Estrategias de marketing y comunicación para una oferta de expresiones artísticas que redunden en el bienestar emocional

Para dar a conocer toda la oferta de expresiones artísticas que redundan en el bienestar emocional de las personas, es necesario emplear diferentes estrategias de marketing y comunicación que van dirigidas a los segmentos seleccionados con la comunicación y medios apropiados para cada target escogido, para el caso de este estudio el target escogido son hombres y mujeres entre los 25 los 45 años de edad de los estratos 6 y 5 de la ciudad de Bogotá. Un segmento que estadísticamente está sometido a mayores estresores por el momento de vida en el que se encuentran y por la misma razón deberían encontrar esos espacios para poder liberarse tanto del estrés como de la ansiedad que les puede generar sus nuevas responsabilidades y cambios de vida.Resumen ; Introducción ; 1. Revisión de literatura ; 2. Metodología de la investigación ; 3. Resultados obtenidos ; Conclusiones ; Recomendaciones ; Lista de referenciasMagíster en Dirección de Marketing, CESA.Maestrí

Platelet-rich plasma favors proliferation of canine adipose-derived mesenchymal stem cells in methacrylate-endcapped caprolactone porous scaffold niches

[EN] Osteoarticular pathologies very often require an implementation therapy to favor regeneration processes of bone, cartilage and/or tendons. Clinical approaches performed on osteoarticular complications in dogs constitute an ideal model for human clinical translational applications. The adipose-derived mesenchymal stem cells (ASCs) have already been used to accelerate and facilitate the regenerative process. ASCs can be maintained in vitro and they can be differentiated to osteocytes or chondrocytes offering a good tool for cell replacement therapies in human and veterinary medicine. Although ACSs can be easily obtained from adipose tissue, the amplification process is usually performed by a time consuming process of successive passages. In this work, we use canine ASCs obtained by using a Bioreactor device under GMP cell culture conditions that produces a minimum of 30 million cells within 2 weeks. This method provides a rapid and aseptic method for production of sufficient stem cells with potential further use in clinical applications. We show that plasma rich in growth factors (PRGF) treatment positively contributes to viability and proliferation of canine ASCs into caprolactone 2-(methacryloyloxy) ethyl ester (CLMA) scaffolds. This biomaterial does not need additional modifications for cASCs attachment and proliferation. Here we propose a framework based on a combination of approaches that may contribute to increase the therapeutical capability of stem cells by the use of PRGF and compatible biomaterials for bone and connective tissue regeneration.This research was funded by the Fundación García-Cugat and the Government of Spain.Rodriguez-Jimenez, FJ.; Valdes-Sanchez, T.; Carrillo, JM.; Rubio, M.; Monleón Pradas, M.; García Cruz, DM.; Garcia, M.... (2012). Platelet-rich plasma favors proliferation of canine adipose-derived mesenchymal stem cells in methacrylate-endcapped caprolactone porous scaffold niches. Journal of Functional Biomaterials. 3(3):556-568. doi:10.3390/jfb3030556S5565683

Síntesis, caracterización y aplicaciones biomédicas de redes de copolímeros basados en poliésteres

La ingeniería tisular es una ciencia multidisciplinaria que incluye tanto los principios fundamentales de la ingeniería de materiales como de la biología celular y molecular para dar lugar al desarrollo de tejidos y órganos artificiales. Específicamente, la ingeniería de tejido óseo ha estado a la vanguardia. La combinación de células osteoblásticas o en su defecto células capaces de diferenciarse en tejido óseo, unido a la presencia de moléculas bioactivas y materiales tridimensionales "scaffolds" hacen de ésta técnica una realidad en la regeneración y reparación del hueso. Es por ello que el gran reto de éste trabajo ha sido el desarrollo de nuevos materiales basados en cadenas poliméricas de poliésteres que puedan ser útiles en ésta aplicación. La incorporación de unidades hidrófilas en sus estructuras nos ha permitido disminuir el carácter hidrófobo y la alta cristalinidad de estos materiales permitiendo incluir en la lista de sus propiedades (biocompatibilidad, buenas propiedades mecánicas, etc.) la capacidad de absorber agua de forma controlada, sin perder la buena adhesión celular que presentan, aumentar su velocidad de degradación y que como objetivo final pudieran ser utilizados en ingeniería tisular. En este sentido, se sintetizaron y caracterizaron los copolímeros de caprolactona 2-(metacriloiloxi) etil ester (CLMA) con acrilato de 2-hidroxietilo (HEA) en diferentes proporciones con el objetivo de obtener materiales con hidrofilicidad controlada. Se prepararon scaffolds de estructura de poros interconectados y se realizaron cultivos de células mesenquimales provenientes de médula ósea de cabras, diferenciadas a tejido óseo, con resultados satisfactorios. Debido a que las unidades de -caprolactona en el material descrito no formaban parte de la cadena principal de los copolímeros, sintetizamos nuevos materiales con éstas características. Se obtuvieron dos macrómeros a base de -caprolactona (mCL) y L-láctido (mLA), haciendo reaccionar la poli( -caprolactEscobar Ivirico, JL. (2008). Síntesis, caracterización y aplicaciones biomédicas de redes de copolímeros basados en poliésteres [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/3445Palanci

Estudio de hinchamiento “in vitro” y evaluación preliminar de biocompatibilidad de hidrogeles de poli(acrilamida-co-ácido metacrílico)

Los hidrogeles son redes poliméricas compatibles con el agua, los cuales pueden aumentar varias veces su volumen sin perder su forma. Las aplicaciones de este tipo de material dependen del grado de hinchamiento máximo y de las propiedades mecánicas que presentan. En el presente trabajo se describe la síntesis de los hidrogeles mediante la copolimerización radicálica de Ácido metacrílico (AM) con Acrilamida (AA), en solución acuosa a 60ºC utilizando persulfato de potasio como iniciador y N,N’-metilenbisacrilamida como entrecruzante. El objetivo principal del trabajo fue estudiar la influencia de la composición de los copolímeros sobre el proceso de hinchamiento en condiciones fisiológicas y la evaluación preliminar de biocompatibilidad de estos materiales en suero humano. Los resultados indican que para los primeros tiempos de hinchamiento las muestras cumplen satisfactoriamente el modelo Fickiano de la difusión y para los tiempos superiores la cinética de difusión de segundo orden propuesta por Schott. Por otro lado también ha sido investigada la biocompatibilidad de los hidrogeles determinando algunos parámetros bioquímicos de suero humano. Para el análisis de las muestras, éstas fueron incubadas en 10 diferentes sueros humanos por 48 horas a la temperatura de 10ºC. Se determinaron los parámetros antes del estudio, después de sumergidas las muestras en el suero a las 24 horas y posteriormente a las 48 horas. Los resultados obtenidos nos permiten afirmar que no hay diferencias significativas entre las muestras antes y después del estudio y pudiendo concluir que los hidrogeles obtenidos son biocompatibles.Peer Reviewe

Regenerative and resorbable PLA/HA hybrid construct for tendon/ligament tissue engineering

[EN] Tendon and ligament shows extremely limited endogenous regenerative capacity. Current treatments are based on the replacement and or augmentation of the injured tissue but the repaired tissue rarely achieve functionality equal to that of the preinjured tissue. To address this challenge, tissue engineering has emerged as a promising strategy. This study develops a regenerative and resorbable hybrid construct for tendon and ligament engineering. The construct is made up by a hollow poly-lactic acid braid with embedded microspheres carrying cells and an anti-adherent coating, with all the parts being made of biodegradable materials. This assembly intends to regenerate the tissue starting from the interior of the construct towards outside while it degrades. Fibroblasts cultured on poly lactic acid and hyaluronic acid microspheres for 6 h were injected into the hollow braid and the construct was cultured for 14 days. The cells thus transported into the lumen of the construct were able to migrate and adhere to the braid fibers naturally, leading to a homogeneous proliferation inside the braid. Moreover, no cells were found on the outer surface of the coating. Altogether, this study demonstrated that PLA/HA hybrid construct could be a promising material for tendon and ligament repair.This work was supported by AITEX (Textil Research Institute, Alcoi, Alicante, Spain) through the researching contract "Development of braided biomaterials for biomedical applications'' and also funded by AEI "RTI2018-095872-B-C21 and C22/ERDF''.Araque-Monrós, MC.; García-Cruz, DM.; Escobar-Ivirico, JL.; Gil-Santos, L.; Monleón Pradas, M.; Más Estellés, J. (2020). Regenerative and resorbable PLA/HA hybrid construct for tendon/ligament tissue engineering. Annals of Biomedical Engineering. 48(2):757-767. https://doi.org/10.1007/s10439-019-02403-0S757767482Aktas, E., C. S. Chamberlain, E. E. Saether, S. E. Duenwald-Kuehl, J. Kondratko-Mittnacht, M. Stitgen, J. S. Lee, A. E. Clements, W. L. Murphy, and R. Vanderby. Immune modulation with primed mesenchymal stem cells delivered via biodegradable scaffold to repair an Achilles tendon segmental defect. J. Orthop. Res. 35(2):269, 2017. https://doi.org/10.1002/jor.23258 .Araque Monrós, M. C., J. Más Estellés, M. Monleón Pradas, L. Gil Santos, S. Gironés Bernabé. Process for obtaining a biodegradable prosthesis. Patent ES2392857, 2013.Araque-Monrós, M. C., T. C. Gamboa-Martínez, L. Gil Santos, S. Gironés-Bernabé, M. Monleón-Pradas, and J. Más-Estellés. New concept for a regenerative and resorbable prosthesis for tendon and ligament: physicochemical and biological characterization of PLA-braided biomaterial. J. Biomed. Mater. Res. A 101A:3228, 2013.Araque-Monrós, M. C., A. Vidaurre, L. Gil Santos, S. Gironés-Bernabé, M. Monleón-Pradas, and J. Más-Estellés. Study of degradation of a new PLA braided biomaterial in buffer phosphate saline, basic and acid media, intended for the regeneration of tendons and ligaments. Polym. Degrad. Stabil. 98(9):1563, 2013.Chen, J., and G. Abatangelo. Functions of hyaluronan in wound repair. Wound Repair Regen. 7(2):79, 1999.Costa, M. A., C. Wu, B. V. Pham, A. K. S. Chong, H. M. Pham, and J. Chang. Tissue engineering of flexor tendons: optimization of tenocyte proliferation using growth factor supplementation. Tissue Eng. Pt. A 12(7):1937, 2006.Daniel, K. L. Achilles tendon repair with acellular tissue graft augmentation in neglected ruptures. J. Foot Ankle Surg. 46(6):451, 2007.Deborah, P. L. The costs of musculoskeletal disease: health needs assessment and health economics. Best Pract. Res. Clin. Rheumatol. 17(3):529, 2003.Deng, D., W. Liu, F. Xu, Y. Yang, G. Zhou, W. J. Zhang, L. Cui, and Y. Cao. Engineering human neo-tendon tissue in vitro with human dermal fibroblasts under static mechanical strain. Biomaterials 30(35):6724, 2009.Dominkus, M., M. Sabeti, C. Toma, F. Abdolvahab, K. Trieb, and R. I. Kotz. Reconstructing the extensor apparatus with a new polyester ligament. Clin. Orthop. Relat. Res. 453:328, 2006.Freeman, J. W., M. D. Woods, and C. T. Laurencin. Tissue engineering of the anterior cruciate ligament using a braid-twist scaffold design. J. Biomech. 40(9):2029, 2007.García Cruz, D. M., J. L. Escobar Ivirico, M. Gomes, J. L. Gómez Ribelles, M. Salmerón Sánchez, R. L. Reis, and J. F. Mano. Chitosan microparticles as injectable scaffolds for tissue engineering. J. Tissue Eng. Regen. Med. 2(6):378, 2008.Gaspar, D., K. Spanoudes, C. Holladay, A. Pandit, and D. Zeugolis. Progress in cell-based therapies for tendon repair. Adv. Drug Deliv. Rev. 84:240, 2015.Iannace, S., A. Maffezzoli, G. Leo, and L. Nicolais. Influence of crystal and amorphous phase morphology on hydrolytic degradation of PLLA subjected to different processing conditions. Polymer 42(8):3799, 2001.Iwuagwu, F. C., and D. A. McGrouther. Early cellular response in tendon injury: the effect of loading. Plast. Reconstr. Surg. 102(6):2064, 1998.Jayasinghe, S. N., A. N. Qureshi, and P. A. M. Eagles. Electrohydrodynamic jet processing: an advanced electric-field-driven jetting phenomenon for processing living cells. Small 2:216, 2006.Kimura, Y., A. Hokugo, T. Takamoto, Y. Tabata, and H. Kurosawa. Regeneration of anterior cruciate ligament by biodegradable scaffold combined with local controlled release of basic fibroblast growth factor and collagen wrapping. Tissue Eng. Pt. C-Meth. 14(1):47, 2006.Krampera, M., G. Pizzolo, G. Aprili, and M. Franchini. Mesenchymal stem cells for bone, cartilage, tendon and skeletal muscle repair. Bone 39(4):678, 2006.Kuo, C., J. Marturano, and R. Tuan. Novel strategies in tendon and ligament tissue engineering: advanced biomaterials and regeneration motifs. Sports Med. Arthrosc. Rehabil. Ther. Technol. 2(1):20, 2010.Lao, L., H. Tan, Y. Wang, and C. Gao. Chitosan modified poly(l-lactide) microspheres as cell microcarriers for cartilage tissue engineering. Colloids Surf. B Biointerfaces 66(2):218, 2008.Lu, H. H., J. A. Cooper, S. Manuel, J. W. Freeman, M. A. Attawia, F. K. Ko, and C. T. Laurencin. Anterior cruciate ligament regeneration using braided biodegradable scaffolds: in vitro optimization studies. Biomaterials 26(23):4805, 2005.Mengstreab, P. Y., L. S. Nair, and C. T. Laurencin. The past, present and future of ligament regenerative engineering. Regen. Med. 11(8):871, 2016.Molloy, T., Y. Wang, and G. A. C. Murrell. The roles of growth factors in tendon and ligament healing. Sports Med. 33(5):381, 2003.Murray, A. W., and M. F. Macnicol. 10–16 year results of Leeds–Keio anterior cruciate ligament reconstruction. Knee 11(1):9, 2004.Nelson, C. M., and C. S. Chen. Cell–cell signaling by direct contact increases cell proliferation via a PI3K-dependent signal. FEBS Lett. 514(2–3):238, 2002.Nixon, A. J., A. E. Watts, and L. V. Schnabel. Cell- and gene-based approaches to tendon regeneration. J. Shoulder Elbow Surg. 21:278, 2012.Nurettin Sahiner, X. J. One-step synthesis of hyaluronic acid-based (sub)micron hydrogel particles: process optimization and preliminary characterization. Turk. J. Chem. 32:397, 2008.Ortuño-Lizarán, I., G. Vilariño-Feltrer, C. Martínez-Ramos, M. Monleón Pradas, and A. Vallés-Lluch. Influence of synthesis parameters on hyaluronic acid hydrogels intended as nerve conduits. Biofabrication 8(4):1–12, 2016. https://doi.org/10.1088/1758-5090/8/4/045011 .Pen-hsiu, G. C., H. Hsiang-Yi, and T. Hsiao-Yun. Electrospun microcrimped fibers with nonlinear mechanical properties enhance ligament fibroblast phenotype. Biofabrication 6(3):035008, 2014. https://doi.org/10.1088/1758-5082/6/3/035008 .Porzionato, A., E. Stocco, S. Barbon, F. Grandi, V. Macchi, and R. De Caro. Tissue-engineered grafts from human decellularized extracelular matrices: a systematic review and future perspectives. Int. J. Mol. Sci. 19(12):4117, 2018.Roach, P., D. Farrar, and C. C. Perry. Interpretation of protein adsorption: surface-induced conformational changes. J. Am. Chem. Soc. 127(22):8168, 2005.Townsend-Nicholson, A., and S. N. Jayasinghe. Cell electrospinning: a unique biotechnique for encapsulating living organisms for generating active biological microthreads/scaffolds. Biomacromol 7(12):3364, 2006.Tsuji, H., K. Ikarashi, and N. Fukuda. Poly(l-lactide): XII. Formation, growth, and morphology of crystalline residues as extended-chain crystallites through hydrolysis of poly(l-lactide) films in phosphate-buffered solution. Polym. Degrad. Stabil. 84(3):515, 2004.Vuornos, K., M. Bjorninen, E. Talvitie, K. Paakinaho, M. Kellomaki, H. Huhtala, S. Miettinen, R. Seppanen-Kaijansinkko, and S. Haimi. Human adipose stem cells differentiated on braided polylactide scaffolds is a potential approach for tendon tissue engineering. Tissue Eng. Pt. A 22(5–6):513, 2016.Walden, G., X. Liao, S. Donell, M. J. Raxworthy, G. P. Riley, and A. Saeed. A clinical, biological, and biomaterials perspective into tendon injuries and regeneration. Tissue Eng. Pt. B 23(1):44, 2017.Wei, X. L., L. Lin, Y. Hou, X. Fu, J. Y. Zhang, Z. B. Mao, and C. L. Yu. Construction of recombinant adenovirus co-expression vector carrying the human transforming growth factor-beta1 and vascular endothelial growth factor genes and its effect on anterior cruciate ligament fibroblasts. Chin. Med. J. 121(15):1426, 2008.Workman, V. L., L. B. Tezera, P. T. Elkington, and S. N. Jayasinghe. Controlled generation of microspheres incorporating extracellular matrix fibrils for three-dimensional cell culture. Adv. Funct. Mater. 24:2648, 2014.Wu, S., Y. Wang, P. N. Streubel, and B. Duan. Living nanofiber yarn-based woven biotextiles for tendon tissue engineering using cell tri-culture and mechanical stimulation. Acta Biomater. 62:102, 2005

Bioactive organic inorganic poly(CLMA-co-HEA)/silica nanocomposites

[EN] A series of novel poly(CLMA-co-HEA)/silica nanocomposites is synthesized from caprolactone 2-(methacryloyloxy)ethyl ester (CLMA) and 2-hydroxyethyl acrylate (HEA) as organic comonomers and the simultaneous sol-gel polymerization of tetraethyloxysilane (TEOS) as silica precursor, in different mass ratios up to a 30 wt% of silica. The nanocomposites are characterized as to their mechanical and thermal properties, water sorption, bioactivity and biocompatibility, reflecting the effect on the organic matrix provided by the silica network formation. The nanocomposites nucleate the growth of hydroxyapatite (HAp) on their surfaces when immersed in the simulated body fluid of the composition used in this work. Proliferation of the MC3T3 osteoblast-like cells on the materials was assessed with the MTS assay showing their biocompatibility. Immunocytochemistry reveals osteocalcin and type I collagen production, indicating that osteoblast differentiation was promoted by the materials, and calcium deposition was confirmed by von Kossa staining. The results indicate that these poly(CLMA-co-HEA)/silica nanocomposites could be a promising biomaterial for bone tissue engineering.The authors acknowledge the financial support from the Spanish Ministry of Science and Innovation through projects DPI2010-20399-c04-03 and MAT2011-28791-C03-02. AJCF acknowledges support through Torres Quevedo grant PTQ08-02-06321. GGF and MMP acknowledge support of CIBER-BBN initiative, financed by Instituto de Salud Carlos III (Spain) with the assistance of the European Regional Development Fund.Ivashchenko, S.; Escobar Ivirico, JL.; García Cruz, DM.; Campillo Fernández, AJ.; Gallego Ferrer, G.; Monleón Pradas, M. (2015). Bioactive organic inorganic poly(CLMA-co-HEA)/silica nanocomposites. Journal of Biomaterials Applications. 29(8):1096-1108. https://doi.org/10.1177/0885328214554816S10961108298Ivirico, J. L. E., Martínez, E. C., Sánchez, M. S., Criado, I. M., Ribelles, J. L. G., & Pradas, M. M. (2007). Structure and properties of methacrylate-endcapped caprolactone networks with modulated water uptake for biomedical applications. Journal of Biomedical Materials Research Part B: Applied Biomaterials, 83B(1), 266-275. doi:10.1002/jbm.b.30792Ivirico, J. L. E., Salmerón-Sánchez, M., Ribelles, J. L. G., Pradas, M. M., Soria, J. M., Gomes, M. E., … Mano, J. F. (2009). Proliferation and differentiation of goat bone marrow stromal cells in 3D scaffolds with tunable hydrophilicity. Journal of Biomedical Materials Research Part B: Applied Biomaterials, 91B(1), 277-286. doi:10.1002/jbm.b.31400Escobar Ivirico, J. L., Salmerón Sánchez, M., Sabater i Serra, R., Meseguer Dueñas, J. M., Gómez Ribelles, J. L., & Monleón Pradas, M. (2006). Structure and Properties of Poly(ɛ-caprolactone) Networks with Modulated Water Uptake. Macromolecular Chemistry and Physics, 207(23), 2195-2205. doi:10.1002/macp.200600399Boxberg, Y., Schnabelrauch, M., Vogt, S., Sánchez, M. S., Ferrer, G. G., Pradas, M. M., & Antón, J. S. (2006). Effect of hydrophilicity on the properties of a degradable polylactide. Journal of Polymer Science Part B: Polymer Physics, 44(4), 656-664. doi:10.1002/polb.20723Salgado, A. J., Coutinho, O. P., & Reis, R. L. (2004). Bone Tissue Engineering: State of the Art and Future Trends. Macromolecular Bioscience, 4(8), 743-765. doi:10.1002/mabi.200400026Sprio, S., Ruffini, A., Valentini, F., D’Alessandro, T., Sandri, M., Panseri, S., & Tampieri, A. (2011). Biomimesis and biomorphic transformations: New concepts applied to bone regeneration. Journal of Biotechnology, 156(4), 347-355. doi:10.1016/j.jbiotec.2011.07.034Barone, D. T.-J., Raquez, J.-M., & Dubois, P. (2011). Bone-guided regeneration: from inert biomaterials to bioactive polymer (nano)composites. Polymers for Advanced Technologies, 22(5), 463-475. doi:10.1002/pat.1845Jones, J. R. (2009). New trends in bioactive scaffolds: The importance of nanostructure. Journal of the European Ceramic Society, 29(7), 1275-1281. doi:10.1016/j.jeurceramsoc.2008.08.003Paital, S. R., & Dahotre, N. B. (2009). Calcium phosphate coatings for bio-implant applications: Materials, performance factors, and methodologies. Materials Science and Engineering: R: Reports, 66(1-3), 1-70. doi:10.1016/j.mser.2009.05.001Arcos, D., & Vallet-Regí, M. (2010). Sol–gel silica-based biomaterials and bone tissue regeneration. Acta Biomaterialia, 6(8), 2874-2888. doi:10.1016/j.actbio.2010.02.012Boccaccini, A. R., Erol, M., Stark, W. J., Mohn, D., Hong, Z., & Mano, J. F. (2010). Polymer/bioactive glass nanocomposites for biomedical applications: A review. Composites Science and Technology, 70(13), 1764-1776. doi:10.1016/j.compscitech.2010.06.002Hanemann, T., & Szabó, D. V. (2010). Polymer-Nanoparticle Composites: From Synthesis to Modern Applications. Materials, 3(6), 3468-3517. doi:10.3390/ma3063468Pantaleón, R., & González-Benito, J. (2010). Structure and thermostability of PMMA in PMMA/silica nanocomposites: Effect of high-energy ball milling and the amount of the nanofiller. Polymer Composites, 31(9), 1585-1592. doi:10.1002/pc.20946Bera, O., Pilić, B., Pavličević, J., Jovičić, M., Holló, B., Szécsényi, K. M., & Špirkova, M. (2011). Preparation and thermal properties of polystyrene/silica nanocomposites. Thermochimica Acta, 515(1-2), 1-5. doi:10.1016/j.tca.2010.12.006Yan, S., Yin, J., Cui, L., Yang, Y., & Chen, X. (2011). Apatite-forming ability of bioactive poly(l-lactic acid)/grafted silica nanocomposites in simulated body fluid. Colloids and Surfaces B: Biointerfaces, 86(1), 218-224. doi:10.1016/j.colsurfb.2011.04.004Zhang, Z.-G., Li, Z.-H., Mao, X.-Z., & Wang, W.-C. (2011). Advances in bone repair with nanobiomaterials: mini-review. Cytotechnology, 63(5), 437-443. doi:10.1007/s10616-011-9367-4Salinas, A. J., Esbrit, P., & Vallet-Regí, M. (2013). A tissue engineering approach based on the use of bioceramics for bone repair. Biomater. Sci., 1(1), 40-51. doi:10.1039/c2bm00071gIzquierdo-Barba, I., Salinas, A. J., & Vallet-Regí, M. (2013). Bioactive Glasses: From Macro to Nano. International Journal of Applied Glass Science, 4(2), 149-161. doi:10.1111/ijag.12028Hajji, P., David, L., Gerard, J. F., Pascault, J. P., & Vigier, G. (1999). Synthesis, structure, and morphology of polymer-silica hybrid nanocomposites based on hydroxyethyl methacrylate. Journal of Polymer Science Part B: Polymer Physics, 37(22), 3172-3187. doi:10.1002/(sici)1099-0488(19991115)37:223.0.co;2-rCatauro, M., Raucci, M. G., De Gaetano, F., & Marotta, A. (2003). Journal of Materials Science, 38(14), 3097-3102. doi:10.1023/a:1024773113001Catauro, M., Raucci, M. G., de Gaetano, F., Buri, A., Marotta, A., & Ambrosio, L. (2004). Sol–gel synthesis, structure and bioactivity of Polycaprolactone/CaO • SiO2hybrid material. Journal of Materials Science: Materials in Medicine, 15(9), 991-995. doi:10.1023/b:jmsm.0000042684.13247.38Nie, K., Pang, W., Wang, Y., Lu, F., & Zhu, Q. (2005). Effects of specific bonding interactions in poly(ɛ-caprolactone)/silica hybrid materials on optical transparency and melting behavior. Materials Letters, 59(11), 1325-1328. doi:10.1016/j.matlet.2004.12.034Zou, H., Wu, S., & Shen, J. (2008). Polymer/Silica Nanocomposites: Preparation, Characterization, Properties, and Applications. Chemical Reviews, 108(9), 3893-3957. doi:10.1021/cr068035qPoologasundarampillai, G., Ionescu, C., Tsigkou, O., Murugesan, M., Hill, R. G., Stevens, M. M., … Jones, J. R. (2010). Synthesis of bioactive class II poly(γ-glutamic acid)/silica hybrids for bone regeneration. Journal of Materials Chemistry, 20(40), 8952. doi:10.1039/c0jm00930jLee, E.-J., Teng, S.-H., Jang, T.-S., Wang, P., Yook, S.-W., Kim, H.-E., & Koh, Y.-H. (2010). Nanostructured poly(ε-caprolactone)–silica xerogel fibrous membrane for guided bone regeneration. Acta Biomaterialia, 6(9), 3557-3565. doi:10.1016/j.actbio.2010.03.022Vallés Lluch, A., Gallego Ferrer, G., & Monleón Pradas, M. (2009). Biomimetic apatite coating on P(EMA-co-HEA)/SiO2 hybrid nanocomposites. Polymer, 50(13), 2874-2884. doi:10.1016/j.polymer.2009.04.022Kawai, T., Ohtsuki, C., Kamitakahara, M., Hosoya, K., Tanihara, M., Miyazaki, T., … Konagaya, S. (2007). In vitro apatite formation on polyamide containing carboxyl groups modified with silanol groups. Journal of Materials Science: Materials in Medicine, 18(6), 1037-1042. doi:10.1007/s10856-006-0081-2Oliveira, A. (2003). Sodium silicate gel as a precursor for the in vitro nucleation and growth of a bone-like apatite coating in compact and porous polymeric structures. Biomaterials, 24(15), 2575-2584. doi:10.1016/s0142-9612(03)00060-7Rhee, S. H. (2003). Effect of Silica Content on the Bioactivity and Mechanical Properties of Poly(ε-Caprolactone)/Silica Hybrid containing Calcium Salt. Key Engineering Materials, 240-242, 187-190. doi:10.4028/www.scientific.net/kem.240-242.187Kokubo, T. (2005). Design of bioactive bone substitutes based on biomineralization process. Materials Science and Engineering: C, 25(2), 97-104. doi:10.1016/j.msec.2005.01.002Rimer, J. D., Trofymluk, O., Navrotsky, A., Lobo, R. F., & Vlachos, D. G. (2007). Kinetic and Thermodynamic Studies of Silica Nanoparticle Dissolution. Chemistry of Materials, 19(17), 4189-4197. doi:10.1021/cm070708dHernández, J. C. R., Pradas, M. M., & Ribelles, J. L. G. (2008). Properties of poly(2-hydroxyethyl acrylate)-silica nanocomposites obtained by the sol–gel process. Journal of Non-Crystalline Solids, 354(17), 1900-1908. doi:10.1016/j.jnoncrysol.2007.10.016Vallés-Lluch, A., Costa, E., Gallego Ferrer, G., Monleón Pradas, M., & Salmerón-Sánchez, M. (2010). Structure and biological response of polymer/silica nanocomposites prepared by sol–gel technique. Composites Science and Technology, 70(13), 1789-1795. doi:10.1016/j.compscitech.2010.07.008Vallés-Lluch, A., Rodríguez-Hernández, J. C., Ferrer, G. G., & Pradas, M. M. (2010). Synthesis and characterization of poly(EMA-co-HEA)/SiO2 nanohybrids. European Polymer Journal, 46(7), 1446-1455. doi:10.1016/j.eurpolymj.2010.04.010Vallés-Lluch, A., Gallego Ferrer, G., & Monleón Pradas, M. (2010). Effect of the silica content on the physico-chemical and relaxation properties of hybrid polymer/silica nanocomposites of P(EMA-co-HEA). European Polymer Journal, 46(5), 910-917. doi:10.1016/j.eurpolymj.2010.02.004Kokubo, T., & Takadama, H. (2006). How useful is SBF in predicting in vivo bone bioactivity? Biomaterials, 27(15), 2907-2915. doi:10.1016/j.biomaterials.2006.01.017Brinker, C. ., Keefer, K. ., Schaefer, D. ., & Ashley, C. . (1982). Sol-gel transition in simple silicates. Journal of Non-Crystalline Solids, 48(1), 47-64. doi:10.1016/0022-3093(82)90245-9Anselme, K., Ponche, A., & Bigerelle, M. (2010). Relative influence of surface topography and surface chemistry on cell response to bone implant materials. Part 2: Biological aspects. Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, 224(12), 1487-1507. doi:10.1243/09544119jeim901Palacio, M. L. B., & Bhushan, B. (2012). Bioadhesion: a review of concepts and applications. Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 370(1967), 2321-2347. doi:10.1098/rsta.2011.0483Keselowsky, B. G., Collard, D. M., & Garcia, A. J. (2005). Integrin binding specificity regulates biomaterial surface chemistry effects on cell differentiation. Proceedings of the National Academy of Sciences, 102(17), 5953-5957. doi:10.1073/pnas.0407356102Khatiwala, C. B., Peyton, S. R., & Putnam, A. J. (2006). Intrinsic mechanical properties of the extracellular matrix affect the behavior of pre-osteoblastic MC3T3-E1 cells. American Journal of Physiology-Cell Physiology, 290(6), C1640-C1650. doi:10.1152/ajpcell.00455.200

Chitosan microparticles as injectable scaffolds for tissue engineering applications

[Excerpt] Microparticles may be used as a support for the adhesion and proliferation of cells. Therefore, the combination of isolated particles and previously incubated cells on their surface may have potential to be used, in the form of a suspension with media, as an injectable scaffold in the context of tissue regeneration: on expects that the particles might agglomerate after the implantation as a consequence of cells proliferation and extracellular matrix production. [...]info:eu-repo/semantics/publishedVersio

One-dimensional migration of olfactory ensheathing cells on synthetic materials: Experimental and numerical characterization

Olfactory ensheathing cells (OECs) are of great interest for regenerative purposes since they are believed to aid axonal growth. With the view set on the strategies to achieve reconnection between neuronal structures, it is of great importance to characterize the behaviour of these cells on long thread-like structures that may efficiently guide cell spread in a targeted way. Here, rat OECs were studied on polycaprolactone (PCL) long monofilaments, on long bars and on discs. PCL turns out to be an excellent substrate for OECs. The cells cover long distances along the monofilaments and colonize completely these struc- tures. With the help of a one-dimensional (1D) analytical model, a migration coefficient, a net proliferation rate constant and the fraction of all cells which undergo migration were obtained. The separate effect of the three phenomena summarized by these parameters on the colo- nization patterns of the 1D path was qualitatively dis- cussed. Other features of interest were also determined, such as the speed of the advance front of colonization and the order of the kinetics of net cell proliferation. Charac- terizing migration by means of these quantities may be useful for comparing and predicting features of the colo- nization process (such as times, patterns, advance fronts and proportion of motile cells) of different cell substrate combinations.Support of the Spanish Science & Innovation Ministery through project MAT2008-06434 is acknowledged. MMP and CMR acknowledge partial funding through the "Convenio de Colaboracion para la Investigacion Basica y Traslacional en Medicina Regenerativa" between the Instituto Nacional de Salud Carlos III, the Conselleria de Sanidad of the Generalitat Valenciana and the Foundation Centro de Investigacion Principe Felipe.Perez Garnes, M.; Martínez Ramos, C.; Barcia, JA.; Escobar Ivirico, JL.; Gomez Pinedo, UA.; Vallés Lluch, A.; Monleón Pradas, M. (2013). One-dimensional migration of olfactory ensheathing cells on synthetic materials: Experimental and numerical characterization. Cell Biochemistry and Biophysics. 65:21-36. https://doi.org/10.1007/s12013-012-9399-1S213665Stokols, S., Sakamoto, J., Breckon, C., Holt, T., Weiss, J., & Tuszynski, M. H. (2006). Templated agarose scaffolds support linear axonal regeneration. Tissue Engineering, 12(10), 2777–2787.Wei, Y. T., Tian, W. M., Yu, X., Cui, F. Z., Hou, S. P., Xu, Q. Y., et al. (2007). Hyaluronic acid hydrogels with IKVAV peptides for tissue repair and axonal regeneration in an injured rat brain. Biomedical Materials, 2(3), 142–146.Yao, L., Wang, S., Cui, W., Sherlock, R., O’Connell, C., Damodaran, G., et al. (2009). Effect of functionalized micropatterned PLGA on guided neurite growth. Acta Biomaterialia, 5(2), 580–588.Chehrehasa, F., Windus, L. C. E., Ekberg, J. A. K., Scott, S. E., Amaya, D., Mackay-Sim, A., et al. (2010). Olfactory glia enhance neonatal axon regeneration. Molecular and Cellular Neuroscience, 45(3), 277–288.Chen, B. K., Knight, A. M., de Ruiter, G. C., Spinner, R. J., Yaszemski, M. J., Currier, B. L., et al. (2009). Axon regeneration through scaffold into distal spinal cord after transection. Journal of Neurotrauma, 26(10), 1759–1771.Goto, E., Mukozawa, M., Mori, H., & Hara, M. (2010). A rolled sheet of collagen gel with cultured Schwann cells: Model of nerve conduit to enhance neurite growth. Journal of Bioscience and Bioengineering, 109(5), 512–518.Lietz, M., Dreesmann, L., Hoss, M., Oberhoffner, S., & Schlosshauer, B. (2006). Neuro tissue engineering of glial nerve guides and the impact of different cell types. Biomaterials, 27(8), 1425–1436.Radtke, C., Sasaki, M., Lankford, K. L., Vogt, P. M., & Kocsis, J. D. (2008). Potential of olfactory ensheathing cells for cell-based therapy in spinal cord injury. Journal of Rehabilitation Research and Development, 45(1), 141–151.Wei, Y., Miao, X., Xian, M., Zhang, C., Liu, X., Zhao, H., et al. (2008). Effects of transplanting olfactory ensheathing cells on recovery of olfactory epithelium after olfactory nerve transection in rats. Medical Science Monitor, 14(10), 198–204.Tennent, R., & Chuah, M. I. (1996). Ultrastructural study of ensheathing cells in early development of olfactory axons. Brain Research, Developmental Brain Research, 95(1), 135–139.Doucette, R. (1990). Glial influences on axonal growth in the primary olfactory system. Glia, 3(6), 433–449.Field, P., Li, Y., & Raisman, G. (2003). Ensheathment of the olfactory nerves in the adult rat. Journal of Neurocytology, 32(3), 317–324.Boyd, J. G., Doucette, R., & Kawaja, M. D. (2005). Defining the role of olfactory ensheathing cells in facilitating axon remyelination following damage to the spinal cord. Faseb Journal, 19(7), 694–703.Franklin, R. J., Gilson, J. M., Franceschini, I. A., & Barnett, S. C. (1996). Schwann cell-like myelination following transplantation of an olfactory bulb-ensheathing cell line into areas of demyelination in the adult CNS. Glia, 17(3), 217–224.Imaizumi, T., Lankford, K. L., Waxman, S. G., Greer, C. A., & Kocsis, J. D. (1998). Transplanted olfactory ensheathing cells remyelinate and enhance axonal conduction in the demyelinated dorsal columns of the rat spinal cord. Journal of Neuroscience, 18(16), 6176–6185.Raisman, G. (2001). Olfactory ensheathing cells - another miracle cure for spinal cord injury? Nature Reviews Neuroscience, 2(5), 369–375.Ramón-Cueto, A., Cordero, M. I., Santos-Benito, F. F., & Avila, J. (2000). Functional recovery of paraplegic rats and motor axon regeneration in their spinal cords by olfactory ensheathing glia. Neuron, 25(2), 425–435.Chuah, M. I., Choi-Lundberg, D., Weston, S., Vincent, A. J., Chung, R. S., Vickers, J. C., et al. (2004). Olfactory ensheathing cells promote collateral axonal branching in the injured adult rat spinal cord. Experimental Neurology, 185(1), 15–25.Bellamkonda, R. V. (2006). Peripheral nerve regeneration: An opinion on channels, scaffolds and anisotropy. Biomaterials, 27(19), 3515–3518.Liu, Y., Gong, Z., Liu, L., & Sun, H. (2010). Combined effect of olfactory ensheathing cell transplantation and glial cell line-derived neurotrophic factor (GDNF) intravitreal injection on optic nerve injury in rats. Molecular Vision, 16, 2903–2910.Zhu, Y., Cao, L., Su, Z., Mu, L., Yuan, Y., Gao, L., et al. (2010). Olfactory ensheathing cells: Attractant of neural progenitor migration to olfactory bulb. Glia, 58(6), 716–729.Basiri, M., & Doucette, R. (2010). Sensorimotor cortex aspiration: A model for studying Wallerian degeneration-induced glial reactivity along the entire length of a single CNS axonal pathway. Brain Research Bulletin, 81(1), 43–52.Li, Y., Carlstedt, T., Berthold, C.-H., & Raisman, G. (2004). Interaction of transplanted olfactory-ensheathing cells and host astrocytic processes provides a bridge for axons to regenerate across the dorsal root entry zone. Experimental Neurology, 188(2), 300–308.Li, Y., Yamamoto, M., Raisman, G., Choi, D., & Carlstedt, T. (2007). An experimental model of ventral root repair showing the beneficial effect of transplanting olfactory ensheathing cells. Neurosurgery, 60(4), 734–741.Ramón-Cueto, A., Plant, G. W., Avila, J., & Bunge, M. B. (1998). Long-distance axonal regeneration in the transected adult rat spinal cord is promoted by olfactory ensheathing glia transplants. The Journal of Neuroscience, 18(10), 3803–3815.Gómez-Pinedo, U., Vidueira, S., Sancho, F. J., García-Verdugo, J. M., Matías-Guiu, J., & Barcia, J. A. (2011). Olfactory ensheathing glia enhances reentry of axons into the brain from peripheral nerve grafts bridging the substantia nigra with the striatum. Neuroscience Letters, 494(2), 104–108.Graziadei, P. P., Levine, R. R., & Graziadei, G. A. (1978). Regeneration of olfactory axons and synapse formation in the forebrain after bulbectomy in neonatal mice. Proceedings of the National academy of Sciences of the United States of America, 75(10), 5230–5234.Cao, L., Liu, L., Chen, Z. Y., Wang, L. M., Ye, J. L., Qiu, H. Y., et al. (2004). Olfactory ensheathing cells genetically modified to secrete GDNF to promote spinal cord repair. Brain, 127(3), 535–549.Cao, L., Su, Z., Zhou, Q., Lv, B., Liu, X., Jiao, L., et al. (2006). Glial cell line-derived neurotrophic factor promotes olfactory ensheathing cells migration. Glia, 54(6), 536–544.Woodhall, E., West, A. K., & Chuah, M. I. (2001). Cultured olfactory ensheathing cells express nerve growth factor, brain-derived neurotrophic factor, glia cell line-derived neurotrophic factor and their receptors. Brain Research. Molecular Brain Research, 88(1–2), 203–213.Cao, L., Zhu, Y. L., Su, Z., Lv, B., Huang, Z., Mu, L., et al. (2007). Olfactory ensheathing cells promote migration of Schwann cells by secreted nerve growth factor. Glia, 55(9), 897–904.Doucette, R. (1996). Immunohistochemical localization of laminin, fibronectin and collagen type IV in the nerve fiber layer of the olfactory bulb. International Journal of Developmental Neuroscience, 14(7–8), 945–959.Franceschini, I. A., & Barnett, S. C. (1996). Low-affinity NGF-receptor and E-N-CAM expression define two types of olfactory nerve ensheathing cells that share a common lineage. Developmental Biology, 173(1), 327–343.Runyan, S. A., & Phelps, P. E. (2009). Mouse olfactory ensheathing glia enhance axon outgrowth on a myelin substrate in vitro. Experimental Neurology, 216(1), 95–104.Shen, Y., Qian, Y., Zhang, H., Zuo, B., Lu, Z., Fan, Z., et al. (2010). Guidance of olfactory ensheathing cell growth and migration on electrospun silk fibroin scaffolds. Cell Transplantation, 19(2), 147–157.Li, B.-C., Jiao, S.-S., Xu, C., You, H., & Chen, J.-M. (2010). PLGA conduit seeded with olfactory ensheathing cells for bridging sciatic nerve defect of rats. Journal of Biomedical Materials Research, Part A, 94(3), 769–780.Clements, I. P., Kim, Y. T., English, A. W., Lu, X., Chung, A., & Bellamkonda, R. V. (2009). Thin-film enhanced nerve guidance channels for peripheral nerve repair. Biomaterials, 30(23–24), 3834–3846.Martín-López, E., Nieto-Díaz, M., & Nieto-Sampedro, M. (2012). Differential adhesiveness and neurite-promoting activity for neural cells of chitosan, gelatin, and poly-l-lysine films. Journal of Biomaterials Applications, 26(7), 791–809.Cai, J., Peng, X., Nelson, K. D., Eberhart, R., & Smith, G. M. (2005). Permeable guidance channels containing microfilament scaffolds enhance axon growth and maturation. Journal of Biomedical Material Research Part A, 75(2), 374–386.Novikova, L. N., Mosahebi, A., Wiberg, M., Terenghi, G., Kellerth, J. O., & Novikov, L. N. (2006). Alginate hydrogel and matrigel as potential cell carriers for neurotransplantation. Journal of Biomedical Materials Research, Part A, 77(2), 242–252.Tang, Z. P., Liu, N., Li, Z. W., Xie, X. W., Chen, Y., Shi, Y. H., et al. (2010). In vitro evaluation of the compatibility of a novel collagen-heparan sulfate biological scaffold with olfactory ensheathing cells. Chinese Medical Journal (English), 123(10), 1299–1304.Wang, B., Zhao, Y., Lin, H., Chen, B., Zhang, J., Zhang, J., et al. (2006). Phenotypical analysis of adult rat olfactory ensheathing cells on 3-D collagen scaffolds. Neuroscience Letters, 401(1–2), 65–70.Guarnieri, D., De Capua, A., Ventre, M., Borzacchiello, A., Pedone, C., Marasco, D., et al. (2010). Covalently immobilized RGD gradient on PEG hydrogel scaffold influences cell migration parameters. Acta Biomaterialia, 6(7), 2532–2539.Ngo, T. T., Waggoner, P. J., Romero, A. A., Nelson, K. D., Eberhart, R. C., & Smith, G. M. (2003). Poly(l-lactide) microfilaments enhance peripheral nerve regeneration across extended nerve lesions. Journal of Neuroscience Research, 72(2), 227–238.Schnell, E., Klinkhammer, K., Balzer, S., Brook, G., Klee, D., Dalton, P., et al. (2007). Guidance of glial cell migration and axonal growth on electrospun nanofibers of poly-e-caprolactone and a collagen/poly-e-caprolactone blend. Biomaterials, 28(19), 3012–3025.Lim, S. H., Liu, X. Y., Song, H., Yarema, K. J., & Mao, H. Q. (2010). The effect of nanofiber-guided cell alignment on the preferential differentiation of neural stem cells. Biomaterials, 31(34), 9031–9039.Wong, D. Y., Hollister, S. J., Krebsbach, P. H., & Nosrat, C. (2007). Poly(epsilon-caprolactone) and poly (l-lactic-co-glycolic acid) degradable polymer sponges attenuate astrocyte response and lesion growth in acute traumatic brain injury. Tissue Engineering, 13(10), 2515–2523.Wong, D. Y., Krebsbach, P. H., & Hollister, S. J. (2008). Brain cortex regeneration affected by scaffold architectures. Journal of Neurosurgery, 109(4), 715–722.Wong, D. Y., Leveque, J. C., Brumblay, H., Krebsbach, P. H., Hollister, S. J., & Lamarca, F. (2008). Macro-architectures in spinal cord scaffold implants influence regeneration. Journal of Neurotrauma, 25(8), 1027–1037.Pierucci, A., de Duek, E. A., & de Oliveira, A. L. (2008). Peripheral nerve regeneration through biodegradable conduits prepared using solvent evaporation. Tissue Engineering Part A, 14(5), 595–606.Vleggeert-Lankamp, C. L., de Ruiter, G. C., Wolfs, J. F., Pego, A. P., van den Berg, R. J., Feirabend, H. K., et al. (2007). Pores in synthetic nerve conduits are beneficial to regeneration. Journal of Biomedical Material Research Part A, 80(4), 965–982.Cai, A. Q., Landman, K. A., & Hughes, B. D. (2007). Multi-scale modeling of a wound-healing cell migration assay. Journal of Theoretical Biology, 245(3), 576–594.Maini, P. K., McElwain, D. L., & Leavesley, D. I. (2004). Traveling wave model to interpret a wound-healing cell migration assay for human peritoneal mesothelial cells. Tissue Engineering, 10(3–4), 475–482.Dokukina, I. V., & Gracheva, M. E. (2010). A model of fibroblast motility on substrates with different rigidities. Biophysical Journal, 98(12), 2794–2803.Schneider, I. C., & Haugh, J. M. (2004). Spatial analysis of 3′ phosphoinositide signaling in living fibroblasts: II. Parameter estimates for individual cells from experiments. Biophysical Journal, 86(1), 599–608.Marcy, Y., Prost, J., Carlier, M.-F., & Sykes, C. C. (2004). Forces generated during actin-based propulsion: A direct measurement by micromanipulation. Proceedings of the National academy of Sciences of the United States of America, 101(16), 5992–5997.Mogilner, A., & Oster, G. (2003). Polymer motors: Pushing out the front and pulling up the back. Current Biology, 13(18), R721–R733.Cheng, G., Youssef, B. B., Markenscoff, P., & Zygourakis, K. (2006). Cell population dynamics modulate the rates of tissue growth processes. Biophysical Journal, 90(3), 713–724.Galbusera, F., Cioffi, M., Raimondi, M. T., & Pietrabissa, R. (2007). Computational modeling of combined cell population dynamics and oxygen transport in engineered tissue subject to interstitial perfusion. Computer Methods Biomechanics and Biomedical Engineering, 10(4), 279–287.Hatzikirou, H., & Deutsch, A. (2008). Cellular automata as microscopic models of cell migration in heterogeneous environments. Current Topics in Developmental Biology, 81, 401–434.Reffay, M., Petitjean, L., Coscoy, S., Grasland-Mongrain, E., Amblard, F., Buguin, A., et al. (2011). Orientation and polarity in collectively migrating cell structures: Statics and dynamics. Biophysical Journal, 100(11), 2566–2575.Chung, C. A., Yang, C. W., & Chen, C. W. (2006). Analysis of cell growth and diffusion in a scaffold for cartilage tissue engineering. Biotechnology and Bioengineering, 94(6), 1138–1146.Dunn, J. C., Chan, W. Y., Cristini, V., Kim, J. S., Lowengrub, J., Singh, S., et al. (2006). Analysis of cell growth in three-dimensional scaffolds. Tissue Engineering, 12(4), 705–716.Harms, B. D., Bassi, G. M., Horwitz, A. R., & Lauffenburger, D. A. (2005). Directional persistence of EGF-induced cell migration is associated with stabilization of lamellipodial protrusions. Biophysical Journal, 88(2), 1479–1488.Lemon, G., & King, J. (2007). Travelling-wave behaviour in a multiphase model of a population of cells in an artificial scaffold. Journal of Mathematical Biology, 55(4), 449–480.Fisher, R. (1937). The wave of advance of advantageous genes. Annals of Eugenics, 7, 355–369.Graner, F.o., & Glazier, J. A. (1992). Simulation of biological cell sorting using a two-dimensional extended Potts model. Physical Review Letters, 69(13), 2013–2016.Ouaknin, G. Y., & Bar-Yoseph, P. Z. (2009). Stochastic collective movement of cells and fingering morphology: No maverick cells. Biophysical Journal, 97(7), 1811–1821.Savill, N. J., & Hogeweg, P. (1997). Modelling morphogenesis: From single cells to crawling slugs. Journal of Theoretical Biology, 184(3), 229–235.Brockes, J. P., Fields, K. L., & Raff, M. C. (1979). Studies on cultured rat Schwann cells. I. Establishment of purified populations from cultures of peripheral nerve. Brain Research, 165, 105–118.Selinummi, J., Seppala, J., Yli-Harja, O., & Puhakka, J. A. (2005). Software for quantification of labeled bacteria from digital microscope images by automated image analysis. BioTechniques, 39(6), 859–863.Gupta, D., Venugopal, J., Prabhakaran, M. P., Dev, V. R., Low, S., Choon, A. T., et al. (2009). Aligned and random nanofibrous substrate for the in vitro culture of Schwann cells for neural tissue engineering. Acta Biomaterialia, 5(7), 2560–2569.Nisbet, D. R., Yu, L. M., Zahir, T., Forsythe, J. S., & Shoichet, M. S. (2008). Characterization of neural stem cells on electrospun poly(epsilon-caprolactone) submicron scaffolds: Evaluating their potential in neural tissue engineering. Journal of Biomaterials Science, Polymer Edition, 19(5), 623–634.Huang, Z. H., Wang, Y., Cao, L., Su, Z. D., Zhu, Y. L., Chen, Y. Z., et al. (2008). Migratory properties of cultured olfactory ensheathing cells by single-cell migration assay. Cell Research, 18, 479–490.Ekberg, J. A. K., Amaya, D., Mackay-Sim, A., & St. John, J. A. (2012). The migratory of olfactory ensheathing cells during development and regeneration. Neurosignals. doi: 10.1159/000330895 .Ruitenberg, M. J., Vukovic, J., Sarich, J., Busfield, S. J., & Plant, G..W. (2006). Olfactory ensheathing cells: characteristics, genetic engineering, and therapeutic potential. Journal of Neurotrauma, 23, 468–478.Chaikin, P. M., & Lubensky, T. C. (1995). Principles of condensed matter physics (p. 371). Cambridge, UK: Cambridge University Press.Simpson, M. J., Landman, K. A., & Hughes, B. D. (2010). Cell invasion with proliferation mechanisms motivated by time-lapse data. Physica A, 389, 3779–3790

Hydrolytic and enzymatic degradation of a poly(å-caprolactone) network

“NOTICE: this is the author’s version of a work that was accepted for publication in Polymer Degradation and Stability. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Polymer Degradation and Stability, [Volume 97, Issue 8, August 2012, Pages 1241–1248] DOI 10.1016/j.polymdegradstab.2012.05.038Long-term hydrolytic and enzymatic degradation profiles of poly(å-caprolactone) (PCL) networks were obtained. The hydrolytic degradation studies were performed in water and phosphate buffer solution (PBS) for 65 weeks. In this case, the degradation rate of PCL networks was faster than previous results in the literature on linear PCL, reaching a weight loss of around 20% in 60 weeks after immersing the samples either in water or in PBS conditions. The enzymatic degradation rate in Pseudomonas Lipase for 14 weeks was also studied, with the conclusion that the degradation profile of PCL networks is lower than for linear PCL, also reaching a 20% weight loss. The weight lost, degree of swelling, and calorimetric and mechanical properties were obtained as a function of degradation time. Furthermore, the morphological changes in the samples were studied carefully through electron microscopy and crystal size through X-ray diffraction. The changes in some properties over the degradation period such as crystallinity, crystal size and Young¿s modulus were smaller in the case of enzymatic studies, highlighting differences in the degradation mechanism in the two studies, hydrolytic and enzymatic.The authors would like to acknowledge the support of the Spanish Ministry of Science and Education through the DPI2010-20399-004-03 project. JM Meseguer-Duenas and A Vidaurre also would like to acknowledge the support of the CIBER-BBN, an initiative funded by the VI National R&D&i Plan 2008-2011, Iniciativa Ingenio 2010, Consolider Program, CIBER Actions and financed by the Instituto de Salud Carlos III with assistance from the European Regional Development Fund. The translation of this paper was funded by the Universidad Politecnica de Valencia, SpainCastilla Cortázar, MIC.; Más Estellés, J.; Meseguer Dueñas, JM.; Escobar Ivirico, JL.; Marí Soucase, B.; Vidaurre, A. (2012). Hydrolytic and enzymatic degradation of a poly(å-caprolactone) network. Polymer Degradation and Stability. 97(8):1241-1248. https://doi.org/10.1016/j.polymdegradstab.2012.05.038S1241124897

Molecular dynamics in polymer networks containing caprolactone and ethylene glycol moieties studied by dielectric relaxation spectroscopy

Copolymer networks with methacrylate main chain and caprolactone and ethylene glycol side groups were obtained by free radical copolymerisation of caprolactone methacrylate (CLMA) and poly(ethylene glycol) methacrylate (PEGMA). Dielectric relaxation spectroscopy was used to analyse molecular mobility of the different groups in the system. Only one main dielectric relaxation process was found in CLMA/PEGMA copolymer networks, located between those of the corresponding homonetworks, indicating that the system does not present phase separation. The copolymers show a secondary relaxation process at temperatures below −50 °C, which can be assigned to the overlapping of the corresponding secondary processes for the homopolymer networks; one of them was related to the local mobility of caprolactone units in CLMA and the second one was assigned to the twisting motions within ethylene glycol moiety in PEGMA. Besides the relaxation processes, the mobility of space charges has been analysed by means of conductivity and electric modulus formalisms.The support from the Spanish Ministry of Economy and Competitiveness (MINECO) and FEDER funds under the project MAT2012-38359-C03-01 is gratefully acknowledged.Sabater I Serra, R.; Escobar Ivirico, JL.; Romero Colomer, FJ.; Andrio Balado, A.; Gómez Ribelles, JL. (2014). Molecular dynamics in polymer networks containing caprolactone and ethylene glycol moieties studied by dielectric relaxation spectroscopy. Journal of Non-Crystalline Solids. 404:109-115. https://doi.org/10.1016/j.jnoncrysol.2014.08.013S10911540