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Controlled Delivery Models of Bioactive Factors for the Maturation of Engineered Tissues
Published in Emmanuel Opara, Controlled Drug Delivery Systems, 2020
Ashkan Shafiee, Elham Ghadiri, Jareer Kassis, Anthony Atala
Two strategies are used when using growth factors for tissue regeneration: these are either physical encapsulation as part of a delivery system or chemical immobilization into/onto the ECM. The latter procedure can be accomplished via covalent and noncovalent techniques. The covalent method involves the direct covalent immobilization of growth factors in the matrix, whereas noncovalent approaches include the use of hydrophobicity or protein hydrogen bonding for the physical adsorption and immobilization of the growth factor onto the matrix. As an example of the latter method, Xiong et al. applied quinone groups to facilitate the immobilization of vascular endothelial growth factor, given that substrates coated with these structures can covalently immobilize molecules with thiol or amine groups. Therefore, a functional coating with quinone groups was fabricated by first using amine-bearing plasma-polymerized allylamine, after which tannic acid was used to introduce phenolic hydroxylic hydroxyl/quinone groups. The immobilization was confirmed using surface energy measurements, X-ray photoelectron spectroscopy, and Fourier-transform infrared spectroscopy. This system produced a significant enhancement in the proliferation and functionality of human umbilical vein endothelial cells in the biological construct.
Molecular Structure and Spectroscopy
Published in W. M. Haynes, David R. Lide, Thomas J. Bruno, CRC Handbook of Chemistry and Physics, 2016
W. M. Haynes, David R. Lide, Thomas J. Bruno
Name Acenaphthene Acetaldehyde Acetamide Acetic acid Acetic anhydride Acetone Acetonitrile Acetophenone Acetyl chloride Acetylene-carbon dioxide complex Acetylene-carbon monoxide complex Acetylene-carbon oxysulfide trimer complex Acetylene-hydrogen cyanide complex Acetyl fluoride Acrylonitrile Allyl alcohol Allylamine Aluminum monofluoride Ammonia Aniline Anisole Arsenic(III) chloride Arsenic(III) fluoride Arsine Azulene Barium oxide Barium sulfide Benzaldehyde Benzeneacetonitrile Benzene-hydrogen sulfide complex Benzene-krypton complex Benzene-sulfur dioxide complex Benzenethiol Benzonitrile Benzyl acetate Benzyl alcohol Benzyl benzoate Bis(2-aminoethyl)amine Mol. form. C12H10 C2H4O C2H5NO C2H4O2 C4H6O3 C3H6O C2H3N C8H8O C2H3ClO C2H2CO2 C2H2CO C2H2C3O3S3 C2H2CHN C2H3FO C3H3N C3H6O C3H7N AlF H3N C6H7N C7H8O AsCl3 AsF3 AsH3 C10H8 BaO BaS C7H6O C8H7N C6H6H2S C6H6Kr C6H6O2S C6H6S C7H5N C9H10O2 C7H8O C14H12O2 C4H13N3 /D 0.85 2.750(6) 3.68(3) 1.70(3) 2.8 2.88(3) 3.92519 3.02(6) 2.72(14) 0.161(1) 0.311(1) 1.23(2) 3.29(3) 2.96(3) 3.92(7) 1.60(8) 1.2 1.53(15) 1.4718(2) 1.13(2) 1.38(7) 1.59(8) 2.59(5) 0.217(3) 0.80(2) 7.954(3) 10.86(2) 3.0 liq 3.5 liq 1.14(2) 0.136(2) 2.061(2) 1.23 liq 4.18(8) 1.22 liq 1.71(9) 2.06 liq 1.89 liq Ref. 1 3 5 2 1 1 5 1 1 22 32 53 32 1 5 1 1 1 5 3 1 1 1 5 1 5 3 7 7 40 58 33 7 1 7 1 7 7
Systemic toxicology
Published in Chris Winder, Neill Stacey, Occupational Toxicology, 2004
W.M. Haschek, N.H. Stacey, C. Winder
Reaction with functionally or structurally important molecules by a chemical or its metabolite can cause a direct effect on the heart, frequently resulting in degeneration and necrosis of cardiac muscle, sometimes accompanied by inflammation. Allylamine, an industrial chemical, is metabolised by amine oxidase to acrolein and hydrogen peroxide, which conjugates to and depletes glutathione. Selective vasculotoxicity occurs with damage to smooth muscle. Chronic exposure results in atherosclerosis. In addition, acrolein conjugates to and depletes glutathione, putting cardiac muscle at risk for damage due to free radicals. Chemotherapeutic agents such as the anthracyclines (for example, adriamycin) form reactive oxygen radicals which can directly injure cardiac muscle. Cadmium, lead and cobalt exhibit negative inotropic and dromotropic effects and produce structural changes in the heart. Immune-mediated hypersensitivity reactions can also affect the cardiovascular system. These are not dose-related, are primarily induced by drugs, and characterised by inflammation, especially vasculitis.
Fabrication of cationic polymer surface through plasma polymerization and layer-by-layer assembly
Published in Materials and Manufacturing Processes, 2020
Rui Chen, Changgui Shi, Yanhai Xi, Peng Zhao, Hailong He
In this study, a combination of the plasma polymerization and LbL self-assembly technique was adopted to coat amine cationic polymers onto the surface of titanium alloy implants without obviously compromising their physicochemical properties. Primary amine groups on the surface were prepared by plasma polymerization of allylamine to provide a positively charged surface, which allowed following LbL self-assembly. Anionic PSS and cationic PAH have been widely used as polyelectrolytes in different biomedical applications because of their good biocompatibility. So they were used herein to achieve a multilayered nanostructured polymer coating through the LbL self-assembly technique. This is the first report to demonstrate that the amine cationic polymers deposited on the titanium alloy surface can improve antibacterial capability for implants to avoid implant-related infection.
Mini review: Recent advances in long period fiber grating biological and chemical sensors
Published in Instrumentation Science & Technology, 2019
Furthermore, many innovative gas sensors based on LPFG have been explored. Partridge et al.[91] used hemoglobin for the first time as a direct sensing element in conjunction with an optical fiber. The dissolved oxygen content was held constant while changing the dissolved carbon dioxide content during the measurements. The relative content of dissolved oxygen is reduced and the conversion of carboxyhemoglobin to oxyhemoglobin is carried out accordingly. In this case, the determination of dissolved oxygen was realized by detecting the shift of resonance peak caused by the change of refractive index of hemoglobin coating. The results showed that the sensor has good repeatability and is suitable for chemical analysis. Hromadka et al.[92] proposed a volatile organic compound sensor modified with a coating of SiO2 nanoparticles/poly(allylamine hydrochloride) polycation and infused with p-sulphanato calix4 arene or p-sulphanato calix8 arene. The sensor has a short response time.
The gas-phase pyrolysis of cyclopropylamine. Quantum chemical characterisation of the intermediates involved
Published in Molecular Physics, 2021
Yeljair Monascal, María Paula Badenes
Although numerous experimental kinetic reports on the pyrolysis of substituted cyclopropanes are available [7–17], there has been less attention to evaluate the transition states in these isomerisations. Because of that, it remains unclear if there is a preferential reaction path, especially when the ring is attached to a heteroatom. An interesting case that exemplifies the above is the pyrolysis of cyclopropylamine, (c-C3H5)NH2 (CPA). Parry and Robinson found this reaction is homogeneous, unimolecular and obeys a first-order law, where the observed products are (c-C3H5)N=CHCH2CH3 and NH3 [12]. Scheme 2 shows the possible intermediates that may lie in the main reaction channel: Paths 1 and 2 involve the formation of the 1,3-biradical ĊH2CH2ĊHNH2 and carbene CH3CH2C̈NH2, respectively; while Path 3 implies concerted ring-opening and hydrogen transfer to give 1-aminopropene, CH3CH=CHNH2. The co-pyrolysis of CPA with allylamine, which produces ammonia and N-propylideneallylamine, indicates that this compound may not be involved in the pyrolysis of isolated CPA [12]. In a posterior report, the small isotope effect obtained in the pyrolysis of cyclopropylamine-d2 (kH/kD = 1.06 at 376–405°C) allows discarding the formation of 1-propanimine, CH3CH2CH=NH, in the slow step [13]. However, since the imine carbon atom is susceptible to the nucleophilic attack of another molecule of CPA, this species probably participates in an intermediate step to form (c-C3H5)NHCH(NH2)CH2CH3, which finally decomposes to give the observed products.