The use of iron oxide magnetic nanoparticles (IMNP) in medical and pharmaceutical areas dates to the beginning of the 1970s, as carriers. Some other uses to these nanoparticles are in vitro ...separation, magnetic resonance imaging and drug targeting agent. Many preparations containing IMNP have been described and used in drug delivery, hyperthermia, in vitro separation, tissue repair, cellular therapy, for magnetic separation, magnetic resonance imaging, as spoilers for magnetic resonance spectroscopy, and more recently as sensors for metabolites and other biomolecules. The use of these nanostructures as antibacterial agents has also been reported, which could kill some bacteria species causing no damage to the human host cells. Recently, they have been used as hyperthermia agents to treat infections or cancer, which are more susceptible than the healthy host's cells. Engineering designs, physiochemical characteristics, biomedical applications of IMNP, toxicity and magnetic nanotoxicology have been discussed. However, the application of IMNP as antimicrobials is very important. Thus, this review explores the therapeutic activities of IMNP and their use as antimicrobial agents. These nanoparticles can be efficient for the treatment of microbial infections, probably acting as membrane permeability enhancer, damaging the cell wall or by generating reactive oxygen species.
Mucoadhesive nanostructured systems comprising poloxamer 407 and Carbopol 974P
have already demonstrated good mucoadhesion, as well as improved mechanical and rheological properties. Curcumin ...displays excellent biological activity, mainly in oral squamous cancer; however, its physicochemical characteristics hinder its application. Therefore, the aim of this study was to develop nanostructured formulations containing curcumin for oral cancer therapy. The photophysical interactions between curcumin and the formulations were elucidated by incorporation kinetics and location studies. They revealed that the drug was quickly incorporated and located in the hydrophobic portion of nanometer-sized polymeric micelles. Moreover, the systems displayed plastic behavior with rheopexy characteristics at 37 °C, viscoelastic properties and a gelation temperature of 36 °C, which ensures increased retention after application in the oral cavity. The mucoadhesion results confirmed the previous findings with the nanostructured systems showing a residence time of 20 min in porcine oral mucosa under flow system conditions. Curcumin was released after 8 h and could permeate through the porcine oral mucosa. Cytotoxicity testing revealed that the formulations were selective to cancer cells over healthy cells. Therefore, these systems could improve the physicochemical characteristics of curcumin by providing improved release and permeation, while selectivity targeting cancer cells.
Semi-solid emulsion systems constitute important platforms for drug delivery, due to the easiness of administration, increasing residence time and also improve the drug availability. They are usually ...stabilized by emulsifiers and hydrophilic polymers may be used to form a tridimensional network in the hydrophilic phase resulting in a structure than can disperse the hydrophobic phase and the drug. These systems can be administered by oral, parenteral, and topical routes as platforms for delivery of biologically active agents from different origins such as mineral, animal or vegetal. Propolis has a complex chemical composition and displays many important biological activities (antibacterial, fungicidal, antioxidant, antiviral, anti-inflammatory, immunostimulant, anti-cancer, antiulcer, hypotensive and cytostatic). Propolis ethanolic extract (PE) and extract of propolis by-product (BPE) are usually utilized in therapeutics. In this work, three vegetable oils (passion fruit, andiroba and sweet almond oils) were used to develop emulsion-systems composed of Carbopol 934P (C934P) for propolis delivery. The mechanical and rheological properties of formulations were investigated to select potential emulsion systems. A factorial design was employed to determine the influence of C934P concentration and the different vegetable oils on the physicochemical characteristics of systems, considering the presence of PE or BPE. Emulsion systems displayed physicochemical stability and mechanical characteristics dependent of C934P 1% (w/w). Formulations displayed pseudoplastic flow behavior and viscoelasticity dependent of vegetable oil type, temperature and type of propolis extract. The results indicated that the PE resulted in a more structured emulsion system due to the greater content of resin and gum than the BPE. Emulsion systems displayed softness and are worthy of investigation intended the administration on the skin and mucous membranes.
•Carbomer amount and vegetal oil type were studied to prepare emulsion for propolis delivery.•Passion fruit, sweet almond and andiroba oils were used to prepare emulsion systems.•Carbopol 934P 1% (w/w) resulted the best systems for delivery propolis or by-product extract.•Propolis extract yielded more structured and soft systems with improved mechanical properties.
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•Nanostructured lipid systems containing propolis and its by-product are proposed.•All systems show good morphology, size, and X-ray diffractometry characteristics.•Solid lipid ...nanoparticles (SLN) display the best size stability result.•The occlusive capacity, drug content and release profile show the best formulations.•The systems SLN display no toxicity in HaCaT cells and accelerate wound healing.
Propolis, a natural compound that can accelerate the wound healing process, is mainly used as ethanolic extract. The extractive solution may also be obtained from the propolis by-product (BP), transforming this waste material into a pharmaceutical active ingredient. Even if propolis does not show toxicity, when used as an extract over harmed skin or mucosa, the present ethanol content may be harmful to the tissue recovering, besides hindering the drug release. This study describes the development of solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC) as topical propolis delivery systems and the investigation of their in vitro and in vivo activities. The extracts were evaluated to guarantee their quality, and the lipid dispersions were characterized with respect to morphology (cryo-TEM), size and diffractometry (X-ray) properties. The occlusive capacity of formulations was also evaluated by an in vitro technique, which determines the occlusion factor. The drug entrapment efficiency (EE), as well as the in vitro drug release profile from the nanoparticulate systems was investigated as well. The size analysis performed through 90days was favorable to a topical administration and the polydispersity index, though not ideal in all cases due to the high content of resins and gums from the extracts, were relatively stable for the SLN. The propolis extract contributes to the occlusive potential of the formulations. The human immortalized keratinocytes presented good cell viability when tested with both extracts (propolis and BP) freely or entrapped in the systems. SLN modified with propolis material provided an acceleration of the in vivo wound healing process.
Emulgels are obtained by the entrapment of an organic phase within a three-dimensional network built by hydrophilic molecules. Polymers based on cross-linked poly(acrylic acid) have been utilized as ...gel matrices, improving adhesiveness, rheological and mechanical performance. Propolis (PRP) produced by Apis mellifera L. bees displays a wide range of biological activities. Together with curcumin (CUR), they may show synergic anti-inflammatory, antioxidant and antimicrobial action on skin disorders. This work investigated the effect of vegetable oils (sweet almond, andiroba, and passion fruit) with regard to the physicochemical properties of emulgels composed of Carbopol 934P®, Carbopol 974P®, or polycarbophil aiming the CUR and PRP delivery. Physicochemical stability enabled the selection of systems containing passion fruit or andiroba oil. Mechanical and rheological characteristics provided rational comprehension of how vegetable oils and bioactive agents affect the structure of emulsion gels. All formulations exhibited high physiochemical stability and properties dependent on the polymer type, oil, and bioactive agent. Formulations displayed pseudoplastic, thixotropic and viscoelastic properties. Emulgels containing andiroba oil were the most stable systems. Carbopol 934P® or polycarbophil presence resulted in formulations with improved smoothness and mechanical properties. Systems containing andiroba oil and one of these two polymers are promising for further investigations as topical delivery systems of CUR and/or PRP on the skin and mucous membranes.
Metronidazole is an antimicrobial agent utilized for the treatment of protozoa and anaerobic bacteria infections. Many times, it is necessary to modify the metronidazole release, and the development ...of modified release systems may be suggested. In this study, we are able to investigate the use of the residue normally thrown out from the preparation of propolis extracts (BP) as strategy to modify the metronidazole release. We prepared films containing polymeric adjuvant (gelatin or ethylcellulose) and metronidazole, by solvent casting method. Density, mechanical properties, water vapor permeability (WVP), moisture uptake capacity (MUC), thermogravimetry, differential scanning calorimetry, Fourier transform infrared spectroscopy (FT-IR), and in vitro metronidazole release were investigated. Thickness and density of the preparations indicated that the compounds were homogeneously dispersed throughout. Mechanical properties were influenced by film composition. Films containing gelatin showed higher resistance to stress while those containing ethylcellulose presented greater flexibility. The greater the adjuvant concentrations lower the resistance to rupture and the elasticity, but higher MUC and WVP of formulations. FT-IR tests suggested interactions between BP and the adjuvants. Films were capable to protect the metronidazole and changed its release profile. BP films are of great practical importance constituting a novel strategy to modify the metronidazole release.
The present work at hands deals with physicochemical properties of an organogel composed of non-ionic triblock copolymer poloxamer 188 and passion fruit oil. To provide the characterization it was ...investigated the rheological (continuous shear and oscillatory) properties, sol-gel transition temperature, mechanical properties (hardness, compressibility, adhesiveness, cohesiveness and elasticity) and softness index. Moreover, we investigated the possible correlation between the rheological and mechanical characteristics to study the structuring of formulations and to select the best organogel for pharmaceutical applications. Mechanical and rheological characteristics showed to be temperature, polymer and oil concentration dependent. The increase of poloxamer 188 and passion fruit oil amounts in formulations displayed more expressive textural properties and softness. The organogels exhibited plastic flow with higher yield value, consistency index and thixotropic behavior at higher poloxamer 188 concentrations. All formulations showed viscoelastic properties and the sol-gel transition temperature was dependent of polymer and oil concentration in formulations. Rheological-mechanical correlation coefficient evidenced that rheological methods were more sensible than the mechanical ones. Considering the mechanical and rheological characteristics, the organogel composed of poloxamer 188 (35%, w/w) and passion fruit oil (16.7%, w/w) can be considered potentially promising as a drug delivery platform for pharmaceutical applications.
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•Physicochemical properties of an organogel composed of poloxamer 188 and passion fruit oil were investigated.•Mechanical and rheological characteristics of systems showed to be temperature, polymer and oil concentration dependent.•Increased poloxamer 188 and passion fruit oil amounts in systems displayed more expressive textural properties and softness.•Viscoelasticity and the sol-gel transition temperature of systems were dependent of polymer and oil concentration.•The system containing poloxamer 188 (35%, w/w) and passion fruit oil (16.7%, w/w) is potentially promising.
The use of propolis by-product (PBP) microparticles (MP) as delivery systems can be a promising tool to surpass drawbacks related to low stability of ascorbic acid (AA). The objective of this study ...was to develop and characterize MP prepared with PBP containing AA. The MP was characterized regarding morphology, particle size, polydispersity index (PDI), association efficiency (AE), drug loading (DL), infrared and Raman spectroscopy as well as antioxidant and radical scavenging activity,
in vitro
release, and cellular studies. MP was shown to be spherical with some agglomeration. Its particle size was 1654 ± 0.210 nm with a PDI of 0.7. The AE and DL were, respectively, 100.30 ± 2.66% and 13.16 ± 0.59. Spectroscopic studies indicated a possible interaction between the PBP and AA. 2,2-Diphenyl-1-picrylhydrazyl (DPPH&z.rad;), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) and ferric reducing antioxidant power (FRAP) assays demonstrated that the MP containing AA have an excellent antioxidant capacity as well as a considerable scavenging activity against reactive oxygen and nitrogen species. The
in vitro
release profile showed a slow pattern of drug release of AA from MP. Viability studies with intestinal cells revealed that MP did not present toxicity in Caco-2 and HT29-MTX. Moreover, AA could permeate Caco-2 monolayers and triple co-culture substantially at the end of 8 h, opposite to the MP. Therefore, the proposed MP formulation represents a promising platform for oral delivery of AA with a local effect on intestines.
The use of propolis by-product (PBP) microparticles (MP) as delivery systems can be a promising tool to surpass drawbacks related to low stability of ascorbic acid (AA).
Studies were performed to investigate the physicochemical properties of polymeric systems containing poloxamer 407 and acrylic acid derivatives (Carbopol 974P® or polycarbophil) for delivery of ...curcuminoids. To optimise the preparation method, the active and passive incorporation methodologies were investigated and the storage temperatures (5 and 25 °C) were evaluated by spectroscopic analysis. Colloidal systems containing Carbopol 974P® promoted stronger interactions and better structuring between curcumin and the polymeric micelles and higher temperatures showed higher anisotropy values. Kinetic studies showed that curcumin was quickly incorporated in the polymeric micelles. Location and storage studies showed that curcumin was in a more internalised portion of hydrophobic core of poloxamer 407 micelles and could be stable even after three months of preparation, when the formulations were composed of Carbopol 974P® and stored at 25 °C. In this sense, the active incorporation was chosen as the optimised method for preparation of curcuminoids-formulations for future pharmaceutical applications.
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•Polymer blends for curcuminoids delivery were investigated.•Curcumin was quickly included in the micelles due to the affinity of poloxamer 407.•Systems with Carbopol 974P® (25 °C) showed drug in an inner portion of poloxamer 407.•Curcumin location promotes protection from degradation and a probable drug release control.•Active incorporation was chosen the optimised method for preparation of formulations.
abstract This study investigated the development and characterized the physicochemical properties of films obtained from by-products (BP) from the preparation of propolis extracts. Films were ...produced in the presence and absence of a polymeric adjuvant (gelatin or ethylcellulose) and propylene glycol by a solvent casting method. Density, surface topography by scanning electron microscopy, mechanical properties (folding endurance, tensile strength and percentage elongation), water vapour permeability (WVP), moisture uptake capacity, thermogravimetry, differential scanning calorimetry and Fourier transform infrared spectroscopy (FTIR) were determined. The films were a transparent, light greenish-yellow colour, with a uniform surface, and were flexible and easy to handle. The thickness and density of the preparations indicated that the compounds were homogeneously dispersed throughout the film. Mechanical properties were influenced by the film composition; films containing gelatin were more resistant to stress, while those containing ethylcellulose were more flexible. Increasing the adjuvant concentration decreased the elasticity and the rupture resistance, but increased the moisture uptake capacity and WVP of the formulations. BP was thermally stable as were the films. FTIR tests suggested interactions between BP and the adjuvants. This work could contribute to the utilization of BP to prepare films for food and pharmaceutical uses
resumo Este estudo investigou o desenvolvimento e as características físico-químicas de filmes obtidos com o resíduo (BP), normalmente descartado, advindo da preparação de extratos de própolis. Os filmes foram produzidos com e sem adjuvantes poliméricos (gelatina ou etilcelulose) e propilenoglicol, pelo método de evaporação de solvente. Foram determinadas a densidade, a topografia de superfície usando microscopia eletrônica de varredura, as propriedades mecânicas (resistência à dobra, tensão e elongação), transmissão de vapor de água (WVP), capacidade de absorção de umidade, termogravimetria, calorimetria exploratória diferencial e espectroscopia de infravermelho com transformada de Fourier (FTIR). Os filmes demonstraram coloração verde-amarelada, transparência, uniformidade de superfície, homogeneidade, flexibilidade e fácil manuseio. A espessura e a densidade das preparações indicaram que os compostos estavam dispersos de forma homogênea. As propriedades mecânicas foram influenciadas pela composição dos filmes e aqueles que continham gelatina apresentaram-se mais resistentes enquanto os compostos por etilcelulose demonstraram maior flexibilidade. Com o aumento da concentração polimérica, a resistência e a elasticidade diminuíam, porém aumentou a capacidade de absorção de água e a WVP das formulações. BP apresentou estabilidade térmica assim como os filmes. Os testes de FTIR sugeriram interações entre o BP e os adjuvantes utilizados. Este trabalho pôde contribuir com a utilização de BP na preparação de filmes para uso alimentício e farmacêutico.
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