Preparation and Characterization of Resveratrol Loaded Pectin/Alginate Blend Gastro-Resistant Microparticles

Recent advances in drug delivery systems based on natural and synthetic polymes for treating obesity

Obesity stands as a pervasive global public health issue, posing a formidable threat to human well-being as its prevalence continues to surge year by year. Presently, pharmacological treatment remains the favored adjunct strategy for addressing obesity. However, conventional delivery methods suffer from low bioavailability and the potential for side effects, underscoring the pressing need for more efficient and targeted delivery approaches. Recent research has delved extensively into emerging drug delivery systems employing polymers as carriers, with numerous preclinical studies contributing to the growing body of knowledge. This review concentrates on the utilization of natural polymers as drug delivery systems for the treatment of obesity, encompassing recent advancements in both natural and synthetic polymers. The comprehensive exploration includes an analysis of the advantages and disadvantages associated with these polymer carriers. The examination of these characteristics provides valuable insights into potential future developments in the field of drug delivery for obesity treatment.

Recent advances in oral delivery systems of resveratrol: foreseeing their use in functional foods

Herein, we review the current state-of-the-art on the use of micro- and nano-delivery systems, a possible solution to some of the drawbacks associated with the incorporation of resveratrol in foods. Specifically, we present an overview of a wide range of micro-nanostructures, namely, lipidic and polymeric, used for the delivery of resveratrol. Also, the gastrointestinal fate of resveratrol-loaded micro-nanostructures, as a critical parameter for their use as functional food, is explored in terms of stability, bioaccessibility, and bioavailability. Different micro-nanostructures are of interest for the development of functional foods given that they can provide different advantages and properties to these foods and even be tailor-made to address specific issues (e.g., controlled or targeted release). Therefore, we discuss a wide range of micro-nanostructures, namely, lipidic and polymeric, used to deliver resveratrol and aimed at the development of functional foods. It has been reported that the use of some production methodologies can be of greater interest than others, for example, emulsification, solvent displacement and electrohydrodynamic processing (EHDP) enable a greater increase in bioaccessibility. Additionally, the use of coatings facilitates further improvements in bioaccessibility, which is likely due to the increased gastric stability of the coated micro-nanostructures. Other properties, such as mucoadhesion, can also help improve bioaccessibility due to the increase in gut retention time. Additionally, cytotoxicity (e.g., biocompatibility, antioxidant, and anti-inflammatory) and possible sensorial impact of resveratrol-loaded micro- and nano-systems in foods are highlighted.

Resveratrol: Its Path from Isolation to Therapeutic Action in Eye Diseases

Due to the confirmed therapeutic potential of resveratrol (Rv) for eye diseases, namely its powerful anti-angiogenic and antioxidant effects, this molecule must be studied more deeply. Nowadays, the pharmaceutic and pharmacokinetic available studies offer a troubling picture because of its low stability and bioavailability. To overcome this problem, researchers started to design and create different delivery systems that could improve the delivery amount of Rv. Therefore, this review aims to shed light on the proper and efficient techniques to isolate, purify and quantify the Rv molecule, and how this therapeutic molecule can be a part of a delivery system. The Rv great impact on aspects regarding its stability, bioavailability and absorption are also debated here, based on the existent literature on in vitro and in vivo human and animal studies. Moreover, after its absorption the Rv influence at the molecular level in ocular pathologies is described. In addition, the present review summarizes the available literature about Rv, hoping that Rv will gain more attention to investigate its unexplored side.

Delivery system for grape seed extract based on biodegradable pectin-Zn-alginate gel particles

Pectin-Zn-alginate gel particles from callus culture pectin with increased linearity and decreased rhamnogalacturonan I branching and degree of methylesterification had a higher gel strength and encapsulation capacity. An increase of the alginate concentration led to an increase in the particle gel strength. The grape seed extract (GSE) loaded and empty particles swelled slightly in the simulated gastric fluid (SGF) and gradually in the intestinal (SIF) fluid. The swelling degrees of the GSE-loaded and empty particles in the simulated colonic fluids (SCF) were decreased in the range SCF-7.0 (pH 7.0 + pectinase) > SCF-5.3 (pH 5.3 + pectinase) > SCF-2.3 (pH 2.3 + pectinase). The FTIR spectra indicated that GSE was embedded in the composite particles. Negligible leakage of GSE in SGF was shown. The increase in GSE release in SIF was due to the decrease in particle gel strength and increased swelling degree. The GSE release in fluids simulating the colon inflammation (SCF-2.3 and SCF-5.3) was similar, and it was lower than that in the SCF-7.0 simulating a healthy colon due to the increased gel strength. The percentage release of GSE increased slightly after exposure to different pH. Pectin-Zn-alginate hydrogel systems may be promising candidates for colon-targeted GSE delivery systems.

Investigation of the Role and Effectiveness of Chitosan Coating on Probiotic Microcapsules

Microencapsulation and coating are preferred methods to increase the viability of the probiotic strains. The effect of microencapsulation technologies and materials used as microcapsule cores on viability is being investigated during development. In the present study, chitosan-coated and Eudragit L100-55-coated alginate microspheres were produced to encapsulate Lactobacillus plantarum probiotic bacteria. After the heat loading and simulated gastrointestinal juice dissolution study, the differences in viability were compared based on the CFU/mL values of the samples. The kinetics of the bacterial release and the ratio of the released live/dead cells of Lactobacillus plantarum were examined by flow cytometry. In all cases, we found that the CFU value for the chitosan-coated samples was virtually zero. The ratio of live/dead cells in the 120 min samples was significantly reduced to less than 20% for chitosan, while it was nearly 90% in the uncoated and Eudragit L100-55-coated samples. In the case of chitosan, based on some published MIC values and the amount of chitosan coating determined in the present study, we concluded the reason for our results. It was the first time to determine the amount of the released chitosan coat of the dried microcapsule, which reached the MIC value during the dissolution studies.

Solubilization of Trans-Resveratrol in Some Mono-Solvents and Various Propylene Glycol + Water Mixtures

This research deals with the determination of solubility, Hansen solubility parameters, dissolution properties, enthalpy-entropy compensation, and computational modeling of a naturally-derived bioactive compound trans-resveratrol (TRV) in water, methanol, ethanol, n-propanol, n-butanol, propylene glycol (PG), and various PG + water mixtures. The solubility of TRV in six different mono-solvents and various PG + water mixtures was determined at 298.2-318.2 K and 0.1 MPa. The measured experimental solubility values of TRV were regressed using six different computational/theoretical models, including van't Hoff, Apelblat, Buchowski-Ksiazczak λh, Yalkowsly-Roseman, Jouyban-Acree, and van't Hoff-Jouyban-Acree models, with average uncertainties of less than 3.0%. The maxima of TRV solubility in mole fraction was obtained in neat PG (2.62 × 10-2) at 318.2 K. However, the minima of TRV solubility in the mole fraction was recorded in neat water (3.12 × 10-6) at 298.2 K. Thermodynamic calculation of TRV dissolution properties suggested an endothermic and entropy-driven dissolution of TRV in all studied mono-solvents and various PG + water mixtures. Solvation behavior evaluation indicated an enthalpy-driven mechanism as the main mechanism for TRV solvation. Based on these data and observations, PG has been chosen as the best mono-solvent for TRV solubilization.

N-acetylcysteine delivery with silica nanoparticles into 3T3-L1 adipocytes

Background: The addition of 5 mM N-acetylcysteine (NAC) to 3T3-L1 adipocytes culture inhibits the accumulation of triglycerides (Tg) by 50%, but after 48 h uptake was only 16% of total NAC available. Based on these results, the aim of this study is to increase the NAC cellular uptake by encapsulating it in silica nanoparticles (NPs). Materials & methods: Silica NPs, 20 ± 4.5 nm in size, were developed, with an inner cavity loaded with 5 mM NAC. At 48 h after treatment, there was a dose-dependent cytotoxic effect. We attempted to reduce the cytotoxicity of silica NPs by coating them with bovine serum albumin. Results: While we obtained nontoxic bovine serum albumin coated NPs, their effect on Tg cellular accumulation was also reduced.

Physicochemical and swelling properties of composite gel microparticles based on alginate and callus cultures pectins with low and high degrees of methylesterification

Composite gel microparticles based on alginate and callus culture pectins with low and high degrees of methylesterification or apple pectin were produced. By varying the chemical composition of the pectic samples and the ratio of alginate to pectin, the gel strength, morphology, and swelling properties of composite microparticles can be altered. The inclusion of increasing concentrations of alginate in gel formulations promoted an increase in the microparticle gel strength and the formation of a smoother surface microrelief independently of the pectin chemical composition. Microparticles based on the pectin with a low degree of methylesterification (DM) and a higher concentration of alginate exhibited an increased swelling degree in the simulated digestive fluids. Microparticles based on the pectin with high DM and low alginate concentration were destroyed in the simulated intestinal fluid within 1 h due to the low Ca²⁺ content, gel strength, and grooved and rough surface of these microparticles. An increase in alginate concentration of gel formulations based on pectin with high DM led to increased stability of the microparticles in the simulated intestinal and colonic fluids due to increased Ca²⁺ content, microparticle gel strength and degree of crosslinking.

Valid Presumption of Shiga Toxin-Mediated Damage of Developing Erythrocytes in EHEC-Associated Hemolytic Uremic Syndrome

The global emergence of clinical diseases caused by enterohemorrhagic Escherichia coli (EHEC) is an issue of great concern. EHEC release Shiga toxins (Stxs) as their key virulence factors, and investigations on the cell-damaging mechanisms toward target cells are inevitable for the development of novel mitigation strategies. Stx-mediated hemolytic uremic syndrome (HUS), characterized by the triad of microangiopathic hemolytic anemia, thrombocytopenia, and acute renal injury, is the most severe outcome of an EHEC infection. Hemolytic anemia during HUS is defined as the loss of erythrocytes by mechanical disruption when passing through narrowed microvessels. The formation of thrombi in the microvasculature is considered an indirect effect of Stx-mediated injury mainly of the renal microvascular endothelial cells, resulting in obstructions of vessels. In this review, we summarize and discuss recent data providing evidence that HUS-associated hemolytic anemia may arise not only from intravascular rupture of erythrocytes, but also from the extravascular impairment of erythropoiesis, the development of red blood cells in the bone marrow, via direct Stx-mediated damage of maturing erythrocytes, leading to “non-hemolytic” anemia.

Preparation and Evaluation of Resveratrol-Loaded Composite Nanoparticles Using a Supercritical Fluid Technology for Enhanced Oral and Skin Delivery

We created composite nanoparticles containing hydrophilic additives using a supercritical antisolvent (SAS) process to increase the solubility and dissolution properties of trans-resveratrol for application in oral and skin delivery. Physicochemical properties of trans-resveratrol-loaded composite nanoparticles were characterized. In addition, an in vitro dissolution-permeation study, an in vivo pharmacokinetic study in rats, and an ex vivo skin permeation study in rats were performed. The mean particle size of all the composite nanoparticles produced was less than 300 nm. Compared to micronized trans-resveratrol, the trans-resveratrol/hydroxylpropylmethyl cellulose (HPMC)/poloxamer 407 (1:4:1) nanoparticles with the highest flux (0.792 μg/min/cm²) exhibited rapid absorption and showed significantly higher exposure 4 h after oral administration. Good correlations were observed between in vitro flux and in vivo pharmacokinetic data. The increased solubility and flux of trans-resveratrol generated by the HPMC/surfactant nanoparticles increased the driving force on the gastrointestinal epithelial membrane and rat skin, resulting in enhanced oral and skin delivery of trans-resveratrol. HPMC/surfactant nanoparticles produced by an SAS process are, thus, a promising formulation method for trans-resveratrol for healthcare products (owing to their enhanced absorption via oral administration) and for skin application with cosmetic products.