Protein matrices for improved wound healing : elastase inhibition by a synthetic peptide model

The unique properties of silk fibroin were combined with keratin to develop new wound-dressing materials. Silk fibroin/keratin (SF/K) films were prepared to reduce high levels of elastase found on chronic wounds. This improved biological function was achieved by the incorporation of a small peptide synthesized based on the reactive-site loop of the Bowman−Birk Inhibitor (BBI) protein. In vitro degradation and release were evaluated using porcine pancreatic elastase (PPE) solution as a model of wound exudate. It was found that biological degradation and release rate are highly dependent on film composition. Furthermore, the level of PPE activity can be tuned by changing the film composition, thus showing an innovative way of controlling the elastase−antielastase imbalance found on chronic wounds.We would like to acknowledge FCT - Portuguese Foundation for Science and Technology for the scholarship concession; European project Lidwine, contract no. NMP2-CT-2006-026741, and Silvia Cappellozza from "Sezione Specializzata per la Bachicoltura" for the supply of silk cocoons

Gestational protein restriction induces CA3 dendritic atrophy in dorsal hippocampal neurons but does not alter learning and memory performance in adult offspring

Studies have demonstrated that nutrient deficiency during pregnancy or in early postnatal life results in structural abnormalities in the offspring hippocampus and in cognitive impairment. In an attempt to analyze whether gestational protein restriction might induce learning and memory impairments associated with structural changes in the hippocampus, we carried out a detailed morphometric analysis of the hippocampus of male adult rats together with the behavioral characterization of these animals in the Morris water maze (MWM). Our results demonstrate that gestational protein restriction leads to a decrease in total basal dendritic length and in the number of intersections of CA3 pyramidal neurons whereas the cytoarchitecture of CA1 and dentate gyrus remained unchanged. Despite presenting significant structural rearrangements, we did not observe impairments in the MWM test. Considering the clear dissociation between the behavioral profile and the hippocampus neuronal changes, the functional significance of dendritic remodeling in fetal processing remains undisclosed

Adhesion and proliferation of human schwann cells on adhesive coatings

Attachment to and proliferation on the substrate are deemed important considerations when Schwann cells (SCs) are to be seeded in synthetic nerve grafts. Attachment is a prerequisite for the SCs to survive and fast proliferation will yield large numbers of SCs in a short time, which appears promising for stimulation of peripheral nerve regeneration. The aim of the present study was to compare the adhesion and proliferation of human Schwann cells (HSCs) on different substrates. The following were selected for their suitability as an internal coating of synthetic nerve grafts; the extracellular matrix proteins fibronectin, laminin and collagen type I and the poly-electrolytes poly( -lysine) (PDL) and poly(ethylene-imine) (PEI). On all coatings, attachment of HSCs was satisfactory and comparable, indicating that this factor is not a major consideration in choosing a suitable coating.\ud \ud Proliferation was best on fibronectin, laminin and PDL, and worst on collagen type I and PEI. Since nerve regeneration is enhanced by laminin and/or fibronectin, these are preferred as coatings for synthetic nerve grafts seeded with SCs

Atomic Force Microscopy as a Tool to Assess the Specificity of Targeted Nanoparticles in Biological Models of High Complexity

The ability to design nanoparticle delivery systems capable of selectively target their payloads to specific cell populations is still a major caveat in nanomedicine. One of the main hurdles is the fact that each nanoparticle formulation needs to be precisely tuned to match the specificities of the target cell and route of administration. In this work, molecular recognition force spectroscopy (MRFS) is presented as a tool to evaluate the specificity of neuron-targeted trimethyl chitosan nanoparticles to neuronal cell populations in biological samples of different complexity. The use of atomic force microscopy tips functionalized with targeted or non-targeted nanoparticles made it possible to assess the specific interaction of each formulation with determined cell surface receptors in a precise fashion. More importantly, the combination of MRFS with fluorescent microscopy allowed to probe the nanoparticles vectoring capacity in models of high complexity, such as primary mixed cultures, as well as specific subcellular regions in histological tissues. Overall, this work contributes for the establishment of MRFS as a powerful alternative technique to animal testing in vector design and opens new avenues for the development of advanced targeted nanomedicines.The authors would like to acknowledge the Bioimaging Center for Biomaterials and Regenerative Therapies of INEB (b.IMAGE) for the support with atomic force and confocal microscopy, Centro de Materiais da Universidade do Porto (CEMUP) for NMR analysis and the Biointerfaces and Nanotechnology Service (INEB-i3S) for nanoparticle size and zeta-potential analysis. The work was financed by Portuguese funds through FCT (Fundação para a Ciência e a Tecnologia) in the framework of the projects UID/BIM/04293/2013, PTDC/CTM-NAN/115124/2009, and PTDC/CTM-NAN/3547/2014. C.P.G. and C.D.F.L. acknowledge FCT for their Ph.D. scholarships SFRH/BD/79930/2011 and SFRH/BD/77933/2011, respectively

Black intraocular lens: another cosmetic approach to leukocoria

Purpose – To present a case report of a black intraocular lens implantation for cosmetic improvement of a blind eye with leukocoria. Setting – Ophthalmology Department - Professor Dr. Fernando Fonseca Hospital, EPE - Amadora, Lisboa, Portugal Methods – We report a 32-year-old woman who was evaluated because of the undesired cosmetic appearance of her amblyopic left eye with exotropia and leukocoria due to traumatic cataract and total retinal detachment during childhood. The Examination revealed no light perception in the left eye and 20/20 visual acuity in the right eye. An external examination showed an obvious leukocoria and exotropia of the left eye and a normal right eye. Biomicroscopy of the left eye showed a clear cornea, quiet anterior chamber, normal iris and a white pupillary reflex due to subluxated white cataract and fibrotic retinal detachment. We proceeded to cosmetic surgery that consisted of retropupillary implantation of an Artisan pupil occluder without cataract extraction, and strabismus correction within the same surgical procedure. Despite the uneventful immediate postoperative course, reevaluation two weeks later revealed dislocation of one of the lens haptics and the increase of the cataract subluxation with need of re-intervention. Intracapsular cataract extraction was done and IOL was repositioned over the iris. A video of the surgeries will be presented. Results - Two months later the eye was still quiet. The exotropia was corrected and the pupil occluder remained well centered with an excellent cosmetic appearance, despite of the optic diameter of 5.4 mm. The leukocoria was thus treated with implantation of a black IOL providing a significant improvement in the patient self-image. Conclusions – This Artisan lens is usually used to pupil occlusion in cases of intractable diplopia. Because of its vaulted configuration, Artisan pupil occluder can be applied in phakic and aphakic eyes but due to the features of this type of lens it´s not very suitable to the retropupillar enclavation . Nevertheless this case shows that in cases of white reflex the use of this pupil occluder can be a cosmetic correction alternative to the classic treatment with contact lenses, corneal tatooing or single crystaline lens extraction

Congenital ocular motor apraxia

PURPOSE: Congenital ocular motor apraxia is a rare disease characterized by defective or absent voluntary and optically induced horizontal saccadic movements. Jerky head movements or thrusts on attempted lateral gaze are a compensatory sign. Most affected children have delayed motor and speech development. Cases associated with systemic diseases, neurologic maldevelopment, metabolic deficits, and chromosomal abnormalities have been described. METHODS: Case report and review of the scientific literature. RESULTS: The authors describe the ophthalmologic, pediatric, and neurologic evaluations and follow up of a child with impaired horizontal saccades, jerky head movements, and delayed motor and speech development. CONCLUSIONS: Congenital ocular motor apraxia is an uncommon disorder of ocular motility. Even so, ophthalmologists should be aware of the developmental delay and the other associated conditions, in order to grant the patients the multidisciplinary assistance they often require

Pais diferentes megalocorneas iguais: caso clínico

Introdução: No Recém-nascido, a presença de córneas de tamanho aumentado deve levantar a suspeita de se estar perante um caso de glaucoma congénito.No entanto, outras patologias não glaucomatosas podem também originar córneas de tamanho aumentado, com ou sem malformações oculares e/ou sistémicas associadas. Método: Descrição restrospectiva de caso clínico. Caso Clinico: Os autores descrevem o caso de uma família na qual os membros do sexo masculino do ramo familiar materno de diferentes gerações, possuíam Megalocorneas. Conclusão: Apesar de pouco frequente, verifica-se a presença de megalocornea com provável transmissão ligada ao cromossoma X

Endothelialization of chitosan porous conduits via immobilization of a recombinant fibronectin fragment (rhFNIII7–10)

The present study aimed to develop a pre-endothelialized chitosan (CH) porous hollowed scaffold for application in spinal cord regenerative therapies. CH conduits with different degrees of acetylation (DA; 4% and 15%) were prepared, characterized (microstructure, porosity and water uptake) and functionalized with a recombinant fragment of human fibronectin (rhFNIII7–10). Immobilized rhFNIII7–10 was characterized in terms of amount (125I-radiolabelling), exposure of cell-binding domains (immunofluorescence) and ability to mediate endothelial cell (EC) adhesion and cytoskeletal rearrangement. Functionalized conduits revealed a linear increase in immobilized rhFNIII7–10 with rhFNIII7–10 concentration, and, for the same concentration, higher amounts of rhFNIII7–10 on DA 4% compared with DA 15%. Moreover, rhFNIII7–10 concentrations as low as 5 and 20 lgml 1 in the coupling reaction were shown to provide DA 4% and 15% scaffolds, respectively, with levels of exposed cell-binding domains exceeding those observed on the control (DA 4% scaffolds incubated in a 20 lgml 1 human fibronectin solution). These grafting conditions proved to be effective in mediating EC adhesion/cytoskeletal organization on CH with DA 4% and 15%, without affecting the endothelial angiogenic potential. rhFNIII7–10 grafting to CH could be a strategy of particular interest in tissue engineering applications requiring the use of endothelialized porous matrices with tunable degradation rates

Comparison of macular thickness and volume in amblyopic children using time domain optical coherence tomography

Purpose: Cortical and lateral geniculate changes are well documented in amblyopia but retinal involvement is controversial. Our aim was to compare macular volume and thickness between the sound and the amblyopic eye, in children with unilateral amblyopia due to anisometropia or strabismus, using optical coherence tomography. Materials and Methods: Amblyopic children up to the age of 18 were examined with Stratus OCT3, assessing macular volume and thickness. Statistical analysis was done using the Wilcoxon signed rank test and a level of significance of 5% was chosen. Results: 19 amblyopic patients were studied, 15 with strabismus and 4 with anisometropia. The foveal minimum thickness was significantly greater in the amblyopic eye; by contrast, significantly reduced thickness was found in the inner nasal, inner inferior and outer inferior macular areas of the amblyopic eye. Macular volume and retinal thickness in the other macular areas were reduced in amblyopic eyes but this was not significant. Conclusions: There seems to be a difference in macular thickness between both eyes in patients with unilateral amblyopia due to strabismus or anisometropia, at least in some areas. Our results are according to some studies performed so far, although others contradict these results, reflecting the different experimental settings used