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- A bi-layer electrospun nanofiber membrane for plasmid DNA recovery from fermentation brothsPublication . Correia, Tiago R.; Antunes, Bernardo Paiva; Castilho, Pedro Henrique Barata; Nunes, José; Amorim, Maria T. Pessoa de; Escobar, Isabel; Queiroz, João; Correia, I.J.; Morão, AntónioThe demanding ever-increasing quantities of highly purified biomolecules by bio-industries, has triggered the development of new, more efficient, purification techniques. The application of membrane-based technologies has become very attractive in this field, for their high throughput capability, simplicity of operation and scale-up. Herein we report the production of a bi-layer membrane by electrospinning (ES), in which a support of poly ε-caprolactone nanofibers was coated with a polyethylene oxide/sodium alginate layer, and subsequently cross-linked with calcium chloride. The membranes were characterized by SEM, ATR-FTIR, contact angle measurements, and were applied in the recovery process of a plasmid. The results show that membranes retained the suspended solids while allowing the permeation of plasmid DNA, with high recovery yields and improved RNA retention. Moreover, they also showed a very low fouling tendency. To the best of our knowledge it is the first time that ES membranes are applied in this type of bioprocess.
- 3D scaffolds coated with nanofibers displaying bactericidal activity for bone tissue applicationsPublication . Sá, Kevin; Figueira, Daniela Sofia Rodrigues; Miguel, Sónia P.; Correia, Tiago R.; Silva, Abílio Manuel Pereira da; Correia, I.J.Bone-limited capacity to fully repair large defects requires the development of new implants. In this context, new approaches have been used to promote bone regeneration and also to avoid the side effects associated with the therapeutics currently used in the clinic. Herein, 3D tricalcium phosphate/alginic acid scaffolds were produced and then coated with an electrospun mesh loaded with two different antibacterial agents, silver nanoparticles, and salicylic acid. The obtained results showed that the produced scaffolds have suitable mechanical properties, swelling, biodegradation, biomineralization activity, enhanced cellular adhesion/proliferation and bactericidal activity, and features essential for bone regeneration.
- Development of UV cross-linked gelatin coated electrospun poly(caprolactone) fibrous scaffolds for tissue engineeringPublication . Correia, Tiago R.; Ferreira, Paula; Vaz, Rita; Alves, Patrícia; Figueiredo, Margarida; Correia, Ilídio Joaquim Sobreira; Coimbra, PatríciaCardiovascular disease is the leading cause of morbidity and mortality among industrialized countries. Vascular grafts are often required for the surgical treatments. Considering the limitations associated with the use of autografts and with the currently available synthetic materials, a growing demand in tissue engineered vascular grafts has been registered. During the work here described, electrospinning technique was used to prepared fibrous matrices to be applied as vascular implants. For that purpose, electrospun polycaprolactone (PCL) fibrous mats were produced and afterwards coated with different hydrogel formulations based in photocrosslinkable gelatin (GelMA) and the macromers poly(ethylene glycol) acrylate (PEGA) and poly(ethylene glycol) diacrylate (PEGDA). These were further photocrosslinked under UV irradiation using Irgacure® 2959 (by BASF) as the photoinitiator. The suitability of the coated scaffolds for the intended application, was evaluated by assessing their chemical/physical properties as well as their interaction with blood and endothelial cells.