Different Amounts Of Chitosan Research Articles

Preparation and Characterization of Hydrogels Fabricated From Chitosan and Poly(vinyl alcohol) for Tissue Engineering Applications.

In this study, we report on the preparation, characterization, and cytocompatibility of hydrogels for biomedical applications made from two different molecular weights of chitosan (CS) blended with poly(vinyl alcohol) (PVA) and chemically cross-linked with tetraethyl orthosilicate (TEOS) followed by freeze-drying. A series of CS-PVA hydrogels were synthesized with different amounts of chitosan (1%, 2%, and 3% by weight). The structure of these CS-PVA hydrogels was characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The hydrogel samples were also characterized for tensile strength, contact angle, swelling behavior, and degradation at physiological body temperature. Their physicochemical properties, biocompatibility, and cell viability when cultured with human dermal fibroblasts were assessed using alamarBlue and live/dead assays and compared to optimize their functionality. SEM analysis showed that the concentration and molecular weight of the chitosan component affected the pore size. Furthermore, the contact angle decreased with increasing chitosan content, indicating that chitosan increased its hydrophilic properties. The in vitro degradation study revealed a nonlinear time-dependent relationship between chitosan concentration or molecular weight, and the rate of degradation was affected by the pore size of the hydrogel. All of the CS-PVA hydrogels exhibited good cell proliferation, particularly with the high molecular weight chitosan samples.

Evaluation of Chemical and Biological Properties of Biodegradable Composites Based on Poly(3-hydroxybutyrate) and Chitosan.

In this study, composite films and scaffolds of polyester poly(3-hydroxybutyrate) and polysaccharide chitosan obtained via a simple and reproducible blending method using acetic acid as a solvent were considered. The degradation process of the films was studied gravimetrically in a model biological medium in the presence of enzymes in vitro for 180 days. The kinetics of weight reduction depended on the amount of chitosan in the composition. The biocompatibility of the films was evaluated using the Alamar blue test and fluorescence microscopy. The materials were non-cytotoxic, and the addition of poly(3-hydroxybutyrate) to chitosan improved its matrix properties on mesenchymal stem cells. Then, the 3D composites were prepared by freeze-drying. Their structure (using SEM), rheological behavior, moisture absorption, and porosity were investigated. The addition of different amounts of chitosan allowed us to vary the chemical and biological properties of poly(3-hydroxybutyrate) materials and their degradation rate, which is extremely important in the development of biomedical poly(3-hydroxybutyrate) materials, especially implantable ones.

Chitosan Modification-Enhanced Silencing Effect of Ad5-shPDGF-D Vector in Breast Cancer Cell Line MDA-MB-231.

Gene therapeutics are being developed to treat metastatic breast tumors, which are mostly resistant to conventional therapies. Targeting platelet-derived growth factor-D (PDGF-D) is a viable approach because it is known to play roles in angiogenesis and tumor growth. The success of gene therapy is largely dependent on delivery vectors, but both viral and nonviral delivery vectors have their disadvantages. Evolving hybrid vectors are being used to overcome those disadvantages. In this study, we aimed to prepare a recombinant adenovirus type-5 (Ad5)/chitosan hybrid vector to deliver shPDGF-D in a breast cancer cell line by the noncovalent coating of the Ad5 surface with chitosan, a natural polymer. The Ad5/chitosan hybrid vector was prepared by the noncovalent coating of the Ad5 surface with different molecular weights (low and high) and different amounts of chitosan (12.5, 25, and 50 μg), and the effect of silencing PDGF-D was investigated in the MDA-MB-231 cell line. In vitro characterization studies showed that the noncovalent chitosan coating increased the size of the Ad5 particle and changed the surface charge from -16.53 mV to slightly neutral. In vitro cell culture studies also showed that the addition of chitosan with both low (73.61%) and high (65.86%) molecular weight increased the PDGF-D silencing efficiency of the Ad5 vector (42.44%) at 48 hours. While low-molecular-weight chitosan had faster effects, high-molecular-weight chitosan provided a more sustained effect in PDGF-D silencing. The results indicate that noncovalent chitosan modification may improve the therapeutic effects of the Ad5 vector, offering the potential for further in vitro and in vivo experiments.

Effect of chitosan bio-polymer stabilization on the mechanical and dynamic characteristics of marl soils

The strength of marl soils decreases drastically in the variation of the water content. This has caused such soil to be introduced as problematic soil in geotechnical projects. In the present study, the effect of chitosan biopolymer on the static and dynamic properties of marl soil was investigated. To this end, different amounts of chitosan (up to 0.16%) were mixed with marl soil. Then samples were cured for 7, 28 and 90 days and finally subjected to 0, 1, 4 and 8Freeze-Thaw (F-T) cycles. Unconfined compressive strength (UCS), direct shear, Ultrasonic Pulse Velocity (UPV) and bender element tests were performed on the samples. The results showed that the UCS of the samples stabilized with 0.16% chitosan (as the optimal composition) increased by 227% after 7 days compared to that of unstabilized soil. Moreover, the values of cohesion and internal friction angle for the optimum mixture after 7 days of curing were equal to 38.76 kPa and 21.07°, which was much higher than 21 kPa and 18.26° related to the unstabilized marl soil. Chitosan was able to increase dynamic characteristics such as shear wave velocity and maximum shear modulus of samples by about 51 and 128% after 7 days of curing even after 8F-T cycles compared to those of unstabilized samples. Finally, chitosan exhibited that it can be a suitable alternative to traditional additives as an environmentally-friendly material, as confirmed by Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD) analyses.

Synthesis, microhardness, fracture toughness and microstructural features of chitosan containing alkali activated geopolymers

In this work, geopolymer matrix samples containing different amounts of chitosan, specifically 1, 3, 5 and 10 wt%, were produced to study the effect of a ductile phase within a much more brittle one.The reference geopolymer was produced mixing a commercial metakaolin with sodium silicate solution and sodium hydroxide solution. Geopolymeric slurries were caste into mold and hardened by a thermal treatment at 70 °C and then at ambient temperature for 28 days. Hardened materials, containing different amount of chitosan, were examined by mean of X-ray diffraction, Fourier Transform Infrared Radiation, Scanning Electron Microscope investigation. Microhardness and fracture toughness were measured to study the effects on the samples chemistry and microstructure caused by the introduction of chitosan into the geopolymer. It has been observed that the addition of chitosan lowers materials porosity and microhardness, but slightly improves their fracture toughness.

Preparation and characterization of chitosan/hydroxyapatite scaffolds containing mesoporous SiO2-HA for drug delivery applications

In this study, chitosan/hydroxyapatite/mesoporous SiO2-HA scaffolds were prepared by the freeze-drying method, and their properties were investigated for drug delivery applications. Synthesized hydroxyapatite (HA) powder and mesoporous SiO2-HA particles were studied by field emission scanning electron microscope (FESEM), X-ray diffraction (XRD), and fourier transform infrared spectroscopy (FTIR). Different amounts of chitosan (CS) (1–3 wt%) and HA (1–4 wt%) were used to prepare the scaffolds, and their morphologies was observed by FESEM. The images showed that the scaffolds had large-sized pores, and adding 2 wt% mesoporous SiO2-HA particles to scaffolds improved their porous nature. Although the pore size of the scaffolds became smaller by adding hydroxyapatite, the inclusion of mesoporous SiO2-HA made the pore size smaller. XRD results affirmed a strong interaction between chitosan and hydroxyapatite in scaffolds. The compressive strength reached 18.76 MPa by adding hydroxyapatite to CS, and 23.9 MPa by adding mesoporous particles to the scaffolds. The swelling ratio of CS/HA scaffolds equaled to 1.02, and it decreased to 0.17 by adding mesoporous SiO2-HA which indicates the best stability of mesoporous-containing scaffolds inside fluids. It was also shown that the amount of tramadol released from the CS/HA/mesoporous SiO2-HA scaffold reached 98% after 240 h. All tests confirmed that the introduction of adding mesoporous SiO2-HA to CS/HA scaffolds boosted their both mechanical and biological performances.

Three-dimensional nanofibrous and porous scaffolds of poly(ε-caprolactone)-chitosan blends for musculoskeletal tissue engineering.

One of the established tissue engineering strategies relies on the fabrication of appropriate materials architectures (scaffolds) that mimic the extracellular matrix (ECM) and assist the regeneration of living tissues. Fibrous structures produced by electrospinning have been widely used as reliable ECM templates but their two-dimensional structure restricts, in part, cell infiltration and proliferation. A recent technique called thermally-induced self-agglomeration (TISA) allowed to alleviate this drawback by rearranging the 2D electrospun membranes into highly functional 3D porous-fibrous systems. Following this trend, the present research focused on preparing polycaprolactone/chitosan blends by electrospinning, to then convert them into 3D structures by TISA. By adding different amounts of chitosan, it was possible to accurately modulate the physicochemical properties of the obtained 3D nanofibrous scaffolds, leading to highly porous constructs with distinct morphologic and mechanical features. Viability and proliferation studies using adult human chondrocytes also revealed that the biocompatibility of the scaffolds was not impaired after 28 days of cell culture, highlighting their potential to be included into musculoskeletal tissue engineering applications, particularly cartilage repair.

Impact of Gypsum and Bio-Priming of Maize Grains on Soil Properties, Physiological Attributes and Yield under Saline–Sodic Soil Conditions

In order to enhance soil qualities and boost crop output, gypsum, plant-growth-promoting rhizobacteria (PGPR), and chitosan are all viable solutions. This study’s goal was to find out how different amounts of chitosan—0, 25, 50, 75, and 100 mg L−1—in combination with gypsum and PGPR inoculation (Azospirillum lipoferum + Bacillus subtilis), affected the yield of maize plants growing in saline–sodic soil. Field tests were carried out in triplicate across two growing seasons, 2020 and 2021, using a split plot design. According to the findings, applying the gypsum + PGPR + 50 mg L−1 chitosan treatment (T8) considerably improved plant physiology (chlorophyll, carotenoids, and proline levels), nutrient indicators (N, K+ and K+/Na+ ratio), soil enzyme activity (dehydrogenase, urease, amylase, and invertase), cation exchange capacity (CEC), and porosity. On the other hand, we revealed positive effects on Na+, bulk density (BD), electrical conductivity (EC), and the proportion of exchangeable sodium (ESP), thus, enhancing the productivity compared to the alternative treatment. Therefore, it might be inferred that using gypsum, microbial inoculation, and 50 mg L−1 chitosan may be a key strategy for reducing the detrimental effects of salinity on maize plants.

Preparation and performance study of a reactive polyurethane hot-melt adhesive/CS-Fe3O4 magnetic nanocomposite film/fabric.

Magnetic nanoparticles are attracting significant attention for their wide application as biomaterials and magnetic storage materials. As an environmentally friendly adhesive, reactive polyurethane hot-melt adhesive (PUR) is a biocompatible polymer with a wide range of applications. In this paper, chitosan (CS)-surface-modified magnetic Fe3O4 nanoparticles were synthesized by the sol–gel method. Surface modification of the Fe3O4 nanoparticles with CS enhanced their mechanical properties in PUR. The nanoparticles were characterized by Fourier transform infrared (FTIR) and X-ray diffraction (XRD) analyses, while their surface morphology was elucidated using scanning electron microscopy (SEM) and projection electron microscopy (TEM) techniques. Subsequently, PUR/CS–Fe3O4 magnetic nanocomposite films were prepared using an in situ method, wherein different amounts of CS–surface-modified magnetic Fe3O4 nanoparticles were doped into the PUR and coated on the films. The thermal, UV resistance and mechanical properties of the PUR/CS–Fe3O4 magnetic nanocomposite films were investigated by TGA, UV spectrometer and tensile testing. CS–Fe3O4 nanoparticles were successfully prepared using the sol–gel method and CS to modify the surface of the Fe3O4 nanoparticles. The results show that the mechanical properties and UV resistance of PUR/CS–Fe3O4 magnetic nanocomposites are improved by almost 50%, so the constructed PUR/CS–Fe3O4 magnetic nanocomposites have good UV-resistant properties and mechanical properties. The as-synthesized CS–Fe3O4 magnetic nanocomposites show great potential for application to mechanical and textile development.

Fabrication of tissue-engineered tympanic membrane patches using 3D-Printing technology

In recent years, scaffolds produced in 3D printing technology have become more widespread tool due to providing more advantages than traditional methods in tissue engineering applications. In this research, it was aimed to produce patches for the treatment of tympanic membrane perforations which caused significant hearing loss by using 3D printing method. Polylactic acid(PLA) scaffolds with Chitosan(CS) and Sodium Alginate(SA) added in various ratios were prepared for artificial eardrum patches. Different amounts of chitosan and sodium alginate added to PLA increased the biocompatibility of the produced scaffolds. The created patches were designed by mimicking the thickness of the natural tympanic membrane thanks to the precision provided by the 3D printed method. The produced scaffolds were analyzed separately for chemical, morphological, mechanical and biocompatibility properties. Scanning electron microscope (SEM), Fourier-transform infrared (FT-IR) spectroscopy was performed to observe the surface morphology and chemical structure of the scaffolds. Mechanical, thermal and physical properties, swelling and degradation behaviors were examined to fully analyze whole characteristic features of the samples. Cell culture study was also performed to demonstrate the biocompatibility properties of the fabricated scaffolds with human adipose tissue-derived mesenchymal stem cells (hAD-MSCs). 15 wt % PLA was selected as the control group and among all concentrations of CS and SA, groups containing 3 wt% CS and 3 wt% SA showed significantly superior and favorable features in printing quality. The research continued with these two scaffolds (3 wt% CS, and 3 wt% SA), which showed improved print quality when added to PLA. Overall, these results show that PLA/CS and PLA/SA 3D printed artificial patches have the potential to tissue engineering solutions to repair tympanic membrane perforation for people with hearing loss.

Porous biochar/chitosan composites for high performance cellulase immobilization by glutaraldehyde

In this work, porous biochar derived from sugarcane bagasse was prepared and then coated with different amounts of chitosan (C@CS) for cellulase immobilization. Cellulase was covalently immobilized on the support by using glutaraldehyde as a linker. The chemical characteristics and morphology of the samples were determined by SEM, BET, FT-IR and XPS. The properties of immobilized enzyme were evaluated by activity recovery, optimum pH value and temperature, and recyclability. The results showed that all the three kinds of immobilized cellulase did not change the optimum pH value of 4 and temperature of 60 °C, and they also exhibited good activity and reusability. Especially for C@CS25 (the feeding ratio of porous biochar to chitosan was 0.5 g: 25 mg), the support retained the morphology of porous biochar well. The corresponding immobilized cellulase kept 67 % activity of free cellulase at pH = 4 and 60 °C, and showed a glucose productivity of 90.8 % even after 10 cycles.

Characteristics of glucose oxidase immobilized on Magnetic Chitosan Nanoparticles

Abstract Immobilization process is used to facilitate the enzyme recovery and reusability. The aims of this study were to evaluate the effect of different amounts of chitosan on immobilization efficiency of Glucose Oxidase (GOX), pH effect on enzyme activity and changes of kinetic characteristics of enzyme immobilized on Magnetic Chitosan Nanoparticles (MCNP). GOX was immobilized on MCNP with cross bonds and Schiff base covalent connections. The sample with 0.3 g of chitosan had the highest immobilization efficiency (41.30%). Morphology of nanoparticles was investigated by Scanning Electron Microscopy (SEM). Immobilization of GOX on magnetic nanoparticles was verified with Fourier Transform Infrared (FTIR). The effect of pH on enzyme activity was similar on both immobilized enzyme (IE) and free enzyme (FE). The evaluation of kinetic parameters for IE and FE has showed that the effectiveness factor was 0.45. Generally, it could be concluded that magnetic nanoparticles with 0.3 g chitosan could provide a suitable medium for immobilization of GOX.

Evaluation of Polycaprolactone/Gelatin/Chitosan Electrospun Membrane for Peritoneal Adhesion Reduction.

In this study, a novel antiadhesion membrane made of polycaprolactone, gelatin, and chitosan was fabricated using the electrospinning technique. A series of polycaprolactone/gelatin/chitosan (PGC) electrospun membranes with different amounts of chitosan (0%, 0.5%, 1%, and 2% in weight percentage) was synthesized. The physicochemical properties and biocompatibility of the fabricated membranes were examined and compared with the aim to select an effective antiadhesion membrane. Scanning electron microscopy showed that these 4 electrospun membranes had similar fiber diameter and pore area, with no statistical differences between them. Furthermore, the contact angle decreased with increased chitosan content, indicating that chitosan may contribute to increased hydrophilic properties. The in vitro degradation test revealed that the higher chitosan content corresponded to a lower degradation rate in PGC membranes within 7 days. All PGC membranes exhibited similar cell proliferation; however, cell proliferation was lower than tissue culture polystyrene (P < 0.05). To compare antiadhesion ability, the adhesion between the cecum and abdominal wall was created in a rat model. Assessment after implantation of electrospun membranes revealed that PGCs with higher chitosan content (PGC2) had better antiadhesion effects, as evaluated by an adhesion score at day 14 postsurgery. Thus, PGC2 was effective in reducing the formation of tissue adhesion. Therefore, PGC electrospun membrane may provide a potential peritoneal antiadhesion barrier for clinical use.

Synthesis and characterization of silica-chitosan hybrid materials as antibacterial coatings for titanium implants

To avoid dental implant-related infections and to promote the osseointegration of titanium implants, the application of silicon and chitosan containing coatings is proposed. Silicon is a well-known osteogenic element and chitosan was selected to confer the antibacterial properties. The synthesis of hybrid silica-chitosan coatings using the sol-gel process is presented and the characterization using 29Si-NMR to verify the correct formation of the network is discussed. The 13C NMR spectroscopy was used to confirm the covalent union between chitosan and the silicon network. Hydrolytic degradation and silicon release studies showed the effective silicon release from the hybrids and, hence, the possibility to promote bone formation. The introduction of different amounts of chitosan and tetraethyl orthosilicate (TEOS) modulated the Si release. The analysis of cell cultures in vitro demonstrated that the hybrid coatings were not cytotoxic and promoted cell proliferation on their surfaces. The coatings containing 5%–10% chitosan had substantial antibacterial properties.

A simple approach to design chitosan functionalized Fe3O4 nanoparticles for pH responsive delivery of doxorubicin for cancer therapy

The use of magnetic nanoparticles (MNPs) in cancer therapy offer many advantages due to their unique size, physical and biocompatible properties. In this study we have developed a formulation, comprising of anti-cancer drug doxorubicin (Dox) conjugated to iron oxide nanoparticles via a pH sensitive imine linker. Different amounts of chitosan functionalized superparamagnetic iron oxide nanoparticles (Fe3O4-CHI) were synthesized in-situ by a simple hydrolysis method at room temperature. The synthesized nanoparticles were well characterized by TEM, Zeta Potential, TOC, XPS, TGA and VSM for their physicochemical properties. Dox was conjugated to the Fe3O4-CHI nanoparticles via a glutaraldehyde cross linker with the imine (CN) bond, which is sensitive to cleavage in the pH range of 4.4–6.4. The synthesized Fe3O4-Dox nanoparticles exhibited enhanced drug release in lower pH conditions which mimics the tumor microenvironment or intracellular organelles such as endosomes/lysosomes. The cell uptake and therapeutic efficacy of Fe3O4-Dox nanoparticles carried out in ovarian cancer cell (SK-OV-3) and breast cancer cell line (MCF7) showed improved therapeutic efficacy of Dox by nearly four-fold with Fe3O4-Dox nanoparticles.

Experimental investigation of novel curdlan/chitosan coatings on packaging paper

Abstract In the research, paper was successfully coated with curdlan and chitosan (CR/CH) coating solutions at different ratios (CR/CH ≈ 10:0, 8:2, 6:4, 5:5, 2:8, 4:6, 0:10% w/w). The novelty of this paper is in the use of combination of curdlan and chitosan, which led to a positive effect on the mechanical and water barrier properties. The tensile properties were improved when the ratio between polymers was 5:5. Coated papers were further investigated for their bursting strength, tear and bending resistance. Pure curdlan coating worsen the tensile and moisture properties and allowed to prepare the blend coatings with different amounts of chitosan. The equilibrium thickness of coatings as a function of curdlan content and tensile strength has shown a decrease in tensile strength. This has resulted in reduction of tensile strength especially at higher thickness. The resulting blend curdlan/chitosan coatings exhibited good water barrier and mechanical properties and could be used in many fields.

Facile Synthesis of Nitrogen‐Doped Graphene Aerogels for Electrode Materials in Supercapacitors

AbstractThree‐dimensional porous nitrogen‐doped graphene aerogels (NGAs) were synthesized by using graphene oxide (GO) and chitosan (CS) via a self‐assembly process by one‐pot hydrothermal method. The morphology and structure of the as‐prepared materials were characterized by means of scanning electron microscopy, transmission electron microscopy, X‐ray diffraction, XPS spectroscopy, Raman spectroscopy, nitrogen adsorption/desorption measurement and Fourier transform infrared spectroscopy. The electrochemical performance of NGAs was studied by cyclic voltammetry, galvanostatic charge/discharge and impedance spectroscopy measurements. The microstructure, surface area and capacitance of NGAs could be facilely controlled by adding different amounts of chitosan. The prepared NGA‐4 showed a specific capacitance of 148.0 F/g at the discharge current density of 0.5 A/g and also retained 95.3% of the initial capacitance after 5000 cycles at the scan rate of 10 mV/s. It provided a possible way to obtain graphene based materials with high surface area and capacitance.

Characterization of chitosan/montmorillonite bionanocomposites by inverse gas chromatography

Montmorillonite was modified with different amounts of chitosan to obtain chitosan/montmorillonite bionanocomposites (CSMMT). The structural and surface characteristics of the raw materials and bionanocomposites were analyzed. XPS results showed that the obtained bionanocomposites had MMT-rich surfaces with chitosan essentially intercalated in the host clay galleries. IGC at infinite dilution confirmed that the increase of CS mass ratio in the bionanocomposites significantly affected the surface properties. IGC at finite concentration revealed a clear evolution in the surface heterogeneity in chitosan/montmorillonite bionanocomposites by the progressive disappearance of shoulders of high energy with the increase of CS mass ratio in MMT.

Biohybrid cardiac ECM-based hydrogels improve long term cardiac function post myocardial infarction.

This work describes the development of new injectable scaffolds for cardiac tissue regeneration that are based on solubilized porcine cardiac extracellular matrix (ECM), combined with natural biomaterials: genipin, and chitosan. The design of such scaffolds aims at leveraging the natural bioactivity and unique structure of cardiac ECM, while overcoming its limited mechanical strength, which may fail to provide the long-term support required for heart contraction and relaxation. Here, we present a biocompatible gel-platform with custom-tailored mechanical properties that significantly improve cardiac function when injected into rat hearts following acute and chronic myocardial infarction. We clearly demonstrate the substantial therapeutic potential of these scaffolds, which not only preserved heart functions but also alleviated MI damage, even after the formation of a mature scar tissue.

Engineering hydrophobically modified chitosan for enhancing the dispersion of respirable microparticles of levofloxacin

The potential of amphiphilic chitosan formed by grafting octanoyl chains on the chitosan backbone for pulmonary delivery of levofloxacin has been studied. The success of polymer synthesis was confirmed using FT-IR and NMR, whilst antimicrobial activity was assessed against Pseudomonas aeruginosa. Highly dispersible dry powders for delivery as aerosols were prepared with different amounts of chitosan and octanoyl chitosan to study the effect of hydrophobic modification and varying concentration of polymer on aerosolization of drug. Powders were prepared by spray-drying from an aqueous solution containing levofloxacin and chitosan/amphiphilic octanoyl chitosan. l-leucine was also used to assess its effect on aerosolization. Following spray-drying, the resultant powders were characterized using scanning electron microscopy, laser diffraction, dynamic light scattering, HPLC, differential scanning calorimetry, thermogravimetric analysis and X-ray powder diffraction. The in vitro aerosolization profile was determined using a Next Generation Impactor, whilst in vitro antimicrobial assessment was performed using MIC assay. Microparticles of chitosan have the property of mucoadhesion leading to potential increased residence time in the pulmonary mucus, making it important to test the toxicity of these formulations. In-vitro cytotoxicity evaluation using MTT assay was performed on A549 cell line to determine the toxicity of formulations and hence feasibility of use. The MTT assay confirmed that the polymers and the formulations were non-cytotoxic. Hydrophobically modifying chitosan showed significantly lower MIC (4-fold) than the commercial chitosan against P. aeruginosa. The powders generated were of suitable aerodynamic size for inhalation having a mass median aerodynamic diameter less than 4.5μm for formulations containing octanoyl chitosan. These highly dispersible powders have minimal moisture adsorption and hence an emitted dose of more than 90% and a fine particle fraction (FPF) of 52%. Powders with non-modified chitosan showed lower dispersibility, with an emitted dose of 72% and FPF of 20%, as a result of high moisture adsorption onto the chitosan matrix leading to cohesiveness and subsequently decreased dispersibility.