This review provides a comprehensive and updated overview of the state of the art related to the biomedical applications of nanoparticles coated with chitosan. Discussions were based on selected ...literature in the field. Here, we discussed nanoparticles constituted by polymer, lipid and metal materials, which have been coated with chitosan. In addition, the methodological aspects of the coating process, which is performed by the addition of a chitosan solution into previously prepared nanoparticles or during nanoparticle formation, was reviewed, as well as the techniques employed to confirm an efficient coating process, such as determinations of particle size and zeta potential. Special attention is given to physicochemical and biological advantages brought by the chitosan-coating, such as increase in physicochemical stability, controlled release, improvement of tissue/cells interaction, and increase in the bioavailability of drugs (or active substances) and drug efficacy. We also pointed out safety concerns regarding chitosan-coated nanoparticles based on the results presented so far in the literature.
•Chitosan used as a coating has numerous advantages•Chitosan coated nanoparticles can be prepared by different techniques•Different characterization techniques can be used to prove the coating.
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For an improved understanding of the relevant particle features for cutaneous use, we studied the effect of the surface charge of acrylic nanocapsules (around 150nm) and the effect of ...a chitosan gel vehicle on the particle penetration into normal and stripped human skin ex vivo as well as local tolerability (cytotoxicity and irritancy). Rhodamin-tagged nanocapsules penetrated and remained in the stratum corneum. Penetration of cationic nanocapsules exceeded the penetration of anionic nanocapsules. When applied on stripped skin, however, the fluorescence was also recorded in the viable epidermis and dermis. Cationic surface charge and embedding the particles into chitosan gel favored access to deeper skin. Keratinocytes took up the nanocapsules rapidly. Cytotoxicity (viability<80%), following exposure for ≥24h, appears to be due to the surfactant polysorbate 80, used for nanocapsuleś stabilization. Uptake by fibroblasts was low and no cytotoxicity was observed. No irritant reactions were detected in the HET-CAM test. In conclusion, the surface charge and chitosan vehicle, as well as the skin barrier integrity, influence the skin penetration of acrylic nanocapsules. Particle localization in the intact stratum corneum of normal skin and good tolerability make the nanocapsules candidates for topical use on the skin, provided that the polymer wall allows the release of the active encapsulated substance.
Synopsis
Sensory analysis has become a valuable tool in qualifying consumer perception regarding cosmetic products. This study aims to explore the application of discriminative and affective ...consumers sensory analysis in evaluating the influence of nanoencapsulation on the sensory properties and rheological characteristics of a cosmetic formulation containing lipoic acid. The nanocapsules were prepared by the pre‐formed polymer precipitation method. Semisolid formulations were prepared using a silicone emulsion system, and these pseudoplastic fluids were characterized using rheological methods. The panellists (n = 88) analysed the formulations with and without nanoencapsulated lipoic acid as paired comparisons within the discriminative and affective sensory analysis. In these measurements, spreadability, stickiness, oiliness and sulphur odour were evaluated. The panellists had no previous training in conducting these measurements. It was shown that nanotechnology can change some sensory characteristics of the formulations. The spreadability, stickiness and oiliness are the attributes for which the panellists noted differences with statistical significance. The spreadability difference could be due to the results found in the rheological profiles and consistency indexes between formulations. In the discriminative analysis, the panellists could not detect any noticeable differences in the sulphur odour or residual properties between samples, attributes that would influence whether consumers adhered to the selected treatment. Considering affective analysis, the consumers communicated that the formulation containing the nanoencapsulated lipoic acid, which presented less consistency, was preferred based on the reduction in immediate stickiness and residual sulphur odour. The free lipoic acid formulation was preferred in terms of residual oiliness and spreadability.
Résumé
L'analyse sensorielle est devenue un outil précieux pour évaluer la perception des produits cosmétiques par les consommateurs. Cet article vise à étudier l'application de l'analyse sensorielle discriminatoire et affective des consommateurs dans l'évaluation de l'influence de la nanoencapsulation sur les propriétés sensorielles et les caractéristiques rhéologiques d'une formulation cosmétique contenant de l'acide lipoïque. Les nanocapsules ont été préparés par le procédé de précipitation de polymère pré‐formé. Des formulations semi‐solides ont été préparées l'aide d'un système d'émulsion de silicone et ces fluides pseudo‐plastiques ont été caractérisés en utilisant des procédés rhéologiques. Les panélistes (n = 88) ont analysé les formulations avec et sans acide lipoïque nanoencapsulé en tant que comparaison par paires à l'aide de l'analyse sensorielle affective et discriminatoire. Dans ces mesures, l'étalement, la viscosité, l'onctuosité et une odeur de soufre ont été évalués. Les panélistes n'ont eu aucune formation préalable en la réalisation de ces mesures. Il a été montré que les nanotechnologies peuvent changer certaines caractéristiques sensorielles des formulations. L'étalement, la viscosité et l'onctuosité sont les attributs pour lesquels les panélistes ont noté des différences avec des statistiques significatives. La différence de l'étalement pourrait être due aux résultats présentés dans les profils rhéologiques et les indices de consistance entre les formulations. Dans l'analyse discriminante, les panelistes ne pouvaient pas détecter d'éventuelles différences notables dans l'odeur du soufre ou des propriétés résiduelles entre les échantillons, des attributs qui pourraient influencer les choix des consommateurs. Considérant l'analyse affective, les consommateurs ont communiqué que la formulation contenant l'acide lipoïque nanoencapsulé, qui a présenté moins de consistance, a été préférée basée sur la réduction immédiate d'adhérence et de l'odeur résiduelle de soufre. La formulation à l'acide lipoïque libre a été préférée en termes de toucher huileux résiduel et d'étalement.
An innovative nanocapsule formulation for parenteral administration using selected vegetable oils (mango, jojoba, pequi, oat, annatto, calendula, and chamomile) was developed that has the potential ...to encapsulate various drugs. The vegetable oil-loaded nanocapsules were prepared by interfacial deposition and compared with capric/caprylic triglyceride-loaded lipid core nanocapsules. The major objective was to investigate the effect of vegetable oils on particle size distribution and physical stability and to determine the hemolytic potential of the nanocapsules, considering their applicability for intravenous administration. Taking into account the importance of accurately determining particle size for the selected route of administration, different size characterization techniques were employed, such as Laser Diffraction, Dynamic Light Scattering, Multiple Light Scattering, Nanoparticle Tracking Analysis, and Transmission Electronic Microscopy. Laser diffraction studies indicated that the mean particle size of all nanocapsules was below 300 nm. For smaller particles, the laser diffraction and multiple light scattering data were in agreement (D3,2-130 nm). Dynamic light scattering and nanoparticle tracking analysis, two powerful techniques that complement each other, exhibited size values between 180 and 259 nm for all nanoparticles. Stability studies demonstrated a tendency of particle creaming for jojoba-nanocapsules and sedimentation for the other nanoparticles; however, no size variation occurred over 30 days. The hemolysis test proved the hemocompatibility of all nanosystems, irrespective of the type of oil. Although all developed nanocapsules presented the potential for parenteral administration, jojoba oil-loaded nanocapsules were selected as the most promising nanoformulation due to their low average size and high particle size homogeneity.
Capsaicin, a topical analgesic used in the treatment of chronic pain, has irritant properties that frequently interrupt its use. In this work, the effect of nanoencapsulation of the main ...capsaicinoids (capsaicin and dihydrocapsaicin) on skin irritation was tested in humans. Skin tolerance of a novel vehicle composed of chitosan hydrogel containing nonloaded nanocapsules (CH-NC) was also evaluated. The chitosan hydrogel containing nanoencapsulated capsaicinoids (CH-NC-CP) did not cause skin irritation, as measured by an erythema probe and on a visual scale, while a formulation containing free capsaicinoids (chitosan gel with hydroalcoholic solution CH-ET-CP) and a commercially available capsaicinoids formulation caused skin irritation. Thirty-one percent of volunteers reported slight irritation one hour after application of CH-NC-CP, while moderate (46% CH-ET-CP and 23% commercial product) and severe (8% CH-ET-CP and 69% commercial product) irritation were described for the formulations containing free capsaicinoids. When CH-NC was applied to the skin, erythema was not observed and only 8% of volunteers felt slight irritation, which demonstrates the utility of the novel vehicle. A complementary in vitro skin permeation study showed that permeation of capsaicinoids through an epidermal human membrane was reduced but not prevented by nanoencapsulation.
To evaluate the effect of cationic coating of polymeric nanocapsules in sunscreen formulations on the in vitro skin penetration of benzophenone-3.
Benzophenone-3-loaded nanocapsules were prepared by ...the interfacial deposition of poly(ε-caprolactone) and coated by using a chitosan solution. The nanoparticles were characterized and incorporated in hydrogels. The presence of nanoparticles in hydroxyethyl cellulose gels was observed by transmission electron microscopy and photon correlation spectroscopy. Penetration studies were carried out using Franz cells with porcine skin membranes.
Benzophenone-3-loaded chitosan-coated nanocapsules presented a mean size of 202 ± 7 nm and positive zeta potential (+21 ± 1 mV), while these values for the uncoated nanocapsules were 175 ± 1 nm and -8 ± 1 mV. Penetration profiles showed that a higher amount of benzophenone-3 remained at the skin surface and a lower amount was found in the receptor compartment after the application of the formulation containing chitosan-coated nanocapsules compared to a formulation containing its free form.
Hydrogel containing benzophenone-3 chitosan-coated nanocapsules represents an innovative formulation to overcome limitations of sunscreen daily use.
The vaginal route of administration is an alternative for several treatments for either local or systemic pharmacological effects. However, the permanence of a drug in this route represents a ...challenge for formulation development that can be overcome by using nanoencapsulation and chitosan gel. Thus, this work aimed to evaluate the performance of chitosan hydrogels containing cationic and anionic acrylic-based nanocapsules (Eudragit RS 100 and Eudragit S 100, respectively) with Nile red as a model of lipophilic substance in the vaginal route of administration, as measured by increases in the residence time and the penetration of these formulations. Several formulations were prepared with increasing chitosan concentrations, and were analyzed in terms of pH and rheological behavior so that the most suitable formulation could be selected. The enhancement of the adhesion (tensile stress test and washability profile) and penetration (confocal laser scanning microscopy and extraction followed by quantification) properties of the formulations, when applied to porcine vaginal mucosa, were evaluated. The nanocapsule suspensions produced presented adequate properties: size of approximately 200 nm (polydispersity index of ≤0.2); zeta potential around +10 mV for the cationic formulation and -10 mV for the anionic formulation; and pH values of 6.1±0.1 (Eudragit RS 100), 5.3±0.2 (Eudragit S 100), 6.2±0.1 (Nile red loaded Eudragit RS 100), and 5.1±0.1 (Nile red loaded Eudragit S 100). The chitosan formulation presented suitable viscosity for vaginal application and acidic pH (approximately 4.5). The tensile stress test showed that both formulations containing polymeric nanocapsules presented higher mucoadhesion when compared with the formulation without nanocapsules. In the washability experiment, no significant differences were found between formulations. Confocal microscopy and fluorescence quantification after extraction from the mucosa showed higher penetration of Nile red when it was nanoencapsulated, particularly in cationic nanocapsules. The formulations developed based on chitosan gel vehicle at 2.5% weight/weight containing polymeric nanocapsules, especially the cationic nanocapsules, demonstrated applicability for the vaginal delivery of hydrophobic substances.
This work explored the effect of the encapsulation in polymeric nanocapsules, as well as of the incorporation of such nanoparticles in a chitosan hydrogel, on the skin adhesion and skin ...penetration/permeation of capsaicinoids (capsaicin and dihydrocapsaicin), which are used as topical analgesic to treat chronic pain. The skin experiments were performed using a modified (drug adhesion and drug diffusion) and a normal Franz diffusion cell (drug diffusion) with porcine skin as membrane. The AUC0-h of the washability profile (% washed away vs. time) determined for the formulation combining both factors studied (chitosan hydrogel containing drug-loaded nanocapsules) was 198.88 +/- 10.05/153.53 +/- 5.99, for capsaicin and dihydrocapsaicin respectively, significantly lower than the values observed for the chitosan hydrogel containing free drug (291.57 +/- 3.83/278.18 +/- 5.28) and for the hydroxyethyl cellulose containing drug-loaded nanocapsules (245.47 +/- 13.18/197.69 +/- 15.78). By adequate fitting to the monoexponential first order equation, the washing rate values indicated that the nanocapsules were more efficient in increasing the drugs skin adhesion than the chitosan gel. Regarding the skin penetration/permeation study, after washing the skin, the formulation which presented the lowest washing rate (chitosan gel containing nanocapsules) was the one which led to a higher amount of capsaicinoids in the skin layers (epidermis and dermis). Without washing the skin, the nanoencapsules caused retention of the drugs in the outer skin layer (epidermis). In conclusion, the skin adhesion of the nanocapsules and their capability of controlling the drug diffusion were shown. Combining chitosan gel to nanocapsules led to a formulation of great skin bioadhesion.
This work aimed to develop a chitosan hydrogel containing polymeric nanocapsules with optimized sensory properties, linking the advantages of the nanocarriers, such as controlled release and ...protection of the substances, to the chitosan properties, such as bioadherence, cicatrizing effect, and antimicrobial activity. Sixty untrained volunteers evaluated the sensory properties of chitosan hydrogels compared to hydroxyethyl cellulose gels (Phase I) and to optimized chitosan gels (Phase II). The volunteers' preference between formulations was also evaluated. The chitosan hydrogel, despite the presence of nanocapsules, presented higher immediate stickiness and film formation on the skin, and lower acceptance than the hydroxyethyl cellulose gels. Regarding the optimized gel, decrease on the film formation and increase on the homogeneity of the film was observed, compared to the prior chitosan gel. So, the optimization of the chitosan gel led to higher acceptance by the volunteers. The presence of nanocapsules, besides increasing the chitosan gel consistence, increased the perception of film formation. For the optimized chitosan gel, the nanocapsules increased the homogeneity of the film formed on the skin, without increasing the perception of film formation. In conclusion, through sensory analysis, the formulation was optimized presenting, at the final stage, adequate sensory properties for cutaneous use.
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Psoriasis is a recurring, immune-mediated dermatological disorder. Many therapeutic agents are available for the treatment of psoriasis, including immunosuppressants and biologic ...treatments with immunosuppressant action. The employment of nanotechnology allows drug tailoring to achieve dermal targeting, improve efficacy and minimize undesirable effects. Here we discuss the use of the topical route in combination with nano-based drug delivery systems containing immunosuppressants for the management of psoriasis. This review is based on articles selected from 2011 to 2022, using the keywords “Psoriasis” AND “Immunosuppressants” AND “Nano*” in the main databases. Fifty-seven articles were retrieved, although only forty-two matched the inclusion criteria. Nanocarriers such as liposomes, ethosomes, niosomes, solid lipid nanoparticle, nanostructured lipid carriers and microspheres containing immunosuppressive drugs (methotrexate, cyclosporine, tacrolimus, and etanercept) were identified. The main findings of these studies are related to the improved in vitro/ex vivo permeation/penetration and therapeutic efficacy of nanoparticles in vitro and in vivo, compared to the drug in solution. Based on the studies discussed in this review, encapsulation in several types of nanocarriers decreases toxicity, dose, and dose frequency. Furthermore, it enables specific targeting of the active drug, pointing to the possibility of improving topical therapy for psoriasis. In conclusion, nanoformulations represent a novel and promising tool for psoriasis treatment.
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