Release mechanism of omega-3 fatty acid in κ-carrageenan/polydextrose undergoing glass transition

Drug release profile of phenytoin-loaded starch-based biomaterials incorporating hierarchical microparticles with photothermal effects

This study aimed to synthesize phenytoin (PHT)-loaded water chestnut starch-based biomaterials and evaluate their drug release kinetics for use in transdermal drug delivery systems for antiepileptic therapy. Hierarchical microparticles (HMPs) extracted from human hair were also used to improve the PHT release efficiency. The physicochemical characteristics of PHT, HMPs, and the prepared biomaterials were evaluated by physical properties, antimicrobial activities, FE-SEM, FT-IR, XRD, 1H NMR, and 13C CPMAS solid-state NMR. The photothermal effect and the PHT release profile were confirmed through 808 nm NIR laser irradiation. After 30 min of the laser exposure, the temperature of the HMP-added biomaterials increased by 1.50-1.59 times compared to that of without the HMPs. PHT release in buffers and artificial skin test under NIR laser irradiation enhanced by 1.20-1.85 times owing to the photothermal effect. The release kinetics in pH buffer and artificial skin were determined using the Fickian diffusion and Korsmeyer-Peppas models. Additionally, to verify the transdermal penetration of PHT, drug-release simulations were conducted using rhodamine B in agar blocks and pig ears. The results implied that the photothermal effect of the HMPs enhanced the penetration of the drug.

κ-Carrageenan-essential oil loaded composite biomaterial film facilitates mechanosensing and tissue regenerative wound healing

Polysaccharides κ-carrageenan (κ-Car) have become a predominant source in developing bioactive materials. We aimed to develop biopolymer composite materials of κ-Car with coriander essential oil (CEO) (κ-Car-CEO) films for fibroblast-associated wound healing. Initially, we loaded the CEO in to κ-Car and CEO through homogenization and ultrasonication to fabricate composite film bioactive materials. After performing morphological and chemical characterizations, we validated the developed material functionalities in both in vitro and in vivo models. The chemical and morphological analysis with physical structure, swelling ratio, encapsulation efficiency, CEO release, and water barrier properties of films examined and showed the structural interaction of κ-Car and CEO-loaded into the polymer network. Furthermore, the bioactive applications of CEO release showed initial burst release followed by controlled release from the κ-Car composite film with fibroblast (L929) cell adhesive capabilities and mechanosensing. Our results proved that the CEO-loaded into the κ-Car film impacts cell adhesion, F-actin organization, and collagen synthesis, followed by in vitro mechanosensing activation, further promoting wound healing in vivo. Our innovative perspectives of active polysaccharide (κ-Car)-based CEO functional film materials could potentially accomplish regenerative medicine.

Decoupling diffusion and macromolecular relaxation in the release of vitamin B6 from genipin-crosslinked whey protein networks

This study examined the release of vitamin B6 from a hydrogel made of whey protein isolate (WPI). Work was carried out at ambient temperature without preheating the whey protein. Native-state macromolecules were crosslinked with a nontoxic compound, genipin. Experimentation included a ninhydrin assay with UV-vis absorbance, FTIR, ¹³C NMR, compression testing, SEM imaging, WPI matrix swelling and vitamin release protocols. It was confirmed that geninin crosslinked effectively the protein chains whose network strength was reinforced with increasing crosslinker concentrations. The modified Flory-Rehner theory predicted the molecular weight between crosslinks, network mesh size and crosslinking density in the swollen WPI gels as a function of added crosslinker. Transport patterns of vitamin B6 through the polymeric matrix were monitored over prolonged periods of observation. These were examined with the generalised Fick's equation and the Peppas-Sahlin equation to unveil the interplay between diffusion and relaxation dynamics in the anomalous transport of the bioactive compound.

Influence of two functional dextrins on the gel properties of kappa-carrageenan

The physicochemical properties of κ-carrageenan (KC) can be improved by incorporation with small-molecule cosolvents. The texture and rheological properties, micromorphology, and crystallinity of KC incorporating indigestible dextrin (IDD) and beta-limit dextrin (BLD) were investigated. The rheological properties and sol-gel transition temperatures of the gels were slightly improved and the hardness of KC gels was significantly increased after the two dextrins were mixed in. Fourier transform infrared spectroscopy results indicated hydrogen-bonding interactions were strengthened in the presence of the dextrins. Confocal laser scanning microscope images revealed that a more homogenous structure was formed of the KC gel after the addition of dextrins. Moreover, X-ray diffraction patterns indicated the crystallinity of KC gel decreased upon dextrin addition. At the same dextrin content, IDD exerted a greater influence than BLD. IDD contents exceeding 3% (w/w) led to undesirable effects, whereas up to 5% (w/w) of BLD could be added. The two dextrins affected the rearrangement of the KC random coils in the sol state, and facilitated aggregation of the KC chains during cooling to form gel network structures after gelation. Therefore, the appropriate addition of these two dextrins can improve the texture and stability of KC gels and expand their application in functional foods.

Structural variation in gelatin networks from low to high-solid systems effected by honey addition

Honey is a biologically active material functioning antibacterial, anti-inflammation and immune responses that enhance wellbeing. This research aims to record and rationalise the structural properties of honey as part of a convenient delivery system in the presence of gelatin that provides the structuring matrix. In doing so, we employ dynamic oscillation in-shear, micro and modulated DSC, WAXD, FTIR and ESEM. A wide range of solids was employed from 10% (w/w) gelatin to mixtures with up to 75% (w/w) honey. Increasing addition of co-solute created thermally stable gelatin networks, which at high levels of total solids undergo a glass transition. This allows deconvolution of the total heat flow into the reversing and non-reversing thermograms. In addition, mechanical spectra can be treated by the combined free volume/reaction rate theory to predict the molecular dynamics of the gelatin-honey system. Molecular interactions between the two components and the relative contribution of honey to the crystalline or amorphous part of the binary preparation are elucidated guiding future applications for orally and topically treated ailments.

Physicochemical and viscoelastic properties of honey from medicinal plants

The present work investigated the physicochemical and structural properties of Tulsi, Alfalfa and two varieties of Manuka honey derived from medicinal plants. Chemical analysis yielded data on the content of reducing sugars (glucose and fructose) that dominate the honey matrix, and of the minor constituents of protein, phenols and flavonoids. Standard chemical assays were used to develop a database of water content, electrical conductivity, pH, ash content, visual appearance and colour intensity. Physicochemical characteristics were related to structural behaviour of the four honey types, as recorded by small-deformation dynamic oscillation in shear, micro- and modulated differential scanning calorimetry, wide angle X-ray diffraction and infrared spectroscopy. The preponderance of hydrogen bonds in intermolecular associations amongst monosaccharides in honey yields a semi-amorphous or semi-crystalline system. That allowed prediction of the calorimetric and mechanical glass transition temperatures that demarcate the passage from liquid-like to solid-like consistency at subzero temperatures.

Development of a novel sodium fusidate-loaded triple polymer hydrogel wound dressing: Mechanical properties and effects on wound repair

To develop a novel sodium fusidate-loaded triple polymer hydrogel dressing (TPHD), numerious polyvinyl alcohol-based (PVA) hydrogel dressings were prepared with various hydrophilic polymers using the freeze-thaw method, and their hydrogel dressing properties were assessed. Among the hydrophilic polymers tested, sodium alginate (SA) improved the swelling capacity the most, and polyvinyl pyrrolidone (PVP) provided the greatest improvement in bioadhesive stength and mechanical properties. Thus, PVA based-TPHDs were prepared using different ratios of PVP:SA. The effect of selected PVP:SA ratios on the swelling capacity, bioadhesive strength, mechanical properties, and drug release, permeation and deposition characteristics of sodium fusidate-loaded PVA-based TPHDs were assessed. As the ratio of PVP:SA increased in PVA-loaded TPHD, the swelling capacity, mechanical properties, drug release, permeation and deposition were improved. The TPHD containing PVA, PVP, SA and sodium fusidate at the weight ratio of 10/6/1/1 showed excellent hydrogel dressing properties, release, permeation and deposition of drug. Within 24h, 71.8 ± 1.3% of drug was released. It permeated 625.1 ± 81.2 μg/cm(2) through the skin and deposited of 313.8 ± 24.1 μg/cm(2) within 24h. The results of in vivo pharmacodynamic studies showed that sodium fusidate-loaded TPHD was more effective in improving the repair process than was a commercial product. Thus, this sodium fusidate-loaded TPHD could be a novel tool in wound care.