3 research outputs found

    Insights and future directions for the application of perinatal derivatives in eye diseases: A critical review of preclinical and clinical studies.

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    Perinatal derivatives (PnD) are gaining interest as a source for cell-based therapies. Since the eye is easily accessible to local administration, eye diseases may be excellent candidates to evaluate novel therapeutic approaches. With this work, we performed a systematic review of published preclinical and clinical studies addressing PnD in the treatment of ocular diseases. We have set two specific objectives: (i) to investigate the current level of standardization in applied technical procedures in preclinical studies and (ii) to assess clinical efficacy in clinical trials. Hereto, we selected studies that applied amniotic membrane (hAM) and mesenchymal stromal cells derived from amniotic membrane (hAMSC), placenta (hPMSC), umbilical cord (hUC-MSC) and Wharton's Jelly (hUC-WJ-MSC), excluding those where cells were not transplanted individually, following a systematic PubMed search for preclinical studies and consultation of clinical studies on https://clinicaltrials.gov and https://www.clinicaltrialsregister.eu/. Our bibliographic search retrieved 26 pre-clinical studies and 27 clinical trials. There was a considerable overlap regarding targeted ocular structures. Another common feature is the marked tendency towards (i) locally administered treatments and (ii) the PnD type. In the cornea/ocular surface, hAM was preferred and usually applied directly covering the ocular surface. For neuroretinal disorders, intra-ocular injection of umbilical or placental-derived cells was preferred. In general, basic research reported favourable outcomes. However, due to lack of standardization between different studies, until now there is no clear consensus regarding the fate of administered PnD or their mode of action. This might be accountable for the low index of clinical translation. Regarding clinical trials, only a minority provided results and a considerable proportion is in "unknown status". Nevertheless, from the limited clinical evidence available, hAM proved beneficial in the symptomatic relief of bullous keratopathy, treating dry eye disease and preventing glaucoma drainage device tube exposure. Regarding neuroretinal diseases, application of Wharton's Jelly MSC seems to become a promising future approach. In conclusion, PnD-based therapies seem to be beneficial in the treatment of several ocular diseases. However, much is yet to be done both in the pre-clinical and in the clinical setting before they can be included in the daily ophthalmic practice

    The Truth Is Out There: Biological Features and Clinical Indications of Extracellular Vesicles from Human Perinatal Stem Cells

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    The potential of perinatal tissues to provide cellular populations to be used in different applications of regenerative medicine is well established. Recently, the efforts of researchers are being addressed regarding the evaluation of cell products (secreted molecules or extracellular vesicles, EVs) to be used as an alternative to cellular infusion. The data regarding the effective recapitulation of most perinatal cells' properties by their secreted complement point in this direction. EVs secreted from perinatal cells exhibit key therapeutic effects such as tissue repair and regeneration, the suppression of inflammatory responses, immune system modulation, and a variety of other functions. Although the properties of EVs from perinatal derivatives and their significant potential for therapeutic success are amply recognized, several challenges still remain that need to be addressed. In the present review, we provide an up-to-date analysis of the most recent results in the field, which can be addressed in future research in order to overcome the challenges that are still present in the characterization and utilization of the secreted complement of perinatal cells and, in particular, mesenchymal stromal cells

    Preparação de um hidrogel a partir de membranas fetais humanas para cultura de células em 3D

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    Recently, three-dimensional (3D) cell culture platforms have emerged as valuable tools with potential to increase the accuracy of in vitro studies. Inspired by the extracellular matrix (ECM) that compose living tissues, these platforms have been designed to support the attachment and growth of cells, therefore providing reliable data on how they behave and respond to stimulus when within their natural environments. Despite the great advances made on the design of such materials, including the development of ECM-based hydrogels such as Matrigel¬ģ, recapitulate the complexity and function of native ECMs, while producing cost-effective and safe materials, remains a challenge. METATISSUE is a start-up company founded in 2018 that intends to address this challenge by developing human-derived 3D cell culture platforms. Amniotic membrane (AM) is a placental tissue usually discarded after delivery, thus representing a readily available source of human ECM. Although this tissue has been widely explored in the formulation of scaffolds for tissue engineering, its formulation as a hydrogel has been highly limited by the poor mechanical properties of resulting materials. Therefore, the aim of this work was to develop a photopolymerizable hydrogel derived from human AM with tunable mechanical properties for application in 3D cell culture. Amniotic membrane was isolated from placenta, decellularized and solubilized to produce a solution rich in ECM structural proteins and growth factors, and free of cells. Amniotic membrane methacrylated (AMMA) was produced by reacting the previous solution with methacrylic anhydride in order to obtain two different degrees of modification: AMMA100 (low-modification degree) and AMMA300 (high-modification degree). Finally, AMMA hydrogels were successfully obtained upon irradiation with UV or visible light. AMMA hydrogels were characterized in terms of their biochemical, mechanical and biological properties. Although some ECM components were significantly reduced after processing of AM, the hydrogels obtained were robust and stable. Indeed, characterization studies revealed that were obtained hydrogels with tunable mechanical properties. In vitro assays using human adipose-derived stem cell (hASCs) and human umbilical cord endothelial cells (HUVECs) indicated that these materials were able to support growth of top seeding cells. The encapsulation of stem cells confirmed that AM hydrogels support adhesion, proliferation and invasion of this kind of cells. In sum, this work demonstrated that human AM-derived ECM can be efficiently functionalized with photorespondive groups to produce a versatile and robust hydrogel with potential to be used in 3D cell culture.As plataformas para cultura de c√©lulas em tr√™s dimens√Ķes (3D) t√™m emergido nos √ļltimos anos como ferramentas essenciais na investiga√ß√£o pelo seu potencial para aumentar a precis√£o dos ensaios in vitro. Inspiradas na matriz extracelular que comp√Ķe os tecidos vivos, estas plataformas t√™m sido desenhadas de modo a suportar o crescimento celular, permitindo assim estudar como as c√©lulas se comportam e respondem a determinados est√≠mulos como se estivessem no seu microambiente natural. Apesar dos grandes avan√ßos feitos, que incluem a formula√ß√£o de materiais a partir de matriz extracelular animal (e.g. Matrigel ¬ģ), recapitular a complexidade e funcionalidade desta matriz, ao mesmo tempo que se produz materiais economicamente vi√°veis e seguros, continua a ser um grande desafio. METATISSUE √© uma start-up criada em 2018 com o intuito de enfrentar este desafio atrav√©s do desenvolvimento de plataformas de origem humana para cultura de c√©lulas em 3D. A membrana amni√≥tica (AM) √© um tecido perinatal usualmente descartado ap√≥s o parto, podendo por isso ser considerada uma fonte acess√≠vel de matriz extracelular humana. Embora este tecido tenha sido amplamente utilizado na formula√ß√£o de estruturas para engenharia de tecidos, a sua utiliza√ß√£o como um hidrogel continua a estar muito limitada pelas fracas propriedades mec√Ęnicas dos materiais obtidos. Assim, o principal objetivo deste trabalho foi desenvolver um hidrogel fotopolimeriz√°vel a partir de AM humana, com propriedades mec√Ęnicas adapt√°veis para aplica√ß√£o em cultura de c√©lulas em 3D. A AM foi isolada a partir de placenta humana e sujeita a processos de descelulariza√ß√£o e solubiliza√ß√£o, de modo a obter uma solu√ß√£o rica em prote√≠nas estruturais e compostos bioativos da matriz extracelular e livre de c√©lulas. Esta solu√ß√£o foi de seguida modificada com anidrido metacr√≠lico para produzir a AM metacrilada, tendo-se obtido dois graus distintos de modifica√ß√£o AMMA100 (baixo grau de modifica√ß√£o) e AMMA300 (elevado grau de modifica√ß√£o). Por √ļltimo, a solu√ß√£o modificada foi utilizada para produzir hidrog√©is AMMA atrav√©s da exposi√ß√£o √† luz ultravioleta ou vis√≠vel. Estes hidrog√©is foram caracterizados relativamente √†s suas propriedades bioqu√≠micas, mec√Ęnicas e biol√≥gicas. Apesar de alguns dos elementos que comp√Ķe a matriz extracelular terem sido afetados durante o processamento da AM, os hidrog√©is obtidos eram robustos e est√°veis. De facto, a caracteriza√ß√£o destes materiais revelou terem-se obtido hidrog√©is com propriedades mec√Ęnicas ajust√°veis. Os ensaios in vitro, utilizando c√©lulas estaminais do tecido adiposo e c√©lulas endoteliais do cord√£o umbilical, indicaram que estes materiais permitem o crescimento de c√©lulas cultivadas no topo do gel. O encapsulamento de c√©lulas estaminais permitiu confirmar que os g√©is de AM suportam a ades√£o, prolifera√ß√£o e invas√£o deste tipo de c√©lulas. Em suma, este trabalho demonstrou que a matriz extracelular da AM humana pode ser funcionalizada com gupos fotoresponsivos, produzindo hidrog√©is vers√°teis e robustos com potencial para serem usados como plataforma para cultura 3D de c√©lulas.Mestrado em Biotecnologi
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