Spatially controlled proliferation, migration and differentiation of neural stem cells on novel 3D conductive scaffolds [Abstract]

Spatially controlled proliferation, migration and differentiation of neural stem cells on novel 3D conductive scaffolds [Abstract

Influence of topography of nanofibrous scaffolds on functionality of engineered neural tissue

Properly engineered scaffolds combined with functional neurons can be instrumental for the effective repair of the neural tissue. In particular, it is essential to investigate how three-dimensional (3D) systems and topographical features can impact on neuronal activity to obtain engineered functional neural tissues. In this study, polyphenylene sulfone (PPSu) scaffolds constituted by randomly distributed or aligned electrospun nanofibers were fabricated to evaluate the neural activity in 3D culture environments for the first time. The obtained results demonstrated that the nanofibers can successfully support the adhesion and growth of neural stem cells (NSCs) and enhance neuronal differentiation compared to 2D substrates. In addition, NSCs could spread and migrate along the aligned fibers. The percentage of active NSC-derived neurons and the overall network activity in the fibrous substrates were also remarkably enhanced. Finally, the data of neuronal activity showed not only that the neurons cultured on the nanofibers are part of a functional network, but also that their activity increases, and the direction of neural signals can be controlled in the aligned 3D scaffolds

Alginate nanofibers with tunable biodegradability for regenerative medicine [Abstract]

Alginate nanofibers with tunable biodegradability for regenerative medicine [Abstract

Photo-polymerisable electrospun fibres of N-methacrylate glycol chitosan for biomedical applications

The availability of nanofibrous substrates with engineered properties, such as controlled porosity, mechanical conformability, biodegradation profile and drug release, is of strategic importance in the biomedical sector. Here, we demonstrate that N-methacrylate glycol chitosan, a photo-polymerisable, biocompatible and water-soluble derivative of chitosan, can be easily processed to create non-woven mats of nanofibres with controlled physicochemical characteristics. The produced fibrous mats are characterised by thermal stability, Young's modulus of 140 MPa and ultimate strength of 4 MPa. The degree of cross-linking of the realised fibres regulates their durability and degradation profile under conditions of high humidity, but also allows controlling the delivery over time of active agents encapsulated inside the fibres. We demonstrate that the N-methacrylate glycol chitosan nanofibres are able to release an antimicrobial drug within 24 hours. Moreover, cells proliferation of 85% indicates that non-cytotoxic substances were released from the electrospun mats

Alginate–lavender nanofibers with antibacterial and anti-inflammatory activity to effectively promote burn healing

One of the current challenges in wound care is the development of multifunctional dressings that can both protect the wound from external agents and promote the regeneration of the new tissue. Here, we show the combined use of two naturally derived compounds, sodium alginate and lavender essential oil, for the production of bioactive nanofibrous dressings by electrospinning, and their efficacy for the treatment of skin burns induced by midrange ultraviolet radiation (UVB). We demonstrate that the engineered dressings reduce the risk of microbial infection of the burn, since they stop the growth of Staphylococcus aureus. Furthermore, they are able to control and reduce the inflammatory response that is induced in human foreskin fibroblasts by lipopolysaccharides, and in rodents by UVB exposure. In particular, we report a remarkable reduction of pro-inflammatory cytokines when fibroblasts or animals are treated with the alginate-based nanofibers. The down-regulation of cytokines production and the absence of erythema on the skin of the treated animals confirm that the here described dressings are promising as advanced biomedical devices for burn management

Investigation of the electro-spinnability of alginate solutions containing gold precursor HAuCl4

Alginate nanofibers with an average diameter of 75 nm have been prepared by the electrospinning process. In addition, the spinnability of the solutions in the presence of the gold precursor HAuCl4 was investigated. At low concentrations of HAuCl4 well-formed nanofibers were produced, whereas as its concentration increases the nanofibrous mats present an increased number of bead-like defects. Herein, the in situ preparation of gold nanoparticles (Au NPs) is discussed since sodium alginate (SA) acts as the reducing agent and a mechanism is proposed in order to explain the bead-effect as well as the surface morphology of the alginate fibers decorated with Au NPs

Fumarate-loaded electrospun nanofibers with anti-inflammatory activity for fast recovery of mild skin burns

In the biomedical sector the availability of engineered scaffolds and dressings that control and reduce inflammatory states is highly desired, particularly for the management of burn wounds. In this work, we demonstrate for the first time, to the best of our knowledge, that electrospun fibrous dressings of poly(octyl cyanoacrylate) (POCA) combined with polypropylene fumarate (PPF) possess anti-inflammatory activity and promote the fast and effective healing of mild skin burns in an animal model. The fibers produced had an average diameter of (0.8  ±  0.1) µm and they were able to provide a conformal coverage of the injured tissue. The application of the fibrous mats on the burned tissue effectively reduced around 80% of the levels of pro-inflammatory cytokines in the first 48 h in comparison with un-treated animals, and enhanced skin epithelialization. From histological analysis, the skin thickness of the animals treated with POCA : PPF dressings appeared similar to that of one of the naïve animals: (13.7  ±  1.4) µm and (14.3  ±  2.5) µm for naïve and treated animals, respectively. The density of dermal cells was comparable as well: (1100  ±  112) cells mm−2 and (1358  ±  255) cells mm−2 for naïve and treated mice, respectively. The results demonstrate the suitability of the electrospun dressings in accelerating and effectively promoting the burn healing process

Zwitterionic nanofibers of super-glue for transparent and biocompatible multi-purpose coatings

Here we show that macrozwitterions of poly(ethyl 2-cyanoacrylate), commonly called Super Glue, can easily assemble into long and well defined fibers by electrospinning. The resulting fibrous networks are thermally treated on glass in order to create transparent coatings whose superficial morphology recalls the organization of the initial electrospun mats. These textured coatings are characterized by low liquid adhesion and anti-staining performance. Furthermore, the low friction coefficient and excellent scratch resistance make them attractive as solid lubricants. The inherent texture of the coatings positively affects their biocompatibility. In fact, they are able to promote the proliferation and differentiation of myoblast stem cells. Optically-transparent and biocompatible coatings that simultaneously possess characteristics of low water contact angle hysteresis, low friction and mechanical robustness can find application in a wide range of technological sectors, from the construction and automotive industries to electronic and biomedical devices

Healable Cotton–Graphene Nanocomposite Conductor for Wearable Electronics

Electrically conductive materials based on cotton have important implications for wearable electronics. We have developed flexible and conductive cotton fabrics (∼10 Ω/sq) by impregnation with graphene and thermoplastic polyurethane-based dispersions. Nanocomposite fabrics display remarkable resilience against weight-pressed severe folding as well as laundry cycles. Folding induced microcracks can be healed easily by hot-pressing, restoring initial electrical conductivity. Impregnated cotton fabric conductors demonstrate better mechanical properties compared to pure cotton and thermoplastic polyurethane maintaining breathability. They also resist environmental aging such as solar irradiation and high humidity

Antioxidant and Biocompatible CO2-Based Biocomposites from Vegetable Wastes for Active Food Packaging

In this study, an innovative and scalable strategy is developed to valorize vegetable wastes as valuable and cost-effective natural antioxidant resources in the development of CO2-based biocomposites. The dried vegetable stems (parsley and spinach) are firstly micronized and then incorporated into a CO2- derived poly(propylene carbonate) (PPC) polymer matrix by hot compression molding technique. The vegetable waste microparticles are found to be homogenously dispersed within the PPC matrix. Due to the establishment of a strong intermolecular hydrogen bond network between PPC and vegetable waste microparticles, the obtained biocomposites exhibit improved mechanical properties compared to pure PPC, comparable to these of common plastics use for packaging materials. The water barrier properties of the developed biocomposites are also promising for packaging applications. Additionally, the developed biocomposites are found to be biocompatible and show effective antioxidant scavenging activity against 2,2′-azinobis(3- ethylbenzothiazoline-6-sulfonic acid) radical cation (ABTS•+). Therefore, these antioxidant and biocompatible biocomposites deriving from CO2 greenhouse gas and industrial agro-food wastes are of great interest for active food packaging applications