Dextran-Chitosan Composites: Antioxidant and Anti-Inflammatory Properties.

This study presents the development of new formulations consisting of dextran (Dex) and chitosan (Ch) matrices, with fillings such as chitosan stearate (MCh), citric acid, salicylic acid, or ginger extract. These materials were characterized using Fourier-Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), and mechanical tests, and evaluated for antioxidant properties, including scavenging activities, metal chelation, and ferric ion reducing power, as well as anti-inflammatory properties, measuring the binding affinity between serum albumin and the bioactive substances, which can influence their bioavailability, transport, and overall anti-inflammatory effect. Compounds in ginger such as 6-gingerol reduce inflammation by inhibiting the production of inflammatory substances, such as prostaglandin, cytokines, interleukin-1ß, and pro-inflammatory transcription factor (NF-κB) and, alongside citric and salicylic acids, combat oxidative stress, stabilizes cell membranes, and promote membrane fluidity, thereby preserving membrane integrity and function. Incorporating chitosan stearate in chitosan:dextran samples created a dense, stiff film with an elastic modulus approximately seventeen times higher than for the chitosan:dextran matrix. The Dex:Ch:MCh sample exhibited low compressibility at 48.74 ± 1.64 kPa, whereas the Dex:Ch:MCh:citric acid:salicylic acid composite had a compact network, allowing for 70.61 ± 3.9% compression at 109.30 kPa. The lipid peroxidation inhibitory assay revealed that Dex:Ch:MCh:citric acid had the highest inhibition value with 83 ± 0.577% at 24 h. The study highlights that adding active substances like ginger extract and citric acid to Dex:Ch composites enhances antioxidant properties, while modified chitosan improves mechanical properties. These composites may have potential medical applications in repairing cell membranes and regulating antioxidant enzyme activities.

Xanthan-Based Materials as a Platform for Heparin Delivery.

Heparin (Hep), with its anticoagulant activity, antiangiogenic and apoptotic effects, and growth factor binding, plays an important role in various biological processes. Formulations as drug delivery systems protect its biological activity, and limit the potential side effects of faulty administration. The objective of this study was to develop novel xanthan-based materials as a delivery carrier for heparin. The materials exhibited remarkable elastic behavior and toughness without any crack development within the network, which also support their application for tissue engineering. It was found that all materials possessed the ability to control the release of heparin, according to the Korsmeyer-Peppas release model. All Hep-containing materials caused significant exchanges of the activated partial thromboplastin time (aPTT) and prothrombin time (PT) parameters, indicating that formulated natural/natural synthetic polymeric networks conserved heparin's biological activity and its ability to interrupt the blood coagulation cascade. The obtained results confirmed that developed materials could be carriers for the controlled release of heparin, with potential applications in topical administration.

Antioxidant, Antimicrobial, and Kinetic Studies of Β-Cyclodextrin Crosslinked with Lignin for Drug Delivery.

ß-Cyclodextrin was attached to lignin/lignin crosslinked by epichlorohydrin and served as a drug delivery matrix. Ketoconazole and piroxicam were added into the polymeric matrix as antifungal and anti-inflammatory agents, respectively. The percentage of drug retained ranged from 48.4% to 58.4% for ketoconazole and piroxicam, respectively. It was found that their tensile strengths increased with decreasing particle size, ranging between 59% and 71% for lignin crosslinked with ß-cyclodextrin base matrix (LCD). Depending on the polymeric matrix, the drug release kinetics fit well in the Korsmeyer-Peppas model, with or without Fickian diffusion. From the materials based on the mixture of epoxidized lignin and ß-cyclodextrin, the medicines were released more slowly (the release rate constant presents lower values ranging between 1.117 and 1.783), as compared with those comprising LCD (2.210-4.824). The materials were also demonstrated to have antimicrobial activity. The antioxidant activity of LCD loaded with piroxicam was found to be 23.9% greater than that of the base matrix (LCD). These findings could be useful towards ß-cyclodextrin attached to lignin formulation development of drug carriers with antioxidant activity.

Xanthan and alginate-matrix used as transdermal delivery carrier for piroxicam and ketoconazole.

This study presents new drug delivery systems based on xanthan, unmodified or modified by esterification with oleic acid, and alginate for controlled release of bioactive substances with anti-inflammatory (piroxicam) and antifungal properties (ketoconazole). The mechanical properties of the developed drug carriers showed that their compressive strength was affected by the encapsulation of the bioactive principles. When ketoconazole was added into the xanthan/alginate matrix, an increment in the mechanical strength was recorded (66.68% compression). The release of the active principles from the materials was best described by the Korsmeyer-Peppas model, with non-Fickian or Fickian diffusion (the values of the exponent of release are between 0.29 and 0.75), depending on the composition of the polymeric matrix. The release rate constant presents smaller values for the materials based on chemically modified xanthan (between 0.89 and 20.11) as compared with materials based on the unmodified form (between 4.27 and 25.00). All materials were characterized by Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). The designed systems prove to have antimicrobial and anti-inflammatory activity. The findings make prone these biomaterials for the manufacture of transdermal drug delivery systems.

Development and Characterization of Novel Cellulose Composites Obtained in 1-Ethyl-3-methylimidazolium Chloride Used as Drug Delivery Systems.

Two polysaccharides (cellulose and chitosan) and polyurethane dissolved in 1-ethyl-3-methylimidazolium chloride represented the matrix for the obtainment of new composite formulations comprised of lignin, ferrite-lignin hybrid and ketoconazole. The mechanical performances (Young's modulus and compressive strength) increased with the filler addition. The nature of the filler used in the studied formulations influenced both bioadhesion and mucoadhesion parameters. It was found that the incorporation of lignin and ferrite-lignin hybrid into the matrix has influenced the in vitro rate of ketoconazole release, which is described by the Korsmeyer-Peppas model. All materials exhibited activity against Gram positive (Staphylococcus aureus ATCC 25923) and Gram negative (Escherichia coli ATCC 25922) bacteria.

Transcutaneous Drug Delivery Systems Based on Collagen/Polyurethane Composites Reinforced with Cellulose.

Designing composites based on natural polymers has attracted attention for more than a decade due to the possibility to manufacture medical devices which are biocompatible with the human body. Herein, we present some biomaterials made up of collagen, polyurethane, and cellulose doped with lignin and lignin-metal complex, which served as transcutaneous drug delivery systems. Compared with base material, the compressive strength and the elastic modulus of biocomposites comprising lignin or lignin-metal complex were significantly enhanced; thus, the compressive strength increased from 61.37 to 186.5 kPa, while the elastic modulus increased from 0.828 to 1.928 MPa. The release of ketokonazole from the polymer matrix follows a Korsmeyer-Peppas type kinetics with a Fickian diffusion. All materials tested were shown to be active against pathogenic microorganisms. The mucoadhesiveness, bioadhesiveness, mechanical resistance, release kinetic, and antimicrobial activity make these biocomposites to be candidates as potential systems for controlled drug release.

New cellulose-collagen-alginate materials incorporated with quercetin, anthocyanins and lipoic acid.

Herein we present a new biomaterial based on cellulose, collagen and sodium alginate which served as a matrix for the incorporation of bioactive substances with antioxidant properties. Compared with pure cellulose hydrogels, the compressive strength and the elastic modulus of cellulose-collagen-alginate hydrogels were significantly enhanced, thus the compressive strength increased from 0.256 kPa to 6.91 kPa, while the elastic modulus increased from 0.0023 kPa to 0.115 kPa at 30% strain level. The release kinetic of all drugs through matrix components was done according to the Korsmeyer-Peppas model with a Fickian diffusion. The presence of bioactive principles, quercetin, lipoic acid and anthocyanins, gives biomaterials an antioxidant capacity on average 30% higher compared to the base matrix. The mechanical resistance, mucoadhesiveness, bioadhesiveness, release kinetic, and antioxidant capacity of active principles, recommend these biomaterials for the manufacture of transdermal drug delivery devices.

Development and Performance of Bioactive Compounds-Loaded Cellulose/Collagen/Polyurethane Materials.

Here we present a new biomaterial based on cellulose, collagen and polyurethane, obtained by dissolving in butyl imidazole chloride. This material served as a matrix for the incorporation of tannin and lipoic acid, as well as bioactive substances with antioxidant properties. The introduction of these bioactive principles into the base matrix led to an increase of the compressive strength in the range 105-139 kPa. An increase of 29.85% of the mucoadhesiveness of the film containing tannin, as compared to the reference, prolongs the bioavailability of the active substance; a fact also demonstrated by the controlled release studies. The presence of bioactive principles, as well as tannins and lipoic acid, gives biomaterials an antioxidant capacity on average 40%-50% higher compared to the base matrix. The results of the tests of the mechanical resistance, mucoadhesiveness, bioadhesiveness, water absorption and antioxidant capacity of active principles recommend these biomaterials for the manufacture of cosmetic masks or patches.

New composites based on starch/Ecoflex®/biomass wastes: Mechanical, thermal, morphological and antimicrobial properties.

Different biomass wastes were successfully blended with starch and Ecoflex® viz. poly(butylene adipate-co-terephthalate), without glycerol addition, to obtain biocomposite materials. The mechanical properties, as well as thermal and surface properties, of the developed composites were evaluated. It was found that the tensile strength and impact strength improved upon the addition of lignin, while the water uptake capacity decreased. The presence of 5% lignin determined an increase in tensile strength of 125.4% for materials comprising celery (CEL), 109.6% for materials comprising poplar seed hair fibers (PSH), 92.9% for materials comprising pomace (POM) and 127.7% for materials comprising Asclepias syriaca fibers (ASF), compared with a reference sample. The addition of lignin to all the formulations conferred good antimicrobial properties against different microorganisms, S. aureus and especially E. coli. The good mechanical properties, water resistance and antimicrobial activity against pathogens recommend these composites to be used in the manufacture of packaging materials.

Antioxidant capacity and total phenolic contents of oregano (Origanum vulgare), lavender (Lavandula angustifolia) and lemon balm (Melissa officinalis) from Romania.

The study reported here presents a comparative screening of three medicinal plants including oregano (Origanum vulgare L.), lavender (Lavandula angustifolia) and lemon balm (Melissa officinalis) having the same geographical origin, the Southeast region of Romania, and growing in the same natural conditions. The contents of total phenolics and total flavonoids for the extracts of these were determined. Furthermore, the total antioxidant capacity was also evaluated. It was found that Origanum vulgare and Melissa officinalis extracts present the most effective antioxidant capacity in scavenging DPPH radicals, while Lavandula angustifolia is less active. High performance liquid chromatography-mass spectrometry analysis was used to identify the components of extracts. Major phenolic acids identified in the analysed species were ferulic, rosmarinic, p-coumaric and caffeic, while predominant flavonoids were quercetin, apigenin kaempherol, which were present as glucosides.