RESUMEN
The rapid growth of industrialization has resulted in the release of large quantities of pollutants into the environment, especially dyes and heavy metals, which are environmentally hazardous for humans and animals. It is considered as the most promising and environmentally friendly route to develop green materials by using the green modification method, which has no negative impact on the environment. In this work, the green material of polylactic acid (PLA) was used as the substrate material, and a novel modification method of polydopamine (PDA)-assisted polyethyleneimine (PEI) grafting was developed. The electrospun PLA fibers are mainly composed of stereocomplex crystallites, which were achieved via the electrospinning of poly(l-lactic acid) and poly(d-lactic acid). The water-soluble PEI was grafted onto the PDA-modified PLA fibers through the glutaraldehyde-assisted cross-linking reaction. The prepared composite fibers can be degraded, which is environmentally friendly and meets the requirements of sustainable development. The potential application of such PLA composite fibers in wastewater treatment was intensively evaluated. The results show that at appropriate fabrication conditions (PDA concentration of 3 g·L-1 and a PEI molecular weight of 70,000 g·mol-1), the composite fibers exhibit the maximum adsorption capacities of 612 and 398.41 mg·g-1 for methyl orange (MO) and hexavalent chromium [Cr(VI)], respectively. Simultaneously, about 64.79% of Cr(VI) adsorbed on the composite fibers was reduced to Cr(III). The above results show that the PLA composite fibers have a good development prospect in the field of wastewater treatment.
RESUMEN
The urgent needs for water protection are not only developing the highly efficient wastewater treatment technologies but also designing the eco-friendly materials. In this work, the eco-friendly composite fibers composed of poly(L-lactide) (PLLA), poly(D-lactide) (PDLA) and maghemite nanoparticles γ-Fe2O3 nanoparticles were fabricated through electrospinning technology. Through regulating the processing parameters and introducing additional annealing treatment, nanoscale porous structure and the stereocomplex crystallites (SCs) are simultaneously constructed in the composite electrospun fibers. Physicochemical performances measurements exhibited that the fiber membranes had excellent lipophilicity, good mechanical performances, and high hydrolysis resistance, and all of which endowed the fiber membranes with high oil adsorption capacities, and the maximum oil adsorption capacities achieved 148.9â¯g/g at 23⯰C and 114.8â¯g/g at 60⯰C. Further results showed that the fiber membranes had good oil/water separation ability. The gravity-driven oil flux was 6824.4â¯L/m2h2, and the water rejection ratio was nearly 100% during separating oil/water mixture. Specifically, the fiber membranes showed good stability during the cycling measurements. It is evidently confirmed that the composite PLLA-based fiber membranes with porous structure and SCs can be used in wastewater treatment, especially in some rigorous circumstances.
RESUMEN
Anticancer therapies are often compromised by nonspecific effects and challenged by tumour environments' inherent physicochemical and biological characteristics. Often, therapeutic effect can be increased by addressing multiple parameters simultaneously. Here we report on exploiting extravasation due to inherent vascular leakiness for the delivery of a pH-sensitive polymer carrier. Tumours' acidic microenvironment instigates a charge reversal that promotes cellular internalization where endosomes destabilize and gene delivery is achieved. We assess our carrier with an aggressive non-small cell lung carcinoma (NSCLC) in vivo model and achieve >30% transfection efficiency via systemic delivery. Rejuvenation of the p53 apoptotic pathway as well as expression of KillerRed protein for sensitization in photodynamic therapy (PDT) is accomplished. A single administration greatly suppresses tumour growth and extends median animal survival from 28 days in control subjects to 68 days. The carrier has capacity for multiple payloads for greater therapeutic response where inter-individual variability can compromise efficacy.
Asunto(s)
Apoptosis/fisiología , Carcinoma de Pulmón de Células no Pequeñas/terapia , Técnicas de Transferencia de Gen , Proteínas Fluorescentes Verdes/metabolismo , Fotoquimioterapia/métodos , Microambiente Tumoral/fisiología , Proteína p53 Supresora de Tumor/metabolismo , Animales , Línea Celular Tumoral , Dimetilsulfóxido , Endosomas/metabolismo , Glutamatos , Humanos , Concentración de Iones de Hidrógeno , Etiquetado Corte-Fin in Situ , Indoles , Espectroscopía de Resonancia Magnética , Ratones , Ratones Endogámicos BALB CRESUMEN
A small interfering RNA (siRNA)-loaded polyelectrolyte constructed with branched polyethylenimine (bPEI) and copolymers, consisting of polyethylene glycol (PEG), histidine (His), and glutamic acid (Glu), was developed in order to provide a tumor acidosis-triggered delivery system with low cytotoxicity.