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Gorbunova MA, Anokhin DV, Badamshina ER. Recent Advances in the Synthesis and Application of Thermoplastic Semicrystalline Shape Memory Polyurethanes. POLYMER SCIENCE SERIES B 2020. [DOI: 10.1134/s1560090420050073] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Pascoal DRC, Velozo ES, Braga MEM, Sousa HC, Cabral-Albuquerque ECM, Vieira de Melo SAB. Bioactive compounds of Copaifera sp. impregnated into three-dimensional gelatin dressings. Drug Deliv Transl Res 2020; 10:1537-1551. [PMID: 32557352 DOI: 10.1007/s13346-020-00797-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
This study investigates the immersion impregnation process of the copaiba oleoresin and leaf extract into SpongostanTM gelatin dressings to be used in wound healing treatment. Copaiba oleoresin and leaf extract were characterized by spectroscopic analyses in order to confirm the identity of bioactive compounds and their compatibility with dressing material. Their antibacterial properties were evaluated and oleoresin activity against Escherichia coli and Staphylococcus aureus bacteria was confirmed while the leaf extract showed activity against S. aureus. Solubility assays in organic solvents revealed that copaiba oleoresin is miscible into dichloromethane, while leaf extract showed a 20 g/ml solubility coefficient at 35 °C in the same solvent. These miscibility and solubility conditions were selected for the impregnation process. Using the organic solvent immersion method, 11 mg of copaiba oleoresin and 19 mg of leaf extract were impregnated into 1 cm3 of 3D matrix. The main bioactives from copaiba products, such as β-caryophyllene and lupeol, were tracked in the gelatin dressing. DSC and TGA assays showed no thermal changes in the samples after impregnation. Furthermore, the spatial organization of foam structure of the dressings was preserved after superficial distribution of oleoresin, as well as amorphous-like particulate deposition of leaf extract. The main compound of copaiba oleoresin, β-caryophyllene, which exhibits well-known anti-inflammatory activities, and the main compound of copaiba leaf extract, lupeol, also an anti-inflammatory agent, were successfully impregnated using organic solvent in wound dressings and are promising for further application on tissue wound healing. Graphical Abstract.
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Affiliation(s)
- Diego R C Pascoal
- Programa de Engenharia Industrial, Escola Politécnica, Universidade Federal da Bahia, Rua Aristides Novis, 2, 6° andar, Federação, Salvador, Bahia, 40210-630, Brazil
| | - Eudes S Velozo
- Departamento de Farmácia, Universidade Federal da Bahia, Rua Barão de Jeremoabo, s/n, Ondina, Salvador, Bahia, 40170-115, Brazil
| | - Mara E M Braga
- CIEPQPF, Department of Chemical Engineering, Universidade de Coimbra, Rua Sílvio Lima, Pólo II-Pinhal de Marrocos, 3030-790, Coimbra, Portugal
| | - Herminio C Sousa
- CIEPQPF, Department of Chemical Engineering, Universidade de Coimbra, Rua Sílvio Lima, Pólo II-Pinhal de Marrocos, 3030-790, Coimbra, Portugal
| | - Elaine C M Cabral-Albuquerque
- Programa de Engenharia Industrial, Escola Politécnica, Universidade Federal da Bahia, Rua Aristides Novis, 2, 6° andar, Federação, Salvador, Bahia, 40210-630, Brazil
| | - Silvio A B Vieira de Melo
- Programa de Engenharia Industrial, Escola Politécnica, Universidade Federal da Bahia, Rua Aristides Novis, 2, 6° andar, Federação, Salvador, Bahia, 40210-630, Brazil. .,Centro Interdisciplinar em Energia e Ambiente, Campus Universitário da Federação/Ondina, Universidade Federal da Bahia, Salvador, Bahia, 40170-115, Brazil.
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Kong H, Xu Q, Yu M. Microstructural Changes of Aramid Fiber Due to Reaction with Toluene 2,4-diisocyanate under Tension in scCO 2. Polymers (Basel) 2019; 11:polym11071110. [PMID: 31266166 PMCID: PMC6680621 DOI: 10.3390/polym11071110] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 06/11/2019] [Accepted: 06/20/2019] [Indexed: 12/04/2022] Open
Abstract
High modulus aramid fiber, such as Kevlar 49, is conventionally prepared by the heat annealing of high strength aramid fiber under a suitable tension at high temperature, especially higher than 500 °C. This enables the mobility of a rigid molecule chain to be rearranged into a more perfect crystalline or orientation structure under tension. However, annealing decreases the tensile strength, since the thermal degradation of the molecular chain at high temperature cannot be avoided. Kevlar 49 fibers treated in supercritical carbon dioxide (scCO2) under tension could improve their mechanical properties at a low temperature. The effects of the tension on the mechanical properties and structure of the Kevlar 49 fibers were studied by mechanical testing, wide-angle and small-angle X-ray scattering (WAXS, SAXS), and scanning electron microscopy (SEM). The results show that the mechanical properties, crystallinity and orientation of the fiber can be improved when the tension is less than 0.6 cN/dtex, which may be due to the increasing of the mobility of a rigid segment with the help of the plasticization of scCO2 and re-arrangement of macromolecular chain into crystalline and orientation structure under tension. What’s more, the amorphous region also was enhanced by crosslinking reaction of toluene 2,4-diisocyanate (TDI) with the chain end groups of the macromolecules in the amorphous regions. However, a decrease of tenacity was found when the tension was higher than 0.6 cN/dtex, which is because the tension was so high that the microfibril was broken. The results indicated that treating the Kevlar 49 fiber in scCO2 under a suitable tension with TDI as a crosslink agent can simultaneously improve both the tenacity and modulus of the fiber.
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Affiliation(s)
- Haijuan Kong
- School of Materials Engineering, Shanghai University of Engineering Science, Shanghai 201620, China.
| | - Qian Xu
- School of Materials Engineering, Shanghai University of Engineering Science, Shanghai 201620, China
| | - Muhuo Yu
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Material Science and Engineering, Donghua University, Shanghai 201620, China.
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Santos T, Rebelatto E, Chaves B, Lanza M, Oliveira J, Albuquerque EC, Vieira de Melo S. High pressure phase equilibrium data for carbon dioxide, methyl methacrylate and poly (dimethylsiloxane) systems. J Supercrit Fluids 2019. [DOI: 10.1016/j.supflu.2018.09.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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da Silva C, Pereira V, Costa G, Cabral-Albuquerque E, Vieira de Melo S, de Sousa H, Dias A, Braga M. Supercritical solvent impregnation/deposition of spilanthol-enriched extracts into a commercial collagen/cellulose-based wound dressing. J Supercrit Fluids 2018. [DOI: 10.1016/j.supflu.2017.11.028] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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