α-Tocopherol acetate-loaded chitosan microparticles: Stability during spray drying process, photostability and swelling evaluation

Fabrication, characterization and release behavior of α-tocopherol acetate-loaded pH-responsive polyhydroxybutyrate/cellulose acetate phthalate microbeads

Microbeads are used in personal care and cosmetic products (PCCPs) but are produced from nondegradable materials. Biodegradable polyhydroxybutyrate (PHB) has been recognized as a promising alternative material for use in PCCPs; however, utilizing PHB to encapsulate PCCPs is challenging because PCCPs need to be protected from the environment but their release needs to be permitted under specific physiological conditions. The aim of this work was to develop and evaluate pH-responsive cellulose acetate phthalate (CAP) to formulate lipophilic α-tocopherol acetate (α-TA)-loaded pH-responsive PHB/CAP microbeads. The influences of the PHB/CAP ratio and initial α-TA loading on the microbead size, surface morphology, encapsulation efficiency (%EE), loading capacity (%LC), and α-TA release profile were studied. The microbeads exhibited a spherical shape with a size of 328.7 ± 2.9 μm. The EE and LC were 86.7 ± 2.6 % and 13.5 ± 0.4 %, respectively. The release profile exhibited pH-responsive characteristics. These α-TA-loaded pH-responsive microbeads were stable with >50 % of the α-TA remaining after 90 days at 4, 25 and 45 °C in the dark. The results from the cytotoxicity assay with PSVK1 cells demonstrated that the microbeads were nontoxic. Hence, our developed formulation has the potential to be used to encapsulate oil-based drugs to formulate lipophilic substance-loaded pH-responsive microbeads.

Self-assembled low molecular weight chitosan-based cationic micelle for improved water solubility, stability and sustained release of α-tocopherol

New amphiphilic low molecular weight chitosan-graft-nicotinic acid bearing decyl groups (LCND) was synthesized by two-step reaction and spontaneously assembled into cationic micelle by ultra-sonication method to improve water solubility and photostability properties of α-tocopherol. The chemical structure of LCND was characterized and physical properties of cationic micelle were evaluated. Results displayed that cationic micelle exhibited strong self-assemble ability with nanoscale spherical morphology and showed best loading ability with loading content of 18.50% when the feeding ratio of LCND to α-tocopherol reached 10:3. Meanwhile, the greatly enhanced water solubility, photostability and sustained release behavior of α-tocopherol in cationic micelle were observed. The cumulative release of α-tocopherol in cationic micelle reached up 82.18% within 96 h while free α-tocopherol was completely released within 10 h. Additionally, release kinetics models were also fitted. The LCND cationic micelle could be promising nanocarrier for improving the physicochemical properties of α-tocopherol in food fields.

Biopolymer from Water Kefir as a Potential Clean-Label Ingredient for Health Applications: Evaluation of New Properties

The present work aimed to characterize the exopolysaccharide obtained from water kefir grains (EPSwk), a symbiotic association of probiotic microorganisms. New findings of the technological, mechanical, and biological properties of the sample were studied. The EPSwk polymer presented an Mw of 6.35 × 105 Da. The biopolymer also showed microcrystalline structure and characteristic thermal stability with maximum thermal degradation at 250 °C. The analysis of the monosaccharides of the EPSwk by gas chromatography demonstrated that the material is composed of glucose units (98 mol%). Additionally, EPSwk exhibited excellent emulsifying properties, film-forming ability, a low photodegradation rate (3.8%), and good mucoadhesive properties (adhesion Fmax of 1.065 N). EPSwk presented cytocompatibility and antibacterial activity against Escherichia coli and Staphylococcus aureus. The results of this study expand the potential application of the exopolysaccharide from water kefir as a potential clean-label raw material for pharmaceutical, biomedical, and cosmetic applications.

Development of Novel Silica-based Formulation of α-Lipoic Acid: Evaluation of Photo and Thermal Stability of the Encapsulated Drug

Powerful antioxidant α-lipoic acid (LA) is easily degraded under light and heating. This creates difficulties in its manufacture, storage and reduces efficiency and safety of the drug. The purpose of this work was to synthesize novel silica-based composites of LA and evaluate their ability to increase photo and thermal stability of the drug. It was assumed that the drug stabilization can be achieved due to LA-silica interactions. Therefore, the composites of LA with unmodified and organomodified silica matrixes were synthesized by sol-gel method at the synthesis pH below or above the pKa of the drug. The effects of silica matrix modification and the synthesis pH on the LA-silica interactions and kinetics of photo and thermal degradation of LA in the composites were studied. The nature of the interactions was revealed by FTIR spectroscopy. It was found that the rate of thermal degradation of the drug in the composites was significantly lower compared to free LA and mainly determined by the LA-silica interactions. However, photodegradation of LA in the composites under UV irradiation was either close to that for free drug or significantly more rapid. It was shown that kinetics of photodegradation was independent of the interactions and likely determined by physical properties of surface of the composite particles (porosity and reflectivity). The most promising composites for further development of novel silica-based formulations were identified.

Wound healing and antimicrobial effect of active secondary metabolites in chitosan-based wound dressings: A review

Wound healing can lead to complex clinical problems, hence finding an efficient approach to enhance the healing process is necessary. An ideal wound dressing should treat wounds at reasonable costs, with minimal inconveniences for the patient. Chitosan is one of the most investigated biopolymers for wound healing applications due to its biocompatibility, biodegradability, non-toxicity, and antimicrobial activity. Moreover, chitosan and its derivative have attracted numerous attentions because of the accelerating wound healing, and easy processability into different forms (gels, foams, membranes, and beads). All these properties make chitosan-based materials particularly versatile and promising for wound dressings. Besides, secondary natural metabolites could potentially act like the antimicrobial and anti-inflammatory agents and accelerate the healing process. This review collected almost all studies regarding natural compounds applications in wound healing by focusing on the chitosan-based bioactive wound dressing systems. An accurate analysis of different chitosan formulations and the influence of bioactive compounds on their wound healing properties are reported.

Potato snacks added with active components: effects of the vacuum impregnation and drying processes

Potato snacks can be used as an ideal strategy for nutrient delivery, since they are one of the most widely consumed products in the world. Due to fried snacks are known to be a significant source of fat intake, consumption is changing towards healthier alternatives. The aim of this research is to evaluate the effect of vacuum impregnation and three dehydration techniques: heated air drying, freeze drying, and microwave vacuum drying of the potato snack that has been fortified with active components: calcium and vitamins C and E. Vacuum impregnation was evaluated using the response surface methodology that had a central composite experimental design with the following independent variables: vacuum pressure, vacuum stage time, and atmospheric stage time. The following were the dependent variables: fraction and volumetric deformation in the vacuum stage and at the end of the process and effective porosity. Finally, a sensorial analysis was carried out on the dehydrated potatoes. The results of the optimal vacuum impregnation process conditions were: a vacuum pressure of 77.3 kPa for 3.0 min followed by 4.0 min at atmospheric pressure. The content of calcium, vitamin C, and vitamin E in the impregnated potato were 956, 472, and 35 mg 100 g^-1 dry solids, respectively. The highest retention of the active components in snacks was obtained by the combination of vacuum impregnation and the dehydration techniques in the following order: freeze drying, microwave vacuum drying, and then heated air drying. It can be concluded that the integration processes give an added value to potato snacks due to the increased content of the active components; additionally, the vacuum impregnation process together with microwave vacuum drying was the alternative that had the highest sensorial acceptability.

Tocopherol-loaded transfersomes: In vitro antioxidant activity and efficacy in skin regeneration

Transfersomes were prepared by using different polysorbates (i.e., Tween 20, 40, 60 and 80) and loaded with tocopherol acetate, a naturally-occurring phenolic compound with antioxidant activity. The vesicles showed unilamellar morphology, small size (∼85 nm), low polydispersity index (≤0.27), and high entrapment efficiency, which increased as a function of the length of the Tween fatty acid chain (from 72% to 90%). The long-term stability of the formulations was evaluated by means of the Turbiscan™ technology, which indicated their good stability, irrespective of the Tween used. The vesicles efficiently delivered tocopherol to the skin, and showed biocompatibility in vitro in keratinocytes and fibroblasts. Regardless of the Tween used, the transfersomes were able to protect skin cells from the oxidative damage induced by hydrogen peroxide. Additionally, transfersomes promoted cell proliferation and migration, which resulted in an acceleration of skin wound closure. These results demonstrated that tocopherol-loaded transfersomes bear potential as topical delivery system with antioxidant activity and wound healing properties.