12 research outputs found
Multimaterial tandem electrospinning for spatially modulated neural guidance
The goal of this work is the creation of an in vitro platform to investigate the combined effects of patterned topographical and bioactive cues towards achieving the spatially controlled growth of peripheral sensory neurons
A One‐Step Biofunctionalization Strategy of Electrospun Scaffolds Enables Spatially Selective Presentation of Biological Cues
To recapitulate the heterogeneous complexity of tissues in the human body with synthetic mimics of the extracellular matrix (ECM), it is important to develop methods that can easily allow the selective functionalization of defined spatial domains. Here, a facile method is introduced to functionalize microfibrillar meshes with different reactive groups able to bind biological moieties in a one‐step reaction. The resulting scaffolds prove to selectively support a differential neurite growth after being seeded with dorsal root ganglia. Considering the general principles behind the method developed, this is a promising strategy to realize enhanced biomimicry of native ECM for different regenerative medicine applications
A one-step biofunctionalization strategy of electrospun scaffolds enables spatially selective presentation of biological cues
To recapitulate the heterogeneous complexity of tissues in our body with synthetic mimics of the extracellular matrix (ECM), it is important to develop methods that can easily allow the selective functionalization of defined spatial domains. Here, we introduce a facile method to functionalize microfibrillar meshes with different reactive groups able to bind biological moieties in a one-step reaction. The resulting scaffolds proved to selectively support a differential neurite growth after being seeded with dorsal root ganglia. Considering the general principles behind the method developed, this is a promising strategy to realize enhanced biomimicry of native ECM for different regenerative medicine applications
A One-Step Biofunctionalization Strategy of Electrospun Scaffolds Enables Spatially Selective Presentation of Biological Cues
To recapitulate the heterogeneous complexity of tissues in the human body with synthetic mimics of the extracellular matrix (ECM), it is important to develop methods that can easily allow the selective functionalization of defined spatial domains. Here, a facile method is introduced to functionalize microfibrillar meshes with different reactive groups able to bind biological moieties in a one-step reaction. The resulting scaffolds prove to selectively support a differential neurite growth after being seeded with dorsal root ganglia. Considering the general principles behind the method developed, this is a promising strategy to realize enhanced biomimicry of native ECM for different regenerative medicine applications
Ultraviolet Functionalization of Electrospun Scaffolds to Activate Fibrous Runways for Targeting Cell Adhesion
A critical challenge in scaffold design for tissue engineering is recapitulating the complex biochemical patterns that regulate cell behavior in vivo. In this work, we report the adaptation of a standard sterilization methodology-UV irradiation-for patterning the surfaces of two complementary polymeric electrospun scaffolds with oxygen cues able to efficiently immobilize biomolecules. Independently of the different polymer chain length of poly(ethylene oxide terephthalate)/poly(butylene terephthalate) (PEOT/PBT) copolymers and PEOT/PBT ratio, it was possible to easily functionalize specific regions of the scaffolds by inducing an optimized and spatially controlled adsorption of proteins capable of boosting the adhesion and spreading of cells along the activated fibrous runways. By allowing an efficient design of cell attachment patterns without inducing any noticeable change on cell morphology nor on the integrity of the electrospun fibers, this procedure offers an affordable and resourceful approach to generate complex biochemical patterns that can decisively complement the functionality of the next generation of tissue engineering scaffolds
An assessment of biomedical CoCrMo alloy fabricated by direct metal laser sintering technique for implant applications
CoCrMo alloys have been used for several decades in implantable devices due to their favourable mechanical properties, low wear rate in addition to good biocompatibility and high corrosion resistance. These alloys are conventionally produced via casting and/or forging route, however additive manufacturing techniques being recently employed in their fabrication. In this work, CoCrMo samples were produced by direct metal laser sintering additive manufacturing process. The microstructure and surface composition were examined employing scanning electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy (XPS). The corrosion resistance was measured in 0.14 M sodium chloride solution and in phosphate buffered solution (PBS) both with and without addition of albumin at pH 7.4 and 37 degrees C. For this, potentiodynamic tests in addition to electrochemical impedance spectroscopy were employed. The studied CoCrMo alloy exhibits a good corrosion resistance in solutions tested being the highest in PBS solution without albumin addition. The XPS analysis showed that the passive film composition and its thickness are not modified by the adsorbed layer. Microstructural analysis revealed occurrence of strain-induced martensitic transformation107COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP50/20112016/09350-2; 2007/54829-
Interrelationship between chromosome 8 aneuploidy, C-MYC amplification and increased expression in individuals from northern Brazil with gastric adenocarcinoma
AIM: To investigate chromosome 8 numerical aberrations, C-MYC oncogene alterations and its expression in gastric cancer and to correlate these findings with histopathological characteristics of gastric tumors.METHODS: Specimens were collected surgically from seven patients with gastric adenocarcinomas. Immunostaining for C-MYC and dual-color fluorescence in situ hybridization (FISH) for C-MYC gene and chromosome 8 centromere were performed.RESULTS: All the cases showed chromosome 8 aneuploidy and C-MYC amplification, in both the diffuse and intestinal histopathological types of Lauren. No significant difference (P < 0.05) was observed between the level of chromosome 8 ploidy and the site, stage or histological type of the adenocarcinomas. C-MYC high amplification, like homogeneously stained regions (HSRs) and double minutes (DMs), was observed only in the intestinal-type. Structural rearrangement of C-MYC, like translocation, was observed only in the diffuse type. Regarding C-MYC gene, a significant difference (P < 0.05) was observed between the two histological types. The C-MYC protein was expressed in all the studied cases. In the intestinal-type the C-MYC immunoreactivity was localized only in the nucleus and in the diffuse type in the nucleus and cytoplasm.CONCLUSION: Distinct patterns of alterations between intestinal and diffuse types of gastric tumors support the hypothesis that these types follow different genetic pathways. (C) 2006 The WJG Press. All rights reserved.Fed Univ Para, Ctr Ciencias Biol, Dept Biol, Lab Citogenet Humana & Genet Toxicol, BR-66075900 Belem, Para, BrazilUniv Fed Sao Paulo, Dept Morphol, Div Genet, Sao Paulo, BrazilFed Univ Para, Dept Pathol, BR-66059 Belem, Para, BrazilFed Univ Para, Surg Serv, BR-66059 Belem, Para, BrazilFed Univ Para, Joao de Barros Barreto Univ Hosp, BR-66059 Belem, Para, BrazilFed Univ Ceara, Sch Med, Dept Pathol, Genet Mol Lab, Fortaleza, Ceara, BrazilUniv Fed Sao Paulo, Dept Morphol, Div Genet, Sao Paulo, BrazilWeb of Scienc