improve solubility, metal adsorption and water decontamination, chitosan was modified into carboxymethyl chitosan and the modification was confirmed through various characterization techniques. The characteristic bands in the FTIR spectrum confirm substitution of carboxymethyl group in the chitosan. This was further illustrated that the characteristic proton peaks of CMCh observed at δ = 4.097 to 4.192 ppm, suggesting O-carboxy methylation of chitosan by 1H NMR. The second order derivative of potentiometric analysis confirmed 0.83 degree of substitution. The antimony (Sb) loaded modified chitosan were confirmed by FTIR and XRD analysis. The potential effectiveness of chitosan matrix was determined and compared toward reductive removal of the Rhodamine b dye. Rhodamine b mitigation is following first order kinetics with R2 value of 0.9832 and 0.969 with a constant rate of 0.0977 and 0.2534 ml/min for Sb loaded chitosan and carboxymethyl chitosan respectively. The Sb/CMCh-CFP enables us to achieve 98.5 % mitigation efficiency within 10 min. The CMCh-CFP chelating substrate was found stable and efficient even after 4th batches of cycles with <4 % decrease in efficiency. The in-situ synthesized material was found tailored composite, in terms of dyes remediation, reusability and biocompatibility as compared to chitosan.

Synthesis of Chitosan Derivative Compounds Through Chloroacetic Acid and Heparin Grafting and Their Application as Membrane Materials with Polyvinyl Alcohol (PVA)

A chitosan membrane modified with chloroacetic acid with heparin (hep) and polyvinyl alcohol (PVA) has been successfully prepared. Chitosan was modified with chloroacetic acid through a nucleophilic substitution reaction to form N-carboxyl methyl chitosan (N-CMC) and then combined with PVA. N-CMC/PVA grafting with heparin was conducted using the immersion method and produced N-CMC/PVA.g.Hep membrane. This study aims to obtain a membrane with the best chemical and physical characteristics and the highest creatinine transport. Membrane characterization includes water absorption test, tensile strength, thickness, biodegradation, resistance to pH, and transport of creatinine and vitamin B12. Chemical characterization of active groups and morphology using FTIR and SEM. The characterization results show that the reaction of grafting chitosan using chloroacetic acid produces N-carboxymethyl chitosan (N-CMC). The N-CMC/PVA membrane has a creatinine transport capacity of 19.61%. The N–CMC/PVA.g.Hep membrane has a creatinine transport capacity of 24.81%. Supporting PVA improves the hydrophilicity and mechanical strength of the membrane.

Green synthesis of quaternized chitosan nanogel using emulsion-photopolymerization as redox-responsive drug carrier

We report the green synthesis of trimethyl chitosan-functionalized poly(2-hydroxyethyl methacrylate) (PHEMA-TMC) nanogels via surfactant-free emulsion photopolymerization. TMC, a quaternized derivative of chitosan, was synthesized through methylation of chitosan, resulting in quaternary and tertiary amine groups as the main substitution products. TMC tertiary amine moiety and riboflavin (RF) acted as a redox photo-initiating system to generate free radicals for the polymerization under light irradiation. The effects of polymerization parameters such as irradiation time, concentrations of TMC and RF were investigated using MBA as crosslinker. Under the optimal condition of 1 % TMC, 4 % HEMA, 0.8 μM RF, 5 % MBA, and 4 h of polymerization time, the cationic PHEMA-TMC nanogel was synthesized with 76 % monomer conversion and an average diameter of about 106 nm. Moreover, the disulfide-crosslinked PHEMA-TMC nanogel was also synthesized using the disulfide dimethacrylate crosslinker, which exhibited a redox-induced degradation and release of encapsulated melatonin, potentially useful as a redox-responsive drug delivery carrier.

Green synthesis of carboxy methyl chitosan based curcumin nanoparticles and its biological activity: Influence of size and conductivity

The exceptional and appealing qualities of the polysaccharide biopolymer chitosan, such as biodegradability, biocompatibility and nontoxicity have been successfully utilized in the creation of specialized polysaccharide-based composite material. The bio-nano composites in the current work were prepared by combining curcumin nanoparticles of two distinct sizes that were produced using a green method with carboxymethyl chitosan (CMC). Additional testing methods used for the composite include XRD, TEM, UV-Vis, and FTIR. XRD and TEM provided data on things like grain size, crystalline nature, shape and size respectively. Curcumin interacts with the NH2 group of Carboxymethyl Chitosan (CMC) which is confirmed through FTIR spectra. UV-Vis spectra indicate a blue shift when the particle size decreases. The conductivity of the CMC with curcumin is high than the pristine. The CMC with curcumin enhances the conductivity. The CMC with curcumin nanoparticle S1 has higher conductivity than the curcumin nanoparticle S2 has the lower conductivity. The conductivity for the curcumin with smaller size (9 nm) has higher conductivity(12.35 mS) when compare with larger size (18 nm) of curcumin has the lower conductivity (11.38 mS). The composite with higher conductivity has good antimicrobial activities against C. glabrata and A.niger .The detailed results are presented and discussed.

Preparation and mechanism study of a high efficiency bio-based flame retardant for simultaneously enhancing flame retardancy, toughness and crystallization rate of poly (lactic acid)

Polylactic acid (PLA) is regarded as one of the most promising sustainable bioplastics in response to the global energy crisis and white pollution problems. However, the inherent high flammability , poor crystallinity and brittleness of PLA composites severely limit their application in the emerging fields of electronics and rail transit. Although the current phosphorus-nitrogen flame retardants exhibit excellent flame-retardant efficiency in PLA, they are often synthesized mainly through traditional petrochemical-based compounds and their function is confined to improving the flame-retardant performance of PLA. Herein, a novel multi-functional bio-based additive chitosan methyl phosphonate (CMP) was synthesized through the self-assembly of marine organism-derived chitosan (CS) and methylphosphonic acid. The incorporation of CMP simultaneously enhanced the fire safety, toughness and crystallization rate of PLA composites. The introduction of only 4 wt% CMP gave the PLA the UL-94 V-0 rating and high LOI of 30.6% due to its excellent gas-phase effect. It meant that the final PLA bio-based composites fully met the stringent flame-retardant requirements in the emerging fields. Moreover, the crystallization rate of PLA/CMP composites was significantly enhanced and the crystallinity of PLA/CMP4 was improved from 9.08% of pure PLA to 18.66% with the increase of 105%. Because of the uniform dispersion of CMP in PLA matrix and the good interface between them, PLA/CMP4 maintained almost the same strength as pure PLA and its impact strength was slightly improved compared to that of pure PLA. This research provided a novel strategy for the preparation of a high-performance and multi-functional PLA bio-based composites, which was of great significance to expand the practical application value of PLA bio-based composites in the current environment of advocating recyclable development. • A multifunctional bio-based flame retardant (CMP) was designed and synthesized. • Only 4 wt% CMP enabled PLA to obtain the desirable UL-94 V-0 rating. • CMP exerted efficaciously the inhibitory effect in gas phase. • CMP significantly improved the crystallization rate and toughness of PLA bio-based composites.

A 3D printable dynamic nanocellulose/nanochitin self-healing hydrogel and soft strain sensor

Presented here is the synthesis of a 3D printable nano-polysaccharide self-healing hydrogel for flexible strain sensors. Consisting of three distinct yet complementary dynamic bonds, the crosslinked network comprises imine, hydrogen, and catecholato-metal coordination bonds. Self-healing of the hydrogel is demonstrated by macroscopic observation, rheological recovery, and compression measurements. The hydrogel was produced via imine formation of carboxyl methyl chitosan, oxidized cellulose nanofibers, and chitin nanofibers followed by two subsequent crosslinking stages: immersion in tannic acid (TA) solution to create hydrogen bonds, followed by soaking in FeIII solution to form catecholato-metal coordination bonds between TA and FeIII. The metal coordination bonds were critical to imparting conductivity to the hydrogel, a requirement for flexible strain sensors. The hydrogel exhibits excellent shear-thinning and dynamic properties with high autonomous self-healing (up to 89%) and self-recovery (up to 100%) at room temperature without external stimuli. Furthermore, it shows good printability, biocompatibility, and strain sensing ability.

Biodistribution of Cy5-labeled Thiolated and Methylated Chitosan-Carboxymethyl Dextran Nanoparticles in an Animal Model of Retinoblastoma.

PurposeThe use of more potent medicine for local chemotherapy of retinoblastoma in order to minimize local and systemic adverse effects is essential. The main goal of this investigation was to assess the biodistribution of thiolated and methylated chitosan-carboxymethyl dextran nanoparticles (CMD-TCs-NPs and CMD-TMC-NPs) following intravitreal (IVT) injection into rat eyes with retinoblastoma.MethodsAn ionic gelation method was used to fabricate Cy5-labelled CMD-TCs-NPs and CMD-TMC-NPs. The NPs were characterized. Cellular internalization of Cy5-labelled NPs was investigated using confocal microscopy and the absorption of labeled NPs was quantified by flow cytometry in human retinoblastoma (Y79) cells. In addition, the Cy5-labeled distribution of nanoparticles in the posterior segment of the eye was histologically imaged by confocal microscopy after IVT injection of NPs into the eyes of rats with retinoblastoma.ResultsCMD-TCs-NPs and CMD-TMC-NPs showed a mean diameter of 34 3.78 nm and 42 4.23 nm and zeta potential of +11 2.27 mV and +29 4.31mV, respectively. The in vivo study of intraocular biodistribution of Cy5-labeled CMD-TCs-NPs and CMD-TMC-NPs revealed that there is more affinity of CMD-TCs-NPs to the retina and retinoblastoma tumor after IVT administration while methylated chitosan nanoparticles are immobilized in the vitreous and are not able to reach the retina even after 24 hr.ConclusionThe ionic gelation technique was efficient in synthesizing a biocompatible polymeric nanosystem for drug delivery into the posterior segment of the eye. The current study demonstrated increased ocular bioavailability of CMD-TCs-NPs relative to CMD-TMC-NPs in retinoblastoma induced rat eyes.

Physicochemical and Toxicity Investigation of Chitosan-based dsRNA Nanocarrier Formation

Technologies involving the use of double-stranded RNA (dsRNA) to elicit RNA interference (RNAi) in pest control have emerged as an alternative to traditional pesticides. RNAi can mediate natural cell protection being a promising tool to provide prompt responses in plant defense against pathogens. The present study is focused on the physicochemical characterization of formed dsRNA-loaded nanoparticles as a result of chitosan-dsRNA ionic interactions. Additionally, a preliminary investigation was conducted of the in-vitro toxicity of loaded nanoparticles in lettuce and human red blood cells. dsRNA molecules, homologous to partial phytopathogenic tomato mosaic virus (ToMV) sequence, were used as a model. The main groups involved in the chitosan-dsRNA ionic coupling were identified by Fourier-transform infrared spectroscopy, and the stability of formed nanoparticles was accessed by dynamic light scattering, electrophoresis, and thermal analyses. The chitosan showed a higher ability to bind to dsRNA at low charge ratios (N/P = 1), ruled by positively charged chitosan methyl groups and negatively charged phosphate groups from the RNA backbone, resulting in small nanoparticles (73.25 nm size) at low polydispersity (0.25). The toxic assays of these particles, on lettuce seeds and in human erythrocytes, revealed very low toxicity demonstrating their safety as a platform, thereby holding potential use as biodefensive for crop protection.

Eudragit L-100 Capsules Aromatize and Quaternerize Chitosan for Insulin Nanoparticle Oral Delivery During Toxic Oxidative Stress in Rat Liver and Kidney.

Insulin, like most peptides, is classified as a hydrophilic and macromolecular drug that is considered as a low permeable and unstable compound in the gastrointestinal (GI) tract. The acidic condition of the stomach can degrade insulin molecules. Moreover, the presence of proteolytic activities of some enzymes such as trypsin and chymotrypsin can hydrolyze amide-bonds between various amino-acids in the structures of peptides and proteins. However, due to its simplicity and high patient compliance, oral administration is the most preferred route of systemic drug delivery, and for the development of an oral delivery system, some obstacles in oral administration of peptides and proteins including low permeability and low stability of the proteins in GI should be overcome. In this study, the effects of orally insulin nanoparticles (INPs) prepared from quaternerized N-aryl derivatives of chitosan on the biochemical factors of the liver in diabetic rats were studied. INPs composed of methylated (amino benzyl) chitosan were prepared by the PEC method. Lyophilized INPs were filled in pre-clinical capsules, and the capsules were enteric-coated with Eudragit L100. Twenty Male Wistar rats were randomly divided into four groups: group1: normal control rats, group 2: diabetic rats, group 3: diabetic rats received capsules INPs(30 U/kg/day, orally), group 4: the diabetic rats received regular insulin (5 U/kg/day, subcutaneously). At the end of the treatment, serum, liver and kidney tissues were collected. Biochemical parameters in serum were measured using spectrophotometric methods. Also, oxidative stress was measured in plasma, liver and kidney. Histological studies were performed using H and E staining . Biochemical parameters, and liver and kidney injury markers in serum of the diabetic rats that received INPs improved significantly compared with the diabetic group. INPs reduced oxidative toxic stress biomarkers in serum, liver and kidney of the diabetic treated group. Furthermore, a histopathological change was developed in the treated groups. Capsulated INPs can prevent diabetic liver and oxidative kidney damages (similar regular insulin). Therefore oral administration of INPs appears to be safe. Lay Summary: Although oral route is the most preferred route of administration, but oral delivery of peptides and proteins is still a challenging issue. Diabetes Mellitus may lead to severe complications, which most of them are life-threatening. In this study, we are testing the toxicity of oral insulin nanoparticles in kidney and liver of rats. For this investigation, we will prepare insulin nanoparticles composed of a quaternized derivative of chitosan. The nanoparticles will be administered orally to rats and the level of oxidative stress in their liver and kidney will be determined. The data will be compared to the subcutaneous injection of insulin.

Synthesis and Characterization of Carboxymethyl Chitosan–Methyl Cellulose Containing Drug Loaded Ag2O–Fe3O4 Nanocomposites as a Drug Delivery System

Fe3O4 and Ag2O nanoparticles have good bio-compatibility and chemical stability properties, the possibility of these nanomaterials could be applied as a carrier in anti-cancer drug delivery system. In this project, Curcumin, an anti-cancer compound drug, loaded on Ag2O–Fe3O4/carboxymethyl chitosan–methyl cellulose (Ag2O–Fe3O4/CMCS–MCS) was studied at changing pH amounts for significance drug delivery. The samples were studied by scanning electron microscope, Fourier transform infrared spectroscopy, dynamic light scattering, energy dispersive spectra analysis (EDS), and diffraction X-ray. The weight amount of the prepared nanocomposites was also characterized by thermal gravimetric method. The release of curcumin were tested by UV–Vis spectroscopy in pH 7.8 and pH 5.4 media, respectively. The outcomes confirm suitable and gradual curcumin release in times 150 min.

Comparative Study of Chitosan and Carboxy Methyl Chitosan Nanoparticles in Mefenamic Acid Drug Delivery

Nanoparticle based technologies improve the efficiency and speed of already existing processes.The larger size materials and reagents which are in reactive form, can be nanosized to give efficient output. Chitosan and the carboxy methyl chitosan nanoparticles were prepared by using solvent evaporation nanoprecpitation method, loaded with mefenamic acid, (anthranilic acid derivative) a poorly aqueous soluble drug. Mefenamic acid, if used as conventional dosage form, duration of action was 6 hours; when the drug loaded into Chitosan and the carboxy methyl chitosan nanoparticles the drug release profile was up to 26hrs. The particle size, entrapment efficiency, poly dispersity index, drug loading, drug release profiles of mefenamic acid were compared for both nanoparticles and it was observed that carboxy methyl chitosan nanoparticles released mefenamic acid more effectively than chitosan nanoparticles.&#x0D; Keywords: Nanoparticles, Chitosan, Carboxy methyl chitosan, Mefenamic acid

Inhibitory activity of biofunctionalized silver-capped N-methylated water-soluble chitosan thiomer for microbial and biofilm infections

One of the most important self-defense strategies employed by bacteria to resist the action of antibiotics is a biofilm formation upon the infected surface. Thus, there is an urgent need to explore novel candidates that have potent antibacterial and anti-biofilm effects to tackle this challenge. In this endeavor, we have transformed shrimp shell wastes to N-methylated water-soluble chitosan thiomer (MWSCT) which was used as either a chelating agent or bio-reductant and capping agent for Ag(I) ions in the preparation of a Ag(I)MWSCT complex or silver nanocomposite (Ag(0)MWSCT), for targeting antibacterial and anti-biofilm applications. The antibacterial and anti-biofilm performance of the new methylated chitosan thiomer (MWSCT) and its silver architectures (Ag(I)MWSCT, Ag(0)MWSCT) were assessed in vitro against E. coli and S. aureus. These new materials have significant capacities to synergistically inhibit the proliferation of the targeted bacterial cells and biofilm formation, in a structure- and species-dependent manner. Ag(0)MWSCT emerged as the most potent compound in inhibiting the growth of bacterial strains (MICE. coli/ MICS. aureus = 0.05/ 0.34 μg/mL, 1.6-/ 2.5-times lower than that recorded for the clinical drug (ciprofloxacin, Cipro). Also, this nanocomposite showed the highest anti-biofilm effects (only 1.7% E. coli biofilm growth; 11.8% staphylococcal biofilm growth).

Methyl chitosan coating for glycoform analysis of glycoproteins by capillary electrophoresis.

CE is a promising technique for the analysis of glycosylated proteins, especially at the intact level. In the present study, the utility of CE for the separation of protein glycoforms is developed by using methyl chitosan as capillary coating. Methyl chitosan, in contrast to the polymers commonly used for coating, bears different types of amine groups, allowing for tunable charge states for various applications. The addition of methyl chitosan in background electrolyte can modulate the EOF and improve the separation performance. The methyl chitosan-coated capillary provided good separation of acidic or basic glycosylated proteins. Five ribonuclease B glycoforms were resolved by CE in less than 18min, and the profile was essentially in agreement with that obtained by MALDI-TOF MS. The recombinant human erythropoietin glycoforms were well separated within 9min. The developed method shows a great potential in protein glycoform analysis.

Single-Step Methylation of Chitosan Using Dimethyl Carbonate as a Green Methylating Agent.

N,N,N-Trimethyl chitosan (TMC) is one chitosan derivative that, because of its improved solubility, has been studied for industrial and pharmaceutic applications. Conventional methods for the synthesis of TMC involve the use of highly toxic and harmful reagents, such as methyl iodide and dimethyl sulfate (DMS). Although the methylation of dimethylated chitosan to TMC by dimethyl carbonate (DMC, a green and benign methylating agent) was reported recently, it involved a formaldehyde-based procedure. In this paper we report the single-step synthesis of TMC from chitosan using DMC in an ionic liquid. The TMC synthesised was characterised by 1H NMR spectroscopy and a functionally meaningful degree of quaternisation of 9% was demonstrated after a 12-h reaction time.

Synergistic effect of pressure cold atmospheric plasma and carboxymethyl chitosan to mesenchymal stem cell differentiation on PCL/CMC nanofibers for cartilage tissue engineering

Cell attachment and differentiation on biomaterials might be enhanced by surface modification techniques. The main aim of this study was to improve stem cell/material interaction by pressure cold atmospheric plasma (CAP). We developed a combination of electrospun poly (ε‐caprolactone) (PCL)‐chitosan (CTS) and PCL‐carboxy methyl chitosan (CMC) scaffolds. In order to make nanofiber surfaces more appropriate for mesenchymal stem cell (MSC) attachment and proliferation, CAP was used. Proliferation and cartilage differentiation of MSCs were then evaluated during 21 days. Biocompatibility test, scanning electron microscopy (SEM) analysis, 3‐[4,5‐dimethylthiazol‐2yl]‐2, 5‐diphenyl tetrazolium bromide (MTT) and 4′,6‐diamidino‐2‐phenylindole (DAPI) staining were performed. After 21 days, induction of cartilage differentiation was approved through expression of SRY‐Box 9 (SOX9) and collagen type II (COL2) genes by reverse transcription polymerase chain reaction (RT‐PCR), and COL2 protein expression was accordingly confirmed by immunocytochemistry (ICC). Thus, our data showed the PCL/CMC scaffolds can support and induce the differentiation of MSC to cartilage‐like cells.

Scanning electron microscopy evaluation of chitosan and carboxymethyl chitosan as retrograde smear layer removing agents.

Background:The smear layer acts as a physical barrier against penetration of root canal medicaments and sealers, thus compromising the seal leading to microleakage.Objectives:This study was conducted to evaluate the efficacy of 17% ethylenediaminetetraacetic acid (EDTA), 0.2% chitosan solution, and 0.2% carboxymethyl chitosan (CMC) used as smear layer removing agents in retrograde root canal preparation using scanning electron microscopy (SEM).Materials and Methodology:Eighty single-rooted teeth extracted for periodontal reasons were collected for the study. Root canals were prepared and obturated with gutta-percha coated with AH plus resin sealer. Apical 3 mm of each root resected and Class I retrograde preparation carried out using ultrasonic handpiece and ultrasonic retro tips to a depth of 3 mm along the root long axis. In Group 1 (control), normal saline solution alone was used for smear layer removal. In Group II, 17% EDTA, Group III and IV were treated with 5 ml of 0.2% chitosan and 0.2% carboxyl methyl chitosan, respectively, for 3 min. Blinded evaluation of specimens using SEM was performed independently by two operators who registered the amount of the smear layer present on the surface of the canal walls based on the score described by Hülsmann et al.Results:Group I (saline) was least efficient in the removal of the smear layer. Group II (17% EDTA), Group III (0.2% Chitosan), and Group IV (0.2% CMC) efficiently removed the smear layer from the retrograde cavity with mean scores 1.35, 1.60, and 1.35, respectively. Statistically, no significant difference found in Group II (17% EDTA), Group III (0.2% Chitosan), and Group IV (0.2% CMC).Conclusions:About 0.2% CMC and 0.2% chitosan can be better alternatives to 17% EDTA for smear layer removal due to their biological advantages.

Vitamin B12 buccoadhesive tablets: auspicious non-invasive substitute for intra muscular injection: formulation, in vitro and in vivo appraisal

Attempting to prepare a convenient bioavailable formulation of vitamin B12 (cyanocobalamin), 17 tablet formulations were prepared by direct compression. Different concentrations of hydroxypropyl methyl cellulose (HPMC), carbopol 971p (CP971p), and chitosan (Cs) were used. The tablets were characterized for thickness, weight, drug content, hardness, friability, surface pH, in vitro drug release, and mucoadhesion. Kinetic analysis of the release data was conducted. Vitamin B12 bioavailability from the optimized formulations was studied on rabbits by the aid of enzyme-linked immunosorbent assay. Neurotone® I.M. injection was used for comparison. HPMC (F1-F4), CP971p (F5-F8), and HPMC/CP971p (F12-F15)-based formulations showed acceptable mechanical properties. The formulated tablets showed maximum swelling indices of 232 ± 0.13. The surface pH values ranged from 5.3 ± 0.03 to 6.6 ± 0.02. Bioadhesive force ranged from 66 ± 0.6 to 150 ± 0.5 mN. Results showed that CP971p-based tablets had superior in vitro drug release, mechanical, and mucoadhesive properties. In vitro release date of selected formulations were fitted well to Peppas model. HPMC/CP971p-based formulations showed bioavailability up to 2.7-folds that of Neurotone® I.M. injection.