Staff member

Zaida Álvarez Pinto
Postdoctoral Researcher
+34 934 020 211
Staff member publications

Mattotti, M., Alvarez, Z., Delgado, L., Mateos-Timoneda, M. A., Aparicio, C., Planell, J. A., Alcántara, S., Engel, E., (2017). Differential neuronal and glial behavior on flat and micro patterned chitosan films Colloids and Surfaces B: Biointerfaces 158, 569-577

Chitosan is a biodegradable natural polysaccharide that has been widely studied for regenerative purposes in the central nervous system. In this study we assessed the in vitro glial and neuronal cells response to chitosan either flat or patterned with grooves in the micrometric range. Chitosan demonstrated to be a good substrate for the attachment and growth of both neurons and glial cells. Chitosan micropatterns promoted glial cell maturation, suggesting astroglial activation. Nevertheless, those mature/reactive glial cells were permissive for axonal growth. Axons aligned and organized along the patterned grooves and the size of the linear topographic patterns is also affecting neurite and cell response. Patterns with 10 μm width induced fasciculation of axons, which can be useful for CNS tissue engineering substrates when precise orientation of the axonal outgrowth is desired.

JTD Keywords: Brain, Chitosan, Glia, Micropattern, Neuron

Álvarez, Zaida, Hyroššová, Petra, Perales, José Carlos, Alcántara, Soledad, (2016). Neuronal progenitor maintenance requires lactate metabolism and PEPCK-M-directed cataplerosis Cerebral Cortex , 26, (3), 1046-1058

This study investigated the metabolic requirements for neuronal progenitor maintenance in vitro and in vivo by examining the metabolic adaptations that support neuronal progenitors and neural stem cells (NSCs) in their undifferentiated state. We demonstrate that neuronal progenitors are strictly dependent on lactate metabolism, while glucose induces their neuronal differentiation. Lactate signaling is not by itself capable of maintaining the progenitor phenotype. The consequences of lactate metabolism include increased mitochondrial and oxidative metabolism, with a strict reliance on cataplerosis through the mitochondrial phosphoenolpyruvate carboxykinase (PEPCK-M) pathway to support anabolic functions, such as the production of extracellular matrix. In vivo, lactate maintains/induces populations of postnatal neuronal progenitors/NSCs in a PEPCK-M-dependent manner. Taken together, our data demonstrate that, lactate alone or together with other physical/biochemical cues maintain NSCs/progenitors with a metabolic signature that is classically found in tissues with high anabolic capacity.


Álvarez, Z., Castaño, O., Castells, A. A., Mateos-Timoneda, M. A., Planell, J. A., Engel, E., Alcántara, S., (2014). Neurogenesis and vascularization of the damaged brain using a lactate-releasing biomimetic scaffold Biomaterials 35, (17), 4769-4781

Regenerative medicine strategies to promote recovery following traumatic brain injuries are currently focused on the use of biomaterials as delivery systems for cells or bioactive molecules. This study shows that cell-free biomimetic scaffolds consisting of radially aligned electrospun poly-l/dl lactic acid (PLA70/30) nanofibers release l-lactate and reproduce the 3D organization and supportive function of radial glia embryonic neural stem cells. The topology of PLA nanofibers supports neuronal migration while l-lactate released during PLA degradation acts as an alternative fuel for neurons and is required for progenitor maintenance. Radial scaffolds implanted into cavities made in the postnatal mouse brain fostered complete implant vascularization, sustained neurogenesis, and allowed the long-term survival and integration of the newly generated neurons. Our results suggest that the endogenous central nervous system is capable of regeneration through the invivo dedifferentiation induced by biophysical and metabolic cues, with no need for exogenous cells, growth factors, or genetic manipulation.

JTD Keywords: Lactate, Nanofibers, Neural stem cells, Neurogenesis, Regeneration, Vascularization

Álvarez, Z., Sena, E., Mattotti, M., Engel, E., Alcántara, S., (2014). An efficient and reproducible method to culture Bergmann and cortical radial glia using textured PMMA Journal of Neuroscience Methods , 232, 93-101

Background: Radial glia cells comprise the principal population of neural stem cells (NSC) during development. Attempts to develop reproducible radial glia and NSC culture methods have met with variable results, yielding non-adherent cultures or requiring the addition of growth factors. Recent studies demonstrated that a 2-μm patterned poly-methyl methacrylate (ln2 PMMA) grooved scaffold, by mimicking the biophysical and microtopographic properties of the embryonic NSC niche, induces the de-differentiation of glial cells into functional radial glia cells. New method: Here we describe a method for obtaining cultures of adherent Bergmann radial glia (BRG) and cortical radial glia (CRG). The growth substrate is ln2 PMMA and the addition of growth factors is not required. Results: Postnatal glia obtained from mouse cerebellum or cerebral cortex and grown on ln2 PMMA adopted a BRG/CRG phenotype characterized by a bipolar shape, the up-regulation of progenitor markers such as nestin and Sox2, and the down-regulation of vimentin and GFAP. Neurons cultured over the BRG/CRG aligned their processes with those of the glial shafts, thus mimicking the behavior of migrating neuronal cells. Comparison with existing methods: The ln2 PMMA culture method offers an ideal system for analyzing both the biochemical factors controlling the neurogenic potential of BRG/CRG and neuronal migration. Conclusions: The ln2 PMMA method is a reproducible system to obtain immature BRG/CRG preparations in vitro. It can be used to study the properties of CNS progenitor cells as well as the interactions between radial glia and neurons, and supports cultured progenitors for use in different applications. © 2014 Elsevier B.V.

JTD Keywords: Astrocytes, Bergmann glia, Micro-patterning, Poly-methyl methacrylate (PMMA), Progenitors, Radial glia, Surface topography

Álvarez, Zaida, Mateos-Timoneda, Miguel A., Hyrossová, Petra, Castaño, Oscar, Planell, Josep A., Perales, José C., Engel, Elisabeth, Alcántara, Soledad, (2013). The effect of the composition of PLA films and lactate release on glial and neuronal maturation and the maintenance of the neuronal progenitor niche Biomaterials 34, (9), 2221-2233

To develop tissue engineering strategies useful for repairing damage in the central nervous system (CNS) it is essential to design scaffolds that emulate the NSC niche and its tight control of neural cell genesis, growth, and differentiation. In this study we tested two types of poly l/dl lactic acid (PLA95/5 and PLA70/30), a biodegradable material permissive for neural cell adhesion and growth, as materials for nerve regeneration. Both PLA were slightly hydrophobic and negatively charged but differed in crystallinity, stiffness and degradation rate. PLA95/5 films were highly crystalline, stiff (GPa), and did not degrade significantly in the one-month period analyzed in culture. In contrast, PLA70/30 films were more amorphous, softer (MPa) and degraded faster, releasing significant amounts of lactate into the culture medium. PLA70/30 performs better than PLA95/5 for primary cortical neural cell adhesion, proliferation and differentiation, maintaining the pools of neuronal and glial progenitor cells in vitro. l-lactate in the medium recapitulated PLA70/30's maintenance of neuronal restricted progenitors but did not sustain bipotential or glial restricted progenitors in the cultures, as occurred when neural cells were grown on PLA70/30. Our results suggest that PLA70/30 may mimic some of the physical and biochemical characteristics of the NSC niche. Its mechanical and surface properties may act synergistically in the modulation of bipotential and glial restricted progenitor phenotypes, while it is l-lactate, either added to the medium or released by the film that drives the maintenance of neuronal restricted progenitor cell phenotypes.

JTD Keywords: Polylactic acid, Degradation, Neurons, Progenitors, Lactate, Glial cells, NSC niche

Mattotti, Marta, Alvarez, Zaida, Ortega, Juan A., Planell, Josep A., Engel, Elisabeth, Alcántara, Soledad, (2012). Inducing functional radial glia-like progenitors from cortical astrocyte cultures using micropatterned PMMA Biomaterials 33, (6), 1759-1770

Radial glia cells (RGC) are multipotent progenitors that generate neurons and glia during CNS development, and which also served as substrate for neuronal migration. After a lesion, reactive glia are the main contributor to CNS regenerative blockage, although some reactive astrocytes are also able to de-differentiate in situ into radial glia-like cells (RGLC), providing beneficial effects in terms of CNS recovery. Thus, the identification of substrate properties that potentiate the ability of astrocytes to transform into RGLC in response to a lesion might help in the development of implantable devices that improve endogenous CNS regeneration. Here we demonstrate that functional RGLC can be induced from in vitro matured astrocytes by using a precisely-sized micropatterned PMMA grooved scaffold, without added soluble or substrate adsorbed biochemical factors. RGLC were extremely organized and aligned on 2 μm line patterned PMMA and, like their embryonic counterparts, express nestin, the neuron-glial progenitor marker Pax6, and also proliferate, generate different intermediate progenitors and support and direct axonal growth and neuronal migration. Our results suggest that the introduction of line patterns in the size range of the RGC processes in implantable scaffolds might mimic the topography of the embryonic neural stem cell niche, driving endogenous astrocytes into an RGLC phenotype, and thus favoring the regenerative response in situ.

JTD Keywords: Polymethylmethacrylate, Micropatterning, Surface topography, Astrocyte, Nerve guide, Co-culture