Low Molecular Weight Chitosan Research Articles

Carbomer Hydrogels with Microencapsulated α-Tocopherol: Focus on the Biocompatibility of the Microcapsules, Topical Application Attributes, and In Vitro Release Study

The microencapsulation of α-tocopherol based on the complex coacervation of low-molecular-weight chitosan (LMWC) and sodium lauryl ether sulphate (SLES) without harmful crosslinkers can provide biocompatible carriers that protect it from photodegradation and air oxidation. In this study, the influence of the microcapsule wall composition on carrier performance, compatibility with a high-water-content vehicle for topical application, and release of α-tocopherol were investigated. Although the absence of aldehyde crosslinkers decreased the encapsulation efficiency of α-tocopherol (~70%), the variation in the LMWC/SLES mass ratio (2:1 or 1:1) had no significant effect on the moisture content and microcapsule size. The prepared microcapsule-loaded carbomer hydrogels were soft semisolids with pseudoplastic flow behavior. The integrity of microcapsules embedded in the hydrogel was confirmed by light microscopy. The microcapsules reduced the pH, apparent viscosity, and hysteresis area of the hydrogels, while increasing their spreading ability on a flat inert surface and dispersion rate in artificial sweat. The in vitro release of α-tocopherol from crosslinker-free microcapsule-loaded hydrogels was diffusion-controlled. The release profile was influenced by the LMWC/SLES mass ratio, apparent viscosity, type of synthetic membrane, and acceptor medium composition. Better data quality for the model-independent analysis was achieved when a cellulose nitrate membrane and ethyl alcohol 60% w/w as acceptor medium were used.

Megalin-targeted acetylcysteine polymeric prodrug ameliorates ischemia-reperfusion-induced acute kidney injury

Acute kidney injury (AKI), a condition associated with reactive oxygen species (ROS), causes high mortality in clinics annually. Active targeted antioxidative therapy is emerging as a novel strategy for AKI treatment. In this study, we developed a polymeric prodrug that targets the highly expressed Megalin receptor on proximal tubule cells, enabling direct delivery of N-Acetylcysteine (NAC) for the treatment of ischemia reperfusion injury (IRI)-induced AKI. We conjugated NAC with low molecular weight chitosan (LMWC), a biocompatible and biodegradable polymer consisting of glucosamine and N-acetylglucosamine, to enhance its internalization by tubular epithelial cells. Moreover, we further conjugated triphenylphosphonium (TPP), a lipophilic cation with a delocalized positive charge, to low molecular weight chitosan-NAC in order to enhance the distribution of NAC in mitochondria. Our study confirmed that triphenylphosphonium-low molecular weight chitosan-NAC (TLN) exhibits remarkable therapeutic effects on IRI-AKI mice. This was evidenced by improvements in renal function, reduction in oxidative stress, mitigation of pathological progress, and decreased levels of kidney injury molecule-1. These findings suggested that the polymeric prodrug TLN holds promising potential for IRI-AKI treatment.

Антимікробна та противірусна активність нанокомпозитів на основі поліелектролітних комплексів з наночастинками срібла

Recently, nanocomposite materials containing nanoparticles of metals such as silver, copper and zinc oxide have attracted most attention due to their pronounced pharmacological properties, such as antimicrobial, antiviral, antiinflammatory, immunomodulatory ability and high stability in extreme conditions. Polyelectrolyte complexes based on polymers of natural origin, namely polysaccharides of chitosan and pectin, which can stabilize nanoparticles of a smaller size than individual polymers have significant potential for creation of silver-containing nanocomposites. The aim of this article is to study the antimicrobial and antiviral activity of silver-containing nanocomposites based on polyelectrolyte complexes. Methods. Peculiarities of the structural organization of silver-containing nanocomposites were investigated by the method of wide-angle scattering on an XRD-7000 diffractometer. The morphology of Ag nanoparticles in polymer matrixes were studied by transmission electron microscopy method (transmission electron microscope JEOL 100 CXII). The antimicrobial activity of silver-containing nanocomposites was determined by agar diffusion assays against opportunistic pathogens Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Candida albicans. Cytotoxicity and antiviral activity were investigated using the MTT method and staining by gentian violet. Results. Analysis of wide-angle X-ray diffractograms of silver-containing nanocomposites based on polyelectrolyte complexes Na-CMC (pectin) – chitosan showed that at reduction of Ag+ ions to metallic silver, there are two low-intensity diffraction maxima at 2θm ~ 380 and 440 in the diffractograms. These maxima correspond to the crystallographic planes of the face-centered cubic lattice of silver, are characterized by indices (111) and (200), respectively, and confirm the presence of metallic silver in the polymer system. Analysis of micrographs of silver-containing nanocomposites based on Na-CMC and chitosan showed that larger nanoparticles are formed with increasing the molecular weight of chitosan. The dependence of the size of silver nanoparticles on the wavelength of ultraviolet radiation at reduction of silver ion in polyelectrolyte-metal complexes Na-CMC–Ag+–chitosan of low molecular weight was also revealed. In particular, smaller particles are formed under irradiation by light with a shorter wavelength (λ =254 nm) than at λ=365 nm. Silver-containing nanocomposites Na-СMC-Ag-chitosan and pectin citrus-Ag-chitosan, obtained by reduction of Ag+ ions under ultraviolet irradiation at a wavelength λ = 365 nm and λ = 254 nm, exhibit high antimicrobial activity against the test cultures of microorganisms S. aureus, E. coli, and P. aeruginosa C. albicans. No significant dependence of antimicrobial activity on the molecular weight of the studied samples was noted: the obtained data were within close limits and had close values. In addition, no dependence of antimicrobial activity on the type of investigated test cultures of microorganisms was observed either. Nanocomposites based on Na-CMC-chitosan (λ = 365 nm) inhibited infection titer HSV-1 by (3.72–5.45) lgTCID50/mL, whereas the decrease in titer during incubation with samples based on citrus pectin-chitosan was within (2.39–2.42) lgTCID50/mL. A dose-dependent relationship between molecular weight of chitosan and reduction of infection titer was observed. It was found that silver-containing nanocomposites formed by reduction of silver ions in polyelectrolyte-metal complexes under ultraviolet radiation of different wavelengths had no cytotoxic effect on cells of MDCK and BHK. Conclusions. The investigated silver-containing nanocomposites based on Na-CMC (pectin)-chitosan polyelectrolyte complexes show antimicrobial activity against test cultures of S. aureus, E. coli P. aeruginosa, and C. albicans along with antiviral activity against herpes simplex virus type 1 and influenza virus. It was established that the obtained nanocomposites did not show a cytotoxic effect on MDCK and BHK cells. The obtained data allow us to assert that investigated silver-containing nanocomposites are promising antimicrobial means for the development of new effective strategies against microorganisms and viruses and improvement of the population health.

Low molecular weight chitosan based GSH-responsive self-assembled cationic micelle with enhanced anti-tumor effect by combining oxidative damage and chemotherapy

A novel cationic lipoic acid grafted low molecular weight chitosan (LCNE-LA) conjugate was constructed and further self-assembled into GSH-responsive cationic nanocarrier to achieve better antitumor effect by combining encapsulated chemotherapy and oxidative damage induced by ROS. The resultant LCNE-LA cationic micelle exhibited favorable physicochemical properties (low CMC, small size, positively zeta potential and good stability), excellent biosafety and desired redox sensitivity. Next, doxorubicin (Dox) was embedded into hydrophobic core to form stable Dox/LCNE-LA micelle that had superior loading capacity. The GSH-induced release behavior, cellular uptake ability, ROS generation and GSH consumption capacity and in vitro antitumor activity of Dox/LCNE-LA micelle were systematically evaluated. Consequently, Dox/LCNE-LA cationic micelle with positively charged could efficiently enter into cancer cell and redox-sensitive release Dox via disulfide-thiol exchange reaction, which usually expend abundant GSH and disrupt redox homeostasis. Studies further confirmed that Dox/LCNE-LA micelle could increase ROS and reduced GSH content which might cause oxidative damage to tumor cell. Antitumor activity indicated that Dox/LCNE-LA micelle achieved an excellent cancer-killing effect, which might be attributed to combination treatment of Dox and ROS induce oxidative damage. Overall, this research was expected to provide a platform for antitumor treatment by triggering Dox release and promoting ROS generation.

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.

Improved antioxidant and anti-tubercular potential of liquiritigenin grafted on low molecular weight chitosan from gladius of Sepioteuthis lessoniana

Chitosan (CH) is natural abundant biopolymer present on earth after cellulose. CH can be functionalized by numerous functional groups such as amino and carboxyl groups, potential biologically active compounds. The functionalization of CH with polyphenols had a greater biological than non-grafted CH. In the present study, the polyphenolic compound liquiritigenin (LTG) is chemically functionalized on the low molecular weight chitosan (LMW-CH) (693.09 Da). This was extracted and irradiated with gamma radiation from the gladius of Sepioteuthis lessoniana. The grafted compound was to in vitro anti-oxidant employing physicochemical methods and characterization was made by spectroscopic methods.The degree of deacetylation (DDA) of the LMW-CH was detected in 74 % of the samples, and at higher concentrations (100 g/mL). LMW-CH grafted with LTG had improved water solubility (5 mg/mL), and was thermally stable upto 143.58 °C. Its molecular weight was 855.1 Da.In conclusion the in vitro antioxidant and the anti-tuberculosis (anti-TB) properties of the grafted samples were significantly (P < 0.001) increased compared to the unconjugated LMW-CH and LTG. Overall, functionalization of LTG with LMW-CH improved the anti-tuberculosis activity. Further studies are needed to explore the possibilities of its use in vivo models.

Synthesis of new quaternized chitosan Schiff bases and their N-alkyl derivatives as antimicrobial and anti-biofilm retardants in membrane technology

New quaternized salicylidene chitosan Schiff bases (QSCSBs) and their N-octyl derivatives (OQCs) have been synthesized and characterized, aiming to develop innovative antimicrobial and anti-biofilm agents. This research holds immense potential, as these compounds could be utilized as anti-biofouling additives in membrane technology in the future. The synthesis involved the modification of low molecular-weight-chitosan (LMC) through simultaneous Schiff base formation and quaternization processes to create QSCSBs. Subsequently, QSCSBs were catalytically reduced to form quaternized N-benzyl chitosan (QBCs) intermediates, which then underwent nucleophilic substitution reactions affording N-octyl quaternized chitosans (OQCs). Characterization techniques such as elemental, spectral, and microscopic analyses were used to confirm the successful synthesis of these materials. As membrane technology relies on surface charge, QSCSBs and OQCs with large zeta potentials could be used as positively charged additives. Moreover, SEM image revealed the regular distribution of pores and voids across the additives' surfaces raises intriguing questions about their implications for membrane performance. Meanwhile, the superior antibacterial and antibiofilm potential of these materials, particularly QSCSB2 and OQC2, indicate that the utilization of these compounds as anti-biofouling additives in membrane technology could significantly improve the performance and longevity of membranes used in various applications such as water treatment and desalination.

Layer-by-layer assembly of quercetin-loaded zein/γPGA/low-molecular-weight chitosan/fucoidan nanosystem for targeting inflamed blood vessels

Chitosan acts as a versatile carrier in polymeric nanoparticle (NP) for diverse drug administration routes. Delivery of antioxidants, such as quercetin (Qu) showcases potent antioxidant and anti-inflammatory properties for reduction of various cardiovascular diseases, but low water solubility limits uptake. To address this, we developed a novel layer-by-layer zein/gamma-polyglutamic acid (γPGA)/low-molecular-weight chitosan (LC)/fucoidan NP for encapsulating Qu and targeting inflamed vessel endothelial cells. We used zein (Z) and γPGA (r) to encapsulate Qu (Qu-Zr NP) exhibited notably higher encapsulation efficiency compared to zein alone. Qu-Zr NP coated with LC (Qu-ZrLC2 NP) shows a lower particle size (193.2 ± 2.9 nm), and a higher zeta potential value (35.2 ± 0.4 mV) by zeta potential and transmission electron microscopy analysis. After coating Qu-ZrLC2 NP with fucoidan, Qu-ZrLC2Fa NP presented particle size (225.16 ± 0.92 nm), zeta potential (−25.66 ± 0.51 mV) and maintained antioxidant activity. Further analysis revealed that Qu-ZrLC2Fa NP were targeted and taken up by HUVEC cells and EA.hy926 endothelial cells. Notably, we observed Qu-ZrLC2Fa NP targeting zebrafish vessels and isoproterenol-induced inflamed vessels of rat. Our layer-by-layer formulated zein/γPGA/LC/fucoidan NP show promise as a targeted delivery system for water-insoluble drugs. Qu-ZrLC2Fa NP exhibit potential as an anti-inflammatory therapeutic for blood vessels.

Low molecular weight chitosan from Pleurotus ostreatus waste and its prebiotic potential

The booming mushroom industry envisages economic merits, and massive unutilized waste production (~ 20 %) creates an opportunity for valorization. Chitosan, a bioactive polysaccharide, has drawn immense attention for its invaluable therapeutic potential. Thus, the present study was conducted to extract chitosan from mushroom waste (MCH) for its prebiotic potential. The structural characterization of MCH was carried out using NMR, FTIR, and XRD. The CP/MAS-13CNMR spectrum of MCH appeared at δ 57.67 (C2), 61.19 (C6), 75.39 (C3/C5), 83.53 (C4), 105.13 (C1), 23.69 (CH3), and 174.19 (C = O) ppm. The FTIR showed characteristic peaks at 3361 cm−1, 1582 cm−1, and 1262 cm−1 attributed to –NH stretching, amide II, and amide III bands of MCH. XRD interpretation of MCH exhibited a single strong reflection at 2θ =20.19, which may correspond to the “form-II” polymorph. The extracted MCH (~ 47 kDa) exhibited varying degrees of deacetylation from 79 to 84 %. The prebiotic activity score of 0.73 to 0.82 was observed for MCH (1 %) when supplemented with probiotic strains (Lactobacillus casei, L. helveticus, L. plantarum, and L. rhamnosus). MCH enhanced the growth of Lactobacillus strains and SCFA's levels, particularly in L. rhamnosus. The MCH also inhibited the growth of pathogenic strains (MIC of 0.125 and 0.25 mg/mL against E. coli and S. aureus, respectively) and enhanced the adhesion efficiency of probiotics (3 to 8 % at 1 % MCH supplementation). L. rhamnosus efficiency was higher against pathogens in the presence of MCH, as indicated by anti-adhesion assays. These findings suggested that extracted polysaccharides from mushroom waste can be used as a prebiotic for ameliorating intestinal dysbiosis.

Development of a pH-responsive intelligent label using low molecular weight chitosan grafted with phenol red for food packaging applications

In this study, we successfully developed a screen-printed pH-responsive intelligent label using low molecular weight chitosan grafted with phenol red (LCPR) as a colorant for screen printing ink. The LCPR was synthesized via a Mannich reaction, and its successful grafting was confirmed through FT-IR, UV–vis, and NMR spectroscopy. The LCPR exhibited lower crystallinity and thermal stability compared to low molecular weight chitosan (LC) and demonstrated zwitterionic behavior. To create intelligent labels, the LCPR-based ink was efficiently printed on cotton substrates with high resolution. The label exhibited remarkable sensitivity to buffer pH solutions and ammonia gas, leading to distinctive color changes from orange to red to purple. Additionally, the label showed excellent reversibility, storage stability, and leaching resistance to different food simulant solutions. The label was utilized to monitor shrimp freshness, successfully detecting a noticeable color shift upon spoilage. These findings highlight the significant potential of the LCPR-based label as an intelligent food packaging solution, offering pH-responsiveness and color stability for qualitative freshness detection of protein-rich food.

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

Functionalization of chitosan as salicylaldehyde and 2-acetylphenol-based chitosan thiosemicarbazone involving amino group at C2 position of pyranose ring was confirmed by comprehensive characterization by spectroscopic and analytical ways. Both the low molecular weight (Mw) chitosan oligosaccharide (CS) (Mw < 3000 Da, degree of deacetylation (DDA) = 87 %) and the crab shell chitosan (CCS) (Mw = 350 kDa, DDA = 67 %) functionalized thiosemicarbazones behaved as ONS tridentate ligand to form the square planar copper(II) complexes with a chloride ion as an additional ligand to satisfy the co-ordination sphere. All the derivatives were found thermally stable till the commencement of chitosan backbone disruption at 200 °C. The MTT assay profiles showed a conspicuous enhancement in the in vitro antitumorigenic and anticancer activity of native chitosan upon its functionalization as phenolic carbaldehyde chitosan thiosemicarbazones. Further, the assays more often revealed a further lowering of cell viability with chitosan oligosaccharide derivatives in comparison to high molecular weight chitosan derivatives, and a lower viability of the MCF-7 cancer cells than the tumorigenic MDCK cells. Both the low Mw chitosan with high DDA and high Mw chitosan with low DDA, the chitosan-functionalized salicylaldehyde based thiosemicarbazones, and their copper(II) chitosan thiosemicarbazone complexes were found to have minimal toxicity with IC50 >600 μgmL−1 against the mouse embryonic normal fibroblast NIH3T3 cells. These results were indicatives of more protonation and enhanced anticancer activity of chitosan oligosaccharide derivatives, and preferential cytotoxicity of chitosan biomaterials against the tumorigenic and cancer cells with more negatively charged cell surfaces.

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.

Fabrication of Eucalyptus Oil-loaded Ciprofloxacin Hydrochloride Topical Films for Enhanced Treatment of Post-Operative Wound Infection

Background: The efficacious penetration of antimicrobials at infectious sites and the reduction of microbial resistance development are critical in controlling the effective treatment of post-operative wound infection. Methods: To create the enhanced antimicrobial topical films, a solvent casting method for ciprofloxacin hydrochloride (CiproHCl) loaded eucalyptus oil (EO) containing low molecular weight chitosan films was used. Nine batches of CiproHCl with varying chitosan and glycerol concentrations were prepared and tested. Additionally, optimised CiproHCl films with EO were created and tested. The antimicrobial activity of CiproHCl-loaded EO containing low molecular weight chitosan films against S. Aureus, E. Coli, and B. Subtilus was tested. Results: The FT-IR spectroscopy and DSC analysis revealed no interaction between the drug and any of the other excipients, and the drug remained amorphous in chitosan film. The SEM analysis revealed that the prepared CiproHCl-loaded EO-containing films had smooth surfaces and large agglomerates. In vitro drug release testing revealed that the EO-loaded films have a sustained release profile of up to 16 hours with a cumulative drug release of 96.83%. In an ex vivo drug permeation study, CiproHCl-loaded EO-containing films demonstrated 2.44 times more permeation flux than CiproHCl-alone films. After six months, the stability study revealed that the CiproHCl-loaded EO-loaded EO-containing film showed no significant change in drug release profile or folding endurance. Conclusion: This present study highlights the possible usage of CiproHCl-loaded EO containing low molecular weight chitosan films in enhanced post-operative wound treatment.

Foliar Application of Micronutrients and Low Molecular Weight Polysaccharides on White Radish Grown in Impoverished Soil

Foliar application has been considered as the most effective way to supplement nutrients for crops. Besides macro- and micro-nutrients, foliar fertilizers should contain surfactants to wet plant leaves, and other adjuvants to control spray and prolong the retention time of nutrients on the leaf surface. Having diverse structures and properties, some polysaccharides can not only be used as drift control or adhesion agents to improve performance on the leaf and reduce washout of agrochemicals by rainwater, but also be utilized as plant growth promoters (PGP) or immuno-stimulating agents in agricultural production. In this study, low molecular weight chitosan and xanthan obtained by radiation degradation have been added to the microelement fertilizers to control diseases, promote the growth and development of vegetables, and further increase their nutrient uptake. Field trials on white radishes grown on impoverished soil revealed that the resulting foliar fertilizers significantly reduced the infection of popular pests and diseases, remarkably promoted the growth and development of the radish plants. The yield attributes and marketable yield of radish from all treatments were much higher than those of the control. The highest yields were 61.99 and 64.94 tons per ha in season 2019 and 2020, respectively, in the plants treated with the fertilizer containing both chitosan and xanthan. These results suggest that the fertilizer composed of micronutrients and low molecular weight chitosan and xanthan could be applied for better vegetable crops.

Chitosan alleviates ovarian aging by enhancing macrophage phagocyte-mediated tissue homeostasis

BackgroundAge-related changes in the ovarian microenvironment are linked to impaired fertility in women. Macrophages play important roles in ovarian tissue homeostasis and immune surveillance. However, the impact of aging on ovarian macrophage function and ovarian homeostasis remains poorly understood.MethodsSenescence-associated beta-galactosidase staining, immunohistochemistry, and TUNEL staining were used to assess senescence and apoptosis, respectively. Flow cytometry was employed to evaluate mitochondrial membrane potential (MMP) and apoptosis in granulosa cells lines (KGN), and macrophages phagocytosis. After a 2-month treatment with low molecular weight Chitosan (LMWC), ovarian tissues from mice were collected for comprehensive analysis.ResultsCompared with the liver and uterus, the ovary displayed accelerated aging in an age-dependent manner, which was accompanied by elevated levels of inflammatory factors and apoptotic cells, and impaired macrophage phagocytic activity. The aged KGN cells exhibited elevated reactive oxygen species (ROS) and apoptotic levels alongside decreased MMP. H2O2-induced aging macrophages showed reduced phagocytosis function. Moreover, there were excessive aging macrophages with impaired phagocytosis in the follicular fluid of patients with diminished ovarian reserve (DOR). Notably, LMWC administration alleviated ovarian aging by enhancing macrophage phagocytosis and promoting tissue homeostasis.ConclusionsAging ovarian is characterized by an accumulation of aging and apoptotic granulosa cells, an inflammatory response and macrophage phagocytosis dysfunction. In turn, impaired phagocytosis of macrophage contributes to insufficient clearance of aging and apoptotic granulosa cells and the increased risk of DOR. Additionally, LMWC emerges as a potential therapeutic strategy for age-related ovarian dysfunction.

Improving the technology for obtaining of low molecular weight chitosan under conditions of controlled enzymatic cleavage

Relevance. Annotation. Experimental data on improving the production technology of regulated enzymatic cleavage of chitosan to obtain its low-molecular derivatives are presented. Experimental studies were carried out in the conditions of the Department of Disease Diagnostics, Therapy, Obstetrics and Animal Reproduction of the Moscow State Academy of Veterinary Medicine and Biotechnology — MVA named after K.I. Skryabin and on the basis of the All-Russian Research and Technological Institute of the Biological Industry.Methods. Acid-soluble chitosan from king crab shell (MM 700 kDa, SDA 85%), chitosan succinate (MM 330 kDa, SZ 75.2%), low-molecular food chitosan (hydrochloride) (MM 50 kDa) were used as raw materials for obtaining new modifications of chitosan, gel chitosan (2% solution in 2% acetic acid) manufactured by Bioprogress LLC.Results. As a result of the experiment, the technological parameters of obtaining low-molecular chitosan by enzymatic hydrolysis were selected. The greatest decrease in the dynamic viscosity of chitosan was reliably observed in the pilot-industrial series II (by 29.3 times), and the pilot-industrial series I and III — by 6.9 and 10.6 times, respectively. As a result of enzymatic hydrolysis of chitosan in the pilot series II, it was possible to reduce the molecular weight from 700 to 24 kDa, and in series I and III — to 102 and 66 kDa. Based on the research results, a technological scheme for obtaining low-molecular-weight chitosan derivatives by enzymatic hydrolysis has been developed, tested and proposed for industrial use, technical conditions have been developed.

BIOPOLÍMERO QUITOSANA NA ADSORÇÃO DE GLIFOSATO: USO NO MONITORAMENTO OU REMEDIAÇÃO AMBIENTAL

In this work, low molecular weight chitosan was used to adsorb the herbicide glyphosate in aqueous solution. Considering the possibilities of remediation and monitoring in aquatic environments, chitosan was formatted into thin discs 0.8 mm thick and 2.5 cm in diameter. The films were characterized by SEM, EDS and FTIR. In the adsorption study, a chitosan disc was able to adsorb 100% of a 5 mgL-1 glyphosate solution. Pseudo-first-order, pseudo-second-order and Elovich kinetic models were applied and it was found that chemisorption predominates in the adsorption process. Thus, chitosan films can act very well as a material for remediating water bodies contaminated by glyphosate. For monitoring studies, the possibility of using chitosan films in DGT (Diffusive Gradients in Thin Films) technique was verified and the diffusive material used was 1.5% agarose film (m/v). The diffusion coefficient of glyphosate in the agarose gel was determined 7.94 x 10-10 m2s-1.

Engineering of targeting antioxidant polypeptide nanopolyplexes for the treatment of acute lung injury

The pathogenesis of acute lung injury (ALI) involves various mechanisms, such as oxidative stress, inflammation, and epithelial cell apoptosis. However, current drug therapies face limitations due to issues like systemic distribution, drug degradation in vivo, and hydrophobicity. To address these challenges, we developed a pH-responsive nano-drug delivery system for delivering antioxidant peptides to treat ALI. In this study, we utilized low molecular weight chitosan (LMWC) and hyaluronic acid (HA) as carrier materials. LMWC carries a positive charge, while HA carries a negative charge. By stirring the two together, the electrostatic adsorption between LMWC and HA yielded aggregated drug carriers. To specifically target the antioxidant drug WNWAD to lung lesions and enhance therapeutic outcomes for ALI, we created a targeted drug delivery system known as HA/LMWC@WNWAD (NPs) through a 12-h stirring process. In our research, we characterized the particle size and drug release of NPs. Additionally, we assessed the targeting ability of NPs. Lastly, we evaluated the improvement of lung injury at the cellular and animal levels to investigate the therapeutic mechanism of this drug targeting delivery system.

Mucoadhesive capsules based on bacterial nanocellulose and chitosan as delivery system of turmeric extract

Current efforts in stomach-related drug design focus on improving drug bioavailability within the gastric region. Bacterial nanocellulose (BNC) has been established as a suitable material for drug delivery systems; however, it lacks adhesion to the gastric environment. This limitation can be addressed by leveraging the mucoadhesive properties of low molecular weight chitosan (LMWC). Therefore, we aimed to develop mucoadhesive capsules constructed from BNC coated with crosslinked LMWC, intended for targeted drug delivery in the gastric region. The capsules were characterized using scanning electron microscopy, infrared spectroscopy, thermogravimetric analysis, and mucoadhesion assessments. Under acidic conditions, crosslinked chitosan exhibited enhanced swelling relative to neutral conditions. The coating of chitosan onto the BNC fibrillar network of the capsules resulted in the superimposition of vibration bands and enhanced thermal stability. Furthermore, the capsules exhibited significant mucoadhesive properties in the gastric environment, with an attachment force measuring 89.151 ± 6.226 mN. To validate the efficacy of the system, we utilized antioxidant turmeric extract (TE) as a bioactive compound with chemopreventive potential against stomach cancer. TE was adsorbed onto BNC in a reversible multilayer system, enabling controlled adsorption and desorption. These findings highlight the significance of developing mucoadhesive capsules as a tailored drug delivery system for gastric conditions, particularly in the context of treating stomach diseases as cancer.

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.