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. 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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

Aportación de la densitometría ósea en las artroplastias de rodilla

El presente trabajo consiste en una revisión clínica y radiológica de 84 artroplastias modulares de rodilla de las cuales, en 19 se ha estudiado la masa ósea periprotésica (7 cementadas y 12 sin cementar) antes, al mes y a los seis meses de la intervención mediante un densitómetro de doble fotón. Aparte, se ha probado la correlación directa entre la indicación peroperatoria de no cementar y una mayor masa ósea en todas las zonas periprotésicas; por otro lado, se ha observado una diferente distribución de la densidad mineral ósea en la tibia tras la intervención, según se haya utilizado o no cemento. Estos hallazgos confirman el estudio densitométrico previo a la intervención como un método complementario útil en la indicación de la cementación de la artroplastia total de rodilla.A clinical and radiological revision of 84 modular knee arthroplasties is presented. Periprosthesis bone mineral content was studied in 19 prostheses (7 cemented and 12 uncemented) before, surgery one and 6 months after the intervention using a densitometer of double energy. A direct correlation between the implantation of a non-cemented prosthesis and the growth of the bone mass in all the periprosthesis areas was found, existing a different distribution of the mineral bone density of the tibia after the intervention depending on the use of cement. These findings show that the densitometric study previous to an intervention as a useful complementary method in the indication of cemented total knee arthroplasty

Chitosan-Silica Hybrid Porous Membranes

Chitosan–silica porous hybrids were prepared by a novel strategy in order to improve the mechanical properties of chitosan (CHT) in the hydrogel state. The inorganic silica phase was introduced by sol–gel reactions in acidic medium inside the pores of already prepared porous scaffolds. In order to make the scaffolds insoluble in acidic media chitosan was cross-linked by genipin (GEN) with an optimum GEN concentration of 3.2 wt.%. Sol–gel reactions took place with Tetraethylorthosilicate (TEOS) and 3-glycidoxypropyltrimethoxysilane (GPTMS) acting as silica precursors. GPTMS served also as a coupling agent between the free amino groups of chitosan and the silica network. The morphology study of the composite revealed that the silica phase appears as a layer covering the chitosan membrane pore walls. The mechanical properties of the hybrids were characterized by means of compressive stress–strain measurements. By immersion in water the hybrids exhibit an increase in elastic modulus up to two orders of magnitude.The research project is implemented within the framework of the Action "Supporting Postdoctoral Researchers" of the Operational Program "Education and Lifelong Learning" (Action's Beneficiary: General Secretariat for Research and Technology), and is co-financed by the European Social Fund (ESF) and the Greek State, Grant Number: NARGEL-PE5(2551). JFM thanks the Portuguese Foundation for Science and Technology (FCT) for financial support through the PTDC/FIS/115048/2009 project. JLGR acknowledges the support of the Ministerio de Economia y Competitividad, MINECO, through the MAT2013-46467-C4-1-R project

Water and protein dynamics in protein-water mixtures over wide range of composition

© 2012 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.[EN] Water and protein dynamics in two globular protein-water systems, water-lysozyme and water-BSA (bovine serum albumine), were studied by differential scanning calorimetry (DSC), dielectric relaxation spectroscopy (DRS) and thermally stimulated depolarization currents (TSDC) techniques. Water equilibrium sorption isotherms (ESI) measurements were also recorded at room temperature. The samples covered a wide range of composition, from practically dry solid pellets (2wt% of water) to dilute solutions (82wt% of water). Crystallization and melting events of water were studied by DSC and the amount of uncrystallized water was calculated. The evolution of dynamics with hydration level was followed for various dielectric relaxation processes, the emphasis being given to relaxation processes of polar groups on the surface of the proteins and of uncrystallized water molecules. A relationship between the formation of a conductive percolating water cluster and the saturation of the water process was found.This research has been co-financed by the European Union (European Social Fund - ESF) and Greek national funds through the Operational Program "Education and Lifelong Learning" of the National Strategic Reference Framework (NSRF) - Research Funding Program: Heracleitus II. Investing in knowledge society through the European Social Fund.Kyritsis, A.; Panagopoulou, A.; Pissis, P.; Sabater I Serra, R.; Gómez Ribelles, JL.; Shinyashiki, N. (2012). Water and protein dynamics in protein-water mixtures over wide range of composition. IEEE Transactions on Dielectrics and Electrical Insulation. 19(4):1239-1246. https://doi.org/10.1109/TDEI.2012.6259997S1239124619

Osteomielitis tuberculosa tibial aislada: a propósito de un caso

Se presenta un caso infrecuent e de osteomielitis tuberculosa aislada tibial sin evidencia de focos tuberculosos en otras localizaciones óseas o extraóseas. Con éste motivo, se revisa la bibliografía y se destaca el valor diagnóstico de la biopsia así como la importancia de asociar el curetaje al tratamiento tuberculostátic o y el bue n pronóstico a distancia de estas lesiones.An infrequent cas e of tuberculous isolated tibial osteomyelitis, without any evidenc e of tuberculous focus in eithe r bone or extrabone locations is presented. With this motive the bibliography is reviewed and the diagnostic value of the biopsy is enhance d as well as the importanc e of associating the curettage to he specific treatment and the good prediction in the long run of these lesions

Influence of ferrite nanoparticle type and content on the crystallization kinetics and electroactive phase nucleation of poly(vinilidene fluoride)

This work reports on the nucleation of the β-phase of poly(vinylidene fluoride), PVDF, by incorporating CoFe2O4 and NiFe2O4 nanoparticles, leading in this way, to the preparation of magnetoelectric composites. The fraction of filler nanoparticles needed to produce the same β- to α-phase ratio in crystallized PVDF is one order of magnitude lower in the Cobalt nanoparticles. The interaction between nanoparticles and PVDF chains induce the all trans conformation in PVDF segments and this structure then propagates in crystal growth. The nucleation kinetics is enhanced by the presence of nanoparticles, as corroborated by the increasing number of spherulites with increasing nanoparticle content and by the variations of the Avrami’s exponent. Further, the decrease of the crystalline fraction of PVDF with increasing nanoparticles content indicates that an important fraction of polymer chains are confined in interphases with the filler particle.Centro de Investigación Principe FelipeInstituto de Salud Carlos III (Ministry of Science and Innovation).FEDER funds through the "Programa Operacional Factores de Competitividade – COMPETE"Fundação para a Ciência e a Tecnologia (FCT) - NANO/NMed-SD/0156/2007, PTDC/CTM/69316/2006, SFRH/BPD/63148/2009Conselleria de Sanidad (Generalitat Valenciana)Spanish Ministry of Education through project No. MAT2010-21611-C03-01, EUI2008-0012

Viscoelastic behaviour of polymethyl methacrylate networks with different crosslinking degrees

The influence of the cross-linking degree on the dynamics of the segmental motions close to the glass transition of poly(methyl methacrylate), PMMA, networks was investigated by three different mechanical spectroscopy techniques: thermally stimulated recovery (TSR), dynamic mechanical analysis (DMA), and creep. The application of the time-temperature superposition principle to isothermal DMA and creep results permitted to successfully construct master curves for PMMA networks with distinct cross-linking degrees. The former results were fitted to the KWW equation. The obtained variation of âKWW for the distinct networks indicated that the relaxation curves tend to broaden as the cross-linking degree increases. TSR results clearly revealed a significant shift of the R-relaxation to longer times and a broader relaxation as the cross-linking degree increases, what was also observed by DMA and creep. A change from a Vogel to an Arrhenius behavior was detected by the three techniques with the decrease of temperature below Tg. The temperature dependence of the apparent activation energies (Ea) was calculated from DMA, creep, and TSR experiments; above Tg a good agreement was seen between the Ea values for all the techniques. Furthermore, the effect of the cross-linking degree on the fragility of PMMA networks was evaluated. For these materials an increase of fragility with increasing cross-linking degree was observed

Structure, morphology, adhesion and in vitro biological evaluation of antibacterial multi-layer HA-Ag/SiO2/TiN/Ti coatings obtained by RF magnetron sputtering for biomedical applications

[EN] Biocompatible and antibacterial multi-layer coatings of hydroxyapatite (HA)-Ag/SiO2/TiN/Ti were obtained on the Ti-6Al-4V alloy, by means of the magnetron sputtering technique. During characterization of the coatings, the chemical composition was evaluated by energy dispersive X-ray spectroscopy and the phase analysis was carried out by X-ray diffraction. The morphology of the coatings was observed by field emission scanning electron microscopy, while transmission electron microscopy was used to appreciate their structure. The adhesion of the coatings to the substrate was evaluated by micro scratch test. The in vitro biological response was evaluated in terms of cytotoxicity, adhesion and differentiation of mouse mesenchymal stem cells, as well as adhesion and bacterial viability of Staphylococcus aureus strain. Through the compositional study carried out, the deposition of the HA phase was verified, with a Ca/P ratio close to 1.67 and the characteristic diffraction peaks of this compound. The structural study of the coatings evidenced the obtention of multi-layer architectures. The use of an intermediate SiO2/TiN/Ti trilayer was found to improve adhesion between HA-Ag and the substrate by 84%. Finally, the in vitro biological tests carried out indicated a potentially non-toxic character in the coatings. Additionally, an antibacterial effect was registered at low concentrations of Ag (3.0.co;2-3Lalueza, P., Monzón, M., Arruebo, M., & Santamaría, J. (2011). Bactericidal effects of different silver-containing materials. Materials Research Bulletin, 46(11), 2070-2076. doi:10.1016/j.materresbull.2011.06.041Peetsch, A., Greulich, C., Braun, D., Stroetges, C., Rehage, H., Siebers, B., … Epple, M. (2013). Silver-doped calcium phosphate nanoparticles: Synthesis, characterization, and toxic effects toward mammalian and prokaryotic cells. Colloids and Surfaces B: Biointerfaces, 102, 724-729. doi:10.1016/j.colsurfb.2012.09.040Yanovska, A. A., Stanislavov, A. S., Sukhodub, L. B., Kuznetsov, V. N., Illiashenko, V. Y., Danilchenko, S. N., & Sukhodub, L. F. (2014). Silver-doped hydroxyapatite coatings formed on Ti–6Al–4V substrates and their characterization. Materials Science and Engineering: C, 36, 215-220. doi:10.1016/j.msec.2013.12.011DeVasConCellos, P., Bose, S., Beyenal, H., Bandyopadhyay, A., & Zirkle, L. G. (2012). Antimicrobial particulate silver coatings on stainless steel implants for fracture management. Materials Science and Engineering: C, 32(5), 1112-1120. doi:10.1016/j.msec.2012.02.020VALLETREGI, M. (2004). Calcium phosphates as substitution of bone tissues. Progress in Solid State Chemistry, 32(1-2), 1-31. doi:10.1016/j.progsolidstchem.2004.07.001Surmenev, R. A., Surmeneva, M. A., Evdokimov, K. E., Pichugin, V. F., Peitsch, T., & Epple, M. (2011). The influence of the deposition parameters on the properties of an rf-magnetron-deposited nanostructured calcium phosphate coating and a possible growth mechanism. Surface and Coatings Technology, 205(12), 3600-3606. doi:10.1016/j.surfcoat.2010.12.039Surmeneva, M. A., Sharonova, A. A., Chernousova, S., Prymak, O., Loza, K., Tkachev, M. S., … Surmenev, R. A. (2017). Incorporation of silver nanoparticles into magnetron-sputtered calcium phosphate layers on titanium as an antibacterial coating. Colloids and Surfaces B: Biointerfaces, 156, 104-113. doi:10.1016/j.colsurfb.2017.05.016Mohseni, E., Zalnezhad, E., Bushroa, A. R., Abdel Magid Hamouda, Goh, B. T., & Yoon, G. H. (2015). Ti/TiN/HA coating on Ti–6Al–4V for biomedical applications. Ceramics International, 41(10), 14447-14457. doi:10.1016/j.ceramint.2015.07.081Ghasemi, S., Shanaghi, A., & Chu, P. K. (2017). Nano mechanical and wear properties of multi-layer Ti/TiN coatings deposited on Al 7075 by high-vacuum magnetron sputtering. Thin Solid Films, 638, 96-104. doi:10.1016/j.tsf.2017.07.049Hamdi, D. A., Jiang, Z.-T., No, K., Rahman, M. M., Lee, P.-C., Truc, L. N. T., … Dlugogorski, B. Z. (2019). Biocompatibility study of multi-layered hydroxyapatite coatings synthesized on Ti-6Al-4V alloys by RF magnetron sputtering for prosthetic-orthopaedic implant applications. Applied Surface Science, 463, 292-299. doi:10.1016/j.apsusc.2018.08.157Qi, J., Yang, Y., Zhou, M., Chen, Z., & Chen, K. (2019). Effect of transition layer on the performance of hydroxyapatite/titanium nitride coating developed on Ti-6Al-4V alloy by magnetron sputtering. Ceramics International, 45(4), 4863-4869. doi:10.1016/j.ceramint.2018.11.183Lenis, J. A., Hurtado, F. M., Gómez, M. A., & Bolívar, F. J. (2019). 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El enclavamiento encerrojado de Grosse-Kempf en el tratamiento de las fracturas diafisarias del fémur

Se presentan 50 fracturas diafisarias de fémur tratadas mediante enclavamiento endomedular encerrojado de Grosse-Kempf. Realizamos un estudio retrospectivo utilizando para la valoración del resultado la escala de Thorensen, que considera la existencia de callos viciosos radiológicos, la flexión de rodilla, la dismetría y la presencia de dolor e inflamación. El resultado a los 20 meses del tratamiento (12-27) es excelente en 32 casos, bueno en 13, regular en 4 y malo en 1. Creemos que este método de enclavamiento constituye un buen procedimiento para el tratamiento de este tipo de fracturas, especialmente de las fracturas conminutas de las zonas 2, 3, 4 y 5 de Wiss. La mayoría de los resultados regulares y malos son debidos a fallos en la técnica quirúrgica.We present 50 femoral shaft fractures treated by Grosse-Kempf intramedullary nailing. A retrospective study was performed by using the Thorensen scale for the evaluation of results. This scale takes into account different parameters such as radiological malposition, range of motion of the knee, shortening of the femur, pain, and swelling. Twenty months after treatment (range: 12-27), the results were excellent in 32 cases, good in 13, fair in 4 and poor in one. Grosse-Kempf nailing seems to be a good method for treating this type of fractures, particularly in conminuted fractures localized in the 2, 3, 4 and 5 Wiss's zones. The majority of fair and poor results are caused by errors in the surgical technique