RESUMEN
Resorbable polylactic acid (PLA) ultrathin fibers have been applied as scaffolds for tissue engineering applications due to their micro- and nanoporous structure that favor cell adhesion, besides inducing cell proliferation and upregulating gene expression related to tissue regeneration. Incorporation of multiwalled carbon nanotubes into PLA fibers has been reported to increase the mechanical properties of the scaffold, making them even more suitable for tissue engineering applications. Ideally, scaffolds should be degraded simultaneously with tissue growth. Hydration and swelling are factors related to scaffold degradation. Hydration would negatively impact the mechanical properties since PLA shows hydrolytic degradation. Water absorption critically affects the catalysis and allowance of the hydrolysis reactions. Moreover, either mass transport and chemical reactions are influenced by confined water, which is an unexplored subject for PLA micro- and nanoporous fibers. Here, we probe and investigate confined water onto highly porous PLA microfibers containing few amounts of incorporated carbon nanotubes by Fourier transform infrared (FTIR) spectroscopy. A hydrostatic pressure was applied to the fibers to enhance the intermolecular interactions between water molecules and C=O groups from polyester bonds, which were evaluated over the wavenumber between 1600 and 2000 cm-1. The analysis of temperature dependence of FTIR spectra indicated the presence of confined water which is characterized by a non-Arrhenius to Arrhenius crossover at T0 = 190 K for 1716 and 1817 cm-1 carbonyl bands of PLA. These bands are sensitive to a hydrogen bond network of confined water. The relevance of our finding relies on the challenge detecting confined water in hydrophobic cavities as in the PLA one. To the best of our knowledge, we present the first report referring the presence of confined water in a hydrophobic scaffold as PLA for tissue engineering. Our findings can provide new opportunities to understand the role of confined water in tissue engineering applications. For instance, we argue that PLA degradation may be affected the most by confined water. PLA degradation involves hydrolytic and enzymatic degradation reactions, which can both be sensitive to changes in water properties.
RESUMEN
Melaleuca alternifolia essential oil (MaEO) is a green antimicrobial agent suitable for confection eco-friendly disinfectants to substitute conventional chemical disinfectants commonly formulated with toxic substances that cause dangerous environmental impacts. In this contribution, MaEO-in-water Pickering emulsions were successfully stabilized with cellulose nanofibrils (CNFs) by a simple mixing procedure. MaEO and the emulsions presented antimicrobial activities against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). Moreover, MaEO deactivated the SARS-CoV-2 virions immediately. FT-Raman and FTIR spectroscopies indicate that the CNF stabilizes the MaEO droplets in water by the dipole-induced-dipole interactions and hydrogen bonds. The factorial design of experiments (DoE) indicates that CNF content and mixing time have significant effects on preventing the MaEO droplets' coalescence during 30-day shelf life. The bacteria inhibition zone assays show that the most stable emulsions showed antimicrobial activity comparable to commercial disinfectant agents such as hypochlorite. The MaEO/water stabilized-CNF emulsion is a promissory natural disinfectant with antibacterial activity against these bacteria strains, including the capability to damage the spike proteins at the SARS-CoV-2 particle surface after 15 min of direct contact when the MaEO concentration is 30 % v/v.
Asunto(s)
Antiinfecciosos , COVID-19 , Desinfectantes , Melaleuca , Aceite de Árbol de Té , Celulosa/química , Emulsiones/química , SARS-CoV-2 , Escherichia coli , Staphylococcus aureus , Antiinfecciosos/farmacología , Agua/químicaRESUMEN
BACKGROUND: The aim of this study was to evaluate the short and mid-term safety and efficacy of the EPIC™ nitinol vascular stent system for the treatment of lesions located in the superficial femoral artery (SFA). METHODS: From October 2010 to June 2012, 83 subjects were enrolled in a prospective, multicenter, non-randomized study designed to demonstrate that the EPIC nitinol vascular stent system for SFA lesions is non-inferior to the published patency rates found in literature. Inclusion criteria were stenosis or occlusion of the SFA or SFA and proximal popliteal artery, with total length from 4 to 11 cm and amenable for treatment with a single stent, in patients with a score from 2 to 5 on Rutherford classification. The primary endpoint was primary patency rate at 12 months as determined by Duplex ultrasound. The secondary endpoints evaluated were: initial arteriographic success, primary patency rate at 6 months, major adverse event rate at one year and technical success. Follow-up with a complete clinical and physical exam, including ABI and Duplex ultrasound was performed at 6 and 12 months. RESULTS: Most patients (56.6%) were men and the mean age was 68.59 (33.1-99.15) years. 25.3% of the total population had intermittent claudication and 73.5% presented with critical limb ischemia. Most lesions were total occlusions (75.9%) and the mean lesion length was 71.16 mm. Contralateral femoral access was performed in 26.5%cases, and ipsilateral femoral approach was used for the remaining 73.5% patients. Technical and arteriographic success was obtained in all 83 (100.00%) patients. Duplex controlled primary patency rate at 6 and 12 months was 95.8% and 76.1%, respectively. The freedom from target lesion revascularization rate was 98.7% and 92.6% at 6 and 12 months, respectively. No stent fractures were observed in this study. Major adverse event rate at 1 year (clinically driven TLR, major amputation, and all-cause mortality) was 15.7%: two target lesion revascularizations (2.4%), one major amputation (1.2%) and ten deaths not related to the procedure (12%). CONCLUSIONS: In conclusion, this study demonstrates the safety and efficacy of the EPIC™ Nitinol Vascular Stent System for the treatment of SFA lesions.
Asunto(s)
Aleaciones , Procedimientos Endovasculares/instrumentación , Arteria Femoral , Enfermedad Arterial Periférica/terapia , Stents , Adulto , Anciano , Anciano de 80 o más Años , Angiografía , Índice Tobillo Braquial , Brasil , Supervivencia sin Enfermedad , Procedimientos Endovasculares/efectos adversos , Femenino , Arteria Femoral/diagnóstico por imagen , Arteria Femoral/fisiopatología , Humanos , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Enfermedad Arterial Periférica/diagnóstico por imagen , Enfermedad Arterial Periférica/fisiopatología , Estudios Prospectivos , Diseño de Prótesis , Factores de Tiempo , Resultado del Tratamiento , Ultrasonografía Doppler Dúplex , Grado de Desobstrucción VascularRESUMEN
BACKGROUND: The aim of this study was to evaluate the short and mid-term safety and efficacy of the EPIC nitinol vascular stent system for the treatment of lesions located in the superficial femoral artery (SFA).METHODS: From October 2010 to June 2012, 83 subjects were enrolled in a prospective, multicenter, non-randomized study designed to demonstrate that the EPIC nitinol vascular stent system for SFA lesions is non-inferior to the published patency rates found in literature. Inclusion criteria were stenosis or occlusion of the SFA or SFA and proximal popliteal artery, with total length from 4 to 11 cm and amenable for treatment with a single stent, in patients with a score from 2 to 5 on Rutherford classification. The primary endpoint was primary patency rate at 12 months as determined by Duplex ultrasound. The secondary endpoints evaluated were: initial arteriographic success, primary patency rate at 6 months, major adverse event rate at one year and technical success. Follow-up with a complete clinical and physical exam, including ABI and Duplex ultrasound was performed at 6 and 12 months.
Asunto(s)
Humanos , Masculino , Femenino , Adulto , Persona de Mediana Edad , Anciano , Angiografía , Grado de Desobstrucción Vascular , Procedimientos Endovasculares/efectos adversos , Procedimientos Endovasculares/instrumentación , StentsRESUMEN
Cardiovascular benefits from estradiol activation of nitric oxide endothelial production may depend on vascular wall and on estrogen receptor alpha (ESR1) and nitric oxide synthase (NOS3) polymorphisms. We have evaluated the microcirculation in vivo through nailfold videocapillaroscopy, before and after acute nasal estradiol administration at baseline and after increased sheer stress (postocclusive reactive hyperemia response) in 100 postmenopausal women, being 70 controls (healthy) and 30 simultaneously hypertensive and diabetic (HD), correlating their responses to PvuII and XbaI ESR1 polymorphisms and to VNTR, T-786C and G894T NOS3 variants. In HD women, C variant allele of ESR1 Pvull was associated to higher vasodilatation after estradiol (1.72 vs 1.64 mm/s, pâ=â0.01 compared to TT homozygotes) while G894T and T-786C NOS3 polymorphisms were connected to lower increment after shear stress (15% among wild type and 10% among variant alleles, pâ=â0.02 and 0.04). The G variant allele of ESR1 XbaI polymorphism was associated to higher HOMA-IR (3.54 vs. 1.64, pâ=â0.01) in HD and higher glucose levels in healthy women (91.8 vs. 87.1 mg/dl, pâ=â0.01), in which increased waist and HOMA-IR were also related to the G allele in NOS3 G894T (waist 93.5 vs 88.2 cm, pâ=â0.02; HOMA-IR 2.89 vs 1.48, pâ=â0.05). ESR1 Pvull, NOS3 G894T and T-786C polymorphism analysis may be considered in HD postmenopausal women for endothelial response prediction following estrogen therapy but were not discriminatory for endothelial response in healthy women. ESR1 XbaI and G894T NOS3 polymorphisms may be useful in accessing insulin resistance and type 2 diabetes risks in all women, even before menopause and occurrence of metabolic disease.
Asunto(s)
Enfermedades Cardiovasculares/fisiopatología , Endotelio Vascular/fisiología , Receptor alfa de Estrógeno/fisiología , Resistencia a la Insulina , Óxido Nítrico Sintasa de Tipo III/fisiología , Posmenopausia , Enfermedades Cardiovasculares/genética , Receptor alfa de Estrógeno/genética , Femenino , Humanos , Persona de Mediana Edad , Óxido Nítrico Sintasa de Tipo III/genética , Factores de RiesgoRESUMEN
The amount and sources of carbon and nitrogen used to produce Bacillus thuringiensis (Berliner)-based biopesticide may infl uence the quality of the fi nal product. The objective of this research was to test different levels of carbon and nitrogen: medium 1 - 1.5% maize glucose + 0.5% soy fl our,medium 2 - 3.0% maize glucose + 1.0% soy fl our, medium 3 - 1.0% maize glucose + 3.0% soy fl our and medium 4 - Luria Bertani (LB) + salts (FeSO4, ZnSO4, MnSO4, MgSO4). The seed culture was produced in LB medium plus salt, under agitation (200 rpm) for 18h at 30oC. The strain 344 of Bt wasused (B. thuringiensis var tolworthi belonging to the Embrapa´s Bt Bank). The pH was measured at regular intervals. and After culturing for 96h, the pH of the four tested media was basifi ed (6.91 and 8.15), the number of spores yielded 4.39 x 109 spores/ml in medium 3, where the amount of proteinis high. The dry biomass weight accumulated in media 3 was 39.3 g/l. Mortality of 2-day-old larvae Spodoptera frugiperda (J.E. Smith) was 100% when using Bt produced in media 3 and 4. CL50 for medium 3 was 8.4 x 106 spores/ml. All tested media were satisfactory to Bt growth, and medium 3wass the most promising to be used on a large scale Bt-based biopesticide production.
A quantidade de carbono e nitrogênio usados para produzir biopesticidas à base de Bacillus thuringiensis (Berliner) pode infl uenciar a qualidade fi nal do produto. O objetivo deste trabalho foi testar meios com diferentes níveis de carbono e nitrogênio: meio 1 - glicose de milho a 1.5% + farinha de soja a 0,5%, meio 2 - glicose de milho a 3,0% + farinha de soja a 1,0%, meio 3 - glicose de milho a 1,0% + farinha de soja a 3,0% e meio 4 - Luria Bertani (LB) + sais (FeSO4, ZnSO4, MnSO4 e MgSO4). O inóculo semente foi produzido usando 150 ml de meio LB mais sais incubados por 18h a 30oC, sob agitação de 200 rpm. A cepa utilizada foi 344 (B. thuringiensis var tolworthi pertencente ao Banco de Microorganismos da Embrapa). O pH foi medido a intervalos regulares. Após 96h de cultivo, o pH de todos os meios testados tenderam ao básico (entre 6,91 e 8,15), o maior número de esporos foi de 4,39 x 109 sporos/ml no meio 3, onde o teor de proteína usado foi o mais alto. A produção de massa celular foi maior no meio 3, com total acumulado de 39,3 g/l. A mortalidade de larvas de Spodoptera frugiperda (J.E. Smith) de dois dias de idade nos meios 3 e 4 foi de 100%. A CL50 para o meio 3 foi de 8,4 x 106 esporos/ml. Os meios alternativos usados promoveram crescimento satisfatório de Bt, sendo o meio 3 o mais promissor para ser usadona produção de biopesticida à base de Bt.
Asunto(s)
Bacillus thuringiensis/crecimiento & desarrollo , Medios de Cultivo , Carbono/administración & dosificación , Nitrógeno/administración & dosificación , Control Biológico de Vectores/métodos , Glycine max , Zea maysRESUMEN
The amount and sources of carbon and nitrogen used to produce Bacillus thuringiensis (Berliner)-based biopesticide may influence the quality of the final product. The objective of this research was to test different levels of carbon and nitrogen: medium 1 - 1.5% maize glucose + 0.5% soy flour, medium 2 - 3.0% maize glucose + 1.0% soy flour, medium 3 - 1.0% maize glucose + 3.0% soy flour and medium 4 - Luria Bertani (LB) + salts (FeSO4, ZnSO4, MnSO4, MgSO4). The seed culture was produced in LB medium plus salt, under agitation (200 rpm) for 18h at 30 masculineC. The strain 344 of Bt was used (B. thuringiensis var tolworthi - belonging to the Embrapa's Bt Bank). The pH was measured at regular intervals. and After culturing for 96h, the pH of the four tested media was basified (6.91 and 8.15), the number of spores yielded 4.39 x 10(9) spores/ml in medium 3, where the amount of protein is high. The dry biomass weight accumulated in media 3 was 39.3 g/l. Mortality of 2-day-old larvae Spodoptera frugiperda (J.E. Smith) was 100% when using Bt produced in media 3 and 4. CL50 for medium 3 was 8.4 x 10(6) spores/ml. All tested media were satisfactory to Bt growth, and medium 3 wass the most promising to be used on a large scale Bt-based biopesticide production.