Papers by Jose Ramon Sarasua
Polymers, 2021
Lactide-valerolactone copolymers have potential application in the packaging sector. Different co... more Lactide-valerolactone copolymers have potential application in the packaging sector. Different copolymers were synthesized, and the kinetics of the copolymerization reactions and the microstructure of the copolymers were analysed. Lactide showed higher reactivity than valerolactone which leads to composition drift through the reaction. Thermal, mechanical and barrier properties of the selected copolymers were studied. Overall, the incorporation of valerolactone results in copolymers with higher ductility than poly(lactide) with intermediate water and oxygen permeability which makes these materials appropriate candidates for use in the packaging sector.
Cell Reports Physical Science, 2021
Establishment of controlled nano-and mesoscopic energized entities that gather, in a concerted ef... more Establishment of controlled nano-and mesoscopic energized entities that gather, in a concerted effort, into motile aggregated patterns is at the forefront of scientific discovery. Lomora et al. report on coccolith-polydopamine hybrids (Robocoliths) that heat and move collectively upon light excitation and accommodate antifouling brushes on their surface.
Scientific Reports, 2021
By providing a bidirectional communication channel between neural tissues and a biomedical device... more By providing a bidirectional communication channel between neural tissues and a biomedical device, it is envisaged that neural interfaces will be fundamental in the future diagnosis and treatment of neurological disorders. Due to the mechanical mismatch between neural tissue and metallic neural electrodes, soft electrically conducting materials are of great benefit in promoting chronic device functionality. In this study, carbon nanotubes (CNT), silver nanowires (AgNW) and poly(hydroxymethyl 3,4-ethylenedioxythiophene) microspheres (MSP) were employed as conducting fillers within a poly(ε-decalactone) (EDL) matrix, to form a soft and electrically conducting composite. The effect of a filler type on the electrical percolation threshold, and composite biocompatibility was investigated in vitro. EDL-based composites exhibited favourable electrochemical characteristics: EDL/CNT—the lowest film resistance (1.2 ± 0.3 kΩ), EDL/AgNW—the highest charge storage capacity (10.7 ± 0.3 mC cm− 2),...
International Journal of Molecular Sciences, 2021
Human dental pulp stem cells (hDPSCs) are some of the most promising stem cell types for regenera... more Human dental pulp stem cells (hDPSCs) are some of the most promising stem cell types for regenerative therapies given their ability to grow in the absence of serum and their realistic possibility to be used in autologous grafts. In this review, we describe the particular advantages of hDPSCs for neuroregenerative cell therapies. We thoroughly discuss the knowledge about their embryonic origin and characteristics of their postnatal niche, as well as the current status of cell culture protocols to maximize their multilineage differentiation potential, highlighting some common issues when assessing neuronal differentiation fates of hDPSCs. We also review the recent progress on neuroprotective and immunomodulatory capacity of hDPSCs and their secreted extracellular vesicles, as well as their combination with scaffold materials to improve their functional integration on the injured central nervous system (CNS) and peripheral nervous system (PNS). Finally, we offer some perspectives on th...
International Journal of Molecular Sciences, 2020
This work reports the versatility of polydopamine (PD) when applied as a particle coating in a co... more This work reports the versatility of polydopamine (PD) when applied as a particle coating in a composite of polylactide (PLA). Polydopamine was observed to increase the particle–matrix interface strength and facilitate the adsorption of drugs to the material surface. Here, barium sulfate radiopaque particles were functionalized with polydopamine and integrated into a polylactide matrix, leading to the formulation of a biodegradable and X-ray opaque material with enhanced mechanical properties. Polydopamine functionalized barium sulfate particles also facilitated the adsorption and release of the antibiotic levofloxacin. Analysis of the antibacterial capacity of these composites and the metabolic activity and proliferation of human dermal fibroblasts in vitro demonstrated that these materials are non-cytotoxic and can be 3D printed to formulate complex biocompatible materials for bone fixation devices.
Polymers, 2019
Porous scaffolds made of elastomeric materials are of great interest for soft tissue engineering.... more Porous scaffolds made of elastomeric materials are of great interest for soft tissue engineering. Poly(L-lactide-co-ε-caprolactone) (PLCL) is a bio-resorbable elastomeric copolymer with tailorable properties, which make this material an appropriate candidate to be used as scaffold for vascular, tendon, and nerve healing applications. Here, extrusion was applied to produce porous scaffolds of PLCL, using NaCl particles as a leachable agent. The effects of the particle proportion and size on leaching performance, dimensional stability, mechanical properties, and ageing of the scaffolds were analyzed. The efficiency of the particle leaching and scaffold swelling when wet were observed to be dependent on the porogenerator proportion, while the secant moduli and ultimate tensile strengths were dependent on the pore size. Porosity, swelling, and mechanical properties of the extruded scaffolds were tailorable, varying with the proportion and size of porogenerator particles and showed simil...
Polymers, 2018
There is a great interest in incorporating catechol moieties into polymers in a controlled manner... more There is a great interest in incorporating catechol moieties into polymers in a controlled manner due to their interesting properties, such as the promotion of adhesion, redox activity or bioactivity. One possibility is to incorporate the catechol as end-group in a polymer chain using a functional initiator by means of controlled polymerization strategies. Nevertheless, the instability of catechol moieties under oxygen and basic pH requires tedious protection and deprotection steps to perform the polymerization in a controlled fashion. In the present work, we explore the organocatalyzed synthesis of catechol end-functional, semi-telechelic polylactide (PLLA) using non-protected dopamine, catechol molecule containing a primary amine, as initiator. NMR and SEC-IR results showed that in the presence of a weak organic base such as triethylamine, the ring-opening polymerization (ROP) of lactide takes place in a controlled manner without need of protecting the cathechol units. To further confirm the end-group fidelity the catechol containing PLLA was characterized by Cyclic Voltammetry and MALDI-TOF confirming the absence of side reaction during the polymerization. In order to exploit the potential of catechol moieties, catechol end-group of PLLA was oxidized to quinone and further reacted with aliphatic amines. In addition, we also confirmed the ability of catechol functionalized PLLA to reduce metal ions to metal nanoparticles to obtain well distributed silver nanoparticles. It is expected that this new route of preparing catechol-PLLA polymers without protection will increase the accessibility of catechol containing biodegradable polymers by ROP.
RSC Advances, 2019
Correction for ‘Novel biodegradable and non-fouling systems for controlled-release based on poly(... more Correction for ‘Novel biodegradable and non-fouling systems for controlled-release based on poly(ε-caprolactone)/Quercetin blends and biomimetic bacterial S-layer coatings’ by Eva Sanchez-Rexach et al., RSC Adv., 2019, 9, 24154–24163.
RSC Advances, 2019
S-Layer coating on PCL–Quercetin miscible blends acts as a release controller from films and scaf... more S-Layer coating on PCL–Quercetin miscible blends acts as a release controller from films and scaffolds, as well as antifouling agent.
EKAIA Euskal Herriko Unibertsitateko Zientzia eta Teknologia Aldizkaria, 2019
Azken aldian, biobateragarriak diren eta zelulen itsaspen selektiboa baimentzen duten gainazalak ... more Azken aldian, biobateragarriak diren eta zelulen itsaspen selektiboa baimentzen duten gainazalak oso desiragarriak dira biomedikuntzako zenbait aplikazio ezberdinetarako. Bide honetatik, material biobateragarrietan honelako gainazalak lortzeko posible da mikrotxantiloiak (maila mikrometrikoan eginiko gainazaleko formak) erabiltzea, hauek substratu konkretu baten gainean zelulen hazkunde kontrolatua eta bideratua baimendu ditzaketelarik. Hala, mikrotxantiloien bidez, azalera oso konkretuetan zelulentzat ingurune egokiak defini daitezke eta hauen aplikazio dira, esaterako, biosentsoreak, ehun-ingeniaritzarako in vitro eginiko kultibo zelularrak edo inplanteen gainazal egokiak sortzea. Gainera, mikrotxantiloiak sortzeko zenbait teknika ezberdin daude, bakoitzak dituen abantaila eta desabantailekin. Hain zuzen ere, gure ikerketa lanean teknika guzti hauetatik 3D inpresioa edo fabrikazio gehigarria delakoa erabili da, lortzen diren mikrotxantiloien zehaztasun, errepikakortasun eta egonko...
Composites from Renewable and Sustainable Materials, 2016
The aim of this chapter is to introduce to the use and possible applications of polylactide-based... more The aim of this chapter is to introduce to the use and possible applications of polylactide-based composites. Polylactides are biodegradable aliphatic polyesters, which are widely used in medical and ecological-friendly fields. First of all, a deep description of main characteristics of polylactides is shown. This chapter summarizes many concepts, which comprehend a general view of polylactide biopolymers such as synthesis and structures, physical-chemical and mechanical characterization and possible applications of final products. Then, an overview of composites based on polylactides and their benefits compared with bare polylactides are described.
RSC Advances, 2015
Coating bioactive glass particles with polydopamine hinders the degradation reaction occurring at... more Coating bioactive glass particles with polydopamine hinders the degradation reaction occurring at high temperatures between PLLA and bioactive glass particles.
ISRN Tissue Engineering, 2013
We explored the effect of poly(L-lactic acid) (PLLA) containing various percentages (0.1, 0.5, 1,... more We explored the effect of poly(L-lactic acid) (PLLA) containing various percentages (0.1, 0.5, 1, and 3 wt.%) of multi walled carbon nanotubes (MWCNTs) on the myogenic differentiation of C2C12 murine myoblast progenitor cells. We showed that all PLLA/MWCNTs nanocomposite materials support the myotubes formation more efficiently than neat PLLA as indicated by the high expression of the most significant myogenic markers: MyoD, Myosin Heavy Chain, dimension of myofibres, and fusion myogenic index. Interestingly, we note that both MyoD and myogenic fusion index levels were in the order 0.1 MWCNTs = 0.5 MWCNTs > 1 MWCNTs > 3 MWCNTs > neat PLLA, suggesting that the amount of MWCNTs influenced the cell differentiation.
Biomatter, 2014
Thermoplastic biodegradable polymers displaying elastomeric behavior and mechanical consistency a... more Thermoplastic biodegradable polymers displaying elastomeric behavior and mechanical consistency are greatly appreciated for the regeneration of soft tissues and for various medical devices. However, while the selection of a suitable base material is determined by mechanical and biodegradation considerations, it is the surface properties of the biomaterial that are responsible for the biological response. In order to improve the interaction with cells and modulate their behavior, biologically active molecules can be incorporated onto the surface of the material. With this aim, the surface of a lactide and caprolactone based biodegradable elastomeric terpolymer was modified in two stages. First, the biodegradable polymer surface was aminated by atmospheric pressure plasma treatment and second a crosslinker was grafted in order to covalently bind the biomolecule. In this study, albumin was used as a model protein. According to X-ray photoelectron spectroscopy (XPS) and atomic force mic...
Macromolecules, 1998
Six polylactides, polymerized with Salen-Al-OCH 3 initiator and having optical purities between 4... more Six polylactides, polymerized with Salen-Al-OCH 3 initiator and having optical purities between 43% and 100%, were analyzed by differential scanning calorimetry, X-ray diffraction, and optical microscopy, following various crystallization conditions. It was found that each of those polylactides can crystallize, even those with low optical purities; their crystallization rate is, however, slower than those for high optical purity polyesters. Moreover, the low optical purity polymers tend to form stereocomplexes between the L and D sequences of the same polylactide, which behavior is ascribed to their multiblock microstructure. A correlation was found between the measured melting temperature of optically active polylactides and their average sequence length.
Carbohydrate Polymers, 2014
Poly(vinyl alcohol) (PVA) has been grafted with glycolic acid (GL), a biodegradable hydroxyl acid... more Poly(vinyl alcohol) (PVA) has been grafted with glycolic acid (GL), a biodegradable hydroxyl acid to yield modified poly(vinyl alcohol) (PVAGL). The formation of hydrogels at pH = 6.8 and physiological temperature through blending chitosan (CS) and PVAGL at different concentrations has been investigated. FTIR, DOSY NMR and oscillatory rheology measurements have been carried out on CS/PVAGL hydrogels and the results have been compared to those obtained for CS/PVA hydrogels prepared under the same conditions. The experimental results point to an increase in the number of interactions between chitosan and PVAGL in polymer hydrogels prepared with modified PVA. The resulting materials with enhanced elastic properties and thixotropic behavior are potential candidates to be employed as injectable materials for biomedical applications.
Biomacromolecules, 2011
This work relies on the CNT dispersion in either solution or a polymer matrix through the formati... more This work relies on the CNT dispersion in either solution or a polymer matrix through the formation of a three component supramolecular system composed of PEO-b-PLLA diblock copolymer, carbon nanotubes (CNTs) and lithium chloride. According to a one-pot procedure in solution, the "self-assembly" concept has demonstrated its efficiency using suspension tests of CNTs. Characterizations of the supramolecular system by photon correlation spectroscopy, raman spectroscopy and molecular dynamics simulations highlight the charge transfer interaction from the CNTs towards the PEO-b-PLLA/LiCl complex. Finally, this concept was successfully extended in bulk (absence of solvent) via melt-processing techniques by dispersing these complexes in a poly(L-Lactide) (PLA) matrix. Electrical conductivity measurements and transmission electron microscopy attested for the remarkable dispersion of CNTs, leading to high-performance PLA-based materials.
Biomaterial adimentsuen ikerketan azken urteotan eman den ebolu- zioak estimuluei erantzuteko gai... more Biomaterial adimentsuen ikerketan azken urteotan eman den ebolu- zioak estimuluei erantzuteko gai diren polisakarido naturaletan oinarritutako hidrogelen garapena bultzatu du; izan ere, material horiek bio-bateragarritasuna eta biodegradagarritasuna izateaz gain, giza ehunen birsorkuntzan lagundu dezaketelako. Hidrogel horiek ura xurgatzeko gaitasuna dute eta baita estimulu elektriko, magnetiko, termiko eta kimikoen aurrean erantzuteko gaitasuna; hala, hidrogel polimerikoek zabalik dituzte aplikazio biomedikoetarako ateak.
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Papers by Jose Ramon Sarasua