Introduction

Szycher, Michael

doi:10.1201/b12343-2

Cited by 69 publications

(122 citation statements)

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“…Notably, a tunable biomaterial platform that can recapitulate a range of tissue properties is desired, from the elastic moduli of muscle (∼10 MPa) to that of tendon and ligament (∼200 MPa). − One promising class of materials with the tunability and resilience to better match native tissue is segmented polyurethane elastomers. Biomedical polyurethanes have been used in medical devices since the 1960s due to their combination of highly tunable mechanical properties, fatigue resistance, and biocompatibility. − To extend the application of these versatile polymers to tissue engineering, biodegradable moieties were incorporated into the polyurethane structure. These new biodegradable polyurethane formulations have been used in several tissue engineering applications, including but not limited to cardiac patches, − fibrocartilage repair, , nerve guidance channels, , wound dressings, , and bone grafts. , …”

Section: Introductionmentioning

confidence: 99%

Synthesis and Characterization of Plug-and-Play Polyurethane Urea Elastomers as Biodegradable Matrixes for Tissue Engineering Applications

Kishan

Wilems

Mohiuddin

et al. 2017

ACS Biomater. Sci. Eng.

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The highly tunable mechanical properties and resilience of polyurethanes make them promising candidates for tissue engineering applications. Biodegradability is conferred by incorporation of hydrolytically or enzymatically cleavable moieties into the polyurethane structure. A common choice for the biodegradable soft segment is a poly(ether ester) triblock copolymer synthesized by ring opening polymerization of the polyester from a polyether macroinitiator. Herein, we describe a new “plug-and-play” approach for triblock synthesis based on urethane block coupling that enables finer control of block lengths and ease of segmental tuning. The inclusion of urethane linkages in the soft segment was also hypothesized to promote hydrogen bonding between the segments with an associated increase in modulus, tensile strength, and ultimate elongation. Hard segment content of the biodegradable polyurethane urea was varied to demonstrate the tunable tensile properties and degradation rate. As expected, increasing hard segment content led to large increases in initial secant modulus and tensile strength. A corollary decrease in ultimate elongation, elastic recovery, and degradation rate was also observed with increasing hard segment content. Finally, cytocompatibility and hydrolytic degradation of electrospun polyurethane meshes were evaluated to establish the potential use of these biodegradable matrixes as tissue engineering scaffolds. All of the polyurethane formulations displayed comparable cytocompatibilty to tissue culture plastic controls and hydrolytic chain scission of the polyester soft segment. Overall, this synthetic approach provides a platform to produce biodegradable polyurethane ureas with enhanced control over segmental chemistry, mechanical properties, and degradation rate.

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Section: Introductionmentioning

confidence: 99%

Synthesis and Characterization of Plug-and-Play Polyurethane Urea Elastomers as Biodegradable Matrixes for Tissue Engineering Applications

Kishan

Wilems

Mohiuddin

et al. 2017

ACS Biomater. Sci. Eng.

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“…Segmented PU comprises a soft segment with a low T g and a hard segment of isocyanate and chain-extender. The prepolymers react with the chain extender for increasing a molecular weight and building a linear block copolymer with alternating blocks of the hard segment and soft segment [ 30 ]. The main reaction in PU synthesizing is the formation of the carbamate or urethane bond occurred as the isocyanate reacts with an alcohol and the urea bond generated as the isocyanate reacts with an amine.…”

Section: Synthesis Of Polyurethanes (Pus)mentioning

confidence: 99%

Revised Manuscript with Corrections: Polyurethane-Based Conductive Composites: From Synthesis to Applications

Choi¹,

Shin

et al. 2022

IJMS

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The purpose of this review article is to outline the extended applications of polyurethane (PU)-based nanocomposites incorporated with conductive polymeric particles as well as to condense an outline on the chemistry and fabrication of polyurethanes (PUs). Additionally, we discuss related research trends of PU-based conducting materials for EMI shielding, sensors, coating, films, and foams, in particular those from the past 10 years. PU is generally an electrical insulator and behaves as a dielectric material. The electrical conductivity of PU is imparted by the addition of metal nanoparticles, and increases with the enhancing aspect ratio and ordering in structure, as happens in the case of conducting polymer fibrils or reduced graphene oxide (rGO). Nanocomposites with good electrical conductivity exhibit noticeable changes based on the remarkable electric properties of nanomaterials such as graphene, RGO, and multi-walled carbon nanotubes (MWCNTs). Recently, conducting polymers, including PANI, PPY, PTh, and their derivatives, have been popularly engaged as incorporated fillers into PU substrates. This review also discusses additional challenges and future-oriented perspectives combined with here-and-now practicableness.

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“…The polymeric membranes made of polyurethanes are used for over 25 years as short-term biomedical devices. , The three principal components of PU include polyol, diisocyanate, and cross-linker between which a urethane linkage (−NHCOO−) is formed. There is a variety of possible polyols (over 500 commercially used) that play an important role in controlling the characteristics of the PUs, such as physicochemical and mechanical properties . The PUs used as biomaterials are polyether- and polyester-based, and their choice depends on the application site.…”

Section: Introductionmentioning

confidence: 99%

Characterization of Partially Covered Self-Expandable Metallic Stents for Esophageal Cancer Treatment: In Vivo Degradation

Chytrosz

Gołda-Cępa

Włodarczyk

et al. 2021

ACS Biomater. Sci. Eng.

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Partially covered self-expandable metallic esophageal stent (SEMS) placement is the most frequently applied palliative treatment in esophageal cancer. Structural characterization of explanted 16 nitinol-polyurethane SEMS (the group of 6 females, 10 males, age 40–80) was performed after their removal due to dysfunction. The adverse bulk changes in the polymer structure were identified using differential scanning calorimetry (DSC), differential mechanical thermal analysis (DMTA), and attenuated total reflectance infrared spectroscopy (ATR-IR) and discussed in terms of melting point shift (9 °C), glass-transition shift (4 °C), differences in viscoelastic behavior, and systematic decrease of peaks intensities corresponding to C–H, C=O, and C–N polyurethane structural bonds. The scanning electron and confocal microscopic observations revealed all major types of surface degradation, i.e., surface cracks, peeling off of the polymer material, and surface etching. The changes in the hydrophobic polyurethane surfaces were also revealed by a significant decrease in wettability (74°) and the corresponding increase of the surface free energy (31 mJ/m 2 ). To understand the in vivo degradation, the in vitro tests in simulated salivary and gastric fluids were performed, which mimic the environments of proximal and distal ends, respectively. It was concluded that the differences in the degradation of the proximal and distal ends of prostheses strongly depend on the physiological environment, in particular stomach content. Finally, the necessity of the in vivo tests for SEMS degradation is pointed out.

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Introduction

Cited by 69 publications

References 0 publications

Synthesis and Characterization of Plug-and-Play Polyurethane Urea Elastomers as Biodegradable Matrixes for Tissue Engineering Applications

Synthesis and Characterization of Plug-and-Play Polyurethane Urea Elastomers as Biodegradable Matrixes for Tissue Engineering Applications

Revised Manuscript with Corrections: Polyurethane-Based Conductive Composites: From Synthesis to Applications

Characterization of Partially Covered Self-Expandable Metallic Stents for Esophageal Cancer Treatment: In Vivo Degradation

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