Abstract:Polyurethane nanoparticles (NPs) are promising candidates for the controlled and targeted delivery of therapeutics in a variety of biomedical applications. In this work, a report is made of NPs produced by miniemulsion polymerization with isophorone diisocyanate (IPDI) and castor oil, glycerol, and poly(ethylene glycol) (PEG) with molar masses 400 and 1000 as monomers and Tween 80, Span 80 and Lutensol AT 25 as surfactant and açaí oil as costabilizer. Stable dispersions with sizes between 100 -500 nm were achi… Show more
“…The same behavior can be observed for the particle size dispersity, which decreased from 0.215 to 0.152, 0.218 to 0.167, 0.215 to 0.152, and 0.161 to 0.138, respectively, with 1 wt% and 20 wt% of surfactant for Tween 80, Brij 35, CTAB and SDS. Increasing surfactant concentration helps monomer droplets stabilization during and after sonication decreasing their coalescence and, thus, leading to the formation of smaller particles with a narrower distribution (lower particle size dispersity) [9], [14], and [30]. In addition, smaller particles were obtained when ionic SLS or CTAB were used instead of nonionic Tween 80 or Brij 35.…”
Section: Characterization and Morphology Of Peg-pu-pcl530 Npsmentioning
confidence: 99%
“…The potential of PU nanoparticles (NPs) has been discussed for a variety of pharmaceutical and cosmetic applications, such as medium for controlled release [10], [11], [12], [13] and [14].…”
Section: Introductionmentioning
confidence: 99%
“…PU NPs have been synthesized using several techniques such as suspension, miniemulsion and interfacial polymerization [10], [11], [12], [13], [14], [15] and [16]. Miniemulsion is defined as dispersions of relatively stable oil droplets with a size range from 50 to 500 nm, prepared by shearing a system containing oil, water, surfactant and costabilizer [17] and [18].…”
“…The same behavior can be observed for the particle size dispersity, which decreased from 0.215 to 0.152, 0.218 to 0.167, 0.215 to 0.152, and 0.161 to 0.138, respectively, with 1 wt% and 20 wt% of surfactant for Tween 80, Brij 35, CTAB and SDS. Increasing surfactant concentration helps monomer droplets stabilization during and after sonication decreasing their coalescence and, thus, leading to the formation of smaller particles with a narrower distribution (lower particle size dispersity) [9], [14], and [30]. In addition, smaller particles were obtained when ionic SLS or CTAB were used instead of nonionic Tween 80 or Brij 35.…”
Section: Characterization and Morphology Of Peg-pu-pcl530 Npsmentioning
confidence: 99%
“…The potential of PU nanoparticles (NPs) has been discussed for a variety of pharmaceutical and cosmetic applications, such as medium for controlled release [10], [11], [12], [13] and [14].…”
Section: Introductionmentioning
confidence: 99%
“…PU NPs have been synthesized using several techniques such as suspension, miniemulsion and interfacial polymerization [10], [11], [12], [13], [14], [15] and [16]. Miniemulsion is defined as dispersions of relatively stable oil droplets with a size range from 50 to 500 nm, prepared by shearing a system containing oil, water, surfactant and costabilizer [17] and [18].…”
“…15 Dentro de este marco, se han empleado los aceites esenciales de diferentes semillas oleaginosas (soya, coco, girasol, higuerilla, palma, entre otros) para sintetizar PUs biodegradables, debido a que son económicos, no tóxicos, abundantes y contienen grupos hidroxilos secundarios y triglicéridos de ácidos grasos. [16][17][18][19][20] Dentro de los aceites mencionados el aceite de higuerilla se obtiene de una fuente renovable y la producción se caracteriza por tener bajos precios lo que reduce el costo de la síntesis de PUs y adicional a esto se obtiene un beneficio para el medio ambiente. De otro lado, el aceite de ricino tiene un alto índice hidroxilo que puede reaccionar a temperatura ambiente con un consumo relativamente bajo de energía.…”
ANTIBACTERIAL ACTIVITY, HYDROLYTIC AND MICROBIAL DEGRADATION AND in vitro CYTOTOXICITY OF POLYURETHANE SYNTHESIZED WITH POLYOLS FROM CASTOR OIL DERIVATIVES. Biological activities from polyurethanes (PUs) synthesized from polyols (derived from castor oil) and isophorone diisocyanate were evaluated. In vitro degradability was evaluated by phosphate buffered saline (PBS) and antibacterial degradation with Escherichia coli and Pseudomonas aeruginosa. The biocompatibility was analyzed by: i) the antimicrobial activity against E. coli, S. aureus and P. aeruginosa, and ii) in vitro cytotoxicity assays using mouse embryonic fibroblast cell line L-929 in direct contact with the PUs and with NIH/3T3 cells in indirect contact with the PUs degradation products. PUs with polyol P1 (2,64% molar relation of pentaerythritol and castor oil) was the material with better biodegradation properties: 1.125±0.110% in 72 h by PBS at 100 °C. In general, all materials were degraded up to 1.000±0.223% and 2.251±0.010% in 72 h by E. coli and P. aeruginosa, respectively. On the other hand, it was determined a close relationship between functionality of polyol and bacterial inhibition. The antibacterial effect of the PUs decreased by 67% for E. coli, 55% for S. aureus and 56% for P. aeruginosa after 24 h. Chemical modification of castor oil did not generate a cytotoxic effect on the tested cell lines. The evaluated materials are suggested as candidates to obtain biomaterials due to their mechanical properties and biocompatibility presented in untransformed cells.Keywords: castor oil; polycaprolactone; cytotoxicity; degradability; biomedical applications.
INTRODUCCIÓNLos poliuretanos (PUs) representan una popular e importante parte de productos industriales que se caracterizan por tener buenas propiedades de flexibilidad, elevada resistencia al impacto y durabilidad, características que lo convierten en polímeros con múltiples aplicaciones. 1 Su carácter de copolímero en bloque los dota de una amplia versatilidad en términos de adaptación de sus propiedades físicas y compatibilidad. 2-7 Es así como los PUs son interesantes para usos internos (in vivo), especialmente en aplicaciones a corto plazo, como catéteres o implantes. De igual forma, son interesantes para aplicaciones de uso externo (in vitro), como por ejemplo los sistemas de liberación controlada de medicamentos. 8 De esta forma los PUs son polímeros sintéticos biocompatibles que se emplean en dispositivos médicos y en aplicaciones de ingeniería de tejidos. Los PUs empleados como materiales biomédicos deben cumplir con las propiedades mecánicas para la aplicación destino, deben ser no tóxicos, ser biodegradables de acuerdo con la función a cumplir y deben ser biocompatibles. 9,10 Se han utilizado estrategias para mejorar falencias de estos materiales como las propiedades de fatiga, control de la degradación, incremento de proliferación celular, entre otros. Algunas de estas estrategias consisten en modificar la superficie de los PUs por medio de procesos físicos o químicos. 11 La eval...
“…A obtenção de poli(ureia-uretano) via polimerização em miniemulsão tem atraído muita atenção nas últimas décadas devido ao seu uso em diferentes áreas como farmacêutica, médica e de cosméticos, principalmente como meio para libertação controlada de fármacos devido às suas excelentes propriedades físicas e de biocompatibilidade (Torini et al, 2005;Crespy et al, 2007;Zanetti-ramos et al, 2009;Ding et al, 2011; Gaudin e Sintes-zydowicz de 2011; Valerio et al, 2013). Com base no que foi apresentado, o uso de radiação microondas na polimerização via miniemulsão do diisocianato (IPDI) foi investigada, sendo os efeitos cinéticos dos parâmetros de reação, como temperatura, potência e tipo de poliol investigados, uma vez que a literatura não relata trabalhos de polimerização em miniemulsão em etapas conduzidas em reator microondas como proposto nesse trabalho.…”
RESUMO -A irradição microondas tem sido uma alternativa interessante como sistema de aquecimento em diferentes reações químicas. Neste trabalho foi realizado o estudo das reações em reator microondas em comparação ao aquecimento convencional, onde os efeitos da temperatura e potência do microondas na síntese de poli(ureia-uretano) (PU) via polimerização miniemulsão foram discutidos. O polímero final foi avaliado por FTIR e o tamanho e distribuição das partículas caracterizadas por dispersão dinâmica de luz (DLS). Em um estudo comparativo, a polimerização conduzida em reator microondas apresentou maior velocidade de reação e maior conversão quando comparado com as reações com aquecimento convencional, resultando em uma redução significativa no tempo de reação, bem como a possibilidade de controlar a formação de grupos de ureia/uretano com o uso do reator microondas na sintese de PU via polimerização em miniemulsão.
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