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Polymeric films containing pomegranate peel extract (PPE) can act as a drug-delivery platform for topical treatment of candidiasis. The composition, mechanical resistance, and in vitro antifungal activity of a polymeric film containing PPE at 1.25 mg.mL−1 were investigated. Films were prepared using a solvent casting technique. The incorporation of PPE in the polymeric matrix gave rise to homogeneous, smooth, shiny, and yellowish-brown films. FTIR spectra of the film containing PPE showed differences without compromising the stability of the extract and the matrix. SEM analysis showed the existence of interruptions in the continuity of the films with extract, which promoted a reduction in the mechanical parameters without significantly changing the tensile strength and elongation at break. Films showed adequate mechanical properties and antifungal activity against Candida albicans, C. glabrata, C. krusei and C. tropicalis.

Common adversities as gastrointestinal discomfort are related to conventional administration of diclofenac potassium (DP), and thus the study of a new administration route based on gelatin/polycapr...

Polystyrene-b-poly(ethylene-co-butylene)-b-polystyrene-grafted maleic anhydride (SEBS-MA), a highly available block copolymer (BCP), was employed as a template to selectively guide the incorporatio...

Wound dressings can support healing by acting as physical barriers and drug delivery systems. The present study aimed to evaluate the biological activity of films containing pomegranate peel extract at 1.25% w/w prepared by the electrospinning technique for use as wound dressing. The extract was subjected to an in vitro cytotoxicity assay using fibroblasts. The formation of fibers was confirmed using scanning electron microscopy. Biocompatibility was analyzed by determining the hemolysis index, while the susceptibility of bacterial strains and a fungus was investigated using the disc diffusion method. The extract proved to be nontoxic with cell proliferation occurring at a concentration > 30 µg·mL-1. Photomicrograph images confirmed the formation of nanofibers. Films without or with the extract showed good hemocompatibility. The antimicrobial activity of films loaded with extract was demonstrated by the formation of zones of inhibition of Staphylococcus aureus, Staphylococcus epidermidis, and Candida albicans, suggesting that the release of the extract in the medium occurred at an adequate concentration to inhibit the proliferation of microorganisms. No zone of inhibition was observed for Escherichia coli. These results suggest that the film produced by electrospinning containing 1.25% w/w of the extract might serve as a bioactive wound dressing.

Binary high-density polyethylene (HDPE) composites with natural microtalc (TN), semicrystalline synthetic nanotalc (NTC) and amorphous synthetic (NTA) nanotalc with 1% m/m content were prepared by mixing in the molten state in a twin-screw extruder followed by injection molding. The thermal properties were investigated by thermogravimetric analysis (TGA) and by differential scanning calorimetry (DSC) and showed that the thermal stability of the composites was slightly improved with the incorporation of talcs. The morphology of composites, studied using scanning electron microscopy (SEM), revealed a good dispersion of synthetic talc in composites. The dynamic-mechanical (DMA) properties of the samples were analyzed and showed that the storage modulus was improved with the incorporation of talcs. The tensile strength and impact strength showed a moderate drop for all composites, up to 7.5% and 8.4% respectively, while the elongation at break showed a marked gain of 50% for the HDPE/NTA sample. These results suggest that NTA particles act, with great efficiency, as an internal lubricating agent or plasticizer. This research showed that NTA is a favorable filler when the main objective is to improve the ductility and the rigidity/toughness balance of HDPE and when some loss of tensile strength and impact resistance are tolerated.

Wound dressings can support healing by acting as physical barriers and drug delivery systems. The present study aimed to evaluate the biological activity of films containing pomegranate peel extract at 1.25% w/w prepared by the electrospinning technique for use as wound dressing. The extract was subjected to an in vitro cytotoxicity assay using fibroblasts. The formation of fibers was confirmed using scanning electron microscopy. Biocompatibility was analyzed by determining the hemolysis index, while the susceptibility of bacterial strains and a fungus was investigated using the disc diffusion method. The extract proved to be nontoxic with cell proliferation occurring at a concentration > 30 µg·mL-1. Photomicrograph images confirmed the formation of nanofibers. Films without or with the extract showed good hemocompatibility. The antimicrobial activity of films loaded with extract was demonstrated by the formation of zones of inhibition of Staphylococcus aureus, Staphylococcus epidermidis, and Candida albicans, suggesting that the release of the extract in the medium occurred at an adequate concentration to inhibit the proliferation of microorganisms. No zone of inhibition was observed for Escherichia coli. These results suggest that the film produced by electrospinning containing 1.25% w/w of the extract might serve as a bioactive wound dressing.

Poly(Ɛ-caprolactone) (PCL) electrosprayed nanoparticles (NPs) containing Amphotericin B (AMB) were prepared for the treatment of leishmaniasis. Two variations of PCL nanoparticles with positive sur...

In this study the surface of bio-based polyurethane foam was enriched with different contents of catalyst residue from the petroleum industry. The foams were prepared with different residue contents, 20, 50, and 80 wt% relative to the total mass of the polyols and were characterized by several techniques, with X-ray diffraction, X-ray fluorescence spectrometry, field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, microtomography, Fourier transform infrared spectroscopy and thermogravimetric. To determine the removing process the effects of various operating parameters, pH of the solution (2–12), initial concentration of pesticides (5–50 mg L−1), contact time (15–1440 min), and amount of adsorbent (30–400 mg) were investigated in a batch adsorption technique. The specific surface area of the residue was determined by the BET method as up to 150 m2/g and mean pore diameter of 4.20 ± 0.42 nm (mesopore), which explains the excellent results of the materials in the adsorption process. The high adsorption capacity is probably due to the presence of highly concentrated catalyst residue on the foam surface. Trifluralin pesticide was removed in water using these polyurethane foams with 20.0 mg L−1 initial concentration of herbicide, 30.0 mg adsorbent mass of, 5.0 pH, and 25.0 °C temperature. The chemically prepared foams with 50 wt% residue (PURC50) have higher adsorption capacities (70%) and can be used to remove trifluralin from natural waters effectively. The efficiency of removing the herbicide increased to 83% with the use of 400.0 mg adsorbent mass. The adsorption efficiency of the pure catalyst residue reaches a maximum (95.3%). The established adsorption method was appropriate for adsorption of trifluralin in contaminated waters.

Aim: To enhance the tretinoin (TRE) safety profile through the encapsulation in nanostructured lipid carriers (NLC). Materials & methods: NLC-TRE was developed using a 23 experimental factorial design, characterized (HPLC, dynamic light scattering, differential scanning calorimetry, x-ray diffraction analysis, transmission electron microscopy, cryo-transmission electron microscopy) and evaluated by in vitro studies and in healthy volunteers. Results: The NLC-TRE presented spherical structures, average particle size of 130 nm, zeta potential of 24 mV and encapsulation efficiency of 98%. The NLC-TRE protected TRE against oxidation (p

Binary and ternary systems of HDPE/EVA with amorphous nanotalc contents of 1% m/m were prepared by mixing the components in the molten state in a twin-screw extruder followed by injection molding. The thermal properties were investigated by thermogravimetric analysis (TGA) and by differential scanning calorimetry (DSC) and showed that the thermal stability of the nanocomposites was slightly improved with nanotalc incorporation. The morphology of the nanocomposites, investigated by scanning electron microscopy (SEM), revealed a good dispersion of the nanotalc layers within the polymer matrix, and changes of the morphology from sea-island to co-continuous as a function of the composition, as well as refinement of the size of EVA phase. The dynamic mechanical properties of the samples showed that the storage modulus increased with a diffuse pattern with the addition of the nanotalc, while the tan δ curve showed an intense peak for the 50EVA/NTA nanocomposite at the Tg of EVA. The mechanical properties of nanocomposites were studied by tensile and impact tests. A remarkable behavior was verified for the 50EVA/NTA nanocomposite, which manifested a characteristic of super ductility and high damping capacity, showing that the amorphous nanotalc can be used as a high-performance filler to improve the ductility of polymeric systems.

Adapalene (AD) is one of the main retinoids used in the topical therapy of acne, an extremely common skin disease usually associated with psychological morbidity. However, like other retinoids, AD is frequently associated with skin irritation. To overcome the skin irritation, we proposed the encapsulation of AD in solid lipid nanoparticles (SLNs) using the ion pair strategy. The developed SLN-AD was characterized by high-performance liquid chromatography, differential scanning calorimetry, X-ray diffraction, synchrotron small-angle X-ray scattering, and transmission electron microscopy. In vitro permeation tests using porcine skin and in vivo mice skin irritation test were performed to evaluate, respectively, the drug’s skin distribution and the skin irritation. The characterization studies were able to demonstrate that the proposed strategy effectively provided high AD encapsulation in SLNs and its incorporation into a hydrophilic gel. Sustained release, epidermal targeting, and less skin irritation were observed for SLN-AD gel in comparison to the marketed AD gel. The studies demonstrated that the encapsulation of AD in SLNs through the formation of an ion pair is a valuable alternative to diminish the adverse skin reactions caused by AD and can optimize patient adherence to treatment.

This work aims to develop, characterize, and evaluate the anticancer activity of solid lipid nanoparticles (SLN) containing doxorubicin (DOX), an antitumoral from the antracycline class, and sclareol (SC), a lipophilic labdene diterpene (SLN-DOX-SC). The SLN were characterized by Differential Scanning Calorimetry (DSC), X-ray Diffraction (XRD), Small Angle X-ray Diffraction (SAXS), in vitro release, transmission electron microscopy, and polarized light microscopy. Evaluation of cell viability was performed in two cell cultures: MCF-7 (human breast cancer) and 4T1 (murine breast cancer). The SLN showed a size in the range of 128 nm, negative zeta potential, DOX encapsulation efficiency (EE) of 99%, and drug loading (DL) of 66 mg/g. Characterization of the formulation by DSC, XRD, and SAXS revealed the presence of DOX inside the nanoparticles of SLN and suggested increased expulsion/release of this drug when associated with SC. The release profiles revealed that the SLN-DOX-SC showed controlled release of DOX at pH 7.4 with enhanced drug release at low pH, useful for cancer treatment. The SLN-DOX-SC demonstrated to be more effective than the free DOX against 4T1 cells. So, the developed SLN efficiently encapsulate DOX and SC and show good potential as an alternative for cancer treatment.

The effect of pores with different diameters in polyethylene media on the process of ammonia nitrification during the maturation of biofilters is evaluated. Four types of media were produced: M1 without pores, M2 with 40–112 μm in diameter pores, M3 with 125–187 μm diameter pores, and M4 with 312–437 μm diameter pores. Ammonia concentrations were statistically equal among media. On the majority of days, nitrite concentrations were lowest for M1 and M2, intermediate for M3, and highest for M4. Increased pore diameter favored the formation of biofilm in the interior, but the pores obtained in the expansion process were not interconnected, which may have caused low oxygenation of the water in the internal area. It was concluded that porosity did not reduce biofiltration time and did not increase the efficiency of nitrification of ammonia.

To investigate ways of mitigating the contamination of water with herbicides, which is a well-recognized global problem, we prepared natural resource-based polyurethane foams containing different amounts of petroleum industry catalyst residue (RC) and tested them as atrazine (ATZ, a common herbicide) sorbents in aqueous solutions. The above sorbents were characterized by infrared spectroscopy, electron microscopy, microtomography, thermogravimetric analysis, and X-ray diffraction. The adsorption/desorption of ATZ thereon was investigated as a function of foam composition, pH, initial ATZ concentration, and time. The obtained results showed that the porosity, pore size, and pore interconnectivity of the prepared sorbents were well suited for optimal ATZ removal. At pH 2, foams with high RC contents achieved higher ATZ removal efficiencies (e.g., 25%) than the pristine foam (12%). Conversely, ATZ removal was disfavored at high pH, which was attributed to restricted ATZ–sorbent interactions due to changes in the sorbent surface charge. The presence of other species (such as pectin, which is usually found in fruits) did not interfere with ATZ removal. ATZ desorption was most effective at high pH, enabling the regeneration and re-use of sorbents and thus reducing large-scale application costs.

Polystyrene (PS) was blended with shape memory polyurethanes (SMPU). Styrene blocks were grafted onto PU chains during SMPU synthesis to yield a modified SMPU with a higher affinity towards PS. Furthermore, blends containing a compatibilizer, poly (styrene-co-maleic anhydride) (SMA), were also prepared by melt mixing the components. The non-compatibilized blends display phase separated structures with PS rich and SMPU rich phases, which were less evident in blends prepared with either the modified SMPU or SMA compatibilizer. The elastic storage modulus of PS was less affected when blended with SMPU in samples containing modified SMPU with styrene grafts. The impact strength of the blends with higher contents of SMPU modified with styrene blocks (25 and 50 wt.%), after shape recovery, was higher than the impact strength of neat PS. The incorporation of shape memory polymers into a brittle polymer matrix is a potential strategy to improve the toughness by external stimuli.

Annatto natural colorant was extracted from annatto seeds (Bixa Orellana L.) by using ultrasound. Structural characterization of the extract was done by FTIR. The aim of the present work was the developement and characterization of biodegradable colored films based on poly(3-hydroxybutyrate) by using annatto colorant. The annatto content in the films was varied from 0.2 to 3.0% (w/w). The lightfastness of colored films when exposed to UVA radiation was controlled by using RGB color system. In color image processing, a pixel is often defined by three values corresponding to the tristimuli R (Red), G (Green) and B (Blue). With the addition of the annatto colorant, photodegradation of films under UVA exposure seemed to be improved. The good thermal stability of the colored film with 3.0% (w/w) of annatto colorant was confirmed by thermogravimetric analysis. Surface morphology of the colored film with 3.0% (w/w) of annatto colorant was examined by SEM prior and after 240 h of UVA exposure. The SEM micrographs suggested that annatto colorant has acted as hiding agent, reducing the photodegradation processes.

Transparent, soft, flexible, mechanically resistant films, which are ideal for use as wound dressings were prepared in the presence of 2% papain, a proteolytic enzyme that can play a role in the chemical debridement of the skin and can accelerate the healing process. The films, based on poly(vinyl alcohol):calcium alginate blends with increasing concentrations of polysaccharide (10, 20, and 30% v/v), were obtained by casting method. FTIR and DSC analyses were performed to assess the composition and miscibility of blends. Mechanical properties such as tensile strength, elasticity modulus, and elongation at breakpoint were evaluated. The influence of different concentrations of calcium alginate on physical attributes of films like wettability, swelling capacity and mechanical properties was determined. The stability of papain in the films was assessed indirectly by hemolytic activity assay employing direct contact method and confirmed by technique based on blood agar diffusion. Preliminary cytotoxicity was evaluated with the XTT method. The results showed that at the polymer concentrations tested, the blends were miscible. The increase in the content of the calcium alginate increased the wettability and swelling capacity of the films, which is desirable in wound dressings. On the other hand, mechanical resistance decreased without causing breakage of the films during the swelling tests. The hemolytic activity of the films was maintained during the studied period, suggesting the stability of papain in the proposed formulations. Cellular viability indicated that the films were non-toxic. The analysis of the results showed that it is possible to prepare interactive and bioactive wound dressing containing papain from blends of PVA and calcium alginate polymers.

Summary Purpose To evaluate the antiangiogenic activity of bevacizumab-loaded polyurethane using two animal models of neovascularization. Methods The percentage of blood vessels was evaluated in a chicken chorioallantoic membrane model ( n = 42) and in the rabbit cornea ( n = 24) with neovascularization induced by alkali injury. In each model, the animals were randomly divided into the groups treated with the bevacizumab-loaded polyurethane device, phosphate-buffered-saline (negative control) and bevacizumab commercial solution (positive control). Clinical examination, as well as histopathological and immunohistochemical evaluation, were performed in the rabbit eyes. Microvascular density in hot spot areas was determined in semi-thin sections of corneal tissue by hematoxylin-eosin staining and factor VIII immunohistochemistry. Immunohistochemical analysis was also performed to evaluate VEGF expression. Results In the evaluated models, the use of bevacizumab (Avastin ® ) and the bevacizumab-loaded polyurethane device led to similar results with regard to inhibition of neovascularization. In the chorioallantoic membrane model, the bevacizumab-loaded polyurethane device reduced angiogenesis by 50.27% when compared to the negative control group. In the rabbit model of corneal neovascularization, the mean density of vessels/field was reduced by 46.87% on analysis of factor VIII immunohistochemistry photos in the bevacizumab-loaded polyurethane device group as compared to the negative control (PBS) sections. In both models, no significant difference could be identified between the bevacizumab-loaded polyurethane device and the positive control group, leading to similar results with regard to inhibition of neovascularization. Conclusions The present study shows that the bevacizumab-loaded polyurethane device may release bevacizumab and inhibit neovascularization similarly to commercial bevacizumab solution in the short-term.

The nondestructive nature of X-ray microtomography (µCT) associated with its suitable temporal resolution, obtained with the use of high energy polychromatic radiation from electron acceleration rings, allows in situ investigations of the damage evolution process during tensile loading in composite materials. In this context, the development of adequate scientific instrumentation as well as the understanding of the corresponding technology by research groups is paramount to guarantee reliability of the obtained results. In the present work, a miniaturized universal testing machine (tensile, compression and fatigue) was developed to be applied in in situ µCT experiments using synchrotron radiation with innovative technology. The equipment has a uniaxial load capacity of up to 300 N with 1 N resolution and can impose 0.01 mm resolution displacements following controlled deformation rates. In order to validate the developed equipment, tensile test results performed on sub-sized and standard annealed copper specimens were compared and in situ µCT tensile tests were performed in glass-fiber-reinforced polypropylene matrix composites at the Laboratorio Nacional de Luz Sincrotron (LNLS) in Campinas (SP, Brazil). Data analysis was performed by applying image processing techniques to successive tomograms in order to monitor crack propagation in the initial stages of damage evolution. The results obtained allowed the clarification of crack propagation mechanisms in the investigated composite materials and demonstrated the viability of the equipment’s intended application.

In this work, hybrid hydrogels were prepared based on poly(acrylic acid-co-acrylamide) hydrogels (Gel) and self-assembled nanostructured polyaniline (PANI). These hybrid hydrogels were prepared by in situ UV-assisted aniline polymerization during hydrogel network formation in a controlled interfacial reaction. They were then tested as flexible quasi-solid electrolytes with a counter electrode in dye-sensitized solar cells. This electrolyte-counter electrode system was prepared on top of a titanium dioxide layer deposited on a transparent and conductive anode electrode (ITO). Three different nanostructured Gel–PANI hybrid hydrogels were fabricated by employing different PANI concentrations and used for constructing electrolyte–counter electrode systems that displayed conductivities between 0.003 S/cm and 0.02 S/cm. Dye-sensitized solar cells (DSSC) that had the configuration ITO/TiO2/Gel–PANI/ITO were prepared and tested using natural dye extracted from Myrciaria cauliflora. The energy conversion efficiency was evaluated under AM1.5 (100 mW/cm2) light irradiation and was found to reach values above 2.0%. The device’s energy conversion efficiency was found to be higher than those of others with the same natural dye. The process proved to be fast and facile, and it utilized an inexpensive natural dye.

Hybrid delivery systems can release multiple drugs with different profiles and have several applications, including skin dressing. In this work, the co-solvent technique was used for the preparation of nanometric vesicles based on poly(styrene-b-ethylene oxide) block copolymer (BCPVs) containing adapalene (AD). The BCPVs were incorporated into collagen and gelatin matrices together with free AD and silver sulfadiazine (SSD). The AD content of BCPVs and their release capacity were analyzed by using ultraviolet-visible spectroscopy (UV–Vis). The gelatin and collagen matrices were evaluated for their ability to release AD and SSD through an in vitro release study. The obtained results confirmed that the production of empty and AD-loaded BCPVs was viable. The degree of AD encapsulation in BCPVs was 9.0% and the in vitro test revealed a constant, slow, and prolonged release of AD content from AD-loaded BCPVs. The combination of free and encapsulated multiple drugs in hybrid delivery systems based on gelatin and collagen matrices was shown to act as a skin dressing that combined the progressive release of large amounts of drugs within the first hours of use (to restrict infection) with a more prolonged and slow release of AD to enhance skin healing.

In this work, the effect of synthesizing shape memory polyurethanes in aqueous dispersions instead of in organic solvents on the structure and properties of the obtained polymers was investigated. Shape memory polyurethanes based on polycaprolactone diol and isophorone diisocyanate were synthesized by two routes: (1) aqueous dispersion (PU/SMWATER) and (2) dissolution in THF (PU/SMTHF). The samples were analyzed by infrared spectroscopy (FTIR), X-ray diffraction (XRD), static light scattering (SLS), atomic force microscopy (AFM), differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), and mechanical tests. The aqueous dispersion method led to the production of polyurethanes with a higher degree of phase separation and a higher degree of crystallinity. The morphology of the obtained polyurethanes demonstrated that PU/SMWATER displays a structure with better defined phase separated domains. The polyurethanes exhibited similar average molar masses, soft segment glass transitions (Tgs) and mechanical properties. The lower degrees of phase separation and crystallinity of the PU/SMTHF led to lower values for the shape memory properties (shape recovery ratio (Rr)). The observed changes in the structure of the polyurethanes due to the replacement of organic solvent by an aqueous dispersion during their syntheses confirmed the preparation of shape memory polyurethanes with enhanced shape memory properties. POLYM. ENG. SCI., 2016. © 2016 Society of Plastics Engineers

Packaging materials based on natural polymers are becoming popular because these polymers are derived from renewable resources and can display biodegradability. However, natural polymers are typically highly hydrophilic, and packaging films produced with them can absorb water, leading to dimensional changes and reductions in mechanical properties. In this work, films of thermoplastic starch (TPS) and blends of TPS/low-density polyethylene (LDPE) were prepared, and their surfaces were decorated to alter their hydrophilic characteristics. Micro- (polymer microspheres) and nano-components (polycaprolactone electrospun nanofibers) were deposited on the surface of starch and its blends with LDPE. Nanofibers containing silver sulfadiazine were also used to decorate the starch and its blends to change the topography (evaluated by SEM and atomic force microscopy) and to provide anti-bacterial properties. High values of contact angle (CA) and low values of CA hysteresis were measured for the modified surfaces, including a CA higher than 150° and a hysteresis lower than 10°. Therefore, it was demonstrated that the intrinsically hydrophilic surfaces of biodegradable natural polymers could be altered by creating topographical patterns through decoration with nano-/micro-components to generate hydrophobic and even superhydrophobic features that can be useful in minimizing the water absorption of these materials.

Soft actuators with a fast response to low electrical potentials are critical for wearables and robotics. In this work, hybrid hydrogel nanofiber mats were prepared and tested as soft actuators. Hybrid hydrogel nanofibers were produced by combining electrospinning with in situ photopolymerization of the hydrogel and polymerization of aniline during the formation of the nanofibers. The electrical conductivity of the obtained nanofibers measured by the 4-probe method reached values close to 0.01 S cm−1. Images obtained by atomic force microscopy in conductive mode (I-AFM) were also successfully acquired and proved the conductive and nanometric nature of the hybrid hydrogel nanofibers. Infrared spectra (FTIR) showed that photopolymerization of the hydrogel precursors and aniline polymerization during nanofiber formation were effectively achieved. The elastic modulus of the nanofibers was estimated from AFM nanoindentations, and values close to 10 MPa for the swollen samples were obtained. The swelling ability of the hybrid hydrogel nanofibers was evaluated by comparing AFM images of the nanofibers in dried and swollen conditions to reveal that the swelling degree is reduced by the presence of polyaniline in the nanofibers. The obtained hybrid hydrogel nanofiber mats were tested as actuators in an electrochemical cell. The application of low voltage (1 V) in a 1 MΩ cm water led to fast (2.5 mm s−1) and reversible displacement of the samples. During actuation, thin nanofiber mats could also withstand forces on the order of 80 μN that were measured by coupling the electrochemical cell to a load cell.

Chronic wounds constitute a serious public health problem, and developing pharmaceutical dosage forms to ensure patient comfort and safety, as well as optimizing treatment effectiveness, are of great interest in the pharmaceutical, medical and biomaterial fields. In this work, the preparation of films based on blends of poly(vinyl alcohol), starch and poly(acrylic acid), polymers widely used as pharmaceutical excipients, and pomegranate peel extract (PPE), a bioactive compound with antimicrobial and healing activities relevant to the use as a bioactive wound dressing, was proposed. Initially, the minimum inhibitory concentration (MIC) of the PPE was investigated by an in vitro method. Then, the best concentration of the PPE to be used to prepare the films was researched using an antimicrobial susceptibility test with the disc diffusion method. The microbiological assay was performed in films prepared by the solvent casting method in the presence of two concentrations of PPE: 1.25% w/v and 2.5% w/v. Films containing the lower PPE concentration showed antimicrobial activity against Staphylococcus aureus and Staphylococcus epidermidis, with a difference that was not considered statistically significant when compared to the higher concentration of the extract. Therefore, the films prepared with the lower proportion of PPE (1.25% w/v) were considered for the other studies. The miscibility and stability of the extract in the films were investigated by thermal analysis. Parameters that determine the barrier properties of the films were also investigated by complementary techniques. Finally, in vitro biological tests were performed for safety evaluation and activity research. Analysis of the results showed that the incorporation of the higher proportion of starch in the blend (15% v/v) (PVA:S:PAA:PPE4) yielded smooth, transparent, and domain-free films without phase separation. Additionally, the PVA:S:PAA:PPE4 film presented barrier properties suitable for use as a cover. These films, when subjected to the in vitro hemolytic activity assay, were nonhemolytic and biocompatible. No toxicity from the extract was observed at the concentrations studied. The results of the wound healing in vitro test showed that films containing 1.25% PPE are efficient in reducing the scratch open area, provoking almost total closure of the scratches within 48 h without cytotoxicity.

Electrospinning technique has been explored to produce nanofibers incorporated with drugs as alternative drug delivery systems for therapeutic purposes in various organs and tissues. Before such systems could potentially be used, their biocompatibility must be evaluated. In this study, dexamethasone acetate-loaded poly(ɛ-caprolactone) nanofibers (DX PCL nanofibers) were developed for targeted delivery in the vitreous cavity in the treatment of retinal diseases. Ocular biocompatibility was tested in vitro and in vivo. DX PCL nanofibers were characterized by scanning electron microscopy (SEM) and Fourier Transform InfraRed spectroscopy (FTIR) and the in vitro drug release from nanofibers was evaluated. The in vitro biocompatibility of DX PCL nanofibers was tested on both ARPE-19 and MIO-M1 cells using the cytotoxicity (MTT) test by morphological studies based on staining of the actin fibers in ARPE-19 cells and GFAP in MIO-M1 cells. The in vivo biocompatibility of DX PCL nanofibers was investigated after intravitreous injection in the rat eye, using spectral domain Optical Coherence Tomography (OCT) imaging of the retina. SEM results indicated that nanometric fibers were interconnected in a complex network, and that they were composed of polymer. FTIR showed that polymer and drug did not chemically interact after the application of the electrospinning technique. PCL nanofibers provided controlled DX release for 10 days. DX PCL nanofibers were not cytotoxic to the ocular cells, allowing for the preservation of actin fibers and GFAP in the cytoplasm of ARPE-19 and MIO-M1 cells, respectively, which are biomarkers of these ocular cell populations. DX PCL nanofibers did not affect the retinal and choroidal structures, and they did not induce abnormalities, hemorrhages, or retinal detachment, suggesting that the nanofibers were well tolerated. In eyes receiving DX PCL nanofibers, SD-OCT images were corroborated with histological analysis of neuroretina and choroid, which are ocular tissues that are extremely sensitive to toxic agents. Finally, the preservation of cone and rod photoreceptors indicated the light sensitivity of the animals. In conclusion, DX PCL nanofibers exhibited ocular biocompatibility and safety in the rodent eye and allow the release of dexamethasone. Further studies are required to appreciate the potential of these new drug delivery systems for the treatment of retinal diseases.

Vulvovaginal candidiasis is an inflammation localized in the vulvovaginal area. It is mostly caused by Candida albicans. Its treatment is based on the systemic and local administration of antifungal drugs. However, this conventional therapy can fail owing to the resistance of the Candida species and noncompliance of patients. Amphotericin B-loaded poly(lactic-co-glycolic acid) nanofibers are single-use, antifungal, controlled drug delivery systems, and represent an alternative therapeutic scheme for the local treatment of vulvovaginal candidiasis. Nanofibers were characterized by analytical techniques and with an in vitro drug delivery study. In vitro and in vivo fungicidal activity of amphotericin B released from nanofibers was evaluated using the agar diffusion method and an experimental murine model of vulvovaginal candidiasis, respectively. Analytical techniques showed that amphotericin B was physically mixed in the polymeric nanofibers. Nanofibers controlled the delivery of therapeutic doses of amphotericin B for 8 consecutive days, providing effective in vitro antifungal activity and eliminated the in vivo vaginal fungal burden after 3 days of treatment and with only one local application. Amphotericin B-loaded poly(lactic-co-glycolic acid) nanofibers could be potentially applied as an alternative strategy for the local treatment of vulvovaginal candidiasis without inducing fungal resistance, yet ensuring patient compliance.

Age-related macular degeneration (AMD) is a degenerative ocular disease that affects the central retina. It is considered the main cause of blindness and loss of vision worldwide. Angiogenic factors are associated with AMD, which has led to the use of antiangiogenic drugs, such as bevacizumab, to treat the disease using frequent intravitreal injections. In the present study, biodegradable core shell nanofibers containing bevacizumab were prepared by the coaxial electrospinning technique. It is thought that the shell could control the release of the drug, while the core would protect and store the drug. Poly(caprolactone) (PCL) and gelatin were used to form the shell of the nanofibers, while poly(vinyl alcohol) (PVA) and bevacizumab comprised the core. The nanofibers were characterized using microscopy techniques, thermal analysis, and FTIR. The results showed that core-shell nanofibers were produced as designed. Bevacizumab activity was evaluated using a chicken embryo chorioallantoic membrane (CAM) assay. An enzyme-linked immunosorbent assay was used to quantify the amount of the drug released from the different nanofibers in vitro. The toxicity of the nanofibers was evaluated in human retinal pigment epithelial (ARPE) cells. The CAM results demonstrated that bevacizumab maintained its antiangiogenic activity when incorporated into the nanofibers. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) tests revealed that the nanofibers showed no cellular toxicity, even in the presence of bevacizumab. The core-shell structure of the nanofibers reduced the release rate of bevacizumab compared with PVA nanofibers. The bevacizumab-loaded biodegradable nanofibers presented interesting properties that would potentially constitute an alternative therapy to intravitreal injections to treat AMD.

The present study concerns an innovative technology for the extraction of chromium, which is present in leather industry wastes, to facilitate the application of chromium-free protein (collagen) as a slow-release drug carrier in skin treatment when there are burns, ulcers and infected wounds. The study focuses on the excavation of industrial landfills, which are currently saturated, to recycle residual wet blue leather to obtain purified collagen films. These films, as biocompatible materials, offer great potential as drug carriers. We test here the material's ability to retain/release silver sulfadiazine and its potential to impede the proliferation of various bacteria. The very promising results demonstrate that the material possesses a high capacity for delivery of the drug and great efficiency in inhibiting bacteria proliferation. The obtained results indicate that the treatment proposed for chromium removal is capable of generating a material rich in amino acids that can be transformed into films with no cellular incompatibility, therefore creating a new field of study from a material that presents a serious environmental liability.

The great quantity of synthetic plastic discarded inappropriately in the environment is forcing the search for materials that can be reprocessable and biodegradable. Blends between synthetic polymers and natural and biodegradable polymers can be good candidates of such novel materials because they can combine processability with biodegradation and the use of renewable raw materials. However, traditional polymers usually present high levels of recyclability and use the well-established recycling infrastructure that can eventually be affected by the introduction of systems containing natural polymers. Thus, this work aims to evaluate the effect of reprocessing (simulated here by multiple extrusions) on the structure and properties of a low density polyethylene/thermoplastic starch (LDPE/TPS) blend compared to LDPE. The results indicated that multiple extrusion steps led to a reduction in the average size of the starch-rich phases of LDPE/TPS blends and minor changes in the mechanical and rheological properties of the materials. Such results suggest that the LDPE/TPS blend presents similar reprocessability to the LDPE for the experimental conditions used.