Electrospun Poly (Vinyl Alcohol) Nanofibrous Mat Loaded with Green Propolis Extract, Chitosan and Nystatin as an Innovative Wound Dressing Material.

Purposes: The objective of this work was to produce and characterise biodegradable poly (vinyl alcohol) (PVA) nanofibre loaded with green propolis extract (GPE), chitosan (CS) and nystatin (NYS) alone and in mixtures as a potential wound dressing material. Methods: The GPE, NYS and CS1% were loaded in electrospinning compositions based on PVA 7%, 8% and 12% solubilised in milli-Q water or a mixture of water and glacial acetic acid. The electrospinning compositions without actives (blank) and those loaded with actives were characterised by determining the pH, electrical conductivity and rheological properties. An image analysis procedure applied to photomicrographs obtained by scanning electronic microscopy (SEM) allowed the determination of the nanofibres' diameter distribution and average surface porosity. The disintegration time and swelling ratio of the nanofibre mats were also determined. Results: The physicochemical parameters of the electrospinning compositions (pH, electrical conductivity and rheology) and the incorporated active ingredients (GPE, CS and NYS) affected the electrospun nanofibre mats properties. The electrospun nanofibres' mean diameters and surface porosity ranged from 151.5 to 684.5 nm and from 0.29 ± 0.04 to 0.50 ± 0.05. The PVA/CS electrospun nanofibres fibres exhibited the smallest diameters, high surface porosity, water absorption capacity and disintegration time. The characteristics of the PVA/CS nanofibres mat associated with the biodegradability of the polymers make them a novel material with the potential to be applied as wound and burn dressings.

A Sustainable Recycling Alternative: Electrospun PET-Membranes for Air Nanofiltration.

Currently, the inappropriate disposal of plastic materials, such as polyethylene terephthalate (PET) wastes, is a major environmental problem since it can cause serious damage to the environment and contribute to the proliferation of pathogenic microorganisms. To reduce this accumulation, PET-type bottles have been recycled, and also explored in other applications such as the development of membranes. Thus, this research aims to develop electrospun microfiber membranes from PET wastes and evaluate their use as an air filter media. The solution concentrations varied from 20 to 12% wt% of PET wastes, which caused a reduction of the average fiber diameter by 60% (from 3.25 µm to 1.27 µm). The electrospun filter membranes showed high mechanical resistance (4 MPa), adequate permeability (4.4 × 10-8 m2), high porosity (96%), and provided a high collection efficiency (about 100%) and low-pressure drop (212 Pa, whose face velocity was 4.8 cm/s) for the removal of viable aerosol nanoparticles. It can include bacteria, fungi, and also viruses, mainly SARS-CoV-2 (about 100 nm). Therefore, the developed electrospun membranes can be applied as indoor air filters, where extremely clean air is needed (e.g., hospitals, clean zones of pharmaceutical and food industry, aircraft, among others).

Development of Filter Media by Electrospinning for Air Filtration of Nanoparticles from PET Bottles.

Air pollution and solid pollution are considered global problems, and endanger human health mainly due to the emission of fine particulate matter released into the atmosphere and improper disposal of post-consumer plastic bottles. Therefore, it is urgent to develop filter media to effectively protect the public. The properties of plastics make them potential candidates for nanofiber mat formers due to their attractive structural and mechanical characteristics. This work aims to produce and evaluate novel PET electrospun fibers dispensed with the use of support materials to be used as filter media to remove nanoparticles from the air. The electrospinning process was carried out by changing the concentration of the polymer solution, the needle diameter, and the electrospinning processing time at two rotation speeds. The average diameters of the micro- and nanofibers of the filter media produced ranged from 3.25 µm to 0.65 µm and it was possible to conclude that, as the size of the fibers decreased, the mechanical strength increased from 3.2 to 4.5 MPa. In filtration tests, a collection efficiency of up to 99% with low-pressure drops (19.4 Pa) was obtained for nanoparticles, demonstrating high quality factor filter media, which could be applicable in gas filtration.

Biodegradable CA/CPB electrospun nanofibers for efficient retention of airborne nanoparticles.

The increase of the industrialization process brought the growth of pollutant emissions into the atmosphere. At the same time, the demand for advances in aerosol filtration is evolving towards more sustainable technologies. Electrospinning is gaining notoriety, once it enables to produce polymeric nanofibers with different additives and also the obtaining of small pore sizes and fiber diameters; desirable features for air filtration materials. Therefore, this work aims to evaluate the filtration performance of cellulose acetate (CA) nanofibers and cationic surfactant cetylpyridinium bromide (CPB) produced by electrospinning technique for retention of aerosol nanoparticles. The pressure drop and collection efficiency measurements of sodium chloride (NaCl) aerosol particles (diameters from 7 to 300 nm) were performed using Scanning Mobility Particle Sizer (SMPS). The average diameter of the electrospun nanofibers used was 239 nm, ranging from 113 to 398 nm. Experimental results indicated that the nanofibers showed good permeability (10-11 m2) and high-efficiency filtration for aerosol nanoparticles (about 100 %), which can include black carbon (BC) and the new coronavirus. The pressure drop was 1.8 kPa at 1.6 cm s-1, which is similar to reported for some high-efficiency nanofiber filters. In addition, it also retains BC particles present in air, which was about 90 % for 375 nm and about 60 % for the 880 nm wavelength. Finally, this research provided information for future designs of indoor air filters and filter media for facial masks with renewable, non-toxic biodegradable, and potential antibacterial characteristics.

Influência do dreno pleural sobre a dor, capacidade vital e teste de caminhada de seis minutos em pacientes submetidos à ressecção pulmonar / Influence of pleural drainage on postoperative pain, vital capacity and six-minute walk test after pulmonary resection

OBJETIVO: Avaliar a influência do dreno pleural sobre a distância percorrida no teste de caminhada de seis minutos, da intensidade da dor e da capacidade vital de pacientes submetidos à ressecção pulmonar. MÉTODOS: Foram avaliados treze pacientes consecutivos, internados na Enfermaria da Cirurgia de Tórax do Hospital São Paulo, submetidos à drenagem pleural fechada (dreno tubular multiperfurado de 0,5 polegada), no período pós-operatório de ressecção pulmonar (lobectomia, segmentectomia e nodulectomia). A opção pela retirada do dreno seguiu critérios clínicos definidos por médicos da equipe cirúrgica alheios ao estudo. A determinação da capacidade vital, da intensidade da dor através da escala visual analógica de dor e da distância percorrida no teste de caminhada de seis minutos foram realizadas 30 min antes da retirada do dreno e 30 min após. A análise estatística dos dados foi realizada através do teste t pareado, com nível de significância estabelecido em 0,05. RESULTADOS: Após a retirada do dreno, os valores obtidos na avaliação da escala visual analógica de dor foram significativamente menores (3,46 cm vs. 1,77 cm; p = 0,001), e a distância percorrida no teste de caminhada de seis minutos foi significativamente maior (374,34 m vs. 444,62 m; p = 0,03). A capacidade vital antes e após a retirada do dreno não foi alterada de forma significativa (2,15 L vs. 2,25 L, respectivamente; p = 0,540). CONCLUSÕES: Os resultados deste estudo sugerem que a presença do dreno pleural é um importante fator associado à dor pós-operatória e à limitação funcional em pacientes submetidos à ressecção pulmonar.

OBJECTIVE: To evaluate the influence of pleural drainage on the distance covered on the six-minute walk test, pain intensity and vital capacity in patients submitted to pulmonary resection. METHODS: Thirteen consecutive patients from the Thoracic Surgery Infirmary of Hospital São Paulo, Brazil, submitted to closed pleural drainage (0.5-in multiperforated chest tube) in the postoperative period following pulmonary resection (lobectomy, segmentectomy and pulmonary nodule resection) were evaluated. The decision for chest tube removal followed clinical criteria defined by the surgical team, who did not participate in the study. Vital capacity, pain intensity (using a visual analog pain scale) and the distance covered on the six-minute walk test were determined 30 min prior to and 30 min after the removal of the chest tube. The statistical analysis was performed using paired t-tests, and the level of significance was set at 0.05. RESULTS: After the removal of the chest tube, the visual analog scale pain scores were significantly lower (3.46 cm vs. 1.77 cm; p = 0.001) and the distance covered on the six-minute walk test was significantly higher (374.34 m vs. 444.62 m; p = 0.03). Vital capacity prior to and after chest tube removal was not significantly affected (2.15 L and 2.25 L, respectively; p = 0.540). CONCLUSIONS: The results of the present study suggest that the presence of a chest tube is a factor significantly associated with postoperative pain and functional limitation in patients submitted to pulmonary resection.

Influence of pleural drainage on postoperative pain, vital capacity and six-minute walk test after pulmonary resection.

OBJECTIVE: To evaluate the influence of pleural drainage on the distance covered on the six-minute walk test, pain intensity and vital capacity in patients submitted to pulmonary resection. METHODS: Thirteen consecutive patients from the Thoracic Surgery Infirmary of Hospital São Paulo, Brazil, submitted to closed pleural drainage (0.5-in multiperforated chest tube) in the postoperative period following pulmonary resection (lobectomy, segmentectomy and pulmonary nodule resection) were evaluated. The decision for chest tube removal followed clinical criteria defined by the surgical team, who did not participate in the study. Vital capacity, pain intensity (using a visual analog pain scale) and the distance covered on the six-minute walk test were determined 30 min prior to and 30 min after the removal of the chest tube. The statistical analysis was performed using paired t-tests, and the level of significance was set at 0.05. RESULTS: After the removal of the chest tube, the visual analog scale pain scores were significantly lower (3.46 cm vs. 1.77 cm; p = 0.001) and the distance covered on the six-minute walk test was significantly higher (374.34 m vs. 444.62 m; p = 0.03). Vital capacity prior to and after chest tube removal was not significantly affected (2.15 L and 2.25 L, respectively; p = 0.540). CONCLUSIONS: The results of the present study suggest that the presence of a chest tube is a factor significantly associated with postoperative pain and functional limitation in patients submitted to pulmonary resection.