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Carvacrol has shown antimicrobial activity against a wide range of Gram-positive and Gram-negative bacteria. However, its hydrophobic nature, volatility, and susceptibility to oxidation mediated by light or heat limit its use. Nanoencapsulation provides a protective barrier against degradation and volatilization processes and improves the dispersibility of bioactive compounds. A simple, rapid, and sensitive analytical method was developed and validated by UV spectrophotometry to quantify carvacrol in a nanoemulsion obtained by self-nanoemulsification, using acetonitrile as a solvent to recover the analyte from the nanoemulsion. The UV scanning spectrum of carvacrol (240–300 nm) in acetonitrile showed maximum absorbance at wavelength 275 nm, typical of this monoterpene. The calibration curve was linear from 15 to 65 μg/ml, with a determination coefficient of 0.999. The detection and quantification limits found were 1.6455 and 4.9863 μg/ml, respectively. The validation results confirmed that the method developed is specific, linear, accurate, and precise and it can be successfully applied for the determination of encapsulation efficiency and the content of carvacrol present in a nanoemulsion.

Tissue engineering and nanotechnology have developed polymeric nanofibrous scaffolds for tissue regeneration. Propolis is a featured natural product due to its biological properties, including enhancement of the wound healing process. This study developed a polymeric nanofibrous wound dressing of polyvinyl alcohol (PVA) and propolis, and evaluated both in vitro and in vivo its potential in the wound healing process. The optimization of the experimental conditions was performed based on the evaluation of electrospinning process stability and morphology of the resulting nanofibers. The resulting scaffolds were evaluated through cell culture studies, using murine NIH/3T3 fibroblasts as study model, and then in vivo in a diabetic non-contractile wound healing model. PVA scaffolds associated with nanoparticles showed an adequate fiber morphology and did not present any cytotoxicity to fibroblasts in vitro. Furthermore, PVA scaffold with propolis nanoparticles showed the best wound closure rate (68%) after 7 days in comparison with treated (54%) and untreated controls (20%). Withal, preliminary results showed that PVA scaffold associated with propolis nanoparticles has potential to be applied in tissue regeneration. Furthermore, this work features as innovation the development of a nanoscaffold/nanoparticles system, which can be used not only for propolis, but for any natural extract, especially for those insoluble in water.

This study describes the development of propolis nanoparticles (PNP) to treat bovine mastitis. Three PNP prepared with varying concentrations of propolis (5% and 7%, w/v) and the surfactants [poloxamer (1%, 3%, and 4%, w/v) and soy lecithin (0.25%, 0.7%, and 1%, w/v)]. PNP were characterized according to their size, polydispersity, zeta potential, pH, morphology, and physical stability. PNP were evaluated for their in vitro antimicrobial and cytotoxic effects. PNP obtained were spherical with a monodisperse distribution (polydispersity index −1. The IC50 (the concentration responsible for reduction of cellular viability by half) for epithelial cells of bovine mammary gland (MAC-T, mammary alveolar cell-T) varied from 122.2 to 268.4 μg mL−1. Results showed that PNP represent a promising nanocarrier for high concentrations of propolis extract in a stable aqueous medium, while, at the same time, presenting antimicrobial activity accompanied by moderate cytotoxicity to the MAC-T cells.

Polycaprolactone (PCL) fibers were produced by electrospinning using three collectors: rotating drum, static copper wires, and a rotating mandrel. The effect of collector design on the alignment and morphology of fibers was evaluated. The drum collector produced a typical tridimensional structure whereby the rotational speed mechanically stretches fibers and affects their diameter and alignment. Randomly oriented fibers with an average diameter of 1142 ± 391 nm were obtained at 0 rpm, while aligned fibers with an average diameter of 663 ± 334 nm were produced at 2000 rpm. Static copper wires produced a novel fiber pattern in which the degree of orientation of the fibers is related to the electrical field distribution along the collector. The best fiber alignment and lowest average fiber diameter (490 ± 131 nm) were obtained using parallel copper wires with a gap of 1 cm. Two main forces influenced the fibers produced by the rotating mandrel. First, the attraction of the electrical field by the collector induced the deposition of fibers parallel to its axis with an average diameter of 606 ± 329 nm. Second, the stretching force from the high-speed rotation induced the deposition of fused fibers transverse to the collector axis.

Cutaneous leishmaniasis is a worldwide public health problem. Conventional therapies, in addition to the high cost, have many adverse effects and cases of parasite's resistance. Chalcones are secondary metabolites precursors in the flavonoid pathway and can be obtained naturally, but with low yield from plant raw material. Thus, the use of synthetic chalcones has been a promising strategy for the development of molecules with leishmanicidal activity. Thus, this work aimed to develop a controlled release system of two synthetic chalcone (trans-chalcones and 3'-(trifluormethyl)-chalcone) using polyvinyl alcohol nanofibers (PVA) as scaffold. The association of chalcones to the nanofibers was made by nanoemulsions (NE) thereof, i.e., a colloidal system on a nanometric scale, which allows compounds with opposite polarities to remain miscible and stable throughout their manipulation. Chalcone nanoemulsions were developed using the spontaneous emulsification technique. The NE were characterized regarding their particle size, polydispersion index (PDI), and zeta potential. The results showed NE with spherical shape, absolute values of zeta potential were higher than 30 mV and homogeneous distribution pattern (PDI < 0.3). Dynamics light scattering (DLS) analysis showed similar hydrodynamic rays, i.e., 180 nm (trans-chalcone NE) and 178 nm (NE containing 3'-(trifluormethyl)-chalcone, in addition to presenting encapsulation efficiency values close to 100 %. Subsequently, the NE were added to a polymeric solution of polyvinyl alcohol (PVA) and processed via the electrospinning technique affording a PVA matrix (15 %, w/v) nanofiber containing the chalcones NE at 1 mg.mL-1. In a follow-up experiment, the skin permeation assay of the PVA matrix-chalcone NE was performed in vitro using Franz type diffusion cells and porcine ear as biological model of study. The results showed that the treatments with the nanofibers containing the chalcone NE were retained mainly in the stratum corneum, while the NE suspensions containing chalcone were retained in the epidermis and dermis. This result is thought to be relevant, since parasites are located mainly in the dermis. Further, in vitro assay against the amastigote form of L. (L) amazonensis, showed IC50 values to trans-chalcone and 3'-(trifluormethyl)-chalcone of 24.42 ± 6.76 μg.mL-1 and 15.36 ± 4.61 μg.mL-1, respectively. In addition to improving the solubility of the compounds tested in culture medium without using organic solvents, chalcones in nano-emulsified form reduced the IC50 to 9.09 ± 1.24 μg.mL-1 (trans-chalcone) and 10.27 ± 2.27 μg.mL-1 (3'-(trifluormethyl)-chalcone) which confirmed the potential of the nanoemulsion containing chalcone for cutaneous leishmaniasis treatment.

Methicillin-resistant Staphylococcus aureus (MRSA) causes mastitis in dairy cattle with serious economic and public health significance. This study developed nanoemulsions of Linum usitatissimun oil loaded with Achyrocline satureioides (macela) extract and investigated their in vitro antimicrobial activity against MRSA. Macela-nanoemulsions (NE-ML) were prepared using high-pressure homogenization (HPH) with different proportions of flaxseed oil, Tween 80 and crude extract. Four majoritarian flavonoids were identified in the macela extract: 3-O methylquercetin, achyrobichalcone, quercetin and luteolin (187.3 ± 0.1, 155.4 ± 11.6, 76.3 ± 0.1 and 30.4 ± 0.0 μg ml−1, respectively). NE-ML nanoemulsions were successfully obtained by the HPH method and showed a milky aspect with yellowish color. The mean particle size was around 200 nm with monodisperse distribution (PdI in vitro tests on microplates. The MIC of NE-ML against planktonic MRSA showed values ranging from 1.2 to 10% (v/v), while blank-nanoemulsions (NE-B, without macela extract) showed values ranging from 6 to 50% (v/v). MBIC and MBEC of NE-ML were 25 and 80% (v/v), respectively. MBIC showed a mass reduction greater than 64%, and MBEC showed a mass reduction greater than 73%. Macela-nanoemulsions (NE-ML), mainly NE-ML1:5, showed high antimicrobial activity and appeared to represent a new alternative of sustainable antimicrobial product for the control of MRSA. Since this innovative nanoemulsion can impact animal health, future research should include in vitro and in vivo studies to evaluate intramammary therapy and control of MRSA infections in organic and agroecological milk production systems.

In this study, the effects of two elicitors (potassium phosphite and chitosan) on apple scab (Venturia inaequalis) and their ability to modulate plant defences were assessed. Potassium phosphite and chitosan were sprayed on apple seedlings 7 days before fungus inoculation, and disease intensity was evaluated 14 days after inoculation. Samples of leaves treated with phosphite or chitosan that proved to be susceptible and moderately susceptible to disease were then collected for analysis of their metabolic profile by attenuated total reflectance–Fourier transform infrared spectroscopy. The activity of the plant defence enzymes and the phenolic compound content were also determined by spectrophotometry and high performance liquid chromatography, respectively. The effect of product application on the germination of V. inaequalis was also evaluated. Moderately susceptible leaves presented higher peroxidase activity, regardless of the application of a product. Although it reduced spore germination by 45 %, chitosan did not affect the intensity of the disease. On the other hand, potassium phosphite (2 μL mL−1) reduced significantly the severity of scab by up to 62 % and it promoted the accumulation of salicylic acid, protocatechuic acid, and epicatechin in susceptible leaves, especially after the challenge with V. inaequalis. The salt did not exhibit antimicrobial activity. The resistance induced by potassium phosphite could thus play a significant role in scab control.

Nanotechnology is an exciting emerging field with multiple applications in skin regeneration. Nanofibers have gained special attention in skin regeneration based on their structural similarity to the extracellular matrix. A wide variety of polymeric nanofibers with distinct properties have been developed and tested as scaffolds for skin regeneration. Besides providing support for tissue repair, nanofibrous materials can act as delivery systems for drugs, proteins, growth factors, and other molecules. Moreover, the morphology, biodegradability, and other functionalities of nanofibrous materials can be controlled towards specific conditions of wound healing. Other nanostructured drug delivery systems, such as nanoparticles, micelles, nanoemulsions, and liposomes, have been used to improve wound healing at different stages. These nanoscale delivery systems have demonstrated several benefits for the wound healing process, including reduced cytotoxicity of drugs, administration of poorly water-soluble drugs, improved skin penetration, controlled release properties, antimicrobial activity, and protection of drugs against light, temperature, enzymes or pH degradation, as well as stimulation of fibroblast proliferation and reduced inflammation.

Moderate wine intake (i.e., 1-2 glasses of wine a day) is associated with a reduced risk of morbidity and mortality from cardiovascular disease. The aim of this study was to evaluate the anti-atherosclerotic effects of a nonalcoholic ethyl acetate fraction (EAF) from a South Brazilian red wine obtained from Vitis labrusca grapes. Experiments were carried out on low-density lipoprotein (LDL) receptor knockout (LDLr⁻/⁻) mice, which were subjected to a hypercholesterolemic diet and treated with doses of EAF (3, 10, and 30 mg/kg) for 12 weeks. At the end of the treatment, the level of plasma lipids, the vascular reactivity, and the atherosclerotic lesions were evaluated. Our results demonstrated that the treatment with EAF at 3 mg/kg significantly decreased total cholesterol, triglycerides, and LDL plus very low-density lipoprotein levels compared with control hypercholesterolemic mice. The treatment of mice with EAF at 3 mg/kg also preserved the vasodilatation induced by acetylcholine on isolated thoracic aorta from hypercholesterolemic LDLr⁻/⁻ mice. This result is in agreement with the degree of lipid deposit on arteries. Taken together, the results show for the first time that the lowest concentration of an EAF obtained from a red wine produced in southern Brazil significantly reduced the progression of atherosclerosis in mice.

Multipotent stromal cells stimulate skin regeneration after acute or chronic injuries. However, many stem cell therapy protocols are limited by the elevated number of cells required and poor cell survival after transplantation. Considering that the beneficial effects of multipotent stromal cells on wound healing are typically mediated by paracrine mechanisms, we examined whether the conditioned medium from skin-derived multipotent stromal cells would be beneficial for restoring the skin structure of mice after wounding. A proteomic characterization of skin-derived multipotent stromal cell-conditioned medium was performed, and the angiogenic function of this secretome was investigated in vitro using an endothelial cell tube formation assay. We then applied the skin-derived multipotent stromal cell-conditioned medium directly to full-thickness excisional wounds or embedded it into carrageenan or poly(vinyl alcohol) hydrogels to monitor tissue regeneration in mice. Biological processes related to wound healing and angiogenesis were highlighted by the analysis of the skin-derived multipotent stromal cell secretome, and a pro-angiogenic capacity for promoting tubule-like structures was first confirmed in vitro. Skin wounds treated with skin-derived multipotent stromal cell-conditioned medium also displayed increased angiogenesis, independently of the association of the conditioned medium with hydrogels. However, improvements in wound closure and epidermis or decreased inflammatory cell presence were not observed. Hence, the use of the secretome obtained from human skin-derived multipotent stromal cells may be a potential strategy to aid the natural skin repair of full-thickness lesions mainly based on its pro-angiogenic properties.

At the nature, bees consume pollen and nectar to obtain its nutrients (proteins, lipids, carbohydrates, vitamins, and minerals). Changes in bee pastures have occurred as green areas and forests have been replaced by agricultural areas affecting colony health and productivity. Because of this, the efficiency of artificial protein diets for the Africanized honey bee (Apis mellifera, L.) was evaluated - considering the total protein content of the hemolymph, weight of the bees, and dietary consumption. The crude protein of the diets ranged from 12.2 to 24.4%. Newly emerged workers were caged and kept in an incubator with controlled temperature and humidity until six days old, receiving diets and water ad libitum. Hemolymph was collected from 0- and 6-day-old workers. Comparing the diets, significant differences in the protein content in the hemolymph, bee weight, and diet consumption were found among the treatments. A diet composed of 20% sugarcane yeast, 20% textured soy protein, and 60% sucrose was the most efficient according to measures of total protein in the hemolymph, bee weight and diet consumption. The use of protein sources as a supplement for hives can be a safe and viable alternative for beekeepers.

Electrospinning was used to produce self-supporting nanofibrous poly(ethylene terephthalate) membranes with good mechanical properties and straightforward handling. The application of this type of membranes in apple juice clarification process was investigated. Processing characteristics and quality parameters of apple juice were analyzed in order to compare the proposed method to traditional clarification techniques. In general, the apple juice obtained from electrospun nanofiber membrane filtration revealed physico-chemical characteristics comparable to those from juice clarified by ultrafiltration or by conventional clarification using filtering aids. Nevertheless, the new process showed a high flux performance and revealed to be much faster, simple and more economical than the traditional processes. This work demonstrated the filtration potential of an electrospun PET membrane thus introducing a new concept of clarification and opening new approaches for the juice processing industry or even for other food industry fields.

This study describes the preparation and characterization of nanofibrous mats obtained by electrospinning poly(ethylene terephthalate) (PET) solutions in trifluoroacetic acid/dichloromethane (TFA/DCM). Special attention was paid to the effect of polymer concentration and solvent properties on the morphology, structure, and mechanical and thermal properties of the electrospun nonwovens. The results show that the spinnable concentration of PET solution in TFA/DCM solvents is above 10 wt %. Mats have nanofibrous morphology with fibers having an average diameter in the range of 200–700 nm (depending on polymer concentration and solvent composition) and an interconnected pore structure. Higher solution concentration favors the formation of uniform fibers without beads and with higher diameter. Morphology and fiber assembly changed with the solvent properties. Solvent mixtures rich in TFA, i.e., those with higher dielectric constant and lower surface tension, originated fibers with small diameter. However, due to the lower volatility, those solvent mixtures also produced more branched and crosslinking fibers, with less morphologic uniformity. Mechanical properties (Young's modulus, ultimate strength, and elongation at break) and thermal properties (glass transition, crystallization, and melting) have been studied for the PET electrospun nanomats and compared with those of the original polymer. Solvent effect on fiber crystallinity was not significant, but a complex effect was observed on the mechanical properties of the electrospun mats, as a consequence of the different structural organization of the fibers within the mat network. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 460–471, 2008

Plinia cauliflora (jaboticaba) is a native fruit tree from Brazilian rainforest widely used in popular medicine to prevent diarrhea, asthma, and infections. Studies have shown that the major therapeutic potential of jaboticaba fruits is on its peel, a rich source of anthocyanins. These secondary metabolites have well-known antioxidant and anti-inflammatory activities and have been claimed to be effective to treat diabetes, cancer, cardiovascular diseases, and stroke. This chapter describes a series of methodologies to evaluate important in vitro biological activities like cytotoxicity, proliferation, and migration of a hydroalcoholic extract of jaboticaba peel on mouse fibroblast L929 line. Assays to assess total phenolic, flavonoid, and anthocyanin contents and antioxidant activities are described as well.

The formation of embryonic blood vessels, defined as vasculogenesis, is a complex morphogenetic process ultimately related to tubulogenesis, carried out from in situ differentiation of mesoderm-recruited or proliferated progenitor endothelial cells (angioblasts) to endothelial cells for structuring a primary vascular plexus. Subse‐ quent events involving apoptosis versus cell survival (remodeling) in the vessel network stabilizes the primordial microvasculature, which through the angiogenesis process yields new capillaries by sprouting from the preexisting ones. Methylxan‐ thinic alkaloids such as caffeine (compounds present in a number of beverages consumed worldwide) exert some well-known effects upon heart and other cardio‐ vascular structures, in part, by negatively interplaying with phosphodiesterase (PDEs) enzymes. Once caffeine as well as Ilex paraguariensis (yerba mate) infusion extract have shown to enhance the vessel formation (vasculogenesis and angiogene‐ sis), we discuss the impact afforded by I. paraguariensis constituents on the (PDEsrelated) quantities and stability of Protein kinase A (PKA) and Protein kinase C (PKC) enzymes. Besides, the text reflects on a suggested dual roles displayed by PKA and PKC enzymatic pathways in the developmental angiogenic events.

Chitosan samples with different N-deacetylation levels were obtained from β-chitin under heterogeneous alkali conditions. Oxidative depolymerisation was performed to attain low-acetylated chitosan samples with different molecular mass. Water vapour permeability, membrane swelling and tensile mechanical properties were analysed in plasticized self-supporting chitosan membranes. The main purpose was to describe unambigously the effect of the biopolymer molecular mass and acetylation degree on these properties. Commercially available chitosan samples derived from α-chitin were also studied for comparison. The equilibrium degree of swelling in water and the water vapour permeability increase by increasing the molecular mass or the degree of acetylation. Regarding the effect on the mechanical properties, generally harder and tougher membranes were obtained for chitosans with higher molecular mass or lower acetylation degree. These observations are tentatively explained based on the different structural characteristics of the polymer and can lead to a better understanding of the tools necessary to tailor a specific type of chitosan membrane.

Parasitic diseases are a major cause of mortality in many tropical countries, affecting hundreds of millions people, mostly associated with poor socioeconomic and hygienic environment. Diseases caused by species of the genera Trypanosoma (Human African Trypanosomiasis and Chagas disease), Plasmodium species (malaria), and Leishmania (various forms of leishmaniasis) are among the 17 “neglected tropical diseases” (NTDs) defined as such by the World Health Organization, due to the lack of enough financial investment into research and development of new drugs by most of the pharmaceutical industry and neglect of public awareness in high-income countries. Existing therapies suffer from various deficiencies, namely, high degree of toxicity and unwanted effects, limited availability and affordability, and/or problematic application under the life conditions of affected populations. Development of new, safe, and affordable drugs is therefore an urgent need. Many well-known drugs listed in the modern pharmacopoeia have their origins in nature, including, for example, quinine from the bark of the Cinchona tree for the treatment of malaria, which has been followed by the subsequent development of the synthetic derivatives chloroquine, amodiaquine, primaquine, and mefloquine. Similarly, the potent antimalarial activity of artemisinin from the herb Artemisia annua is currently used as an alternative to chloroquinine in China against resistant strains of Plasmodium and also investigated in the United States by the military forces, since malaria can quickly debilitate troops. Besides, artemisinin has led current research to focus on the development of a large number of synthetic and semisynthetic compounds, which are more active than artemisinin. In this regard, our research group has been working on chalcones derivatives as inhibitors of Mycobacterium tuberculosis (tuberculosis), Trypanosoma cruzi, and Leishmania spp., with some patents been issued [Brazil PI 0204079-4 (2004)] because of the positive effects found for the treatment of those NTDs. In this chapter, a comprehensive list of medicinal plants, marine organisms, and other natural products that have shown activity against the etiologic agents and vectors/hosts (mainly to dengue and shistosomiasis) of NTDs is provided. Also emphasis on recent developments in groups of medicinally important natural products, particularly with reference to the structure–activity studies, will be given.

Electrospun materials have been widely explored for biomedical applications because of their advantageous characteristics, i.e., tridimensional nanofibrous structure with high surface-to-volume ratio, high porosity, and pore interconnectivity. Furthermore, considering the similarities between the nanofiber networks and the extracellular matrix (ECM), as well as the accepted role of changes in ECM for hernia repair, electrospun polymer fiber assemblies have emerged as potential materials for incisional hernia repair. In this work, we describe the application of electrospun non-absorbable mats based on poly(ethylene terephthalate) (PET) in the repair of abdominal defects, comparing the performance of these meshes with that of a commercial polypropylene mesh and a multifilament PET mesh. PET and PET/chitosan electrospun meshes revealed good performance during incisional hernia surgery, post-operative period, and no evidence of intestinal adhesion was found. The electrospun meshes were flexible with high suture retention, showing tensile strengths of 3 MPa and breaking strains of 8-33%. Nevertheless, a significant foreign body reaction (FBR) was observed in animals treated with the nanofibrous materials. Animals implanted with PET and PET/chitosan electrospun meshes (fiber diameter of 0.71 ± 0.28 µm and 3.01 ± 0.72 µm, respectively) showed, respectively, foreign body granuloma formation, averaging 4.2-fold and 7.4-fold greater than the control commercial mesh group (Marlex). Many foreign body giant cells (FBGC) involving nanofiber pieces were also found in the PET and PET/chitosan groups (11.9 and 19.3 times more FBGC than control, respectively). In contrast, no important FBR was observed for PET microfibers (fiber diameter = 18.9 ± 0.21 µm). Therefore, we suggest that the reduced dimension and the high surface-to-volume ratio of the electrospun fibers caused the FBR reaction, pointing out the need for further studies to elucidate the mechanisms underlying interactions between cells/tissues and nanofibrous materials in order to gain a better understanding of the implantation risks associated with nanostructured biomaterials.

The purpose of this study was to evaluate hybrid poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV)/chitosan nanofibrous mats as scaffolds for skin engineering. In vitro studies were carried out to test the potential of the scaffolds for fibroblasts adhesion, viability, and proliferation (L929 cell line). The in vivo performance was also studied in a full-thickness wound healing model. PHBV/chitosan 4:1 (w/w) exhibited a higher in vitro biocompatibility and a better ability for cell adhesion and growth, compared to PHBV/chitosan 2:3 (w/w). The in vivo assay also revealed the better performance of this scaffold, improving the wound healing process in rats.

The present study focuses on the effects of a hydro-alcoholic propolis extract collected in autumn (2010) in Santa Catarina State (Southern Brazil), on the angiogenesis, using in vitro and in vivo models. Cultures of human umbilical vein endothelial cells were used to assess the effects of propolis on viability, proliferation, and cell migration, as well as capillary tube formation. The propolis autumnal extracts significantly decreased the cell viability, based on CC 50 values, which decreased (56%) from 297 to 130 μg/ml in 24 h and 72 h of treatment, respectively (cytotoxicity assay). The process of cell proliferation was decreased by 81.7 to 48.4% due to exposure (72 h) to 130–180 μg/ml of propolis extract, as compared with control (vehicle). In these same concentrations, the cell migration was also reduced by 39.6 to 12.6%, respectively (versus control). Furthermore, autumnal propolis extract (100–200 μg/ml) inhibited the tube-like structure formation (tubulogenesis) of endothelial cells on Matrigel™ (16.2–69.9% inhibition). The treatments performed in vivo with administration of 450 mg propolis.kg − 1 inhibited both angiogenesis and vasculogenesis by 82.3 and 66.5% in the chorioallantoic and yolk-sac membranes of chick embryos. Furthermore, by means of UV–vis-spectrophotometry, reverse phase-high performance liquid chromatography analysis and 1D and 2D-nuclear magnetic resonance experiments reveal higher contents of flavonoids and total phenolic compounds with predominance of the flavonol quercetin and the phenolic acids, e.g., gallic acid, protocatechuic acid and chlorogenic acid in the propolis hydro-alcoholic extract. Our findings related to the anti-proliferative, anti-migration, and anti-tubulogenic actions on human umbilical vein endothelial cell line agree with the inhibitory effects in the in vivo vessel formation exerted by propolis extract under study. The results also suggest that autumnal propolis extract might be potentially instrumental in providing alternative tools for angiogenic disease therapeutics.

Developments in analytical techniques (GC-MS, LC-MS, 1H-, 13C-NMR, FT-MS, e.g.) are progressing rapidly and have been driven mostly by the requirements in the healthcare and food sectors. Simultaneous high-throughput measurements of several analytes at the level of the transcript (transcriptomics), proteins, (proteomics), and metabolites (metabolomics) are currently performed, producing a prodigious amount of data. Thus, the advent of omic studies has created an information explosion, resulting in a paradigm shift in the emphasis of analytical research of biological systems. The traditional approaches of biochemistry and molecular cell biology, where the cellular processes have been investigated individually and often independent of each other, are giving way to a wider approach of analyzing the cellular composition in its entirety, allowing achieving a quasi-complete metabolic picture.

Microporous, non-woven fibrous scaffolds made of poly(ethylene terephthalate) and chitosan were produced by electrospinning. Fiber morphology, diameter, pore size, and wettability were manipulated by varying the chemical composition of the electrospinning solution, i.e. chitosan concentration and molecular weight, and by post-electrospinning treatment with glutaraldehyde. In vitro studies were conducted using a fibroblast cell line toward a comprehensive understanding of how scaffolds characteristics can modulate the cell behavior, i.e. viability, adhesion, proliferation, extracellular matrix secretion, and three-dimensional colonization. Substantial differences were found as a result of scaffold morphological changes. Higher levels of adhesion, spreading, and superficial proliferation were achieved for scaffolds with smaller fiber and pore diameters while cell penetration and internal colonization were enhanced for scaffolds with larger pores. Additionally, the available area for cell adhesion, which is related to fiber and pore size, was a crucial factor for the viability of L929 cells. This paper provides significant insights for the development and optimization of electrospun scaffolds toward an improved biological performance.

Novel hybrid fibrous membranes with potential application on the biomedical field were successfully developed via electrospinning of blend solutions of two biocompatible and biodegradable polymers, poly (3-hydroxybutyrate-co-hydroxyvalerate) [PHBV] and chitosan. The effect of solvent, using different proportions of trifluoracetic acid (TFA) and 1,1,1,3,3,3-hexafluoro-2-isopropanol (HFIP), PHBV/chitosan ratio, and chitosan molecular weight on solution spinnability, fiber morphology and size, and in vitro degradation were investigated. Continuous nanofiber structures were obtained from pristine PHBV to a PHBV/chitosan ratio of 2:3 (w/w), at 10% (w/v) total polymer concentration. In general, main fiber average diameters increased as chitosan content and molecular weight increased and decreased with the decrease of HFIP content in the solvent. In vitro dissolution tests revealed that the hybrid fibers show much higher degradation rates than the neat PHBV.

In this work we report the preparation and characterization of nanofibrous mats electrospun from mixed solutions of poly(ethylene terephthalate) (PET) and chitosan, with potential applications in such areas as filtration, tissue scaffolds and protective clothing. Polymer compatibility in solution was rather low due to the dissimilarity in the chemical structure of both polymers. We have defined a suitable solvent to both the synthetic, typically hydrophobic polyester, and the biopolymer, and adequate concentrations and molecular weights in order to obtained miscibility of both polymers in solution and suitable electrospinning conditions. The effect of polymer ratio and chitosan molecular weight in the electrospun mat morphology, composition, mechanical and surface properties was evaluated by SEM, ATR-FTIR spectroscopy, and uniaxial tensile tests. The presence of chitosan increased the diameter and the size distribution of the fibers. The effect on the mechanical properties of the nanofibrous mats showed a complex nature dependent on chitosan molecular weight and concentration. Phase separation during solvent evaporation and fiber formation, taking place at varied extent depending on molecular mobility of one of the components, is suggested to explain the formation of hybrid continuous or core-sheath fibers.