Janus 3D Printed Dynamic Scaffolds for Nanovibration-Driven Bone Regeneration

The application of physical stimuli to cell cultures has shown potential to modulate multiple cellular functions including migration, differentiation and survival. However, the relevance of these invitro models to future potential extrapolation invivo depends on whether stimuli can be applied "externally", without invasive procedures. Here, we report on the fabrication and exploitation of dynamic additive-manufactured Janus scaffolds that are activated on-command via external application of ultrasounds, resulting in a mechanical nanovibration that is transmitted to the surrounding cells. Janus scaffolds were spontaneously formed via phase-segregation of biodegradable polycaprolactone (PCL) and polylactide (PLA) blends during the manufacturing process and behave as ultrasound transducers (acoustic to mechanical) where the PLA and PCL phases represent the active and backing materials, respectively. Remote stimulation of Janus scaffolds led to enhanced cell proliferation, matrix deposition and osteogenic differentiation of seeded human bone marrow derived stromal cells (hBMSCs) via formation and activation of voltage-gated calcium ion channelsThe authors acknowledge the Texas A&M Health Science Center College of Medicine Institute for Regenerative Medicine at Scott & White who isolated and provided the cells through a grant from NCRR of the NIH (Grant #P40RR017447). The authors acknowledge the financial support from the European Commission under the ERC starting grant “Cell Hybridge” of the Horizon2020 framework program (Grant # 637308)

Additive manufactured, highly resilient, elastic, and biodegradable poly(ester)urethane scaffolds with chondroinductive properties for cartilage tissue engineering

Articular cartilage was thought to be one of the first tissues to be successfully engineered. Despite the avascular and non-innervated nature of the tissue, the cells within articular cartilage - chondrocytes - account for a complex phenotype that is difficult to be maintained in vitro. The use of bone marrow-derived stromal cells (BMSCs) has emerged as a potential solution to this issue. Differentiation of BMSCs toward stable and non-hypertrophic chondrogenic phenotypes has also proved to be challenging. Moreover, hyaline cartilage presents a set of mechanical properties - relatively high Young's modulus, elasticity, and resilience - that are difficult to reproduce. Here, we report on the use of additive manufactured biodegradable poly(ester)urethane (PEU) scaffolds of two different structures (500 mu m pore size and 90 degrees or 60 degrees deposition angle) that can support the loads applied onto the knee while being highly resilient, with a permanent deformation lower than 1% after 10 compression-relaxation cycles. Moreover, these scaffolds appear to promote BMSC differentiation, as shown by the deposition of glycosaminoglycans and collagens (in particular collagen II). At gene level, BMSCs showed an upregulation of chondrogenic markers, such as collagen II and the Sox trio, to higher or similar levels than that of traditional pellet cultures, with a collagen II/collagen I relative expression of 2-3, depending on the structure of the scaffold. Moreover, scaffolds with different pore architectures influenced the differentiation process and the final BMSC phenotype. These data suggest that additive manufactured PEU scaffolds could be good candidates for cartilage tissue regeneration in combination with microfracture interventions.</p

Additive manufacturing of an elastic poly(ester)urethane for cartilage tissue engineering

Although a growing knowledge on the field of tissue engineering of articular cartilage exists, reconstruction or in-vitro growth of functional hyaline tissue still represents an unmet challenge. Despite the simplicity of the tissue in terms of cell population and absence of innervation and vascularization, the outstanding mechanical properties of articular cartilage, which are the result of the specificity of its extra cellular matrix (ECM), are difficult to mimic. Most importantly, controlling the differentiation state or phenotype of chondrocytes, which are responsible of the deposition of this specialized ECM. represents a milestone in the regeneration of native articular cartilage. In this study, we fabricated fused deposition modelled (FDM) scaffolds with different pore sizes and architectures from an elastic and biodegradable poly(ester)urethane (PEU) with mechanical properties that can be modulated by design, and that ranged the elasticity of articular cartilage. Cell culture in additive manufactured 3D scaffolds exceeded the chondrogenic potential of the gold-standard pellet culture. In-vitro cell culture studies demonstrated the intrinsic potential of elastic (PEU) to drive the re-differentiation of de-differentiated chondrocytes when cultured in-vitro, in differentiation or basal media, better than pellet cultures. The formation of neo-tissue was assessed as a high deposition of GAGs and fibrillar collagen II, and a high expression of typical chondrogenic markers. Moreover, the collagen II / collagen I ratio commonly used to evaluate the differentiation state of chondrocytes (ratio > 1 being chondrocytes and, ratio <0 being de-differentiated chondrocytes) was higher than 5. Statement of significance Tissue engineering of articular cartilage requires material scaffolds capable of driving the deposition of a coherent and specific ECM representative of articular cartilage. Materials explored so far account for low mechanical properties (hydrogels), or are too stiff to mimic the elasticity of the native tissue (traditional polyesters). Here, we fabricated 3D fibrous scaffolds via FDM with a biodegradable poly(ester)urethane. The compressive Young's modulus and elastic limit of the scaffolds can be tuned by designed, mimicking those of the native tissue. The designed scaffolds showed an intrinsic potential to drive the formation of a GAG and collagen II rich ECM, and to drive a stable chondrogenic cell phenotype. (C) 2019 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved

Tailoring biomaterial scaffolds for osteochondral repair

Articular cartilage is a mechanically and structurally complex, lubricious tissue that permits load-bearing and frictionless movement of our joints upon articulation. Unfortunately, cartilage is unable to properly self-heal as a result of acute trauma or damage, resulting in many cases in significant pain, reduction in physical activity and quality of life for the patient. Due to the inability of resident cells to repair damaged osteochondral tissue, researchers have focused on utilizing endogenously or exogenously sourced cells (chondrocytes or tissue-derived mesenchymal stem cells), with or without scaffolds, to encourage the secretion of extracellular matrix (ECM) that replicates this highly anisotropic osteochondral tissue, in which the phenotype of the cells and the composition and orientation of the ECM varies along its depth. Important advances have been achieved towards the development of scaffolds with macroscopically relevant structures, however, articular cartilage and bone tissue contain complex, hierarchical structures that provide cells with biophysical and biochemical cues spanning multiple length scales, presenting researchers with some substantial challenges. This review summarizes the latest advances in mechanical, biochemical and topographical engineering of biomaterials to drive requisite biological responses, such as cell differentiation and matrix deposition, in an effort to achieve functional repair of osteochondral defects

Bioprinting:From Tissue and Organ Development to <i>in Vitro</i> Models

Bioprinting techniques have been flourishing in the field of biofabrication with pronounced and exponential developments in the past years. Novel biomaterial inks used for the formation of bioinks have been developed, allowing the manufacturing of in vitro models and implants tested preclinically with a certain degree of success. Furthermore, incredible advances in cell biology, namely, in pluripotent stem cells, have also contributed to the latest milestones where more relevant tissues or organ-like constructs with a certain degree of functionality can already be obtained. These incredible strides have been possible with a multitude of multidisciplinary teams around the world, working to make bioprinted tissues and organs more relevant and functional. Yet, there is still a long way to go until these biofabricated constructs will be able to reach the clinics. In this review, we summarize the main bioprinting activities linking them to tissue and organ development and physiology. Most bioprinting approaches focus on mimicking fully matured tissues. Future bioprinting strategies might pursue earlier developmental stages of tissues and organs. The continuous convergence of the experts in the fields of material sciences, cell biology, engineering, and many other disciplines will gradually allow us to overcome the barriers identified on the demanding path toward manufacturing and adoption of tissue and organ replacements.</p

Low molecular weight poly((d,l)-lactide-co-caprolactone) liquid inks for diluent-free DLP printing of cell culture platforms

Digital light processing (DLP) printing offers the possibility of fabricating complex objects in a fast and reproducible manner. A main requirement for DLP printing is the use of inks with low viscosities that can flow under the printing platform in a short period of time. Its exploitation in tissue engineering applications has been centered on the use of hydrogel forming materials diluted in aqueous solutions or the use of polyesters in combination with diluents and heating platforms that aid in the reduction of their viscosity. The use of diluents, however, modifies the mechanical properties and reduces the shape fidelity of the printed objects and, the use of heating platforms results in vats with heterogeneous temperatures and ink viscosities. Here, we report on the synthesis of a library of methacrylated low molecular weight (<3000 g mol−1) homopolymers ((P(D,L)LA and PCL) and copolymers (P((D,L)LA-co-CL)) of 2- and 3-arms based on (D,L)-lactide and ε-caprolactone. The resulting inks possessed low viscosity that made them printable in the absence of diluents and heating elements. DLP printing of cubical and cylindrical patterns resulted in objects with a higher shape fidelity than their counterparts fabricated using diluents and with printed features on the order of 300 μm. The printed materials were biocompatible and supported the growth of human mesenchymal stem cells (hMSCs). Moreover, the variations in the composition resulted in polymers that enabled the attachment of hMSCs to different extents, leading to the formation of well-adhered cell monolayers or loosely adhered cell aggregates.The authors acknowledge the funding bodies and support through the EMAKIKER grant. S. C.-E. acknowledges the Spanish Ministry of Science and Innovation (MICINN) – State Investigation Agency (AEI) (PID2020-114901RA-I00). S. C.-E. and S. R.-D. acknowledge the Basque Government (PIBA_2022_1_0006). G. L.-J. acknowledges the Basque Government Predoctoral grant PRE_2021_1_0403. S. C.-E. and L. I. acknowledge the Provincial Council of Guipuzcoa. The project that gave rise to these results received the support of a fellowship from the “laCaixa” Foundation (ID100010434). The fellowship code is 117145. S. C.-E. acknowledges funding from the University of the Basque Country UPV/EHU within the framework of Grupos de Investigación (GIU21/033). A. A. acknowledges funding from PID2021-127191OB-I00 and RTI2018-101708-A-I00 funded by MCIN/AEI/10.13039/501100011033 and by “ERDF A way of making Europe”. Grant RYC2018-025502-I funded by MCIN/AEI/10.13039/501100011033 and by “ESF Investing in your future”

Recent advances and future perspectives on porous materials for biomedical applications

Unformatted postprint version of the accepted articleThe authors gratefully acknowledge financial support from MCIN/AEI/10.13039/501100011033 and FEDER (RTI2018-098951- B-I00, RTI2018-096294-B-C32), IKERBASQUE-Basque Foundation for Science, Basque Government (Elkartek projects KK- 2019/00086 and KK-2020/00010; proyectos de investigacio´ n ba´ sica/aplicada PIBA 2020 1 0056, IT1069-16), Gipuzkoa Provincial Council (2019-CIEN-000075-01). MSO and S.C-E acknowledge support by the Marie-Slodowska-Curie Action under the H2020 framework program, with the projects ‘THERMUCNA’ [896775] and ‘PRIUS-TE’ [845488], respectively. A.B. thanks to the Spanish Research Agency (AEI) for the financial support (PID2019-110239RB-I00 from I+D call and RYC2018-025923-I from RyC program), including FEDER funds; and BBVA foundation (Leonardo Fellowships, IN [21] CBB QUI 0086). The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed

Mechanosensitive regulation of stanniocalcin-1 by zyxin and actin-myosin in human mesenchymal stromal cells

Stanniocalcin-1 (STC1) secreted by mesenchymal stromal cells (MSCs) has anti-inflammatory functions, reduces apoptosis, and aids in angiogenesis, both in vitro and in vivo. However, little is known about the molecular mechanisms of its regulation. Here, we show that STC1 secretion is increased only under specific cell-stress conditions. We find that this is due to a change in actin stress fibers and actin-myosin tension. Abolishment of stress fibers by blebbistatin and knockdown of the focal adhesion protein zyxin leads to an increase in STC1 secretion. To also study this connection in 3D, where few focal adhesions and actin stress fibers are present, STC1 expression was analyzed in 3D alginate hydrogels and 3D electrospun scaffolds. Indeed, STC1 secretion was increased in these low cellular tension 3D environments. Together, our data show that STC1 does not directly respond to cell stress, but that it is regulated through mechanotransduction. This research takes a step forward in the fundamental understanding of STC1 regulation and can have implications for cell-based regenerative medicine, where cell survival, anti-inflammatory factors and angiogenesis are critical

Mechanical and Shape-Memory Properties of Poly(mannitol sebacate)/Cellulose Nanocrystal Nanocomposites

"This is the peer reviewed version of the following article: Sonseca, Á., Camarero&#8208;Espinosa, S., Peponi, L., Weder, C., Foster, E. J., Kenny, J. M., & Giménez, E. (2014). Mechanical and shape&#8208;memory properties of poly (mannitol sebacate)/cellulose nanocrystal nanocomposites. Journal of Polymer Science Part A: Polymer Chemistry, 52(21), 3123-3133., which has been published in final form at https://doi.org/10.1002/pola.27367. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving."[EN] Polyesters based on polyols and sebacic acid, known as poly(polyol sebacate)s (PPS), are attracting considerable attention, as their properties are potentially useful in the context of soft-tissue engineering applications. To overcome the drawback that PPSs generally display rather low strength and stiffness, we have pursued the preparation of nano composites based poly(mannitol sebacate) (PMS), a prominent example of this materials family, with cellulose nanocrystals (CNCs). Nanocomposites were achieved in a two-step process. A soluble, low-molecular-weight PMS pre-polymer was formed via the polycondensation reaction between sebacic acid and D-mannitol. Nanocomposites with different CNC content were prepared by solution-casting and curing under vacuum using two different profiles designed to prepare materials with low and high degree of crosslinking. The as-prepared nano composites have higher stiffness and toughness than the neat PMS matrix while maintaining a high elongation at break. A highly crosslinked nanocomposite with a CNC content of 5 wt % displays a sixfold increase in Young s modulus and a fivefold improvement in toughness. Nanocomposites also exhibit a shape memory effect with a switch temperature in the range of 15 to 45 C; in particular the materials with a thermal transition in the upper part of this range are potentially useful for biomedical applicationsThe authors gratefully acknowledge financial support received from Spanish Ministry of Economy and Competitiveness (Project MAT2010/21494-C03), as well as the support of FPU grant from MED (MED-FPU; AP2009-2482), JAE-Doc grant (CSIC co-financed by FSE), Swiss National Science foundation (National Research Programme 64, Project #406440_131264/1) and the Adolphe Merkle Foundation.Sonseca, A.; Camarero-Espinosa, S.; Peponi, L.; Weder, C.; Foster, E.; Kenny, JM.; Giménez Torres, E. (2014). Mechanical and Shape-Memory Properties of Poly(mannitol sebacate)/Cellulose Nanocrystal Nanocomposites. Journal of Polymer Science Part A Polymer Chemistry. 52(21):3123-3133. https://doi.org/10.1002/pola.27367S312331335221Bruggeman, J. 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La représentation cartographique des communes de La Mancha au XVIIIe siècle. Le cadastre d'Ensenada

Para geógrafos e historiadores es un hecho evidente que cualquier estudio sobre la historia agraria, social y económica de nuestro país o el paisaje en el siglo XVIII ha de pasar necesariamente por un análisis minucioso de la información que ofrece el catastro de Ensenada. Y ello porque es una fuente geohistórica de gran valor por la cantidad y calidad de la información que contiene, fundamental para entender el paisaje del ayer y del presente. La cartografía incluida en el conjunto documental de dicho catastro, realizado en el territorio de la Corona de Castilla, no tiene carácter técnico y está basada en la percepción que se tenía de estos espacios, lo que generó un conjunto de “croquis” municipales muy significativos. El interés de la cartografía elaborada en la Intendencia de la Mancha es doble: por un lado, su nivel de conservación, por otro, el nivel de detalle y peculiaridades que presentan su conjunto cartográfico. Este este estudio aporta luz sobre el proceso de representación cartográfica que se empleaba en dicho catastro, así como una clasificación de los croquis de las localidades de La Mancha, que servirá de base para estudios posteriores de lo hecho en otras intendenciasFor geographers and historians, it is an obvious fact that any study of the agrarian, social and economic history of our country in the Eighteenth century must necessarily go through a thorough analysis of the information offered by the Cadastre of the Marquis of Ensenada. The cadastral geohistorical sources give us a municipal territorial information that helps us understand the present landscape.The cartography included in the documentation set of the Cadastre, made in the territory of the Crown of Castile, is not technical and is based on the perception that was held of these spaces, which generated a set of “drawings” very significant municipal. The interest in the cartography of the Intendancy of La Mancha is double, as much for its level of conservation, and, on the other hand, for the level of detail and peculiarities that this cartography presents. The goal of this study sheds light on the process of cartographic representation that was used in said Cadastre, as well as a classification of them that will serve as the basis for later studies of other municipalitiesPour les géographes et les historiens, il est évident que toute étude sur l'histoire agraire, sociale et économique de notre pays ou du paysage au XVIIIe siècle doit nécessairement passer par une analyse approfondie des informations proposées par le cadastre d'Ensenada. Et c'est parce que c'est une source géohistorique de grande valeur pour la quantité et la qualité des informations qu'elle contient, fondamentales pour comprendre le paysage d'hier et d'aujourd'hui. La cartographie incluse dans l'ensemble documentaire dudit cadastre, réalisée sur le territoire de la Couronne de Castille, n'a aucun caractère technique et s'appuie sur la perception de ces espaces, ce qui a généré un ensemble de «croquis» municipaux très significatifs . L'intérêt de la cartographie élaborée dans l'Intendencia de la Mancha est double: d'une part, son niveau de conservation, d'autre part, le niveau de détail et les particularités présentées par son ensemble cartographique. Cette étude met en lumière le processus de représentation cartographique qui a été utilisé dans ce cadastre, ainsi qu'une classification des esquisses des localités de La Mancha, qui servira de base pour des études plus approfondies de ce qui a été fait dans d'autres municipalité