P(EMA-co-HEA)/SiO2 hybrid nanocomposites for guided dentin tissue regeneration: structure, characterization and bioactivity

Se sintetizaron nanocompuestos híbridos en bloque de poli(etil metacrilato-co-hidroxietil acrilato) 70/30 wt%/sílice, P(EMA-co-HEA)/SiO2, con distintas proporciones de sílice hasta el 30 wt%. El procedimiento de síntesis consistió en la copolimerización de los monómeros orgánicos durante la polimerización sol-gel simultánea de tetraetoxisilano, TEOS como precursor de sílice. El TEOS se hidroliza eficientemente y condensa dando lugar a sílice, y presenta una distribución homogénea en forma de agregados inconexos de nanopartículas de sílice elementales en los híbridos con bajos contenidos de sílice (10 wt%). La red polimérica orgánica se forma en los poros producidos en el interior de las nanopartículas elementales de sílice, y también en los poros formados entre los agregados de nanopartículas. Los nanohíbridos con contenidos de sílice intermedios (10-20 wt%) exhibieron las propiedades más equilibradas e interesantes: i) refuerzo mecánico de la matriz orgánica conseguida gracias a redes de sílice continuas e interpenetradas, ii) buena capacidad de hinchado debida a la expansión de la red orgánica no impedida todavía por un esqueleto de sílice rígido, y a un número alto de grupos silanol terminales hidrófilos (concentraciones inorgánicas en los alrededores de la coalescencia), y iii) mayor reactividad superficial debido a un contenido relativo bastante elevado de grupos polares silanol terminales disponibles en las superficies. La 'bioactividad' o capacidad de los materiales en bloque de formar hidroxiapatita (HAp) sobre sus superficies fue estudiada in vitro sumergiéndolos en fluido biológico simulado (simulated body fluid, SBF). La formación de la capa de HAp viene controlada por el mecanismo y el tiempo de inducción a la nucleación de la misma, que dependen a su vez de la estructura de la sílice.Vallés Lluch, A. (2008). P(EMA-co-HEA)/SiO2 hybrid nanocomposites for guided dentin tissue regeneration: structure, characterization and bioactivity [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/379

Role of Electrospinning Parameters on Poly(Lactic-co-Glycolic Acid) and Poly(Caprolactone-co-Glycolic acid) Membranes

[EN] Poly(lactic-co-glycolic acid) (PLGA) and poly(caprolactone-co-glycolic acid) (PCLGA) solutions were electrospun into membranes with tailored fiber diameter of 1.8 mu m. This particular fiber diameter was tuned depending on the used co-polymer by adjusting the electrospinning parameters that mainly influence the fiber diameter. The greatest setting of the fiber diameter was achieved by varying the polymer solution parameters (polymer concentration, solvents and solvents ratio). PLGA was adequately electrospun with 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP), whereas PCLGA required a polar solvent (such as chloroform) with a lower dielectric constant. Moreover, due to the amorphous morphology of PCLGA, pyridine as salt had to be added to the starting solution to increase its conductivity and make it electrospinnable. Indeed, the electrospinning of this co-polymer presents notable difficulties due to its amorphous structure. Interestingly, PCLGA, having a higher glycolic acid molar fraction than commonly electrospun co-polymers (caprolactone:glycolic acid ratio of 45:55 instead of 90:10), could be successfully electrospun, which has not been reported to date. To an accurate setting of fiber diameter, the voltage and the distance from needle to collector were varied. Finally, the study of the surface tension, conductivity and viscosity of the polymer solutions allowed to correlate these particular characteristics of the solutions with the electrospinning variables so that prior knowledge of them enables predicting the required processing conditions.M. Herrero acknowledges the Spanish Ministerio de Economia y Competitividad for the BES-2016-078024 grant. A.Valles acknowledges the support of the Generalitat Valenciana, Conselleria de Educacion, Investigacion, Cultura y Deporte through project AEST/2020/052. CIBER-BBN is an initiative funded by the VI National R&D & I Plan 2008-2011, Iniciativa Ingenio 2010, Consolider Program. CIBER actions are financed by the Instituto de Salud Carlos III with assistance from the European Regional Development Fund.Herrero-Herrero, M.; Gómez-Tejedor, J.; Vallés Lluch, A. (2021). Role of Electrospinning Parameters on Poly(Lactic-co-Glycolic Acid) and Poly(Caprolactone-co-Glycolic acid) Membranes. Polymers. 13(5):1-11. https://doi.org/10.3390/polym13050695S11113

Improvement of mechanical and biological properties of Polycaprolactone loaded with Hydroxyapatite and Halloysite Nanotubes

[EN] Hydroxyapatite (HA) and Halloysite nanotubes (HNTs) percentages have been optimized in Polycaprolactone (PCL) polymeric matrices to improve mechanical, thermal and biological properties of the composites, thus, to be applied in bone tissue engineering or as fixation plates. Addition of HA guarantees a proper compatibility with human bone due to its osteoconductive and osteoinductive properties, facilitating bone regeneration in tissue engineering applications. Addition of HNTs ensures the presence of tubular structures for subsequent drug loading in their lumen, of molecules such as curcumin, acting as controlled drug delivery systems. The addition of 20% of HA and different amounts of HNTs leads to a substantial improvement in mechanical properties with values of flexural strength up to 40% over raw PCL, with an increase in degradation temperature. DMA analyses showed stability in mechanical and thermal properties, having as a result a potential composite to be used as tissue engineering scaffold or resorbable fixation plate.Torres-Roca, E.; Fombuena, V.; Vallés Lluch, A.; Ellingham, T. (2017). Improvement of mechanical and biological properties of Polycaprolactone loaded with Hydroxyapatite and Halloysite Nanotubes. Materials Science and Engineering C. 75:418-424. doi:10.1016/j.msec.2017.02.087S4184247

Channeled polymeric scaffolds with polypeptide gel filling for lengthwise guidance of neural cells

CNS damages are often irreversible since neurons of the central nervous system are unable to regenerate after an injury. As a new strategy within the nervous system tissue engineering, multifunctional systems based on two different biomaterials to support axonal guidance in damaged connective tracts have been developed herein. These systems are composed of a channeled scaffold made of ethyl acrylate and hydroxyethyl acrylate copolymer, P(EA-co-HEA), with parallel tubular micropores, combined with an injectable and in situ gelable self-assembling polypeptide (RAD16-I) as pores filler. The polymer scaffold is intended to provide a three-dimensional context for axon growth; subsequently, its morphology and physicochemical parameters have been determined by scanning electron microscopy, density measurements and compression tests. Besides, the hydrogel acts as a cell-friendly nanoenvironment while it creates a gradient of bioactive molecules (nerve growth factor, NGF) along the scaffolds channels; the chemotactic effect of NGF has been evaluated by a quantitative ELISA assay. These multifunctional systems have shown ability to keep circulating NGF, as well as proper short-term in vitro biological response with glial cells and neural progenitors.The authors acknowledge funding through the Spanish Ministerio de Ciencia e Innovacion (MAT2011-28791-C03-02 and -03). Dr. J.M. Garcia Verdugo (Department of Comparative Neurobiology, Cavanilles Institute of Biodiversity and Evolutive Biology, Universitat de Valencia) is thanked for kindly providing the cells employed in this work.Conejero García, Á.; Vilarino-Feltrer, G.; Martínez Ramos, C.; Monleón Pradas, M.; Vallés Lluch, A. (2015). Channeled polymeric scaffolds with polypeptide gel filling for lengthwise guidance of neural cells. European Polymer Journal. 70:331-341. doi:10.1016/j.eurpolymj.2015.07.033S3313417

The effect of salt fusion processing variables on structural, physicochemical and biological properties of poly(glycerol sebacate) scaffolds

"This is an Accepted Manuscript of an article published by Taylor & Francis in International Journal of Polymeric Materials and Polymeric Biomaterials on SEP 21 2020, available online: https://www.tandfonline.com/doi/full/10.1080/00914037.2019.1636247"[EN] Poly(glycerol sebacate), PGS, is a biodegradable elastomer recently proposed in the form of scaffolds for cardiac, vascular, cartilage or neural applications. In the present work, several processing variables for the fabrication of PGS scaffolds by the salt fusion method were systematically studied, namely the pre-polymer/porogen ratio, the salt particles average size, use of tetrahydrofuran to dissolve the pre-polymer for its injection in the porogen template, and the curing pressure. The effect of these variables on their structural, mechanical and biological properties was assessed to select those leading to optimal ones in terms of their potential performance in tissue engineering applications.The authors acknowledge Spanish Ministerio de Economia y Competitividad through DPI2015-65401-C3-2-R project. The authors acknowledge the assistance and advice of the Electron Microscopy Service of the Universitat Politecnica de Valencia (Spain).Vilariño, G.; Muñoz-Santa, A.; Conejero-Garcia, Á.; Vallés Lluch, A. (2020). The effect of salt fusion processing variables on structural, physicochemical and biological properties of poly(glycerol sebacate) scaffolds. International Journal of Polymeric Materials. 69(14):938-945. https://doi.org/10.1080/00914037.2019.1636247S9389456914Fung, Y.-C. (1993). Bioviscoelastic Solids. Biomechanics, 242-320. doi:10.1007/978-1-4757-2257-4_7Chiang, B., Kim, Y. C., Doty, A. C., Grossniklaus, H. E., Schwendeman, S. P., & Prausnitz, M. R. (2016). Sustained reduction of intraocular pressure by supraciliary delivery of brimonidine-loaded poly(lactic acid) microspheres for the treatment of glaucoma. Journal of Controlled Release, 228, 48-57. doi:10.1016/j.jconrel.2016.02.041Appuhamillage, G. A., Reagan, J. C., Khorsandi, S., Davidson, J. R., Voit, W., & Smaldone, R. A. (2017). 3D printed remendable polylactic acid blends with uniform mechanical strength enabled by a dynamic Diels–Alder reaction. Polymer Chemistry, 8(13), 2087-2092. doi:10.1039/c7py00310bZhu, W., Masood, F., O’Brien, J., & Zhang, L. G. (2015). Highly aligned nanocomposite scaffolds by electrospinning and electrospraying for neural tissue regeneration. Nanomedicine: Nanotechnology, Biology and Medicine, 11(3), 693-704. doi:10.1016/j.nano.2014.12.001Gao, S., Guo, W., Chen, M., Yuan, Z., Wang, M., Zhang, Y., … Guo, Q. (2017). Fabrication and characterization of electrospun nanofibers composed of decellularized meniscus extracellular matrix and polycaprolactone for meniscus tissue engineering. Journal of Materials Chemistry B, 5(12), 2273-2285. doi:10.1039/c6tb03299kHu, X., Hu, T., Guan, G., Yu, S., Wu, Y., & Wang, L. (2017). Control of weft yarn or density improves biocompatibility of PET small diameter artificial blood vessels. Journal of Biomedical Materials Research Part B: Applied Biomaterials, 106(3), 954-964. doi:10.1002/jbm.b.33909Recco, M. S., Floriano, A. C., Tada, D. B., Lemes, A. P., Lang, R., & Cristovan, F. H. (2016). Poly(3-hydroxybutyrate-co-valerate)/poly(3-thiophene ethyl acetate) blends as a electroactive biomaterial substrate for tissue engineering application. RSC Advances, 6(30), 25330-25338. doi:10.1039/c5ra26747aRibeiro Lopes, J., Azevedo dos Reis, R., & Almeida, L. E. (2016). Production and characterization of films containing poly(hydroxybutyrate) (PHB) blended with esterified alginate (ALG-e) and poly(ethylene glycol) (PEG). Journal of Applied Polymer Science, 134(1). doi:10.1002/app.44362Wang, Y., Ameer, G. A., Sheppard, B. J., & Langer, R. (2002). A tough biodegradable elastomer. Nature Biotechnology, 20(6), 602-606. doi:10.1038/nbt0602-602Nagata, M., Kiyotsukuri, T., Ibuki, H., Tsutsumi, N., & Sakai, W. (1996). Synthesis and enzymatic degradation of regular network aliphatic polyesters. Reactive and Functional Polymers, 30(1-3), 165-171. doi:10.1016/1381-5148(95)00107-7Radisic, M., Park, H., Chen, F., Salazar-Lazzaro, J. E., Wang, Y., Dennis, R., … Vunjak-Novakovic, G. (2006). Biomimetic Approach to Cardiac Tissue Engineering: Oxygen Carriers and Channeled Scaffolds. Tissue Engineering, 12(8), 2077-2091. doi:10.1089/ten.2006.12.2077Chen, Q.-Z., Bismarck, A., Hansen, U., Junaid, S., Tran, M. Q., Harding, S. E., … Boccaccini, A. R. (2008). Characterisation of a soft elastomer poly(glycerol sebacate) designed to match the mechanical properties of myocardial tissue. Biomaterials, 29(1), 47-57. doi:10.1016/j.biomaterials.2007.09.010Ravichandran, R., Venugopal, J. R., Sundarrajan, S., Mukherjee, S., & Ramakrishna, S. (2011). Poly(Glycerol Sebacate)/Gelatin Core/Shell Fibrous Structure for Regeneration of Myocardial Infarction. Tissue Engineering Part A, 17(9-10), 1363-1373. doi:10.1089/ten.tea.2010.0441Masoumi, N., Annabi, N., Assmann, A., Larson, B. L., Hjortnaes, J., Alemdar, N., … Khademhosseini, A. (2014). Tri-layered elastomeric scaffolds for engineering heart valve leaflets. Biomaterials, 35(27), 7774-7785. doi:10.1016/j.biomaterials.2014.04.039Masoumi, N., Jean, A., Zugates, J. T., Johnson, K. L., & Engelmayr, G. C. (2012). Laser microfabricated poly(glycerol sebacate) scaffolds for heart valve tissue engineering. Journal of Biomedical Materials Research Part A, 101A(1), 104-114. doi:10.1002/jbm.a.34305Motlagh, D., Yang, J., Lui, K. Y., Webb, A. R., & Ameer, G. A. (2006). Hemocompatibility evaluation of poly(glycerol-sebacate) in vitro for vascular tissue engineering. Biomaterials, 27(24), 4315-4324. doi:10.1016/j.biomaterials.2006.04.010Frydrych, M., Román, S., MacNeil, S., & Chen, B. (2015). Biomimetic poly(glycerol sebacate)/poly(l-lactic acid) blend scaffolds for adipose tissue engineering. Acta Biomaterialia, 18, 40-49. doi:10.1016/j.actbio.2015.03.004SUNDBACK, C., SHYU, J., WANG, Y., FAQUIN, W., LANGER, R., VACANTI, J., & HADLOCK, T. (2005). Biocompatibility analysis of poly(glycerol sebacate) as a nerve guide material. Biomaterials, 26(27), 5454-5464. doi:10.1016/j.biomaterials.2005.02.004Deng, Y., Bi, X., Zhou, H., You, Z., Wang, Y., … Fan, X. (2014). Repair of critical-sized bone defects with anti-miR-31-expressing bone marrow stromal stem cells and poly(glycerol sebacate) scaffolds. European Cells and Materials, 27, 13-25. doi:10.22203/ecm.v027a02Zhao, X., Wu, Y., Du, Y., Chen, X., Lei, B., Xue, Y., & Ma, P. X. (2015). A highly bioactive and biodegradable poly(glycerol sebacate)–silica glass hybrid elastomer with tailored mechanical properties for bone tissue regeneration. Journal of Materials Chemistry B, 3(16), 3222-3233. doi:10.1039/c4tb01693aZaky, S. H., Lee, K. W., Gao, J., Jensen, A., Verdelis, K., Wang, Y., … Sfeir, C. (2017). Poly (glycerol sebacate) elastomer supports bone regeneration by its mechanical properties being closer to osteoid tissue rather than to mature bone. Acta Biomaterialia, 54, 95-106. doi:10.1016/j.actbio.2017.01.053Jeong, C. G., & Hollister, S. J. (2010). A comparison of the influence of material on in vitro cartilage tissue engineering with PCL, PGS, and POC 3D scaffold architecture seeded with chondrocytes. Biomaterials, 31(15), 4304-4312. doi:10.1016/j.biomaterials.2010.01.145Kemppainen, J. M., & Hollister, S. J. (2010). Tailoring the mechanical properties of 3D-designed poly(glycerol sebacate) scaffolds for cartilage applications. Journal of Biomedical Materials Research Part A, 94A(1), 9-18. doi:10.1002/jbm.a.32653Sant, S., Hwang, C. M., Lee, S.-H., & Khademhosseini, A. (2011). Hybrid PGS-PCL microfibrous scaffolds with improved mechanical and biological properties. Journal of Tissue Engineering and Regenerative Medicine, 5(4), 283-291. doi:10.1002/term.313Gao, J., Crapo, P. M., & Wang, Y. (2006). Macroporous Elastomeric Scaffolds with Extensive Micropores for Soft Tissue Engineering. Tissue Engineering, 12(4), 917-925. doi:10.1089/ten.2006.12.917Gibson, L. J., & Ashby, M. F. (1997). Cellular Solids. doi:10.1017/cbo9781139878326Maliger, R., Halley, P. J., & Cooper-White, J. J. (2012). Poly(glycerol-sebacate) bioelastomers-kinetics of step-growth reactions using Fourier Transform (FT)-Raman spectroscopy. Journal of Applied Polymer Science, 127(5), 3980-3986. doi:10.1002/app.37719Ifkovits, J. L., Padera, R. F., & Burdick, J. A. (2008). Biodegradable and radically polymerized elastomers with enhanced processing capabilities. Biomedical Materials, 3(3), 034104. doi:10.1088/1748-6041/3/3/034104Chen, Q.-Z., Ishii, H., Thouas, G. A., Lyon, A. R., Wright, J. S., Blaker, J. J., … Harding, S. E. (2010). An elastomeric patch derived from poly(glycerol sebacate) for delivery of embryonic stem cells to the heart. Biomaterials, 31(14), 3885-3893. doi:10.1016/j.biomaterials.2010.01.10

Nanocomposites based on poly(glycerol sebacate) with silica nanoparticles with potential application in dental tissue engineering

"This is an Accepted Manuscript of an article published by Taylor & Francis inInternational Journal of Polymeric Materials and Polymeric Biomaterials on AUG 08 2020, available online: https://www.tandfonline.com/doi/full/10.1080/00914037.2019.1616197"[EN] Nanocomposites based on poly(glycerol sebacate) with silica nanoparticles were synthesized to explore their potential use in the biomedical field. The nanoparticles were two distinct polyhedral oligomeric silsesquioxanes (POSS), both used at 5% wt/wt concentration, specifically methacrylisobutyl POSS and methacryl POSS. These materials were investigated for their possible application as coatings as well as with regenerative purposes in dental engineering, and their viability for this application was assessed. Thus, pure PGS and nanohybrids thereof were obtained as scaffolds (that is, porous structures, designed with regenerative purposes) and as films (intended for coatings and to be used as controls).The authors acknowledge Dr. Kirsten Techmer from Geoscience Center of the Georg-August-University Gottingen for performing the EDX-SEM analysis, the assistance and advice of the Julich Center for Neutron Science (JCNS) and Institute for Complex Systems (ICS), Forschungszentrum Julich GmbH (Germany), and the Electron Microscopy Service of the Universitat Politecnica de Valencia (Spain). This work was partially funded by the Spanish Ministerio de Economía y Competitividad through DPI2015-65401-C3-2-R project and by the German Research Foundation [DFG/MWK INST 1525/39-1 FUGG]. A.V.-Ll. acknowledges the support of the Generalitat Valenciana, Conselleria de Educación, Investigación, Cultura y Deporte through project AEST/2018/014.Tallá Ferrer, C.; Vilariño, G.; Rizk, M.; Sydow, H.; Vallés Lluch, A. (2020). Nanocomposites based on poly(glycerol sebacate) with silica nanoparticles with potential application in dental tissue engineering. International Journal of Polymeric Materials. 69(12):761-772. https://doi.org/10.1080/00914037.2019.1616197S7617726912Wang, Y., Ameer, G. A., Sheppard, B. J., & Langer, R. (2002). A tough biodegradable elastomer. Nature Biotechnology, 20(6), 602-606. doi:10.1038/nbt0602-602Loh, X. J., Abdul Karim, A., & Owh, C. (2015). Poly(glycerol sebacate) biomaterial: synthesis and biomedical applications. Journal of Materials Chemistry B, 3(39), 7641-7652. doi:10.1039/c5tb01048aRai, R., Tallawi, M., Grigore, A., & Boccaccini, A. R. (2012). Synthesis, properties and biomedical applications of poly(glycerol sebacate) (PGS): A review. Progress in Polymer Science, 37(8), 1051-1078. doi:10.1016/j.progpolymsci.2012.02.001Serrano, M. C., Chung, E. J., & Ameer, G. A. (2010). Advances and Applications of Biodegradable Elastomers in Regenerative Medicine. Advanced Functional Materials, 20(2), 192-208. doi:10.1002/adfm.200901040Zhang, X., Jia, C., Qiao, X., Liu, T., & Sun, K. (2016). Porous poly(glycerol sebacate) (PGS) elastomer scaffolds for skin tissue engineering. Polymer Testing, 54, 118-125. doi:10.1016/j.polymertesting.2016.07.006MacDonald, R. A., Laurenzi, B. F., Viswanathan, G., Ajayan, P. M., & Stegemann, J. P. (2005). Collagen-carbon nanotube composite materials as scaffolds in tissue engineering. Journal of Biomedical Materials Research Part A, 74A(3), 489-496. doi:10.1002/jbm.a.30386Saito, N., Usui, Y., Aoki, K., Narita, N., Shimizu, M., Hara, K., … Endo, M. (2009). Carbon nanotubes: biomaterial applications. Chemical Society Reviews, 38(7), 1897. doi:10.1039/b804822nChawla, R., Tan, A., Ahmed, M., Crowley, C., Moiemen, N. S., Cui, Z., … Seifalian, A. M. (2014). A polyhedral oligomeric silsesquioxane–based bilayered dermal scaffold seeded with adipose tissue–derived stem cells: in vitro assessment of biomechanical properties. Journal of Surgical Research, 188(2), 361-372. doi:10.1016/j.jss.2014.01.006Campbell, K., Craig, D. Q. M., & McNally, T. (2008). Poly(ethylene glycol) layered silicate nanocomposites for retarded drug release prepared by hot-melt extrusion. International Journal of Pharmaceutics, 363(1-2), 126-131. doi:10.1016/j.ijpharm.2008.06.027Scott, D. W. (1946). Thermal Rearrangement of Branched-Chain Methylpolysiloxanes1. Journal of the American Chemical Society, 68(3), 356-358. doi:10.1021/ja01207a003Conejero-García, Á., Gimeno, H. R., Sáez, Y. M., Vilariño-Feltrer, G., Ortuño-Lizarán, I., & Vallés-Lluch, A. (2017). Correlating synthesis parameters with physicochemical properties of poly(glycerol sebacate). European Polymer Journal, 87, 406-419. doi:10.1016/j.eurpolymj.2017.01.001Gao, J., Crapo, P. M., & Wang, Y. (2006). Macroporous Elastomeric Scaffolds with Extensive Micropores for Soft Tissue Engineering. Tissue Engineering, 12(4), 917-925. doi:10.1089/ten.2006.12.917Klimek, J., Hellwig, E., & Ahrens, G. (1982). Fluoride Taken Up by Plaque, by the Underlying Enamel and by Clean Enamel from Three Fluoride Compounds in vitro. Caries Research, 16(2), 156-161. doi:10.1159/000260592Zhao, X., Wu, Y., Du, Y., Chen, X., Lei, B., Xue, Y., & Ma, P. X. (2015). A highly bioactive and biodegradable poly(glycerol sebacate)–silica glass hybrid elastomer with tailored mechanical properties for bone tissue regeneration. Journal of Materials Chemistry B, 3(16), 3222-3233. doi:10.1039/c4tb01693aWu, Y., Shi, R., Chen, D., Zhang, L., & Tian, W. (2011). Nanosilica filled poly(glycerol-sebacate-citrate) elastomers with improved mechanical properties, adjustable degradability, and better biocompatibility. Journal of Applied Polymer Science, 123(3), 1612-1620. doi:10.1002/app.34556Liang, S.-L., Cook, W. D., Thouas, G. A., & Chen, Q.-Z. (2010). The mechanical characteristics and in vitro biocompatibility of poly(glycerol sebacate)-Bioglass® elastomeric composites. Biomaterials, 31(33), 8516-8529. doi:10.1016/j.biomaterials.2010.07.105Kokubo, T., & Takadama, H. (2006). How useful is SBF in predicting in vivo bone bioactivity? Biomaterials, 27(15), 2907-2915. doi:10.1016/j.biomaterials.2006.01.017Wahab, M. A., Kim, I., & Ha, C.-S. (2003). Microstructure and properties of polyimide/poly(vinylsilsesquioxane) hybrid composite films. Polymer, 44(16), 4705-4713. doi:10.1016/s0032-3861(03)00429-4Yan Song, X., Ping Geng, H., & Li, Q. F. (2006). The synthesis and characterization of polystyrene/magnetic polyhedral oligomeric silsesquioxane (POSS) nanocomposites. Polymer, 47(9), 3049-3056. doi:10.1016/j.polymer.2006.02.055Kerativitayanan, P., & Gaharwar, A. K. (2015). Elastomeric and mechanically stiff nanocomposites from poly(glycerol sebacate) and bioactive nanosilicates. Acta Biomaterialia, 26, 34-44. doi:10.1016/j.actbio.2015.08.025Liu, J., Zheng, H., Poh, P., Machens, H.-G., & Schilling, A. (2015). Hydrogels for Engineering of Perfusable Vascular Networks. International Journal of Molecular Sciences, 16(7), 15997-16016. doi:10.3390/ijms160715997Gibson, L. J., & Ashby, M. F. (1997). Cellular Solids. doi:10.1017/cbo9781139878326Vallés 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.2009.04.022Jones, J. R. (2006). Scaffolds for Cell and Tissue Engineering. Wiley Encyclopedia of Biomedical Engineering. doi:10.1002/9780471740360.ebs140

Role of Curing Temperature of Poly(Glycerol Sebacate) Substrates on Protein-Cell Interaction and Early Cell Adhesion

[EN] A novel procedure to obtain smooth, continuous polymeric surfaces from poly(glycerol sebacate) (PGS) has been developed with the spin-coating technique. This method proves useful for separating the effect of the chemistry and morphology of the networks (that can be obtained by varying the synthesis parameters) on cell-protein-substrate interactions from that of structural variables. Solutions of the PGS pre-polymer can be spin-coated, to then be cured. Curing under variable temperatures has been shown to lead to PGS networks with different chemical properties and topographies, conditioning their use as a biomaterial. Particularly, higher synthesis temperatures yield denser networks with fewer polar terminal groups available on the surface. Material-protein interactions were characterised by using extracellular matrix proteins such as fibronectin (Fn) and collagen type I (Col I), to unveil the biological interface profile of PGS substrates. To that end, atomic force microscopy (AFM) images and quantification of protein adsorbed in single, sequential and competitive protein incubations were used. Results reveal that Fn is adsorbed in the form of clusters, while Col I forms a characteristic fibrillar network. Fn has an inhibitory effect when incubated prior to Col I. Human umbilical endothelial cells (HUVECs) were also cultured on PGS surfaces to reveal the effect of synthesis temperature on cell behaviour. To this effect, early focal adhesions (FAs) were analysed using immunofluorescence techniques. In light of the results, 130 degrees C seems to be the optimal curing temperature since a preliminary treatment with Col I or a Fn:Col I solution facilitates the formation of early focal adhesions and growth of HUVECs.This research was funded by the Spanish Ministerio de Economia y Competitividad, grant number DPI2015-65401-C3-2-R. A. Valles acknowledges the support of the Generalitat Valenciana, Conselleria de Educacion, Investigacion, Cultura y Deporte through project AEST/2020/052.Martín-Cabezuelo, R.; Rodriguez-Hernandez, J.; Vilariño, G.; Vallés Lluch, A. (2021). Role of Curing Temperature of Poly(Glycerol Sebacate) Substrates on Protein-Cell Interaction and Early Cell Adhesion. Polymers. 13(3):1-14. https://doi.org/10.3390/polym13030382S11413

Biomaterials for Cardiac Tissue Engineering

Semiotics / semiolog

Coating typologies and constrained swelling of hyaluronic acid gels within scaffold pores

[EN] A set of elastomeric scaffolds with a well defined porous structure was prepared with a template leaching procedure and coated with hyaluronic acid solutions. Depending on the coating process parameters the hyaluronic acid deposited on the pores had configurations ranging from thin disconnected aggregates to a thick continuous layer on the pore surface. The development of the coating layer was studied by scanning electron microscopy and the materials were subjected to dynamical and equilibrium swelling experiments in a water vapor ambient of fixed activity. The porosity change due to coating and to swelling of the coating layer were determined. The hyaluronic acid coating the pores has a different swelling capacity depending on the type of layer formed, as a consequence of the scaffold constraint and of the layer typology. These factors were investigated analytically by modifying the standard theory of gel swelling. An experimental quantity is introduced which reflects the constrainment build-up on gel swelling. © 2011 Elsevier Inc.The authors acknowledge the support of the FP7 NMP3-SL-2009-229239 project "Regeneration of cardiac tissue assisted by bioactive implants (RECATABI)". MMP further acknowledges the support of the Spanish Science & Innovation Ministry through project MAT2008-06434. Roberto Garcia Gomez is thanked for his help in preparing the bare scaffolds.Arnal Pastor, MP.; Vallés Lluch, A.; Keicher, M.; Monleón Pradas, M. (2011). Coating typologies and constrained swelling of hyaluronic acid gels within scaffold pores. Journal of Colloid and Interface Science. 361(1):361-369. https://doi.org/10.1016/j.jcis.2011.05.013S361369361

Chapter Biomaterials for Cardiac Tissue Engineering

Semiotics / semiolog