Trans-resveratrol-loaded nonionic lamellar liquid-crystalline systems: structural, rheological, mechanical, textural, and bioadhesive characterization and evaluation of in vivo anti-inflammatory activity

Highly Biocompatible Lamellar Liquid Crystals Based on Hempseed or Flaxseed Oil with Incorporated Betamethasone Dipropionate: A Bioinspired Multi-Target Dermal Drug Delivery System for Atopic Dermatitis Treatment

Purpose

Atopic dermatitis (AD) is the most common chronic inflammatory skin disease that severely impairs patient's life quality and represents significant therapeutic challenge due to its pathophysiology arising from skin barrier dysfunction. Topical corticosteroids, the mainstay treatment for mild to moderate AD, are usually formulated into conventional dosage forms that are impeded by low drug permeation, resulting in high doses with consequent adverse effects, and also lack properties that would strengthen the skin barrier. Herein, we aimed to develop biomimetic lamellar lyotropic liquid crystals (LLCs), offering a novel alternative to conventional AD treatment.

Methods

In screening studies, pseudoternary phase diagrams alongside polarized light microscopy (PLM) and viscosity measurements were utilized. Next, the selected LCCs underwent comprehensive characterization via PLM, small-angle X-ray scattering, differential scanning calorimetry, and rheological analysis. Lastly, their performance was evaluated and compared with the commercially available reference medicine in chemical stability study, in vitro permeation testing, in vitro safety assessment using cell proliferation assay, inverted light microscopy, and Raman mapping of keratinocytes, besides gap closure assay performed by live-cell imaging.

Results

Formulation (L/T)Ho30, containing the highest amount of lecithin/Tween 80 mixture (21%) and hempseed oil (28%), demonstrated lamellar microstructure with high skin hydration potential and favourable rheological features for skin administration. Moreover, in comparison with the reference medicine, it stood out by providing suitable chemical BD (betamethasone dipropionate) stability, improved 3-fold BD permeation, and excellent biocompatibility with over 85% cell proliferation at all tested concentrations, ensuring keratinocytes' integrity, as well as promoting skin healing with gap closure observed after 36 hours.

Conclusion

Unique multi-target drug delivery strategy depicted in newly developed bioinspired lamellar LCCs structurally resembling stratum corneum intercellular lipids, with incorporated BD drug, and composed of multifunctional components that synergistically strengthen skin barrier, was presented here and shows a promising approach for improved AD treatment.

Mesogenic Architectures for Advanced Drug Delivery: Interrogating Lyotropic and Thermotropic Liquid Crystals

The possibility of precisely regulating and targeting drug release with mesophase or Liquid crystal drug delivery systems has drawn much attention recently. This review offers a thorough investigation of liquid crystal drug delivery systems with an emphasis on their mesogenic architecture. It describes the various liquid crystal forms such as thermotropic and lyotropic liquid crystals and their applicability in advanced drug delivery. Liquid crystals are used as excellent carriers due to their distinctive characteristics, such as stimuli-responsive drug delivery and sustained release patterns. Comprehending the materials that form mesophase provides insight into their distinct physiochemical characteristics and their use in drug delivery. This review highlights the important role lyotropic and thermotropic liquid crystals play in drug delivery, underscoring their considerable potential. The transition of thermotropic liquid crystals from their conventional technological applications to drug delivery has been studied. Nonetheless, a few challenges still need to be addressed, including formulation strategy refinement, regulating release rates, maximising the loading of hydrophilic drugs, and storage stability. In the pharmaceutical field, addressing these issues will open the door to a revolutionary paradigm that will revolutionise therapeutic outcomes and improve patient care.

Advances in Engineered Nanoparticles for the Treatment of Ischemic Stroke by Enhancing Angiogenesis

Angiogenesis, or the formation of new blood vessels, is a natural defensive mechanism that aids in the restoration of oxygen and nutrition delivery to injured brain tissue after an ischemic stroke. Angiogenesis, by increasing vessel development, may maintain brain perfusion, enabling neuronal survival, brain plasticity, and neurologic recovery. Induction of angiogenesis and the formation of new vessels aid in neurorepair processes such as neurogenesis and synaptogenesis. Advanced nano drug delivery systems hold promise for treatment stroke by facilitating efficient transportation across the the blood-brain barrier and maintaining optimal drug concentrations. Nanoparticle has recently been shown to greatly boost angiogenesis and decrease vascular permeability, as well as improve neuroplasticity and neurological recovery after ischemic stroke. We describe current breakthroughs in the development of nanoparticle-based treatments for better angiogenesis therapy for ischemic stroke employing polymeric nanoparticles, liposomes, inorganic nanoparticles, and biomimetic nanoparticles in this study. We outline new nanoparticles in detail, review the hurdles and strategies for conveying nanoparticle to lesions, and demonstrate the most recent advances in nanoparticle in angiogenesis for stroke treatment.

Construction and Properties of O/W Liquid Crystal Nanoemulsion

Liquid crystal emulsion is a new type of emulsion, in which the emulsifier molecules are located at the oil/water (O/W) interface and form a long-range ordered and short-range disordered lamellar liquid crystal. The lamellar liquid crystal formed by the emulsifier is similar to the skin stratum corneum lipid structure, which enables it to have a broad application prospect in the fields of cosmetics, pharmaceuticals, etc. In this work, a liquid crystal nanoemulsion was obtained by passing a liquid crystal emulsion stabilized by hydrogenated lecithin and phytosterol combination through a microfluidizer. The microstructure of the prepared liquid crystal nanoemulsion was investigated experimentally by dynamic light scattering, transmission electron microscopy, and small-angle X-ray scattering. The results have shown that the nanoemulsion inherited the liquid crystal emulsion property, namely, the long-range ordered and short-range disordered lamellar structure still existed at the oil/water interface even though they underwent extrusion, friction, and acceleration. At the same time, the underlying mechanisms of the existence of lamellar liquid crystal between the oil phase and the water phase for the nanoemulsion were explored theoretically by molecular dynamics simulations. The simulation results elucidated that the hydrogenated lecithin and phytosterol combination improved the flexibility of the bilayer structure composed of emulsifiers. The bilayers were the basic structure units of lamellar liquid crystals, and thus, the improved flexibility of bilayers provided insurance for the existence of lamellar liquid crystals with larger curvature around the oil droplets. In addition, the applicable properties of liquid crystal nanoemulsion were studied, and the results have shown that the liquid crystal nanoemulsion presented better slow-release and moisturizing properties than traditional nanoemulsions due to the existence of multilayers between oil and water phases. This work not only provides necessary information for the development and effective application of liquid crystal emulsions but also is helpful for in-depth understanding the inner properties of lamellar liquid crystal at molecular level.

Amyloid Fibrils Enhance the Topical Bio-Adhesivity of Liquid Crystalline Mesophase-Based Drug Formulations

Despite their distinctive secondary structure based on cross β-strands, amyloid fibrils (AF) are stable fibrous protein aggregates with features similar to collagen, one of the main components of the extracellular matrix, and thus constitute a potential scaffold for enhancing cell adhesion for topical applications. Here, the contribution of AF to skin bio-adhesivity aiming toward topical treatments is investigated. Liquid crystalline mesophase (LCM) based on phytantriol is formulated, with the aqueous phase containing either water or a solution of 4 wt% amyloid fibrils. Then resveratrol is added as a model anti-inflammatory molecule. The developed LCM presents a double gyroid Ia3d mesophase. The incorporation of AF into the LCM increases its bio-adhesive properties. In vitro release and ex vivo permeation and retention confirm the controlled release property of the system, and that resveratrol is retained in epidermis and dermis, but is also permeated through the skin. All formulations are biocompatible with L929 cells. The in vivo assay confirms that systems with AF lead to a higher anti-inflammatory effect of resveratrol. These results confirm the hypothesis that the incorporation of AF in the LCM increases the bio-adhesiveness and efficiency of the system for topical treatment, and consequently, the therapeutical action of the encapsulated drug.

Lipidic lyotropic liquid crystals: Insights on biomedical applications

Liquid crystals (LCs) possess unique physicochemical properties, translatable into a wide range of applications. To date, lipidic lyotropic LCs (LLCs) have been extensively explored in drug delivery and imaging owing to the capability to encapsulate and release payloads with different characteristics. The current landscape of lipidic LLCs in biomedical applications is provided in this review. Initially, the main properties, types, methods of fabrication and applications of LCs are showcased. Then, a comprehensive discussion of the main biomedical applications of lipidic LLCs accordingly to the application (drug and biomacromolecule delivery, tissue engineering and molecular imaging) and route of administration is examined. Further discussion of the main limitations and perspectives of lipidic LLCs in biomedical applications are also provided. STATEMENT OF SIGNIFICANCE: Liquid crystals (LCs) are those systems between a solid and liquid state that possess unique morphological and physicochemical properties, translatable into a wide range of biomedical applications. A short description of the properties of LCs, their types and manufacturing procedures is given to serve as a background to the topic. Then, the latest and most innovative research in the field of biomedicine is examined, specifically the areas of drug and biomacromolecule delivery, tissue engineering and molecular imaging. Finally, prospects of LCs in biomedicine are discussed to show future trends and perspectives that might be utilized. This article is an ampliation, improvement and actualization of our previous short forum article "Bringing lipidic lyotropic liquid crystal technology into biomedicine" published in TIPS.

Design and Characterization of Lipid-Surfactant-Based Systems for Enhancing Topical Anti-Inflammatory Activity of Ursolic Acid

Skin inflammation is a symptom of many skin diseases, such as eczema, psoriasis, and dermatitis, which cause rashes, redness, heat, or blistering. The use of natural products with anti-inflammatory properties has gained importance in treating these symptoms. Ursolic acid (UA), a promising natural compound that is used to treat skin diseases, exhibits low aqueous solubility, resulting in poor absorption and low bioavailability. Designing topical formulations focuses on providing adequate delivery via application to the skin surface. The aim of this study was to formulate and characterize lipid-surfactant-based systems for the delivery of UA. Microemulsions and liquid crystalline systems (LCs) were characterized by polarized light microscopy (PLM), rheology techniques, and textural and bioadhesive assays. PLM supported the self-assembly of these systems and elucidated their formation. Rheologic examination revealed pseudoplastic and thixotropic behavior appropriate, and assays confirmed the ability of these formulations to adhere to the skin. In vivo studies were performed, and inflammation induced by croton oil was assessed for response to microemulsions and LCs. UA anti-inflammatory activities of ~60% and 50% were demonstrated by two microemulsions and 40% and 35% by two LCs, respectively. These data support the continued development of colloidal systems to deliver UA to ameliorate skin inflammation.

Enhancement of immune responses using ovalbumin-conjugated Eucommia ulmoides leaf polysaccharides encapsulated in a cubic liquid-crystalline phase delivery system

BACKGROUND

To improve the adjuvant activity of polysaccharides from Eucommia ulmoides leaves (PsEUL) in inducing an effective immune response against ovalbumin (OVA), PsEUL were conjugated to OVA using the N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride (EDC) method. The synthesized PsEUL-OVA was encapsulated using phytantriol and F127 to produce PsEUL-OVA cubosomes (Cubs), a novel delivery system. The physicochemical properties and immune modulation effects of this novel delivery system were explored.

RESULTS

In vitro, PsEUL-OVA/Cubs carrying large amounts of OVA were rapidly phagocytized by macrophages and upregulated macrophage proliferation, thereby stimulating cytokine production (interleukin (IL)-6 and IL-4). In vivo, PsEUL-OVA/Cubs increased the titer of OVA-specific antibodies (immunoglobulin (Ig)G, IgG2b, IgG2a and IgG1) and cytokine levels (IL-2, IL-6, IL-4 and interferon-γ). In addition, the cubosomes promoted the differentiation of CD8⁺ and CD4⁺ T cells in the spleen and the maturation of dendritic cells (DCs). These results indicated that PsEUL-OVA/Cubs stimulated both cellular and humoral immune responses by enhancing the phagocytic activity of DCs and macrophages and increasing the antigen presentation efficiency.

CONCLUSION

Collectively, the findings demonstrate that PsEUL-antigen/Cubs can be a useful delivery vehicle with immune response-promoting effects. Therefore, this study lays the foundation for the development of novel adjuvant-antigen delivery systems with potential applications in vaccine design. © 2022 Society of Chemical Industry.

Exploiting Polymeric Films as a Multipurpose Drug Delivery System: a Review

Polymeric films are drug delivery systems that maintain contact with the delivery tissue and sustain a controlled release of therapeutic molecules. These systems allow a longer time of drug contact with the target site in the case of topical treatments and allow the controlled administration of drugs. They can be manufactured by various methods such as solvent casting, hot melt extrusion, electrospinning, and 3D bioprinting. Furthermore, they can employ various polymers, for example PVP, PVA, cellulose derivatives, chitosan, gelling gum, pectin, and alginate. Its versatility is also applicable to different routes of administration, as it can be administered to the skin, oral mucosa, vaginal canal, and eyeballs. All these factors allow numerous combinations to obtain a better treatment. This review focuses on exploring some possible ways to develop them and some particularities and advantages/disadvantages in each case. It also aims to show the versatility of these systems and the advantages and disadvantages in each case, as they bring the opportunity to develop different medicines to facilitate therapies for the most diverse purposes .

Lyotropic liquid crystals for parenteral drug delivery

The necessity for long-term treatments of chronic diseases has encouraged the development of novel long-acting parenteral formulations intending to improve drug pharmacokinetics and therapeutic efficacy. Lately, one of the novel approaches has been developed based on lipid-based liquid crystals. The lyotropic liquid crystal (LLC) systems consist of amphiphilic molecules and are formed in presence of solvents with the most common types being cubic, hexagonal and lamellar mesophases. LC injectables have been recently developed based on polar lipids that spontaneously form liquid crystal nanoparticles in aqueous tissue environments to create the in-situ long-acting sustained-release depot to provide treatment efficacy over extended periods. In this manuscript, we have consolidated and summarized the various type of liquid crystals, recent formulation advancements, analytical evaluation, and therapeutic application of lyotropic liquid crystals in the field of parenteral sustained release drug delivery.

Rethinking Breast Cancer Chemoprevention: Technological Advantages and Enhanced Performance of a Nanoethosomal-Based Hydrogel for Topical Administration of Fenretinide

Herein, we developed an ethosomal hydrogel based on three types of ethosomes: simple, mixed (surfactant-based micelles and lipid vesicles) or binary (comprising two type of alcohols). Ethanol injection was employed for vesicles preparation, and sodium alginate, as gelling agent. We purposed the local-transdermal administration of the off-the-shelf retinoid fenretinide (FENR) for chemoprevention of breast cancer. Rheograms and flow index values for alginate dispersion (without ethosomes) and hydrogels containing simple, mixed or binary ethosomes suggested pseudoplastic behavior. An increase in the apparent viscosity was observed upon ethosome incorporation. The ethosomal hydrogel displayed increased bioadhesion compared to the alginate dispersion, suggesting that the lipid vesicles contribute to the gelling and bioadhesion processes. In the Hen's Egg Test-Chorioallantoic Membrane model, few spots of lysis and hemorrhage were observed for formulations containing simple (score of 2) and mixed vesicles (score 4), but not for the hydrogel based on the binary system, indicating its lower irritation potential. The binary ethosomal hydrogel provided a slower FENR in vitro release and delivered 2.6-fold less drug into viable skin layers compared to the ethosome dispersion, supporting the ability of the gel matrix to slow down drug release. The ethosomal hydrogel decreased by ~ five-fold the IC₅₀ values of FENR in MCF-7 cells. In conclusion, binary ethosomal gels presented technological advantages, provided sustained drug release and skin penetration, and did not preclude drug cytotoxic effects, supporting their potential applicability as topical chemopreventive systems.

Novel transdermal bioadhesive surfactant-based system for release and solubility improvement of antimalarial drugs artemether-lumefantrine

Artemether (ART) and lumefantrine (LUM) are the gold standard antimalarial drugs used for the treatment of malaria in children and pregnant women. Typically, ART and LUM are delivered orally in the form of a combined tablet, however, the appropriateness of this route of administration for these drugs is questionable due to the poor absorption and therefore bioavailability observed unless administered alongside lipid-rich foods. Transdermal drug delivery in the form of a patch-type system has been identified as a viable alternative to the conventional tablet-based therapy. A novel, surfactant-based ART-LUM formulation (S3AL), developed for transdermal delivery, may eliminate the shortcomings associated with oral delivery; namely poor drug absorption which is caused by the inherently low solubility of ART and LUM. Moreover, by successfully delivering these antimalarials transdermally, first-pass metabolism will be avoided leading to enhanced drug bioavailability in both cases. The S3AL formulation contained ART and LUM at equal concentrations (2.5% w/w of each) as well as Procetyl® AWS (30% w/w), oleic acid (10% w/w), 1-methyl-2-pyrrolidone (10% w/w), and water (45% w/w). The addition of LUM to the formulation changed the system from a striae structure to a dark field structure when visualized by a polarized light microscope. Additionally, this system possessed higher viscosity and superior skin bioadhesion, as evidenced by mechanical characterization, when compared to a similar formulation containing ART alone. S3AL was also proven to be biocompatible to human keratinocyte cells. Finally,in vitrostudies demonstrated the propensity of S3AL for successful delivery via the transdermal route, with 2279 ± 295 µg cm^-2of ART and 94 ± 13 µg cm^-2of LUM having permeated across dermatomed porcine skin after 24 h, highlighting its potential as a new candidate for the treatment of malaria.

Ocular lamellar crystalline gels for sustained release and enhanced permeation of resveratrol against corneal neovascularization

Corneal neovascularization (CNV) is the major cause of blindness after eye injury; however, only several drugs can be applied and the invasive administration ways (i.e., intravitreal injection and subconjunctival injection) are used. Resveratrol is a highly effective anti-VEGF agent against CNV. However, its applications are limited due to its strong hydrophobicity and instability. Here, we developed a resveratrol-loaded ocular lamellar crystalline gel (ROLG) for high inhibition of CNV. ROLGs were composed of resveratrol, glyceryl monooleate (GMO), ethanol, and water, and their lamellar crystalline structures were identified by polarizing light microscopy and small-angle X-ray scattering. High drug loading (4.4 mg/g) of ROLGs was achieved due to the hydrogen bonding between GMO and resveratrol. Resveratrol showed sustained release with 67% accumulative release in 7 h, which was attributed to the slow erosion of gels. Resveratrol in ROLGs had a high corneal permeation 3 times higher than resveratrol in hyaluronic acid suspensions (RHSs). ROLGs were administered to rats only once a day because of their strong retention on the cornea surface. ROLGs were safe due to the very little contact of ethanol in ROLGs to the cornea. CNV post-rat corneal alkaline injury was highly inhibited by ROLGs, resulting from the attenuation of corneal VEGF expression and then corneal healing was improved. The ROLG was a promising ocular medicine for the prevention of CNV.

p-Coumaric acid loaded into liquid crystalline systems as a novel strategy to the treatment of vulvovaginal candidiasis

Vulvovaginal candidiasis (VVC) is an extremely common type of vaginal infection, which is mainly caused by Candida albicans. However, non-albicans Candida species are frequently more resistant to conventional antifungal agents and can represent up to 30% of cases. Due to side effects and increasing antifungal resistance presented by standard therapies, phenolic compounds, such as p-coumaric acid (p-CA), have been studied as molecules from natural sources with potential antifungal activity. p-CA is a poorly water-soluble compound, thus loading it into liquid crystals (LCs) may increase its solubility and effectiveness on the vaginal mucosa. Thereby, here we propose the development of mucoadhesive liquid crystalline systems with controlled release of p-CA, for the local treatment of VVC. Developed LCs consisted of fixed oily and aqueous phases (oleic acid and cholesterol (5:1) and poloxamer dispersion 16%, respectively), changing only the surfactant phase components (triethanolamine oleate (TEA-Oleate) or triethanolamine (TEA), the latter producing TEA-Oleate molecules when mixed with oleic acid). Systems were also diluted in artificial vaginal mucus (1:1 ratio) to mimic the vaginal environment and verify possible structural changes on formulations upon exposure to the mucosa. From the characterization assays, p-CA loaded TEA-Oleate systems presented mucoadhesive profile, liquid crystalline mesophases, well-organized structures and pseudoplastic behaviour, which are desirable parameters for topical formulations. Moreover, they were able to control the release of p-CA throughout the 12 h assay, as well as decrease its permeation into the vaginal mucosa. p-CA showed antifungal activity in vitro against reference strains of C. albicans (SC5314), C. glabrata (ATCC 2001) and C. krusei (ATCC 6258), and exhibited higher eradication of mature biofilms than amphotericin B and fluconazole. In vivo experiments demonstrated that the formulations reduced the presence of filamentous forms in the vaginal lavages and provided an improvement in swelling and redness present in the mice vaginal regions. Altogether, here we demonstrated the potential and feasibility of using p-CA loaded liquid crystalline systems as a mucoadhesive drug delivery system for topical treatment of VVC.

Innovative Mucoadhesive Precursor of Liquid Crystalline System Loading Anti-Gellatinolytic Peptide for Topical Treatment of Oral Cancer

Current researches report an actual benefit of a treatment for oral cancer via inhibition of proteolytic matrix metallopro-teinases (MPP) with a peptide drug, called CTT1. However, peptides present poor oral bioavailability. Topical administration on oral mucosa avoids its passage through the gastrointestinal tract and the first-pass liver metabolism, but the barrier function of the oral mucosa can impair the permeation and retention of CTT1. The objective of this study is to incorporate CTT1 into a mucoadhesive precursor of liquid crystalline system (PLCS) as an interesting strategy for the topical treatment of oral cancer. PLCS consisting of oleic acid, ethoxylated 20 and propoxylated cetyl alcohol 5, polyethyleneimine (P)-associated chitosan (C) dispersion and CTT1 (FPC-CTT1) was developed and characterized by polarized light microscopy (PLM) and small-angle X-ray scattering (SAXS). In vitro permeation and retention across esophageal mucosa, In vitro cytotoxicity towards tongue squamous cell carcinoma cells, and in vivo evaluation of vascular changes using the chick embryo chorioallantoic membrane (CAM) model were performed. PLM and SAXS showed that FPC-CTT1acted as PLCS, because it formed a lamellar liquid crystalline system after the addition of artificial saliva. FPC-CTT1increased approximately 2-fold the flux of permeation and 3-fold the retention of CTT1 on the porcine esophageal mucosa. CTT1 does not affect cell viability. CAM tests showed that FPC preserved the blood vessels and it can be a safe formulation. These findings encourage the use of the FPC-CTT1 for topical treatment of oral cancer.

Polyglycerol Ester-Based Low Energy Nanoemulsions with Red Raspberry Seed Oil and Fruit Extracts: Formulation Development toward Effective In Vitro/In Vivo Bioperformance

This study focuses on the development of biocompatible oil-in-water (O/W) nanoemulsions based on polyglycerol esters, as promising carriers for natural actives: red raspberry seed oil—RO and hydro-glycolic fruit extracts from red raspberry—RE and French oak—FE. Nanoemulsions were obtained via phase inversion composition (PIC) method at room temperature by dilution of microemulsion phase, confirmed by visual appearance, percentage of transmittance, microscopic, rheological and differential scanning calorimetry (DSC) investigations. The results have shown that the basic RO-loaded formulation could be further enriched with hydro-glycolic fruit extracts from red raspberry or French oak, while keeping a semi-transparent appearance due to the fine droplet size (Z-ave: 50 to 70 nm, PDI value ≤ 0.1). The highest antioxidant activity (~92% inhibition of the DPPH radical) was achieved in the formulation containing both lipophilic (RO) and hydrophilic antioxidants (FE), due to their synergistic effect. The nanoemulsion carrier significantly increased the selective cytotoxic effect of RO towards malignant melanoma (Fem-X) cells, compared to normal human keratinocytes (HaCaT). In vivo study on human volunteers showed satisfactory safety profiles and significant improvement in skin hydration during 2 h after application for all nanoemulsions. Therefore, polyglycerol ester-based nanoemulsions can be promoted as effective carriers for red raspberry seed oil and/or hydro-glycolic fruit extracts in topical formulations intended for skin protection and hydration.

Resveratrol isoforms and conjugates: A review from biosynthesis in plants to elimination from the human body

The natural isomers of resveratrol, cis- and trans-resveratrol, are natural phenolic substances synthetized via the shikimate pathway and found in many sources, including grapes, peanuts, blackberries, pistachios, cacao, cranberries, and jackfruits. They have functional and pharmacological properties such as anticarcinogenic, antidiabetic, anti-inflammatory, and cardioprotective activities. The aim of this article is to review the data published on resveratrol and its isomers, and their biosynthesis in plants, food sources, health and toxic effects, and the excretion of their metabolites. Due to its contribution to the promotion of human health, it is convenient to gather more knowledge about its functional properties, food sources, and the interactions with the human body during the processes of eating, digestion, absorption, biotransformation, and excretion, to combine this information to improve the understanding of these substances.

Nanosystems against candidiasis: a review of studies performed over the last two decades

The crescent number of cases of candidiasis and the increase in the number of infections developed by non-albicans species and by multi-resistant strains has taken the attention of the scientific community, which has been searching for new therapeutic alternatives. Among the alternatives found the use of nanosystems for delivery of drugs already commercialized and new biomolecules have grown, in order to increase stability, solubility, optimize efficiency and reduce adverse effects. In view of the growing number of studies involving technological alternatives for the treatment of candidiasis, the present review came with the intention of gathering studies from the last two decades that used nanotechnology for the treatment of candidiasis, as well as analysing them critically and pointing out the future perspectives for their application with this purpose. Different studies were considered for the development of this review, addressing nanosystems such as metallic nanoparticles, mesoporous silica nanoparticles, polymeric nanoparticles, liposomes, nanoemulsion, microemulsion, solid lipid nanoparticle, nanostructured lipid carrier, lipidic nanocapsules and liquid crystals; and different clinical presentations of candidiasis. As a general overview, nanotechnology has proven to be an important ally for the treatment against the diversity of candidiasis found in the clinic, whether in increasing the effectiveness of commercialized drugs and reducing their adverse effects, as well as allowing exploring more effectively properties therapeutics of new biomolecules.

Reperfusion combined with intraarterial administration of resveratrol-loaded nanoparticles improved cerebral ischemia-reperfusion injury in rats

Endovascular thrombectomy (EVT) has been recommended as the first line therapy for large artery occlusion (LAO) stroke. However, abrupt recovery of blood flow induces oxidative stress which breaks down the blood-brain barrier (BBB), activates apoptosis and inhibits neurogenesis. Supplement of exogenous antioxidants to relieve the injuries related to oxidative stress is a rational treatment combined to EVT for acute LAO therapy. Resveratrol (RES), an antioxidant, was encapsulated into polymeric nanoparticles (RES-NPs). In transient middle cerebral artery occlusion (tMCAO) rats, intraarterial administration of RES-NPs demonstrated significant protection against cerebral ischemia/reperfusion (I/R) injuries. RES-NPs attenuated the oxidative stress induced by I/R, prevented brain edema, protected neurons from undergoing apoptosis, and contributed to neurogenesis through enhanced expression of brain-derived neurotrophic factor (BDNF). These results suggested that intra-arterial infusion of RES-NPs in conjunction with EVT could be a potential strategy for the LAO stroke therapy.

Low-energy nanoemulsions as carriers for red raspberry seed oil: Formulation approach based on Raman spectroscopy and textural analysis, physicochemical properties, stability and in vitro antioxidant/ biological activity

Considering a growing demand for medicinal/cosmetic products with natural actives, this study focuses on the low-energy nanoemulsions (LE-NEs) prepared via the Phase inversion composition (PIC) method at room temperature as potential carriers for natural oil. Four different red raspberry seed oils (ROs) were tested, as follows: cold-pressed vs. CO2-extracted, organic vs. non-organic, refined vs. unrefined. The oil phase was optimized with Tocopheryl acetate and Isostearyl isostearate, while water phase was adjusted with either glycerol or an antioxidant hydro-glycolic extract. This study has used a combined approach to formulation development, employing both conventional methods (pseudo-ternary phase diagram - PTPD, electrical conductivity, particle size measurements, microscopical analysis, and rheological measurements) and the methods novel to this area, such as textural analysis and Raman spectroscopy. Raman spectroscopy has detected fine differences in chemical composition among ROs, and it detected the interactions within nanoemulsions. It was shown that the cold-pressed, unrefined, organic grade oil (RO2) with 6.62% saturated fatty acids and 92.25% unsaturated fatty acids, was optimal for the LE-NEs. Textural analysis confirmed the existence of cubic gel-like phase as a crucial step in the formation of stable RO2-loaded LE-NEs, with droplets in the narrow nano-range (125 to 135 nm; PDI ≤ 0.1). The DPPH test in methanol and ABTS in aqueous medium have revealed a synergistic free radical scavenging effect between lipophilic and hydrophilic antioxidants in LE-NEs. The nanoemulsion carrier has improved the biological effect of raw materials on HeLa cervical adenocarcinoma cells, while exhibiting good safety profile, as confirmed on MRC-5 normal human lung fibroblasts. Overall, this study has shown that low-energy nanoemulsions present very promising carriers for topical delivery of natural bioactives. Raman spectroscopy and textural analysis have proven to be a useful addition to the arsenal of methods used in the formulation and characterization of nanoemulsion systems.

Adjuvant activities of CTAB-modified Polygonatum sibiricum polysaccharide cubosomes on immune responses to ovalbumin in mice

Recently, the cubosomes have been widely studied as drug carriers. It has been described that cubosomes could further stimulate the immune response after carrying the immune enhancer. Polygonatum sibiricum polysaccharide (PSP), one of the most important biologically active ingredients of Polygonatum sibiricum, has been reported as an immunostimulant to improve immune responses. This study was aimed to observe the immunomodulation effects of ovalbumin (OVA) absorbed cetyltrimethylammonium bromide-modified Polygonatum sibiricum polysaccharide cubosomes (CTAB-modified PSP-Cubs/OVA). Firstly, the antigen uptake of CTAB-modified PSP-Cubs/OVA by macrophages was determined in vitro. After that, mice were immunized with CTAB-modified PSP-Cubs/OVA. The activation of dendritic cells in lymph nodes, activation of lymphocyte, ratios of CD4⁺ to CD8⁺, the concentrations of OVA-specific IgG in serum and the cytokines concentrations were analyzed. As the results showed, CTAB-modified PSP-Cubs/OVA could promote the production of OVA-specific IgG in serum. The ratio of CD4⁺ to CD8⁺ in CTAB-modified PSP-Cubs/OVA group was significantly increased compared with other groups. CTAB-modified PSP-Cubs/OVA could significantly activate dendritic cells and promote lymphocyte proliferation. The results indicated that CTAB-modified PSP-Cubs/OVA could promote the secretion of related cytokines and the proliferation of lymphocytes, stimulate the cellular immune response and increase the level of humoral immunity. Above all, CTAB-modified PSP-Cubs had good adjuvant activity.

Characteristics, Biological Properties and Analytical Methods of Trans-Resveratrol: A Review

Trans-resveratrol (TR) is the biological active isomer of resveratrol and the one responsible for therapeutic effects; both molecules are non-flavonoid phenolics of the stilbenes class found mainly in berries and red grapes. TR biological properties lie in modulation of various enzymatic classes. It is a promising candidate to novel drugs due its applications in pharmaceutical and cosmetic industries, such as anticarcinogenic, antidiabetic, antiacne, antioxidant, anti-inflammatory, neuroprotective, and photoprotector agent. It has effects on bone metabolism, gastrointestinal tract, eyes, kidneys, and in obesity treatment as well. Nevertheless, its low solubility in water and other polar solvents may be a hindrance to its therapeutic effects. Various strategies been developed to overcome these issues, such as the drug delivery systems. The present study performed a research about methods to identify TR and RESV in several samples (raw materials, wines, food supplements, drug delivery systems, and blood plasma). Most of the studies tend to analyze TR and RESV by high performance liquid chromatography (HPLC) coupled with different detectors, even so, there are reports of the use of capillary electrophoresis, electron spin resonance, gas chromatography, near-infrared luminescence, UV-Vis spectrophotometer, and vibrational spectrophotometry, for this purpose. Thus, the review evaluates the biological activity of TR and demonstrates the currently used analytical methods for its quantification in different matrices.

Pectin and Mucin Enhance the Bioadhesion of Drug Loaded Nanofibrillated Cellulose Films

PURPOSE

Bioadhesion is an important property of biological membranes, that can be utilized in pharmaceutical and biomedical applications. In this study, we have fabricated mucoadhesive drug releasing films with bio-based, non-toxic and biodegradable polymers that do not require chemical modifications.

METHODS

Nanofibrillar cellulose and anionic type nanofibrillar cellulose were used as film forming materials with known mucoadhesive components mucin, pectin and chitosan as functional bioadhesion enhancers. Different polymer combinations were investigated to study the adhesiveness, solid state characteristics, film morphology, swelling, mechanical properties, drug release with the model compound metronidazole and in vitro cytotoxicity using TR146 cells to model buccal epithelium.

RESULTS

SEM revealed lamellar structures within the films, which had a thickness ranging 40-240 μm depending on the film polymer composition. All bioadhesive components were non-toxic and showed high adhesiveness. Rapid drug release was observed, as 60-80% of the total amount of metronidazole was released in 30 min depending on the film formulation.

CONCLUSIONS

The liquid molding used was a straightforward and simple method to produce drug releasing highly mucoadhesive films, which could be utilized in treating local oral diseases, such as periodontitis. All materials used were natural biodegradable polymers from renewable sources, which are generally regarded as safe.

Polyethyleneimine and Chitosan Polymer-Based Mucoadhesive Liquid Crystalline Systems Intended for Buccal Drug Delivery

The buccal mucosa is accessible, shows rapid repair, has an excellent blood supply, and shows the absence of the first-pass effect, which makes it a very attractive drug delivery route. However, this route has limitations, mainly due to the continuous secretion of saliva (0.5 to 2 L/day), which may lead to dilution, possible ingestion, and unintentional removal of the active drug. Nanotechnology-based drug delivery systems, such as liquid crystalline systems (LCSs), can increase drug permeation through the mucosa and thereby improve drug delivery. This study aimed at developing and characterizing the mechanical, rheological, and mucoadhesive properties of four liquid crystalline precursor systems (LCPSs) composed of four different aqueous phases (i) water (FW), (ii) chitosan (FC), (iii) polyethyleneimine (FP), or (iv) both polymers (FPC); oleic acid was used as the oil phase, and ethoxylated and propoxylated cetyl alcohol was used as the surfactant. Polarized light microscopy and small-angle X-ray scattering indicated that all LCPSs formed liquid crystalline states after incorporation of saliva. Rheological, texture, and mucoadhesive assays showed that FPC had the most suitable characteristics for buccal application. In vitro release study showed that FPC could act as a controlled drug delivery system. Finally, based on in vitro cytotoxicity data, FPC is a safe buccal drug delivery system for the treatment of several buccal diseases.