Smart Electrospun Hybrid Nanofibers Functionalized with Ligand-Free Titanium Nitride (TiN) Nanoparticles for Tissue Engineering

Herein, we report the fabrication and characterization of novel polycaprolactone (PCL)-based nanofibers functionalized with bare (ligand-free) titanium nitride (TiN) nanoparticles (NPs) for tissue engineering applications. Nanofibers were prepared by a newly developed protocol based on the electrospinning of PCL solutions together with TiN NPs synthesized by femtosecond laser ablation in acetone. The generated hybrid nanofibers were characterised using spectroscopy, microscopy, and thermal analysis techniques. As shown by scanning electron microscopy measurements, the fabricated electrospun nanofibers had uniform morphology, while their diameter varied between 0.403 ± 0.230 µm and 1.1 ± 0.15 µm by optimising electrospinning solutions and parameters. Thermal analysis measurements demonstrated that the inclusion of TiN NPs in nanofibers led to slight variation in mass degradation initiation and phase change behaviour (Tm). In vitro viability tests using the incubation of 3T3 fibroblast cells in a nanofiber-based matrix did not reveal any adverse effects, confirming the biocompatibility of hybrid nanofiber structures. The generated hybrid nanofibers functionalized with plasmonic TiN NPs are promising for the development of smart scaffold for tissue engineering platforms and open up new avenues for theranostic applications

Electrospun hybrid nanofibers / nanomats functionalized with ligand-free nanoparticles as a platform for biomedical applications

Dans cette recherche, l'accent a été mis sur la combinaison des avantages des nanofibres et de l'immobilisation d'agents fonctionnels par électrofilage.Ainsi, dans ce travail des nanofibres multifonctionnelles ont été fabriquées à partir de polymères tels que le chitosane, le poly (oxyde d'éthylène) (PEO), le polystyrène (PS), ou encore le polycaprolactone (PCL). Ceux-ci ont été par la suite fonctionnalisées avec des nanoparticules d'or (AuNPs), des polymères inorganiques et des nanoparticules de nitrure de titane (TiN NPs). Premièrement, les nanofibres hybrides de composition chitosan(PEO) ont été électrofilées et fonctionnalisées avec des AuNPs, synthétisées par ablation laser ou par methode chimique. Les effets des conditions de préparation et des agents de fonctionnalisation sur les propriétés physico-chimiques des nanofibres fonctionnalisées ont été étudiés. Par la suite, des nanofibres de chitosane pur (AuNPs) ont été obtenues à partir d'une formulation améliorée avec des concentrations plus élevées de chitosane et d'AuNP prepares par procédé laser. Des nanofibres hybrides ont également été fabriquées en mélangeant des polymères inorganiques intelligents, à savoir des poly (ferrocénylphosphinoboranes) avec des homopolymères tels que le polystyrène (PS) et le poly (oxyde d'éthylène) (PEO).Enfin, la thèse rapporte la fabrication de nanofibres à base de polycaprolactone (PCL) décorées de NPs TiN (ultra-propres) préparées par laser. Les nanofibres ont été analysées à l'aide de techniques physico-chimiques habituelles, tandis que les études de compatibilité biologique et de toxicité n'ont montré aucun effet indésirable sur la croissance cellulaire.In this research, an emphasis was given to combine the advantages of nanofibers and immobilization of functional agents using electrospinning. Multifunctional hybrid nanofibers were fabricated using electrospinning and functionalized with agents such as inorganic nanoparticles and polymers. Nanofibers were analyzed by a selection of techniques such as microscopy, spectroscopy, and thermal analyses, beside toxicity and bio-compatibility assays. Here, multifunctional nanofibers were fabricated from polymers such as chitosan, poly(ethylene oxide) (PEO), polystyrene (PS), polycaprolactone (PCL) and further functionalized with gold nanoparticles (AuNPs), inorganic polymers, and titanium nitride nanoparticles (TiN NPs). First, PEO-chitosan blended nanofibers were electrospun and functionalized with AuNPs, synthesized via both wet-chemistry and pulsed laser ablation processes where effects of preparation conditions and functionalization agents on physico-chemical properties of functionalized nanofibers were investigated. Thereafter, pure chitosan (AuNPs) nanofibers were obtained from an improved formulation with higher concentrations of chitosan and bare laser-ablated AuNPs. Hybrid nanofibers were also fabricated by blending smart inorganic polymers namely poly (ferrocenylphosphinoboranes) with homopolymers such as polystyrene (PS) and poly (ethylene oxide) (PEO). Finally, the thesis reports the fabrication of polycaprolactone (PCL)-based nanofibers decorated with (ultra-clean) bare laser-ablated TiN NPs. The nanofibers were analyzed using usual physico-chemical techniques, while biological compatibility and toxicity studies showed no adverse effect on the cell growth

Serralves

Hoje, na Festa do Outono na Casa de Serralves, com entrada gratuita entre as 10:00 e as 19:00, vi muitas crianças acompanhadas pelos pais. Dia bonito e muitos visitantes de todas as idades, mas em especial os mais jovens à procura de oficinas, flora e animais da quinta e muito mais coisas, além de uma burroteca. No museu, duas exposições. À esquerda, as obras da holandesa Marijke van Warmerdam (1959), conjunto intitulado De Perto à Distância (Close by in the Distance), com variados vídeos e f..

Hybrid 2D nanofibers based on poly(ethylene oxide)/ polystyrene matrix and poly(ferrocenylphosphinoboranes) as functional agents

International audienceemplate smart inorganic polymers within an organic polymeric matrix to form hybrid nanostructured materials are a unique approach to induce novel multifunctionality. In particular, the fabrication of one‐dimensional materials via electrospinning is an advanced tool, which has gained success in fulfilling the purpose to fabricate two‐dimensional nanostructured materials. We have explored the formation of novel hybrid nanofibers by co‐spinning of poly(ferrocenylphosphinoboranes) Fe A [{Fe(C5H5)(C5H4CH2PHBH2)} n] and Fe B [{Fe(C5H5)(C5H4PHBH2)} n] with poly(ethylene oxide) (PEO) and polystyrene (PS). Fe A and Fe B contain main‐group elements and a ferrocene moiety as pendent group and have different properties compared to their only carbon‐containing counterparts. The use of PEO and polystyrene provided a matrix to spin those inorganic polymers as hybrid nanofibers which were collected in the form of a nonwoven mat. They were characterized by multinuclear NMR spectroscopy, scanning electron microscopy (SEM), and IR spectroscopy. Thermal properties of the polymers have been checked by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). 1H, 31P, and 11B NMR and IR spectroscopy revealed the nature and types of interactions of the components after co‐spinning. The SEM micrographs identify the underlying unidirectional morphology of the generated hybrid nanofibers. Nonetheless, the DSC and TGA confirmed the significant boost toward the thermal stability of the resultant multifunctional fibers. It is believed that these unique types of multifunctional electrospun nanofibers will open new avenues toward the next generation of miniaturized devices

Hybrid Nanomat: Copolymer Template CdSe Quantum Dots In Situ Stabilized and Immobilized within Nanofiber Matrix

Fabrication and characterization of hybrid nanomats containing quantum dots can play a prominent role in the development of advanced biosensors and bio-based semiconductors. Owing to their size-dependent properties and controlled nanostructures, quantum dots (QDs) exhibit distinct optical and electronic characteristics. However, QDs include heavy metals and often require stabilizing agents which are toxic for biological applications. Here, to mitigate the use of toxic ligands, cadmium selenide quantum dots (CdSe QDs) were synthesized in situ with polyvinylpyrrolidone (PVP) at room temperature. The addition of PVP polymer provided size regulation, stability, and control over size distribution of CdSe QDs. The characterization of the optical properties of the CdSe QDs was performed using fluorescence and ultraviolet–visible (UV-Vis) spectroscopy. CdSe QDs exhibited a typical absorbance peak at 280 nm and a photoluminescence emission peak at 580 nm. Transmission electron microscopy (TEM) micrographs demonstrated that CdSe QDs having an average size of 6 ± 4 nm were obtained via wet chemistry method. CdSe QDs were immobilized in a blend of PVP and poly(L-lactide-co-ε-caprolactone) (PL-b-CL) copolymer that was electrospun to produce nanofibers. Scanning electron microscopy (SEM), thermal analyses and attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR) were used to characterize properties of fabricated nanofibers. Both pristine and hybrid nanofibers possessed cylindrical geometry and rough surface features, facilitating increased surface area. Infrared absorption spectra showed a slight shift in absorbance peaks due to interaction of PVP-coated CdSe QDs and nanofiber matrix. The presence of CdSe QDs influenced the fiber diameter and their thermal stability. Further, in vitro biological analyses of hybrid nanofibers showed promising antibacterial effect and decline in cancer cell viability. This study offers a simple approach to obtain hybrid nanomats immobilized with size-controlled PVP-coated CdSe QDs, which have potential applications as biosensors and antibacterial and anticancer cell agents

Smart Electrospun Hybrid Nanofibers Functionalized with Ligand-Free Titanium Nitride (TiN) Nanoparticles for Tissue Engineering

International audienceHerein, we report the fabrication and characterization of novel polycaprolactone (PCL)-based nanofibers functionalized with bare (ligand-free) titanium nitride (TiN) nanoparticles (NPs) for tissue engineering applications. Nanofibers were prepared by a newly developed protocol based on the electrospinning of PCL solutions together with TiN NPs synthesized by femtosecond laser ablation in acetone. The generated hybrid nanofibers were characterised using spectroscopy, microscopy, and thermal analysis techniques. As shown by scanning electron microscopy measurements, the fabricated electrospun nanofibers had uniform morphology, while their diameter varied between 0.403 ± 0.230 µm and 1.1 ± 0.15 µm by optimising electrospinning solutions and parameters. Thermal analysis measurements demonstrated that the inclusion of TiN NPs in nanofibers led to slight variation in mass degradation initiation and phase change behaviour (Tm). In vitro viability tests using the incubation of 3T3 fibroblast cells in a nanofiber-based matrix did not reveal any adverse effects, confirming the biocompatibility of hybrid nanofiber structures. The generated hybrid nanofibers functionalized with plasmonic TiN NPs are promising for the development of smart scaffold for tissue engineering platforms and open up new avenues for theranostic applications

Toward multifunctional hybrid platforms for tissue engineering based on chitosan(PEO) nanofibers functionalized by bare laser-synthesized Au and Si nanoparticles

International audienceExhibiting a variety of unique optical, structural and physicochemical properties, laser-synthesized nanomaterials have become increasingly popular during recent years in a variety of biomedical, catalytic, photovoltaic and other applications. Here, we explore the use of bare laser-synthesized gold and silicon nanoparticles (AuNPs and SiNPs) as additives to functionalize electrospun chitosan(PEO) nanofibers and then assess the potential of such hybrid structures as multifunctional platforms for tissue engineering. We demonstrate that bare AuNPs and SiNPs can be easily grafted on the surface of the chitosan(PEO) nanofibers without any interference, via electrostatic interaction between a strong negative surface charge of NPs and the polycationic surface of the fibers. We also show that the nanofibers functionalized with nanoparticles can affect the morphology and physico-chemical characteristics of the resulting nanostructures. As an example, the functionalization of nanofibers by SiNPs led to quite different thicknesses of fibers (386 AE 80 nm and 632 AE 170 nm), suggesting a potential improvement of fibre surface reactivity. Finally, biological toxicity of the nanofibers was assessed through preliminary viability tests conducted on HaCaT cells. After 24 h of incubation time, no adverse effects were observed confirming satisfactory biocompatibilty of the hybrid nanofiber structures. The proposed concept promises exciting perspectives in the development of innovative multifunctional scaffolds structures gathering new properties for tissue engineering

Recent Advances in Laser-Ablative Synthesis of Bare Au and Si Nanoparticles and Assessment of Their Prospects for Tissue Engineering Applications

International audienceDriven by surface cleanness and unique physical, optical and chemical properties, bare (ligand-free) laser-synthesized nanoparticles (NPs) are now in the focus of interest as promising materials for the development of advanced biomedical platforms related to biosensing, bioimaging and therapeutic drug delivery. We recently achieved significant progress in the synthesis of bare gold (Au) and silicon (Si) NPs and their testing in biomedical tasks, including cancer imaging and therapy, biofuel cells, etc. We also showed that these nanomaterials can be excellent candidates for tissue engineering applications. This review is aimed at the description of our recent progress in laser synthesis of bare Si and Au NPs and their testing as functional modules (additives) in innovative scaffold platforms intended for tissue engineering tasks