Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.324
Filtrar
1.
Biomaterials ; 309: 122598, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-38696943

RESUMEN

Current vascular grafts, primarily Gore-Tex® and Dacron®, don't integrate with the host and have low patency in small-diameter vessels (<6 mm). Biomaterials that possess appropriate viscoelasticity, compliance, and high biocompatibility are essential for their application in small blood vessels. We have developed metal ion crosslinked poly(propanediol-co-(hydroxyphenyl methylene)amino-propanediol sebacate) (M-PAS), a biodegradable elastomer with a wide range of mechanical properties. We call these materials metallo-elastomers. An initial test on Zn-, Fe-, and Cu-PAS grafts reveals that Cu-PAS is the most suitable because of its excellent elastic recoil and well-balanced polymer degradation/tissue regeneration rate. Here we report host remodeling of Cu-PAS vascular grafts in rats over one year. 76 % of the grafts remain patent and >90 % of the synthetic polymer is degraded by 12 months. Extensive cell infiltration leads to a positive host remodeling. The remodeled grafts feature a fully endothelialized lumen. Circumferentially organized smooth muscle cells, elastin fibers, and widespread mature collagen give the neoarteries mechanical properties similar to native arteries. Proteomic analysis further reveals the presence of important vascular proteins in the neoarteries. Evidence suggests that Cu-PAS is a promising material for engineering small blood vessels.


Asunto(s)
Prótesis Vascular , Arterias Carótidas , Elastómeros , Animales , Elastómeros/química , Ratas , Masculino , Materiales Biocompatibles/química , Ratas Sprague-Dawley , Polímeros/química , Ensayo de Materiales
2.
ACS Appl Bio Mater ; 7(6): 3777-3785, 2024 Jun 17.
Artículo en Inglés | MEDLINE | ID: mdl-38754861

RESUMEN

Oral devices, such as foil-type devices, show great potential for the delivery of poorly permeable macromolecules by enabling unidirectional release of the loaded pharmaceutical composition in close proximity to the epithelium in the small intestine or colon. However, one of the primary concerns associated with the use of foil-type devices so far has been the utilization of nonbiodegradable elastomers in the fabrication of the devices. Therefore, research into biodegradable substitute materials with similar characteristics enables drug delivery in a sustainable and environmentally friendly manner. In this study, a biodegradable elastomer, polyoctanediol citrate (POC), was synthesized via a one-pot reaction, with subsequent purification and microscale pattern replication via casting. The microstructure geometry was designed to enable fabrication of foil-type devices with the selected elastomer, which has a high intrinsic surface free energy. The final elastomer was demonstrated to have an elastic modulus ranging up to 2.2 ± 0.1 MPa, with strain at failure up to 110.1 ± 1.5%. Devices were loaded with acetaminophen and enterically coated, demonstrating 100% release at 2.5 h, following dissolution for 1 h in 0.1 M hydrochloric acid and 1.5 h in pH 6.8 phosphate-buffered saline. The elastomer demonstrated promising properties based on mechanical testing, surface free energy evaluation, and degradation studies.


Asunto(s)
Materiales Biocompatibles , Elastómeros , Ensayo de Materiales , Tamaño de la Partícula , Elastómeros/química , Materiales Biocompatibles/química , Materiales Biocompatibles/síntesis química , Sistemas de Liberación de Medicamentos , Humanos , Acetaminofén/química , Acetaminofén/administración & dosificación , Administración Oral , Citratos/química , Sustancias Macromoleculares/química , Sustancias Macromoleculares/síntesis química , Polímeros/química
3.
ACS Nano ; 18(22): 14558-14568, 2024 Jun 04.
Artículo en Inglés | MEDLINE | ID: mdl-38761154

RESUMEN

To propel electronic skin (e-skin) to the next level by integrating artificial intelligence features with advanced sensory capabilities, it is imperative to develop stretchable memory device technology. A stretchable memory device for e-skin must offer, in particular, long-term data storage while ensuring the security of personal information under any type of deformation. However, despite the significance of these needs, technology related to stretchable memory devices remains in its infancy. Here, we report an intrinsically stretchable floating gate (FG) polymer memory transistor. The device features a dual-stimuli (optical and electrical) writing system to prevent easy erasure of recorded data. An FG comprising an intermixture of Ag nanoparticles and elastomer and with proper energy-band alignment between the semiconductor and dielectric facilitated sustainable memory performance, while achieving a high memory on/off ratio (>105) and a long retention time (106 s) with the ability to withstand 50% uniaxial or 30% biaxial strain. In addition, our memory transistor exhibited high mechanical durability over multiple stretching cycles (1000 times), along with excellent environmental stability with respect to factors such as temperature, moisture, air, and delamination. Finally, we fabricated a 7 × 7 active-matrix memory transistor array for personalized storage of e-skin data and successfully demonstrated its functionality.


Asunto(s)
Transistores Electrónicos , Dispositivos Electrónicos Vestibles , Almacenamiento y Recuperación de la Información , Plata/química , Humanos , Elastómeros/química , Equipos de Almacenamiento de Computador , Nanopartículas del Metal/química , Diseño de Equipo
4.
J Mech Behav Biomed Mater ; 155: 106566, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38729087

RESUMEN

The objective of this study is to develop a reliable tribological model to enable a more thorough investigation of the frictional behavior of fascia tissues connected to non-specific lower back pain. Several models were designed and evaluated based on their coefficient of friction, using a low-frequency, low-load reciprocating motion. The study found that two technical elastomers, layered on PDMS to simulate the fascia and underlying muscle, are suitable substitutes for biological tissue in the model. The influence of tribopair geometry was also examined, and the results showed that greater conformity of contact leads to a lower COF, regardless of the material combination used. Finally, the friction properties of HA of various molecular weights and concentrations were tested.


Asunto(s)
Fascia , Fricción , Ensayo de Materiales , Fascia/fisiología , Dimetilpolisiloxanos/química , Fenómenos Biomecánicos , Modelos Biológicos , Elastómeros/química
5.
Int J Biol Macromol ; 268(Pt 2): 131946, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38692545

RESUMEN

The development of flexible wearable multifunctional electronics has gained great attention in the field of human motion monitoring. However, developing mechanically tough, highly stretchable, and recyclable composite conductive materials for application in multifunctional sensors remained great challenges. In this work, a mechanically tough, highly stretchable, and recyclable composite conductive elastomer with the dynamic physical-chemical dual-crosslinking network was fabricated by the combination of multiple hydrogen bonds and dynamic ester bonds. To prepare the proposed composite elastomers, the polyaniline-modified carboxylate cellulose nanocrystals (C-CNC@PANI) were used as both conductive filler to yield high conductivity of 15.08 mS/m, and mechanical reinforcement to construct the dynamic dual-crosslinking network with epoxidized natural rubber latex to realize the high mechanical strength (8.65 MPa) and toughness (29.57 MJ/m3). Meanwhile, the construction of dynamic dual-crosslinking network endowed the elastomer with satisfactory recyclability. Based on these features, the composite conductive elastomers were used as strain sensors, and electrode material for assembling flexible and recyclable self-powered sensors for monitoring human motions. Importantly, the composite conductive elastomers maintained reliable sensing and energy harvesting performance even after multiple recycling process. This study provides a new strategy for the preparation of recyclable, mechanically tough composite conductive materials for wearable sensors.


Asunto(s)
Celulosa , Elastómeros , Conductividad Eléctrica , Goma , Dispositivos Electrónicos Vestibles , Elastómeros/química , Celulosa/química , Goma/química , Humanos , Nanocompuestos/química , Nanopartículas/química , Fenómenos Mecánicos , Compuestos de Anilina/química
6.
ACS Appl Mater Interfaces ; 16(19): 25404-25414, 2024 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-38692284

RESUMEN

Liquid crystal elastomers (LCEs), as a classical two-way shape-memory material, are good candidates for developing artificial muscles that mimic the contraction, expansion, or rotational behavior of natural muscles. However, biomimicry is currently focused more on the actuation functions of natural muscles dominated by muscle fibers, whereas the tactile sensing functions that are dominated by neuronal receptors and synapses have not been well captured. Very few studies have reported the sensing concept for LCEs, but the signals were still donated by macroscopic actuation, that is, variations in angle or length. Herein, we develop a conductive porous LCE (CPLCE) using a solvent (dimethyl sulfoxide (DMSO))-templated photo-cross-linking strategy, followed by carbon nanotube (CNT) incorporation. The CPLCE has excellent reversible contraction/elongation behavior in a manner similar to the actuation functions of skeletal muscles. Moreover, the CPLCE shows excellent pressure-sensing performance by providing real-time electrical signals and is capable of microtouch sensing, which is very similar to natural tactile sensing. Furthermore, macroscopic actuation and tactile sensation can be integrated into a single system. Proof-of-concept studies reveal that the CPLCE-based artificial muscle is sensitive to external touch while maintaining its excellent actuation performance. The CPLCE with tactile sensation beyond reversible actuation is expected to benefit the development of versatile artificial muscles and intelligent robots.


Asunto(s)
Elastómeros , Cristales Líquidos , Nanotubos de Carbono , Cristales Líquidos/química , Elastómeros/química , Nanotubos de Carbono/química , Porosidad , Solventes/química , Tacto/fisiología , Órganos Artificiales , Músculo Esquelético/fisiología , Músculo Esquelético/química , Humanos
7.
ACS Sens ; 9(4): 2156-2165, 2024 04 26.
Artículo en Inglés | MEDLINE | ID: mdl-38629405

RESUMEN

Anisotropic strain sensors capable of multidirectional sensing are crucial for advanced sensor applications in human motion detection. However, current anisotropic sensors encounter challenges in achieving a balance among high sensitivity, substantial stretchability, and a wide linear detection range. To address these challenges, a facile freeze-casting strategy was employed to construct oriented filler networks composed of carbon nanotubes and conductive carbon black within a brominated butyl rubber ionomer (iBIIR) matrix. The resulting anisotropic sensor based on the iBIIR composites exhibited distinct gauge factors (GF) in the parallel and vertical directions (GF∥ = 4.91, while GF⊥ = 2.24) and a broad linear detection range over a strain range of 190%. This feature enables the sensor to detect various human activities, including uniaxial pulse, finder bending, elbow bending, and cervical spine movements. Moreover, the ion-cross-linking network within the iBIIR, coupled with strong π-cation interactions between the fillers and iBIIR macromolecules, imparted high strength (12.3 MPa, nearly twice that of pure iBIIR) and an ultrahigh elongation at break (>1800%) to the composites. Furthermore, the sensor exhibited exceptional antibacterial effectiveness, surpassing 99% against both Escherichia coli and Staphylococcus aureus. Notably, the sensor was capable of wireless sensing. It is anticipated that anisotropic sensors will have extensive application prospects in flexible wearable devices.


Asunto(s)
Elastómeros , Nanotubos de Carbono , Tecnología Inalámbrica , Humanos , Elastómeros/química , Nanotubos de Carbono/química , Anisotropía , Dispositivos Electrónicos Vestibles , Hollín/química , Movimiento , Staphylococcus aureus/aislamiento & purificación
8.
Biomed Mater ; 19(3)2024 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-38636492

RESUMEN

Three-dimensional (3D) printing has emerged as a transformative technology for tissue engineering, enabling the production of structures that closely emulate the intricate architecture and mechanical properties of native biological tissues. However, the fabrication of complex microstructures with high accuracy using biocompatible, degradable thermoplastic elastomers poses significant technical obstacles. This is primarily due to the inherent soft-matter nature of such materials, which complicates real-time control of micro-squeezing, resulting in low fidelity or even failure. In this study, we employ Poly (L-lactide-co-ϵ-caprolactone) (PLCL) as a model material and introduce a novel framework for high-precision 3D printing based on the material plasticization process. This approach significantly enhances the dynamic responsiveness of the start-stop transition during printing, thereby reducing harmful errors by up to 93%. Leveraging this enhanced material, we have efficiently fabricated arrays of multi-branched vascular scaffolds that exhibit exceptional morphological fidelity and possess elastic moduli that faithfully approximate the physiological modulus spectrum of native blood vessels, ranging from 2.5 to 45 MPa. The methodology we propose for the compatibilization and modification of elastomeric materials addresses the challenge of real-time precision control, representing a significant advancement in the domain of melt polymer 3D printing. This innovation holds considerable promise for the creation of detailed multi-branch vascular scaffolds and other sophisticated organotypic structures critical to advancing tissue engineering and regenerative medicine.


Asunto(s)
Materiales Biocompatibles , Elastómeros , Poliésteres , Impresión Tridimensional , Ingeniería de Tejidos , Andamios del Tejido , Elastómeros/química , Andamios del Tejido/química , Ingeniería de Tejidos/métodos , Poliésteres/química , Materiales Biocompatibles/química , Módulo de Elasticidad , Ensayo de Materiales , Humanos , Estrés Mecánico , Vasos Sanguíneos , Prótesis Vascular
9.
ACS Appl Mater Interfaces ; 16(15): 19480-19495, 2024 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-38581369

RESUMEN

Light-driven soft actuators based on photoresponsive materials can be used to mimic biological motion, such as hand movements, without involving rigid or bulky electromechanical actuations. However, to our knowledge, no robust photoresponsive material with desireable mechanical and biological properties and relatively simple manufacture exists for robotics and biomedical applications. Herein, we report a new visible-light-responsive thermoplastic elastomer synthesized by introducing photoswitchable moieties (i.e., azobenzene derivatives) into the main chain of poly(ε-caprolactone) based polyurethane urea (PAzo). A PAzo elastomer exhibits controllable light-driven stiffness softening due to its unique nanophase structure in response to light, while possessing excellent hyperelasticity (stretchability of 575.2%, elastic modulus of 17.6 MPa, and strength of 44.0 MPa). A bilayer actuator consisting of PAzo and polyimide films is developed, demonstrating tunable bending modes by varying incident light intensities. Actuation mechanism via photothermal and photochemical coupling effects of a soft-hard nanophase is demonstrated through both experimental and theoretical analyses. We demonstrate an exemplar application of visible-light-controlled soft "fingers" playing a piano on a smartphone. The robustness of the PAzo elastomer and its scalability, in addition to its excellent biocompatibility, opens the door to the development of reproducible light-driven wearable/implantable actuators and lightweight soft robots for clinical applications.


Asunto(s)
Elastómeros , Robótica , Elastómeros/química , Poliuretanos , Urea
10.
Macromol Rapid Commun ; 45(11): e2300717, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38445752

RESUMEN

This work presents a rheological study of a biocompatible and biodegradable liquid crystal elastomer (LCE) ink for three dimensional (3D) printing. These materials have shown that their structural variations have an effect on morphology, mechanical properties, alignment, and their impact on cell response. Within the last decade LCEs are extensively studied as potential printing materials for soft robotics applications, due to the actuation properties that are produced when liquid crystal (LC) moieties are induced through external stimuli. This report utilizes experiments and coarse-grained molecular dynamics to study the macroscopic rheology of LCEs in nonlinear shear flow. Results from the shear flow simulations are in line with the outcomes of these experimental investigations. This work believes the insights from these results can be used to design and print new material with desirable properties necessary for targeted applications.


Asunto(s)
Elastómeros , Cristales Líquidos , Simulación de Dinámica Molecular , Impresión Tridimensional , Reología , Elastómeros/química , Cristales Líquidos/química , Materiales Biocompatibles/química
11.
Macromol Rapid Commun ; 45(11): e2400010, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38458610

RESUMEN

This work presents a new method for 4D fabrication of two-way shape memory materials that are capable of reversible shapeshifting right after manufacturing, upon application of proper heating and cooling cycles. The innovative solution presented here consists in the combination of highly stretched electrospun shape memory polymer (SMP) nanofibers with a melt electrowritten elastomer. More specifically, the stretched nanofibers are made of a biocompatible thermoplastic polyurethane (TPU) with crystallizable soft segments, undergoing melt-induced contraction and crystallization-induced elongation upon heating and cooling, respectively. Reversible actuation during crystallization becomes possible due to the elastic recovery of the elastomer component, obtained by melt electrowriting of a commercial TPU filament. Thanks to the design freedom offered by additive manufacturing, the elastomer structure also has the role of guiding the shape transformation. Electrospinning and melt electrowriting process parameters are set up so to obtain smart 4D objects capable of two-way shape memory effect (SME), and the possibility of reversible and repeatable actuation is demonstrated. The two components are then combined in different proportions with the aim of tailoring the two-way SME, taking into account the effect of design parameters such as the SMP content, the elastomer pattern, and the composite thickness.


Asunto(s)
Nanofibras , Polímeros , Polímeros/química , Nanofibras/química , Poliuretanos/química , Elastómeros/química , Materiales Inteligentes/química , Materiales Biocompatibles/química
12.
Macromol Rapid Commun ; 45(11): e2400032, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38471754

RESUMEN

A versatile and robust end-group derivatization approach using oximes has been developed for the detection of oxidative degradation of synthetic polyisoprenes and polybutadiene. This method demonstrates broad applicability, effectively monitoring degradation across a wide molecular weight range through ultraviolet (UV)-detection coupled to gel permeation chromatography. Importantly, it enables the effective monitoring of degradation via derivatization-induced UV-maximum shifts, even in the presence of an excess of undegraded polyene, overcoming limitations previously reported with refractive index detectors. Notably, this oxime-based derivatization methodology is used in enzymatic degradation experiments of synthetic polyisoprenes characterized by a cis: trans ratio with the rubber oxygenase LcpK30. It reveals substantial UV absorption in derivatized enzymatic degradation products of polyisoprene with molecular weights exceeding 1000 g mol-1 - an unprecedented revelation for this enzyme's activity on such synthetic polyisoprenes. This innovative approach holds promise as a valuable tool for advancing research into the degradation of synthetic polyisoprenes and polybutadiene, particularly under conditions of low organocatalytic or enzymatic degradation activity. With its broad applicability and capacity to reveal previously hidden degradation processes, it represents a noteworthy contribution to sustainable polymer chemistry.


Asunto(s)
Butadienos , Cromatografía en Gel , Oxigenasas , Rayos Ultravioleta , Butadienos/química , Oxigenasas/química , Oxigenasas/metabolismo , Goma/química , Elastómeros/química , Oximas/química , Estructura Molecular
13.
J Am Chem Soc ; 146(15): 10699-10707, 2024 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-38518116

RESUMEN

Ultralow temperature-tolerant electronic skins (e-skins) can endow polar robots with tactile feedback for exploring in extremely cold polar environments. However, it remains a challenge to develop e-skins that enable sensitive touch sensation and self-healing at ultralow temperatures. Herein, we describe the development of a sensitive robotic hand e-skin that can stretch, self-heal, and sense at temperatures as low as -78 °C. The elastomeric substrate of this e-skin is based on poly(dimethylsiloxane) supramolecular polymers and multistrength dynamic H-bonds, in particular with quadruple H-bonding motifs (UPy). The structure-performance relationship of the elastomer at ultralow temperatures is investigated. The results show that elastomers with side-chain UPy units exhibit higher stretchability (∼3257%) and self-healing efficiency compared to those with main-chain UPy units. This is attributed to the lower binding energy variation and lower potential well. Based on the elastomer with side-chain UPy and man-made electric ink, a sensitive robotic hand e-skin for usage at -78 °C is constructed to precisely sense the shape of objects and specific symbols, and its sensation can completely self-recover after being damaged. The findings of this study contribute to the concept of using robotic hands with e-skins in polar environments that make human involvement limited, dangerous, or impossible.


Asunto(s)
Elastómeros , Dispositivos Electrónicos Vestibles , Humanos , Elastómeros/química , Elasticidad , Piel , Electricidad
14.
Chem Soc Rev ; 53(8): 4086-4153, 2024 Apr 22.
Artículo en Inglés | MEDLINE | ID: mdl-38465517

RESUMEN

Degradable biomedical elastomers (DBE), characterized by controlled biodegradability, excellent biocompatibility, tailored elasticity, and favorable network design and processability, have become indispensable in tissue repair. This review critically examines the recent advances of biodegradable elastomers for tissue repair, focusing mainly on degradation mechanisms and evaluation, synthesis and crosslinking methods, microstructure design, processing techniques, and tissue repair applications. The review explores the material composition and cross-linking methods of elastomers used in tissue repair, addressing chemistry-related challenges and structural design considerations. In addition, this review focuses on the processing methods of two- and three-dimensional structures of elastomers, and systematically discusses the contribution of processing methods such as solvent casting, electrostatic spinning, and three-/four-dimensional printing of DBE. Furthermore, we describe recent advances in tissue repair using DBE, and include advances achieved in regenerating different tissues, including nerves, tendons, muscle, cardiac, and bone, highlighting their efficacy and versatility. The review concludes by discussing the current challenges in material selection, biodegradation, bioactivation, and manufacturing in tissue repair, and suggests future research directions. This concise yet comprehensive analysis aims to provide valuable insights and technical guidance for advances in DBE for tissue engineering.


Asunto(s)
Materiales Biocompatibles , Elastómeros , Medicina Regenerativa , Ingeniería de Tejidos , Humanos , Elastómeros/química , Materiales Biocompatibles/química , Animales
15.
ACS Appl Mater Interfaces ; 16(13): 16880-16892, 2024 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-38506556

RESUMEN

To meet the demands of challenging usage scenarios, there is an increasing need for flexible electronic skins that can operate properly not only in terrestrial environments but also extend to complex aquatic conditions. In this study, we develop an elastomer by incorporating dynamic urea bonds and hydrogen bonds into the polydimethylsiloxane backbone, which exhibits excellent autonomous self-healing and reversible adhesive performance in both dry and wet environments. A multifunctional flexible sensor with excellent sensing stability, amphibious self-healing capacity, and amphibious self-adhesive performance is fabricated through solvent-free 3D printing. The sensor has a high sensing sensitivity (GF = 45.1) and a low strain response threshold (0.25%) and can be used to detect small human movements and physiological activities, such as muscle movement, joint movement, respiration, and heartbeat. The wireless wearable sensing system assembled by coupling this device with a bluetooth transmission system is suitable for monitoring strenuous human movement in amphibious environments, such as playing basketball, cycling, running (terrestrial environments), and swimming (aquatic environments). The design strategy provides insights into enhancing the self-healing and self-adhesive properties of soft materials and promises a prospective avenue for fabricating flexible electronic skin that can work properly in amphibious environments.


Asunto(s)
Elastómeros , Dispositivos Electrónicos Vestibles , Humanos , Elastómeros/química , Cementos de Resina , Adhesivos , Estudios Prospectivos , Electrónica , Impresión Tridimensional
16.
Biosens Bioelectron ; 254: 116222, 2024 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-38518560

RESUMEN

Materials that have the ability to manipulate shapes in response to stimuli such as heat, light, humidity and magnetism offer a means for versatile, sophisticated functions in soft robotics or biomedical implants, while such a reactive transformation has certain drawbacks including high operating temperatures, inherent rigidity and biological hazard. Herein, we introduce biodegradable, self-adhesive, shape-transformable poly (L-lactide-co-ε-caprolactone) (BSS-PLCL) that can be triggered via thermal stimulation near physiological temperature (∼38 °C). Chemical inspections confirm the fundamental properties of the synthetic materials in diverse aspects, and study on mechanical and biochemical characteristics validates exceptional stretchability up to 800 % and tunable dissolution behaviors under biological conditions. The integration of the functional polymer with a bioresorbable electronic system highlights potential for a wide range of biomedical applications.


Asunto(s)
Técnicas Biosensibles , Elastómeros , Elastómeros/química , Materiales Biocompatibles/química , Implantes Absorbibles , Polímeros/química , Poliésteres/química
17.
Biomacromolecules ; 25(3): 1810-1824, 2024 Mar 11.
Artículo en Inglés | MEDLINE | ID: mdl-38360581

RESUMEN

Polyurethanes (PUs) have adjustable mechanical properties, making them suitable for a wide range of applications, including in the biomedical field. Historically, these PUs have been synthesized from isocyanates, which are toxic compounds to handle. This has encouraged the search for safer and more environmentally friendly synthetic routes, leading today to the production of nonisocyanate polyurethanes (NIPUs). Among these NIPUs, polyhydroxyurethanes (PHUs) bear additional hydroxyl groups, which are particularly attractive for derivatizing and adjusting their physicochemical properties. In this paper, polyether-based NIPU elastomers with variable stiffness are designed by functionalizing the hydroxyl groups of a poly(propylene glycol)-PHU by a cyclic carbonate carrying a pendant unsaturation, enabling them to be post-photo-cross-linked with polythiols (thiol-ene). Elastomers with remarkable mechanical properties whose stiffness can be adjusted are obtained. Thanks to the unique viscous properties of these PHU derivatives and their short gel times observed by rheology experiments, formulations for light-based three-dimensional (3D) printing have been developed. Objects were 3D-printed by digital light processing with a resolution down to the micrometer scale, demonstrating their ability to target various designs of prime importance for personalized medicine. In vitro biocompatibility tests have confirmed the noncytotoxicity of these materials for human fibroblasts. In vitro hemocompatibility tests have revealed that they do not induce hemolytic effects, they do not increase platelet adhesion, nor activate coagulation, demonstrating their potential for future applications in the cardiovascular field.


Asunto(s)
Elastómeros , Poliuretanos , Humanos , Poliuretanos/farmacología , Poliuretanos/química , Elastómeros/química , Isocianatos/química , Prótesis e Implantes , Supuración
18.
Acta Biomater ; 177: 165-177, 2024 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-38354873

RESUMEN

Four-dimensional (4D) printing unlocks new potentials for personalized biomedical implantation, but still with hurdles of lacking suitable materials. Herein, we demonstrate a bioresorbable shape memory elastomer (SME) with high elasticity at both below and above its phase transition temperature (Ttrans). This SME can be digital light 3D printed by co-polymerizing glycerol dodecanoate acrylate prepolymer (pre-PGDA) with acrylic acid monomer to form crosslinked Poly(glycerol dodecanoate acrylate) (PGDA)-Polyacrylic acid (PAA), or PGDA-PAA network. The printed complex, free-standing 3D structures with high-resolution features exhibit shape programming properties at a physiological temperature. By tuning the pre-PGDA weight ratios between 55 wt% and 70 wt%, Ttrans varies between 39.2 and 47.2 ℃ while Young's moduli (E) range 40-170 MPa below Ttrans with fractural strain (εf) of 170 %-200 %. Above Ttrans, E drops to 1-1.82 MPa which is close to those of soft tissue. Strikingly, εf of 130-180 % is still maintained. In vitro biocompatibility test on the material shows > 90 % cell proliferation and great cell attachment. In vivo vascular grafting trials underline the geometrical and mechanical adaptability of these 4D printed constructs in regenerating the aorta tissue. Biodegradation of the implants shows the possibility of their full replacement by natural tissue over time. To highlight its potential for personalized medicine, a patient-specific left atrial appendage (LAA) occluder was printed and implanted endovascularly into an in vitro heart model. STATEMENT OF SIGNIFICANCE: 4D printed shape-memory elastomer (SME) implants particularly designed and manufactured for a patient are greatly sought-after in minimally invasive surgery (MIS). Traditional shape-memory polymers used in these implants often suffer from issues like unsuitable transition temperatures, poor biocompatibility, limited 3D design complexity, and low toughness, making them unsuitable for MIS. Our new SME, with an adjustable transition temperature and enhanced toughness, is both biocompatible and naturally degradable, particularly in cardiovascular contexts. This allows implants, like biomedical scaffolds, to be programmed at room temperature and then adapt to the body's physiological conditions post-implantation. Our studies, including in vivo vascular grafts and in vitro device implantation, highlight the SME's effectiveness in aortic tissue regeneration and its promising applications in MIS.


Asunto(s)
Elastómeros , Andamios del Tejido , Humanos , Elastómeros/química , Andamios del Tejido/química , Glicerol , Implantes Absorbibles , Lauratos , Impresión Tridimensional , Acrilatos
19.
ACS Appl Bio Mater ; 7(2): 863-878, 2024 02 19.
Artículo en Inglés | MEDLINE | ID: mdl-38207114

RESUMEN

A pair of alkyne- and thiol-functionalized polyesters are designed to engineer elastomeric scaffolds with a wide range of tunable material properties (e.g., thermal, degradation, and mechanical properties) for different tissues, given their different host responses, mechanics, and regenerative capacities. The two prepolymers are quickly photo-cross-linkable through thiol-yne click chemistry to form robust elastomers with small permanent deformations. The elastic moduli can be easily tuned between 0.96 ± 0.18 and 7.5 ± 2.0 MPa, and in vitro degradation is mediated from hours up to days by adjusting the prepolymer weight ratios. These elastomers bear free hydroxyl and thiol groups with a water contact angle of less than 85.6 ± 3.58 degrees, indicating a hydrophilic nature. The elastomer is compatible with NIH/3T3 fibroblast cells with cell viability reaching 88 ± 8.7% relative to the TCPS control at 48 h incubation. Differing from prior soft elastomers, a mixture of the two prepolymers without a carrying polymer is electrospinnable and UV-cross-linkable to fabricate elastic fibrous scaffolds for soft tissues. The designed prepolymer pair can thus ease the fabrication of elastic fibrous conduits, leading to potential use as a resorbable synthetic graft. The elastomers could find use in other tissue engineering applications as well.


Asunto(s)
Poliésteres , Polímeros , Poliésteres/química , Polímeros/química , Elastómeros/química , Andamios del Tejido/química , Compuestos de Sulfhidrilo
20.
ACS Appl Mater Interfaces ; 16(5): 6356-6366, 2024 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-38262045

RESUMEN

Biodegradable electronic devices have gained significant traction in modern medical applications. These devices are generally desired to have a long enough working lifetime for stable operation and allow for active control over their degradation rates after usage. However, current biodegradable materials used as encapsulations or substrates for these devices are challenging to meet the two requirements due to the constraints of inadequate water resistance, poor mechanical properties, and passive degradation characteristics. Herein, we develop a novel biodegradable elastomer named POC-SS-Res by introducing disulfide linkage and resveratrol (Res) into poly(1,8-octanediol-co-citrate) (POC). Compared to POC, POC-SS-Res exhibits good water resistance and excellent mechanical properties in PBS, providing effective protection for devices. At the same time, POC-SS-Res offers the unique advantage of an active-controllable degradation rate, and its degradation products express low biotoxicity. Good biocompatibility of POC-SS-Res is also demonstrated. Bioelectronic components encapsulated with POC-SS-Res have an obvious prolongation of working lifetime in PBS compared to that encapsulated with POC, and its degradation rate can be actively controlled by the addition of glutathione (GSH).


Asunto(s)
Materiales Biocompatibles , Polímeros , Polímeros/química , Materiales Biocompatibles/química , Ingeniería de Tejidos , Elastómeros/química , Citratos/química
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA