Combined release of platelet-rich plasma and 3D-mesenchymal stem cell encapsulation in alginate hydrogels modified by the presence of silica

We report the modified release of platelet-rich plasma from alginate platelet-rich plasma hydrogels altered by the presence of silica. These PRP–alginate–silica compositions can be used as injectable carriers for viable mesenchymal stem cells

La angustia generada en el vínculo madre-hijo con autismo desde la perspectiva psicoanalítica. Estudio de un caso trabajado en prácticas en la Fundación E. I. N. A. de Quito, en el segundo semestre del 2012

Esta investigación versa sobre la afectación psíquica que genera la angustia materna en la vinculación con su hijo. Debido a esto, se ha planteado la siguiente hipótesis: La angustia en el vínculo madre – hijo con autismo se manifiesta mediante una relación simbiótica. Así se toma como un primer momento el trabajo realizado por Sigmund Freud en sus dos teorizaciones de la angustia. En un segundo lugar se realiza una distinción entre lo que sugiere una vinculación sana y una patógena, donde se abordan varios autores como Maud Mannoni, Alfredo Jerusalinsky, Francoise Dolto, Donald Winnicott, entre otros. Como tercer punto se puntualizó el concepto de autismo y sus características, con el fin de clarificar y contextualizar este término de una forma adecuada para la disertación. En el cuarto capítulo se expone la información obtenida durante las prácticas pre – profesionales del período 2012 en la fundación E.I.N.A. sobre un caso de autismo, el mismo que se analizará en base a la teoría trabajada, donde se comprueba la hipótesis previamente planteada

new insights into the development and progression of geographic atrophy after full thickness autologous choroidal graft

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Cell-seeded thermoreversible hydrogel-polyurethane composites for nucleus pulposus augmentation

Tissue engineering represents an alternative approach to the current invasive surgical procedures for the intervertebral disc (IVD) repair. The combination of injectable hydrogels and elastic biomaterials allow three-dimensional cell cultures and provide mechanical stability. In the present study a thermoreversible hyaluronan (HA) hydrogel as well as fibrin glue were mixed with polyurethane (PU) and their effect was investigated on the proliferation and differentiation of human IVD (hIVD cells) and mesenchymal stem cells (hMSCs) by in vitro and ex-vivo experiments

Celecoxib alleviates nociceptor sensitization mediated by interleukin-1beta-primed annulus fibrosus cells.

PURPOSE This study aims to analyze the effect of pro-inflammatory cytokine-stimulated human annulus fibrosus cells (hAFCs) on the sensitization of dorsal root ganglion (DRG) cells. We further hypothesized that celecoxib (cxb) could inhibit hAFCs-induced DRG sensitization. METHODS hAFCs from spinal trauma patients were stimulated with TNF-α or IL-1β. Cxb was added on day 2. On day 4, the expression of pro-inflammatory and neurotrophic genes was evaluated using RT-qPCR. Levels of prostaglandin E2 (PGE-2), IL-8, and IL-6 were measured in the conditioned medium (CM) using ELISA. hAFCs CM was then applied to stimulate the DRG cell line (ND7/23) for 6 days. Then, calcium imaging (Fluo4) was performed to evaluate DRG cell sensitization. Both spontaneous and bradykinin-stimulated (0.5 μM) calcium responses were analyzed. The effects on primary bovine DRG cell culture were performed in parallel to the DRG cell line model. RESULTS IL-1ß stimulation significantly enhanced the release of PGE-2 in hAFCs CM, while this increase was completely suppressed by 10 µM cxb. hAFCs revealed elevated IL-6 and IL-8 release following TNF-α and IL-1β treatment, though cxb did not alter this. The effect of hAFCs CM on DRG cell sensitization was influenced by adding cxb to hAFCs; both the DRG cell line and primary bovine DRG nociceptors showed a lower sensitivity to bradykinin stimulation. CONCLUSION Cxb can inhibit PGE-2 production in hAFCs in an IL-1β-induced pro-inflammatory in vitro environment. The cxb applied to the hAFCs also reduces the sensitization of DRG nociceptors that are stimulated by the hAFCs CM

The dark atrophy with indocyanine green angiography

PURPOSE. To evaluate differences in fluorescein angiography (FA) and indocyanine green angiography (ICGA), findings between subjects affected by Stargardt disease (STGD) and atrophic AMD. METHODS. This was a consecutive, cross-sectional case series. A total of 24 eyes of 12 patients with STGD and 23 eyes of 14 patients with atrophic AMD were enrolled in the study. Patients underwent dynamic simultaneous FA and ICGA using a dual beam confocal scanning system. Images were recorded from the initial filling of choroidal and retinal vessels throughout all the phases of the angiogram. Spectral-domain optical coherence tomography (SD-OCT) and fundus autofluorescence were also executed. FA and ICGA findings in the two groups were evaluated. RESULTS. In 92% (22/24) of eyes affected by STGD, ICGA showed hypocyanescence from the areas of atrophy, more evident in the late phases. This finding, defined as ICGA-imaged ''dark atrophy,'' was present in only 13% (3/23) of the eyes affected by atrophic AMD. The remaining eyes in both groups showed iso-or mild hypercyanescence from the areas of atrophy. Eyes with ICGA-imaged dark atrophy, both in STGD and in atrophic AMD groups, did not show early obscuration of the choroidal vessels by FA. SD-OCT revealed morphologically intact choroid in STGD patients with ICGA-imaged dark atrophy. In atrophic AMD eyes with ICGA-imaged dark atrophy, SD-OCT revealed a severely thinned choroid. CONCLUSIONS. Hypocyanescence by ICGA from the areas of atrophy was more frequent in STGD compared with atrophic AMD. This finding, along with SD-OCT evidence of intact choroid, suggests a possible selective damage of the choriocapillaris in STGD. (Invest Ophthalmol Vis Sci. 2012;53:3999-4004) DOI:10.1167/iovs.11-9258 R ecessive Stargardt disease (STGD) and age-related macular degeneration (AMD) lead to progressive and severe visual acuity loss. STGD is one of the most common inherited retinal dystrophies, while AMD is the most important cause of central visual acuity loss in western countries. STGD typically appears before age 20. It exhibits simple Mendelian transmission and is caused by mutations in the ABCA4 gene. A reduction in ABCA4 activity in the photoreceptors results in the increased production and accumulation of A2E and related bisretinoids within RPE cells. 1,2 These compounds cannot be readily metabolized and have negative effects on RPE cell function and viability. 3,4 RPE cell loss might originate from several mechanisms, including photooxidative stress, 5 vascular alterations, 6,7 and deposition of toxic lipofuscin material under RPE. Fluorescein angiography (FA) and indocyanine green angiography (ICGA) are important tools for diagnostic and pathogenetic evaluation of the two diseases. In STGD, FA is helpful because it allows for the identification of the dark choroid. This finding is characterized by the absence of normal background fluorescence mainly due to the presence of RPE lipofuscin that absorbs the blue excitatory light. 8 Also, ICGA may provide useful information, in particular about the alterations of the choroid and the choriocapillaris. 10 In addition, partial absorption by retinal pigment epithelial melanin occurs. In contrast, indocyanine green absorbs and emits light in the near-infrared spectrum, and allows better penetration. Furthermore, indocyanine green is predominantly bound to plasma protein (98% compared with 60%-80% for fluorescein), and this limits its diffusion through the fenestrations of the choriocapillaris. 11 Moreover, AMD may be characterized by a presumed macular choroidal watershed filling. 12 ICGA showed diminished choroidal arterial perfusion of the macula and enlargement of choroidal veins in the pathogenesis of AMD. 13 The combination of FA and ICGA facilitates interpretation of the exam and provides more information than either FA or ICGA alone. 10 Therefore, in this study, simultaneous FA and ICGA were used to evaluate possible differences in the pathogenesis of the two clinical entities. METHODS Twenty-six consecutive patients affected by STGD and atrophic AMD

Enthesis tissue engineering: biological requirements meet at the interface

Tendon-to-bone interface (enthesis) exhibits a complex multiscale architectural and compositional organization maintained by a heterogeneous cellular environment. Orthopedic surgeons have been facing several challenges when treating tendon pullout or tear from the bony insertion due to unsatisfactory surgical outcomes and high retear rates. The limited understanding of enthesis hinders the development of new treatment options toward enhancing regeneration. Mimicking the natural tissue structure and composition is still a major challenge to be overcome. In this review, we critically assess current tendon-to-bone interface tissue engineering strategies through the use of biological, biochemical, or biophysical cues, which must be ultimately combined into sophisticated gradient systems. Cellular strategies are described, focusing on cell sources and cocultures to emulate a physiological heterotypic niche, as well as hypoxic environments, alongside with growth factor delivery and the use of platelet-rich hemoderivatives. Biomaterial design considerations are revisited, highlighting recent progresses in tendon-to-bone scaffolds. Mechanical loading is addressed to uncover prospective engineering advances. Finally, research challenges and translational aspects are considered. In summary, we highlight the importance of deeply investigating enthesis biology toward establishing foundational expertise and integrate cues from the native niche into novel biomaterial engineering, aiming at moving today's research advances into tomorrow's regenerative therapies.Authors thank the support from the European Union Framework Programme for Research and Innovation HORIZON2020 [TEAMING Grant agreement No 739572 - The Discoveries CTR]; FCT–Fundação para a Ciência e a Tecnologia for the PhD grant of IC [PD/BD/128088/2016]; the Project NORTE-01-0145-FEDER-000021:“Accelerating tissue engineering and personalized medicine discoveries by the integration of key enabling nanotechnologies, marine-derived biomaterials and stem cells”, supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF) and the ERC Consolidator grant of ME [ERC-2017-CoG-772817]

Celecoxib alleviates nociceptor sensitization mediated by interleukin-1beta-primed annulus fibrosus cells

PURPOSE: This study aims to analyze the effect of pro-inflammatory cytokine-stimulated human annulus fibrosus cells (hAFCs) on the sensitization of dorsal root ganglion (DRG) cells. We further hypothesized that celecoxib (cxb) could inhibit hAFCs-induced DRG sensitization. METHODS: hAFCs from spinal trauma patients were stimulated with TNF-α or IL-1β. Cxb was added on day 2. On day 4, the expression of pro-inflammatory and neurotrophic genes was evaluated using RT-qPCR. Levels of prostaglandin E2 (PGE-2), IL-8, and IL-6 were measured in the conditioned medium (CM) using ELISA. hAFCs CM was then applied to stimulate the DRG cell line (ND7/23) for 6 days. Then, calcium imaging (Fluo4) was performed to evaluate DRG cell sensitization. Both spontaneous and bradykinin-stimulated (0.5 μM) calcium responses were analyzed. The effects on primary bovine DRG cell culture were performed in parallel to the DRG cell line model. RESULTS: IL-1ß stimulation significantly enhanced the release of PGE-2 in hAFCs CM, while this increase was completely suppressed by 10 µM cxb. hAFCs revealed elevated IL-6 and IL-8 release following TNF-α and IL-1β treatment, though cxb did not alter this. The effect of hAFCs CM on DRG cell sensitization was influenced by adding cxb to hAFCs; both the DRG cell line and primary bovine DRG nociceptors showed a lower sensitivity to bradykinin stimulation. CONCLUSION: Cxb can inhibit PGE-2 production in hAFCs in an IL-1β-induced pro-inflammatory in vitro environment. The cxb applied to the hAFCs also reduces the sensitization of DRG nociceptors that are stimulated by the hAFCs CM

Polyurethane scaffold with in situ swelling capacity for nucleus pulposus replacement

Nucleus pulposus (NP) replacement offers a minimally invasive alternative to spinal fusion or total disc replacement for the treatment of intervertebral disc (IVD) degeneration. This study aimed to develop a cytocompatible {NP} replacement material, which is feasible for non-invasive delivery and tunable design, and allows immediate mechanical restoration of the IVD. A bi-phasic polyurethane scaffold was fabricated consisting of a core material with rapid swelling property and a flexible electrospun envelope. The scaffold was assessed in a bovine whole {IVD} organ culture model under dynamic load for 14 days. Nucleotomy was achieved by incision through the endplate without damaging the annulus fibrosus. After implantation of the scaffold and in situ swelling, the dynamic compressive stiffness and disc height were restored immediately. The scaffold also showed favorable cytocompatibility for native disc cells. Implantation of the scaffold in a partially nucleotomized {IVD} down-regulated catabolic gene expression, increased proteoglycan and type {II} collagen intensity and decreased type I collagen intensity in remaining {NP} tissue, indicating potential to retard degeneration and preserve the {IVD} cell phenotype. The scaffold can be delivered in a minimally invasive manner, and the geometry of the scaffold post-hydration is tunable by adjusting the core material, which allows individualized design. Keywords : Intervertebral disc degeneratio