Elementos conceptuales para estudiar el comportamiento bioadhesivo en polímeros

La bioadhesión es un fenómeno interfacial que ocurre entre un material polimérico y una superficie biológica. Las interacciones entre las fases son el resultado tanto de las propiedades del polímero como de la naturaleza del sustrato.En este documento se estudian los aspectos teóricos fundamentales que permiten entender los mecanismos que se proponen para la interpretación del fenómeno desde cada una de las teorías existentes, considerando los factores que determinan el comportamiento bioadhesivo de un polímero y las características del sustrato. Finalmente se analizan las técnicas experimentales existentes para determinar la bioadhesividad en materiales poliméricos y las aplicaciones en el diseño de algunos sistemas terapéuticos farmacéuticos.The bioadhesion is an interfacial phenomenon ocurring between a polymer and a biological surface. Due to the complex nature of polymers and molecules present in the biological surfaces, many factors determine the strength and duration of the adhesion. However, the specific interactions in the polymer/biological substrate interface are governed by both, the properties of the polymer and the nature of the substrate. In this document the theoretical fundamentals of the current mechanisms that have been proposed to explain bioadhesion are reviewed. Also, the main factors determining the bioadhesive behavior of a polymer and the properties of the substrate are discussed. Finally, the experimental techniques to evaluate the bioadhesion in polymers are analyzed, and the applications in some therapeutic pharmaceutical systems presente

Temperature and ph responsive behaviour of antifouling zwitterionic mesoporous silica nanoparticles.

[EN] Zwitterionic brush grafting is considered a serious strategy for surface modification on mesoporous silica nanoparticles (MSN) and a prominent alternative to polyethylene glycol films for antifouling applications. In this study, the solution behavior of poly(sulfobetaine methacrylate) (pSBMA) polymer brushes grafted on MSN (95 +/- 15nm particle diameter, 2.8nm pore size) was evaluated. The layers increased their hydrodynamic diameter (d(H)) with increasing temperature, indicating a conformational change from a surface-collapsed state to a fully solvated brush. This development was marked by a transition temperature, related to the molecular weight and the theoretical length of the polymer chains. Variation of d(H) with pH values was studied and a zwitterionic range of 5-9 was established where the electric charges in the molecule were balanced. Zeta potential (ZP) values for all pSBMA-MSN products were also measured. A decreasing trend of ZP with pH and an isoelectric point around 5.5-6.5 was obtained for all dispersions. Furthermore, the influence of temperature was analyzed on ZP and a directly proportional correlation was found, with increasing rates of 0.50-0.87%/degrees C. Finally, ZP variation with electrolyte concentration was determined and a range of 40-60mM of NaCl concentration was established to reach an almost zero-charge point for all nanoparticles. It was demonstrated that the solution response of pSBMA-MSN can be modulated by temperature, pH, and ionic concentration of the media. These behaviors could be used as controlled release mechanisms for the application of pSBMA-MSN as carriers in biomedicine and nanophamaceutical fields in the future. Published under license by AIP Publishing.Jose L. Gomez Ribelles acknowledges support of the Ministerio de Economia y Competitividad, MINECO (Research No. MAT2016-76039-C4-1-R). CIBER-BBN is 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. This work was also supported by Ministerio de Ciencia, Tecnologia e Innovacion (MINCIENCIAS), Convocatoria 567 Doctorados Nacionales, and Universidad Nacional de Colombia (Grant No. DIB 201010021438). The authors acknowledge the effort of Ramon Martinez Manez, Scientific Director of the Biomedical Research Networking Center in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), and Head of the Interuniversity Research Institute for Molecular Recognition and Technological Development (IDM) at Universitat Politecnica de Valencia, where all measurements were performedBeltran-Osuna, AA.; Gómez Ribelles, JL.; Perilla, JE. (2020). Temperature and ph responsive behaviour of antifouling zwitterionic mesoporous silica nanoparticles. Journal of Applied Physics. 127(13):135106-1-135106-11. https://doi.org/10.1063/1.5140707S135106-1135106-1112713Mirza, A. Z., & Siddiqui, F. A. (2014). Nanomedicine and drug delivery: a mini review. International Nano Letters, 4(1). doi:10.1007/s40089-014-0094-7E. van Andel, “Romantic surfaces—Zwitterionic polymer brushes for biomedical applications,” Doctoral thesis (Wageningen University, 2018).Lombardo, D., Kiselev, M. A., & Caccamo, M. T. (2019). Smart Nanoparticles for Drug Delivery Application: Development of Versatile Nanocarrier Platforms in Biotechnology and Nanomedicine. Journal of Nanomaterials, 2019, 1-26. doi:10.1155/2019/3702518Salmaso, S., & Caliceti, P. (2013). Stealth Properties to Improve Therapeutic Efficacy of Drug Nanocarriers. Journal of Drug Delivery, 2013, 1-19. doi:10.1155/2013/374252Beltrán-Osuna, Á. A., & Perilla, J. E. (2015). Colloidal and spherical mesoporous silica particles: synthesis and new technologies for delivery applications. Journal of Sol-Gel Science and Technology, 77(2), 480-496. doi:10.1007/s10971-015-3874-2Bhattacharyya, S., Wang, H., & Ducheyne, P. (2012). Polymer-coated mesoporous silica nanoparticles for the controlled release of macromolecules. Acta Biomaterialia, 8(9), 3429-3435. doi:10.1016/j.actbio.2012.06.003Peng, H., Dong, R., Wang, S., Zhang, Z., Luo, M., Bai, C., … Xiong, H. (2013). A pH-responsive nano-carrier with mesoporous silica nanoparticles cores and poly(acrylic acid) shell-layers: Fabrication, characterization and properties for controlled release of salidroside. International Journal of Pharmaceutics, 446(1-2), 153-159. doi:10.1016/j.ijpharm.2013.01.071DeMuth, P., Hurley, M., Wu, C., Galanie, S., Zachariah, M. R., & DeShong, P. (2011). Mesoscale porous silica as drug delivery vehicles: Synthesis, characterization, and pH-sensitive release profiles. Microporous and Mesoporous Materials, 141(1-3), 128-134. doi:10.1016/j.micromeso.2010.10.035Lin, C.-Y., Yang, C.-M., & Lindén, M. (2019). Influence of serum concentration and surface functionalization on the protein adsorption to mesoporous silica nanoparticles. RSC Advances, 9(58), 33912-33921. doi:10.1039/c9ra05585aLi, G., Cheng, G., Xue, H., Chen, S., Zhang, F., & Jiang, S. (2008). Ultra low fouling zwitterionic polymers with a biomimetic adhesive group. Biomaterials, 29(35), 4592-4597. doi:10.1016/j.biomaterials.2008.08.021Wang, H., Cheng, F., Shen, W., Cheng, G., Zhao, J., Peng, W., & Qu, J. (2016). Amino acid-based anti-fouling functionalization of silica nanoparticles using divinyl sulfone. Acta Biomaterialia, 40, 273-281. doi:10.1016/j.actbio.2016.03.035Khutoryanskiy, V. V. (2018). Beyond PEGylation: Alternative surface-modification of nanoparticles with mucus-inert biomaterials. Advanced Drug Delivery Reviews, 124, 140-149. doi:10.1016/j.addr.2017.07.015Dogra, P., Adolphi, N. L., Wang, Z., Lin, Y.-S., Butler, K. S., Durfee, P. N., … Brinker, C. J. (2018). Establishing the effects of mesoporous silica nanoparticle properties on in vivo disposition using imaging-based pharmacokinetics. Nature Communications, 9(1). doi:10.1038/s41467-018-06730-zBlackman, L. D., Gunatillake, P. A., Cass, P., & Locock, K. E. S. (2019). An introduction to zwitterionic polymer behavior and applications in solution and at surfaces. Chemical Society Reviews, 48(3), 757-770. doi:10.1039/c8cs00508gD. Jana, S. Unser, I. Bruzas, and L. Sagle, in World Scientific Encyclopedia of Nanomedicine and Bioengineering I, edited by D. Shi (World Scientific Publishing Co. Pte. Ltd., 2017), pp. 103–150.Wu, C., Zhou, Y., Wang, H., & Hu, J. (2019). P4VP Modified Zwitterionic Polymer for the Preparation of Antifouling Functionalized Surfaces. Nanomaterials, 9(5), 706. doi:10.3390/nano9050706Knowles, B. R., Yang, D., Wagner, P., Maclaughlin, S., Higgins, M. J., & Molino, P. J. (2018). Zwitterion Functionalized Silica Nanoparticle Coatings: The Effect of Particle Size on Protein, Bacteria, and Fungal Spore Adhesion. Langmuir, 35(5), 1335-1345. doi:10.1021/acs.langmuir.8b01550Chang, Y., Chen, W.-Y., Yandi, W., Shih, Y.-J., Chu, W.-L., Liu, Y.-L., … Higuchi, A. (2009). Dual-Thermoresponsive Phase Behavior of Blood Compatible Zwitterionic Copolymers Containing Nonionic Poly(N-isopropyl acrylamide). Biomacromolecules, 10(8), 2092-2100. doi:10.1021/bm900208uZhao, Y., Bai, T., Shao, Q., Jiang, S., & Shen, A. Q. (2015). Thermoresponsive self-assembled NiPAm-zwitterion copolymers. Polymer Chemistry, 6(7), 1066-1077. doi:10.1039/c4py01553cZhou, Y., Dong, P., Wei, Y., Qian, J., & Hua, D. (2015). Synthesis of poly(sulfobetaine methacrylate)-grafted chitosan under γ-ray irradiation for alamethicin assembly. Colloids and Surfaces B: Biointerfaces, 132, 132-137. doi:10.1016/j.colsurfb.2015.05.019Chen, C.-Y., & Wang, H.-L. (2014). Dual Thermo- and pH-Responsive Zwitterionic Sulfobataine Copolymers for Oral Delivery System. Macromolecular Rapid Communications, 35(17), 1534-1540. doi:10.1002/marc.201400161Vasantha, V. A., Rusli, W., Junhui, C., Wenguang, Z., Sreekanth, K. V., Singh, R., & Parthiban, A. (2019). Highly monodisperse zwitterion functionalized non-spherical polymer particles with tunable iridescence. RSC Advances, 9(47), 27199-27207. doi:10.1039/c9ra05162gSuzuki, H., Murou, M., Kitano, H., Ohno, K., & Saruwatari, Y. (2011). Silica particles coated with zwitterionic polymer brush: Formation of colloidal crystals and anti-biofouling properties in aqueous medium. Colloids and Surfaces B: Biointerfaces, 84(1), 111-116. doi:10.1016/j.colsurfb.2010.12.023Dong, Z., Mao, J., Wang, D., Yang, M., Wang, W., Bo, S., & Ji, X. (2013). Tunable Dual-Thermoresponsive Phase Behavior of Zwitterionic Polysulfobetaine Copolymers Containing Poly(N,N -dimethylaminoethyl methacrylate)-Grafted Silica Nanoparticles in Aqueous Solution. Macromolecular Chemistry and Physics, 215(1), 111-120. doi:10.1002/macp.201300552Zhu, J., Zhao, X., & He, C. (2015). Zwitterionic SiO2 nanoparticles as novel additives to improve the antifouling properties of PVDF membranes. RSC Advances, 5(66), 53653-53659. doi:10.1039/c5ra05571gTeng, I.-T., Chang, Y.-J., Wang, L.-S., Lu, H.-Y., Wu, L.-C., Yang, C.-M., … Ho, J. A. (2013). Phospholipid-functionalized mesoporous silica nanocarriers for selective photodynamic therapy of cancer. Biomaterials, 34(30), 7462-7470. doi:10.1016/j.biomaterials.2013.06.001Sun, J.-T., Yu, Z.-Q., Hong, C.-Y., & Pan, C.-Y. (2012). Biocompatible Zwitterionic Sulfobetaine Copolymer-Coated Mesoporous Silica Nanoparticles for Temperature-Responsive Drug Release. Macromolecular Rapid Communications, 33(9), 811-818. doi:10.1002/marc.201100876Khatoon, S., Han, H. S., Lee, M., Lee, H., Jung, D.-W., Thambi, T., … Park, J. H. (2016). Zwitterionic mesoporous nanoparticles with a bioresponsive gatekeeper for cancer therapy. Acta Biomaterialia, 40, 282-292. doi:10.1016/j.actbio.2016.04.011Beltrán-Osuna, Á. A., Ródenas-Rochina, J., Gómez Ribelles, J. L., & Perilla, J. E. (2018). Antifouling zwitterionic pSBMA-MSN particles for biomedical applications. Polymers for Advanced Technologies, 30(3), 688-697. doi:10.1002/pat.4505Beltrán-Osuna, Á. A., Gómez Ribelles, J. L., & Perilla, J. E. (2017). A study of some fundamental physicochemical variables on the morphology of mesoporous silica nanoparticles MCM-41 type. Journal of Nanoparticle Research, 19(12). doi:10.1007/s11051-017-4077-2Bhattacharjee, S. (2016). DLS and zeta potential – What they are and what they are not? Journal of Controlled Release, 235, 337-351. doi:10.1016/j.jconrel.2016.06.017Kirby, B. J., & Hasselbrink, E. F. (2004). Zeta potential of microfluidic substrates: 1. Theory, experimental techniques, and effects on separations. ELECTROPHORESIS, 25(2), 187-202. doi:10.1002/elps.200305754Characteristics of Zeta Potential Distribution in Silica Particles. (2005). Bulletin of the Korean Chemical Society, 26(7), 1083-1089. doi:10.5012/bkcs.2005.26.7.1083Khung, Y. L., & Narducci, D. (2015). Surface modification strategies on mesoporous silica nanoparticles for anti-biofouling zwitterionic film grafting. Advances in Colloid and Interface Science, 226, 166-186. doi:10.1016/j.cis.2015.10.009Shih, Y.-J., & Chang, Y. (2010). Tunable Blood Compatibility of Polysulfobetaine from Controllable Molecular-Weight Dependence of Zwitterionic Nonfouling Nature in Aqueous Solution. Langmuir, 26(22), 17286-17294. doi:10.1021/la103186yAntonio Alves Júnior, J., & Baptista Baldo, J. (2014). The Behavior of Zeta Potential of Silica Suspensions. New Journal of Glass and Ceramics, 04(02), 29-37. doi:10.4236/njgc.2014.42004C. J. Brinker and G. W. Scherer, Sol-Gel Science: The Physics and Chemistry of Sol-Gel Processing (Academic Press, Inc., 1990), p. 377.Guo, S., Jańczewski, D., Zhu, X., Quintana, R., He, T., & Neoh, K. G. (2015). Surface charge control for zwitterionic polymer brushes: Tailoring surface properties to antifouling applications. Journal of Colloid and Interface Science, 452, 43-53. doi:10.1016/j.jcis.2015.04.013Chen, X., Cheng, X., Soeriyadi, A. H., Sagnella, S. M., Lu, X., Scott, J. A., … Gooding, J. J. (2014). Stimuli-responsive functionalized mesoporous silica nanoparticles for drug release in response to various biological stimuli. Biomater. Sci., 2(1), 121-130. doi:10.1039/c3bm60148jVenditti, R., Xuan, X., & Li, D. (2006). Experimental characterization of the temperature dependence of zeta potential and its effect on electroosmotic flow velocity in microchannels. Microfluidics and Nanofluidics, 2(6), 493-499. doi:10.1007/s10404-006-0100-0Evenhuis, C. J., Guijt, R. M., Macka, M., Marriott, P. J., & Haddad, P. R. (2006). Variation of zeta-potential with temperature in fused-silica capillaries used for capillary electrophoresis. ELECTROPHORESIS, 27(3), 672-676. doi:10.1002/elps.200500566Du, M., Ma, Y., Su, H., Wang, X., & Zheng, Q. (2015). Rheological behavior of hydrophobically modified polysulfobetaine methacrylate aqueous solution. RSC Advances, 5(43), 33905-33913. doi:10.1039/c5ra05017kJhan, Y.-Y., & Tsay, R.-Y. (2014). Salt effects on the hydration behavior of zwitterionic poly(sulfobetaine methacrylate) aqueous solutions. Journal of the Taiwan Institute of Chemical Engineers, 45(6), 3139-3145. doi:10.1016/j.jtice.2014.08.022Liu, P., & Song, J. (2013). Sulfobetaine as a zwitterionic mediator for 3D hydroxyapatite mineralization. Biomaterials, 34(10), 2442-2454. doi:10.1016/j.biomaterials.2012.12.029Ni, L., Meng, J., Geise, G. M., Zhang, Y., & Zhou, J. (2015). Water and salt transport properties of zwitterionic polymers film. Journal of Membrane Science, 491, 73-81. doi:10.1016/j.memsci.2015.05.03

Silica phase formed by sol-gel reaction in the nano- and micro-pores of a polymer hydrogel

Hybrid composites consisting in a hydrogel matrix with silica micro- and nano-particle reinforcement were produced and characterized. The strategy proposed here to obtain them consisted in a two-step synthesis being the polymer network formation the first step. Porous poly(hydroxyethyl acrylate) hydrogel network was produced by radical polymerization of the monomer diluted in different amounts of ethanol. Polymeric microstructure drives the absorption of a silica precursor solution and the further distribution of the inorganic phase that is formed in situ. A fraction of the resulting silica phase occupies the pores and the other part is in the form of nanoparticles dispersed in the polymer phase. Composites with silica content up to ~ 60% by weight were obtained. Silica phase is continuous and samples maintain their integrity after eliminating the organic phase by pyrolysis. Dependence of hybrid microstructure in compliance, water sorption capacity, bioactivity and the effect of silica content in polymer segmental mobility were assessed.CEPB acknowledges the economic support of COOPEN agreement in the progress of the present work. JLGR acknowledges the support of the Spanish Ministry of Education through project No. MAT2010-21611-C03-01 (including the FEDER financial support) and from Generalitat Valenciana, ACOMP/2012/075 project. The support of the Instituto de Salud Carlos III (ISCIII) through the CIBER Initiative of the Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN) is also acknowledged. Authors want to thank the technical support of the Universitat Politecnica de Valencia's Microscopy Service.Plazas Bonilla, CE.; Gómez-Tejedor, JA.; Perilla, JE.; Gómez Ribelles, JL. (2013). Silica phase formed by sol-gel reaction in the nano- and micro-pores of a polymer hydrogel. Journal of Non-Crystalline Solids. 379:12-20. https://doi.org/10.1016/j.jnoncrysol.2013.07.018S122037

A study of some fundamental physicochemical variables on the morphology of mesoporous silica nanoparticles MCM-41 type

[EN] All variables affecting the morphology of mesoporous silica nanoparticles (MSN) should be carefully analyzed in order to truly tailored design their mesoporous structure according to their final use. Although complete control on MCM-41 synthesis has been already claimed, reproducibility and repeatability of results remain a big issue due to the lack of information reported in literature. Stirring rate, reaction volume, and system configuration (i.e., opened or closed reactor) are three variables that are usually omitted, making the comparison of product characteristics difficult. Specifically, the rate of solvent evaporation is seldom disclosed, and its influence has not been previously analyzed. These variables were systematically studied in this work, and they were proven to have a fundamental impact on final particle morphology. Hence, a high degree of circularity (C = 0.97) and monodispersed particle size distributions were only achieved when a stirring speed of 500 rpm and a reaction scale of 500 mL were used in a partially opened system, for a 2 h reaction at 80 degrees C. Well-shaped spherical mesoporous silica nanoparticles with a diameter of 95 nm, a pore size of 2.8 nm, and a total surface area of 954 m(2) g(-1) were obtained. Final characteristics made this product suitable to be used in biomedicine and nanopharmaceutics, especially for the design of drug delivery systems.This study was funded partially by Departamento Administrativo de Ciencia Tecnología e Innovación–COLCIENCIAS (recipient, Angela A. Beltrán-Osuna); Ministerio de Economía y Competitividad, MINECO, research number MAT2016-76039-C4-1-R (Recipient, José L. Gómez-Ribelles); and Universidad Nacional de Colombia, grant number DIB201010021438 (Recipient, Jairo E. Perilla).Beltrán-Osuna, A.; Gómez Ribelles, JL.; Perilla-Perilla, JE. (2017). A study of some fundamental physicochemical variables on the morphology of mesoporous silica nanoparticles MCM-41 type. Journal of Nanoparticle Research. 19(12):1-14. https://doi.org/10.1007/s11051-017-4077-2S1141912Barrabino A (2011) Synthesis of mesoporous silica particles with control of both pore diameter and particle size. Master Thesis, Chalmers University of Technology, SwedenBastos FS, Lima OA, Filho CR, Fernandes LD (2011) Mesoporous molecular sieve MCM-41 synthesis from fluoride media. Brazilian. J Chem Eng 28:649–658Beck JS, Vartuli JC, Roth WJ, Leonowicz ME, Kresge CT, Schmitt KD, Chu CTW, Olson DH, Sheppard EW, McCullen SB, Higgins JB, Schlenker JL (1992) A new family of mesoporous molecular sieves prepared with liquid crystal templates. J Am Chem Soc 114(27):10834–10843. https://doi.org/10.1021/ja00053a020Beltrán-Osuna AA, Perilla JE (2016) Colloidal and spherical mesoporous silica particles: synthesis and new technologies for delivery applications. J Sol-Gel Sci Technol 77(2):480–496. https://doi.org/10.1007/s10971-015-3874-2Bernardos A, Mondragón L, Aznar E et al (2010) Enzyme-responsive intracellular controlled release using nanometric silica mesoporous supports capped with “saccharides”. ACS Nano 4(11):6353–6368. https://doi.org/10.1021/nn101499dBharti C, Nagaich U, Pal AK, Gulati N (2015) Mesoporous silica nanoparticles in target drug delivery system: a review. Int J Pharm Investig 5(3):124–133. https://doi.org/10.4103/2230-973X.160844Brevet D, Hocine O, Delalande A, Raehm L, Charnay C, Midoux P, Durand JO, Pichon C (2014) Improved gene transfer with histidine-functionalized mesoporous silica nanoparticles. Int J Pharm 471(1-2):197–205. https://doi.org/10.1016/j.ijpharm.2014.05.020Cai Q, Luo Z, Pang W et al (2001) Dilute solution routes to various controllable morphologies of MCM-41 silica with a basic medium. Chem Mater 13(2):258–263. https://doi.org/10.1021/cm990661zChakraborty I, Mascharak PK (2016) Mesoporous silica materials and nanoparticles as carriers for controlled and site-specific delivery of gaseous signaling molecules. Microporous Mesoporous Mater 234:409–419. https://doi.org/10.1016/j.micromeso.2016.07.028Chen L, Zhang Z, Yao X, Chen X, Chen X (2015a) Intracellular pH-operated mechanized mesoporous silica nanoparticles as potential drug carries. Microporous Mesoporous Mater 201:169–175. https://doi.org/10.1016/j.micromeso.2014.09.023Chen X, Yao X, Wang C, Chen L, Chen X (2015b) Mesoporous silica nanoparticles capped with fluorescence-conjugated cyclodextrin for pH-activated controlled drug delivery and imaging. Microporous Mesoporous Mater 217:46–53. https://doi.org/10.1016/j.micromeso.2015.06.012Chen Y, Chen H, Shi J (2013) In vivo bio-safety evaluations and diagnostic / therapeutic applications of chemically designed mesoporous silica nanoparticles. Adv Mater 25(23):3144–3176. https://doi.org/10.1002/adma.201205292Chen Y, Shi X, Han B, Qin H, Li Z, Lu Y, Wang J, Kong Y (2012) The complete control for the nanosize of spherical MCM-41. J Nanosci Nanotechnol 12(9):7239–7249. https://doi.org/10.1166/jnn.2012.6459Cheng Y-J, Zeng X, Cheng D-B, Xu XD, Zhang XZ, Zhuo RX, He F (2016) Functional mesoporous silica nanoparticles (MSNs) for highly controllable drug release and synergistic therapy. Colloids Surfaces B Biointerfaces 145:217–225. https://doi.org/10.1016/j.colsurfb.2016.04.051Crommelin DJA, Florence AT (2013) Towards more effective advanced drug delivery systems. Int J Pharm 454(1):496–511. https://doi.org/10.1016/j.ijpharm.2013.02.020Edler KJ (1997) Synthesis and characterisation of the mesoporous molecular sieve, MCM-41. Doctoral dissertation, The Australian National University, AustraliaGuo Z, Liu X-M, Ma L, Li J, Zhang H, Gao YP, Yuan Y (2013) Effects of particle morphology, pore size and surface coating of mesoporous silica on naproxen dissolution rate enhancement. Colloids Surf B Biointerfaces 101:228–235. https://doi.org/10.1016/j.colsurfb.2012.06.026Han N, Wang Y, Bai J, Liu J, Wang Y, Gao Y, Jiang T, Kang W, Wang S (2016) Facile synthesis of the lipid bilayer coated mesoporous silica nanocomposites and their application in drug delivery. Microporous Mesoporous Mater 219:209–218. https://doi.org/10.1016/j.micromeso.2015.08.006Hu X, Wang Y, Peng B (2014) Chitosan-capped mesoporous silica nanoparticles as pH-responsive nanocarriers for controlled drug release. Chem - An Asian J 9(1):319–327. https://doi.org/10.1002/asia.201301105Huh S, Wiench JW, Yoo J et al (2003) Organic functionalization and morphology control of mesoporous silicas via a co-condensation synthesis method. Chem Mater 15(22):4247–4256. https://doi.org/10.1021/cm0210041Ikari K, Suzuki K, Imai H (2006) Structural control of mesoporous silica nanoparticles in a binary surfactant system. Langmuir 22(2):802–806. https://doi.org/10.1021/la0525527Iliade P, Miletto I, Coluccia S, Berlier G (2012) Functionalization of mesoporous MCM-41 with aminopropyl groups by co-condensation and grafting: a physico-chemical characterization. Res Chem Intermed 38(3-5):785–794. https://doi.org/10.1007/s11164-011-0417-5IUPAC (1985) Reporting physisorption data for gas/solid systems. Pure Appl Chem 57:603–619IUPAC (2014) Compendium of chemical terminology-gold book, 2.3.3. International Union of Pure and Applied ChemistryKhezri K, Roghani-Mamaqani H, Sarsabili M, Sobani M, Mirshafiei-Langari SA (2014) Spherical mesoporous silica nanoparticles/tailor-made polystyrene nanocomposites by in situ reverse atom transfer radical polymerization. Polym Sci Ser B 56(6):909–918. https://doi.org/10.1134/S1560090414660026Kresge CT, Leonowicz ME, Roth WJ, Vartuli JC, Beck JS (1992) Ordered mesoporous molecular sieves synthesized by a liquid-crystal template mechanism. Nature 359(6397):710–712. https://doi.org/10.1038/359710a0Lelong G, Bhattacharyya S, Kline S, Cacciaguerra T, Gonzalez MA, Saboungi ML (2008) Effect of surfactant concentration on the morphology and texture of MCM-41 materials. J Phys Chem C 112(29):10674–10680. https://doi.org/10.1021/jp800898nLv X, Zhang L, Xing F, Lin H (2016) Controlled synthesis of monodispersed mesoporous silica nanoparticles: particle size tuning and formation mechanism investigation. Microporous Mesoporous Mater 225:238–244. https://doi.org/10.1016/j.micromeso.2015.12.024Mamaeva V, Sahlgren C, Lindén M (2013) Mesoporous silica nanoparticles in medicine: recent advances. Adv Drug Deliv Rev 65(5):689–702. https://doi.org/10.1016/j.addr.2012.07.018Manzano M, Aina V, Areán CO, Balas F, Cauda V, Colilla M, Delgado MR, Vallet-Regí M (2008) Studies on MCM-41 mesoporous silica for drug delivery: effect of particle morphology and amine functionalization. Chem Eng J 137(1):30–37. https://doi.org/10.1016/j.cej.2007.07.078Merkus HG (2009) Particle size measurements: fundamentals, practice, quality. Springer Science +Businees Media B.V, The NetherlandsMorishige K, Fujii H, Uga M, Kinukawa D (1997) Capillary critical point of argon, nitrogen, oxygen, ethylene, and carbon dioxide in MCM-41. Langmuir 13(13):3494–3498. https://doi.org/10.1021/la970079ude Padua Oliveira DC, de Barros ALB, Belardi RM et al (2016) Mesoporous silica nanoparticles as a potential vaccine adjuvant against Schistosoma mansoni. J Drug Deliv Sci Technol 35:234–240. https://doi.org/10.1016/j.jddst.2016.07.002Phillips E, Penate-Medina O, Zanzonico PB, Carvajal RD, Mohan P, Ye Y, Humm J, Gonen M, Kalaigian H, Schoder H, Strauss HW, Larson SM, Wiesner U, Bradbury MS (2014) Clinical translation of an ultrasmall inorganic optical-PET imaging nanoparticle probe. Sci Transl Med 6(260):260ra149. https://doi.org/10.1126/scitranslmed.3009524Qu F, Zhu G, Lin H, Zhang W, Sun J, Li S, Qiu S (2006) A controlled release of ibuprofen by systematically tailoring the morphology of mesoporous silica materials. J Solid State Chem 179(7):2027–2035. https://doi.org/10.1016/j.jssc.2006.04.002Rafi AA, Mahkam M, Davaran S, Hamishehkar H (2016) A smart pH-responsive nano-carrier as a drug delivery system: a hybrid system comprised of mesoporous nanosilica MCM-41 (as a nano-container) & a pH-sensitive polymer (as smart reversible gatekeepers): preparation, characterization and in vitro releas. Eur J Pharm Sci 93:64–73. https://doi.org/10.1016/j.ejps.2016.08.005Rouquerol J, Rouquerol F, Llewellyn P, et al (2014) Adsorption by powders and porous solids: principles, methodology and applications. Elsevier Ltd.Selvam P, Bhatia SK, Sonwane CG (2001) Recent advances in processing and characterization of periodic mesoporous MCM-41 silicate molecular sieves. Ind Eng Chem Res 40(15):3237–3261. https://doi.org/10.1021/ie0010666Shi YT, Cheng HY, Geng Y, Nan HM, Chen W, Cai Q, Chen BH, Sun XD, Yao YW, Li HD (2010) The size-controllable synthesis of nanometer-sized mesoporous silica in extremely dilute surfactant solution. Mater Chem Phys 120(1):193–198. https://doi.org/10.1016/j.matchemphys.2009.10.045Shibata H, Chiba Y, Kineri T, Matsumoto M, Nishio K (2010) The effect of heat treatment on the interplanar spacing of the mesostructure during the synthesis of mesoporous MCM-41 silica. Colloids Surfaces A Physicochem Eng Asp 358(1-3):1–5. https://doi.org/10.1016/j.colsurfa.2009.12.020Slowing II, Vivero-Escoto JL, Wu C-W, Lin VSY (2008) Mesoporous silica nanoparticles as controlled release drug delivery and gene transfection carriers. Adv Drug Deliv Rev 60(11):1278–1288. https://doi.org/10.1016/j.addr.2008.03.012Sun R, Wang W, Wen Y, Zhang X (2015) Recent advance on mesoporous silica nanoparticles-based controlled release system: intelligent switches open up. Nano 5(4):2019–2053. https://doi.org/10.3390/nano5042019U.S. Department of Health & Human Services (2015) Cancer Nanotechnology PlanUkmar T, Maver U, Planinšek O, Kaučič V, Gaberšček M, Godec A (2011) Understanding controlled drug release from mesoporous silicates: theory and experiment. J Control Release 155(3):409–417. https://doi.org/10.1016/j.jconrel.2011.06.038Vallet-Regi M, Arcos Navarrete D (2016) Nanoceramics in clinical use, 1st edn. The Royal Society of Chemistry, CambridgeVallet-Regi M, Rámila A, Del Real RP, Pérez-Pariente J (2001) A new property of MCM-41: drug delivery system. Chem Mater 13(2):308–311. https://doi.org/10.1021/cm0011559Varga N, Benko M, Sebok D et al (2015) Mesoporous silica core-shell composite functionalized with polyelectrolytes for drug delivery. Microporous Mesoporous Mater 213:134–141. https://doi.org/10.1016/j.micromeso.2015.02.008Wang Y, Zhao Q, Han N, Bai L, Li J, Liu J, Che E, Hu L, Zhang Q, Jiang T, Wang S (2015) Mesoporous silica nanoparticles in drug delivery and biomedical applications. Nanomed Nanotechnol Biol Med 11(2):313–327. https://doi.org/10.1016/j.nano.2014.09.014Wanyika H, Gatebe E, Kioni P et al (2011) Synthesis and characterization of ordered mesoporous silica nanoparticles with tunable physical properties by varying molar composition of reagents. African J Pharm Pharmacol 5(21):2402–2410. https://doi.org/10.5897/AJPP11.592Wu SH, Mou CY, Lin HP (2013) Synthesis of mesoporous silica nanoparticles. Chem Soc Rev 42(9):3862–3875. https://doi.org/10.1039/c3cs35405aXu X, Lü S, Gao C, Wang X, Bai X, Gao N, Liu M (2015a) Facile preparation of pH-sensitive and self-fluorescent mesoporous silica nanoparticles modified with PAMAM dendrimers for label-free imaging and drug delivery. Chem Eng J 266:171–178. https://doi.org/10.1016/j.cej.2014.12.075Xu X, Lü S, Gao C, Wang X, Bai X, Duan H, Gao N, Feng C, Liu M (2015b) Polymeric micelle-coated mesop orous silica nanoparticle for enhanced fluorescent imaging and pH-responsive drug delivery. Chem Eng J 279:851–860. https://doi.org/10.1016/j.cej.2015.05.085Xu X, Lü S, Gao C, Feng C, Wu C, Bai X, Gao N, Wang Z, Liu M (2016) Self-fluorescent and stimuli-responsive mesoporous silica nanoparticles using a double-role curcumin gatekeeper for drug delivery. Chem Eng J 300:185–192. https://doi.org/10.1016/j.cej.2016.04.087Yang Y, Yu C (2015) Advances in silica based nanoparticles for targeted cancer therapy. Nanomedicine nanotechnology. Biol Med 12(2):317–332. https://doi.org/10.1016/j.nano.2015.10.018Zhang H, Tong C, Sha J, Liu B, Lü C (2015) Fluorescent mesoporous silica nanoparticles functionalized graphene oxide: a facile FRET-based ratiometric probe for Hg2+. Sensors Actuators B Chem 206:181–189. https://doi.org/10.1016/j.snb.2014.09.051Zhou C, Yan C, Zhao J, Wang H, Zhou Q, Luo W (2016) Rapid synthesis of morphology-controlled mesoporous silica nanoparticles from silica fume. J Taiwan Inst Chem Eng 62:307–312. https://doi.org/10.1016/j.jtice.2016.01.03

Mezcla de materiales poliméricos. II. Evaluación de las propiedades físicas, mecánicas y de proceso en mezclas de polietileno virgen y reciclado

En este documento se resumen los resultados en el desarrollo experimental de las etapas necesarias para recuperar polietileno de invernadero. Se estudia la forma en que se alteran las propiedades físicas y de procesabilidad del material virgen al someterlo a largos períodos de exposición al ambiente y la forma en que varían estas propiedades al preparar mezclas de polietileno virgen y reciclado. Los resultados sugieren utilizar como máximo 30 % de polietileno reciclado en las mezclas para evitar grandes variaciones en las propiedades del producto final

Mezcla de materiales poliméricos. I. Evaluación de las mezclas de poliestireno virgen y reciclado

Se evaluó la degradación de residuos de posconsumo de poliestireno de alto impacto, el comportamiento mecánico y las propiedades del estado fundido para mezclas de poliestireno virgen y reciclado. El poliestireno de alto impacto, utilizado para vasos desechables, presenta una disminución de los dobles enlaces del grupo butadieno, lo cual le da menor resistencia al impacto si se compara con un poliestireno virgen. Las mezclas de material virgen y reciclado presentan propiedades cuyos valores están en el intervalo de los de las resinas originales. El Índice de fluidez del poliestireno reciclado y su resistencia al impacto fueron las propiedades que presentaron mayor diferencia respecto al material virgen

Mezcla de materiales poliméricos. i. evaluación de las mezclas de poliestireno virgen y reciclado

Se evaluó la degradación de residuos de posconsumo de poliestireno de alto impacto, el comportamiento mecánico y las propiedades del estado fundido para mezclas de poliestireno virgen y reciclado. El poliestireno de alto impacto, utilizado para vasos desechables, presenta una disminución de los dobles enlaces del grupo butadieno, lo cual le da menor resistencia al impacto si se compara con un poliestireno virgen. Las mezclas de material virgen y reciclado presentan propiedades cuyos valores están en el intervalo de los de las resinas originales. El Índice de fluidez del poliestireno reciclado y su resistencia al impacto fueron las propiedades que presentaron mayor diferencia respecto al material virgen

Polycaprolactone membranes reinforced by toughened sol-gel produced silica networks

The aim of this work is to develop polycaprolactone based porous materials with improved mechanical performance to be used in bone repair. The hybrid membranes consist in a polymeric porous material in which the pore walls are coated by a silica thin layer. Silica coating increases membrane stiffness with respect to pure polymer but in addition filling the pores of the polymer with a silica phase improves bioactivity due to the delivery of silica ions in the neighborhood of the material in vivo. Nevertheless silica network, even that produced by sol–gel, might be too stiff and brittle what is not desirable for its performance as a coating. In this work we produced a toughened silica coating adding chitosan and 3-glycidoxypropyltrimethoxysilane (GPTMS) to the precursor solution looking for having polymer chains linked by covalent bonding to the silica network. Hybrid polymer–silica coating was produced by in situ sol–gel reaction using Tetraethyl orthosilicate (TEOS), GPTMS and chitosan. Chemical reaction between amine groups of chitosan chains and epoxy groups of GPTMS allowed covalent bonding of polymer chains to the silica network. Physical properties of the hybrid membranes were characterized and cell attachment of MC3T3-E1 pre-osteoblastic cells on the surface of these supports was assessed.Fundação para a Ciência e a Tecnologia (FCT)CEPB acknowledges the economic support of COOPEN agreement in the progress of the present work. JFM acknowledges the support from Fundac¸a˜o para a Cieˆncia e Tecnologia through project PTDC/FIS/115048/2009. JLGR acknowledges the support of the Spanish Ministry of Education through project No. MAT2010-21611-C03-01. CIBER-BBN is 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. Authors want to thank the technical support of the Universitat Polite`cnica de Vale`ncia’s Microscopy Service