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Oshiro-Junior JA, Lusuardi A, Beamud EM, Chiavacci LA, Cuberes MT. Nanostructural Arrangements and Surface Morphology on Ureasil-Polyether Films Loaded with Dexamethasone Acetate. NANOMATERIALS (BASEL, SWITZERLAND) 2021; 11:1362. [PMID: 34064153 PMCID: PMC8224347 DOI: 10.3390/nano11061362] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 05/14/2021] [Accepted: 05/15/2021] [Indexed: 12/11/2022]
Abstract
Ureasil-Poly(ethylene oxide) (ureasil-PEO500) and ureasil-Poly(propylene oxide) (u-PPO400) films, unloaded and loaded with dexamethasone acetate (DMA), have been investigated by carrying out atomic force microscopy (AFM), ultrasonic force microscopy (UFM), contact-angle, and drug release experiments. In addition, X-ray diffraction, small angle X-ray scattering, and infrared spectroscopy have provided essential information to understand the films' structural organization. Our results reveal that while in u-PEO500 DMA occupies sites near the ether oxygen and remains absent from the film surface, in u-PPO400 new crystalline phases are formed when DMA is loaded, which show up as ~30-100 nm in diameter rounded clusters aligned along a well-defined direction, presumably related to the one defined by the characteristic polymer ropes distinguished on the surface of the unloaded u-POP film; occasionally, larger needle-shaped DMA crystals are also observed. UFM reveals that in the unloaded u-PPO matrix the polymer ropes are made up of strands, which in turn consist of aligned ~180 nm in diameter stiffer rounded clusters possibly formed by siloxane-node aggregates; the new crystalline phases may grow in-between the strands when the drug is loaded. The results illustrate the potential of AFM-based procedures, in combination with additional physico-chemical techniques, to picture the nanostructural arrangements in polymer matrices intended for drug delivery.
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Affiliation(s)
- João Augusto Oshiro-Junior
- Department of Applied Mechanics and Project Engineering, Mining and Industrial Engineering School of Almaden, University of Castilla-La Mancha, Plaza Manuel Meca 1, 13400 Almadén, Spain; (J.A.O.-J.); (A.L.); (E.M.B.)
- Laboratory of Development and Characterization of Pharmaceutical Products, Department of Pharmacy, Center for Biological and Health Sciences, State University of Paraíba (UEPB), Campina Grande, Paraíba 58429-600, Brazil
| | - Angelo Lusuardi
- Department of Applied Mechanics and Project Engineering, Mining and Industrial Engineering School of Almaden, University of Castilla-La Mancha, Plaza Manuel Meca 1, 13400 Almadén, Spain; (J.A.O.-J.); (A.L.); (E.M.B.)
| | - Elena M. Beamud
- Department of Applied Mechanics and Project Engineering, Mining and Industrial Engineering School of Almaden, University of Castilla-La Mancha, Plaza Manuel Meca 1, 13400 Almadén, Spain; (J.A.O.-J.); (A.L.); (E.M.B.)
| | - Leila Aparecida Chiavacci
- Department of Drugs and Medicines, School of Pharmaceutical Sciences, São Paulo State University (UNESP), Highway Araraquara-Jaú, Araraquara 14800-903, Brazil;
| | - M. Teresa Cuberes
- Department of Applied Mechanics and Project Engineering, Mining and Industrial Engineering School of Almaden, University of Castilla-La Mancha, Plaza Manuel Meca 1, 13400 Almadén, Spain; (J.A.O.-J.); (A.L.); (E.M.B.)
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Zia F, Nazli ZIH, Zia KM, Aftab W, Tabasum S, Asrar M. Synthesis and characterization of hydroxyethyl cellulose copolymer modified polyurethane bionanocomposites. Int J Biol Macromol 2021; 179:345-352. [PMID: 33689773 DOI: 10.1016/j.ijbiomac.2021.03.029] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2020] [Revised: 03/03/2021] [Accepted: 03/05/2021] [Indexed: 11/28/2022]
Abstract
Bio based polyurethane nanocomposites (renewable thermosets) show a diverse range in properties, processing components and production of smart materials for health, food, and energy sectors. In this work, polyurethane nanocomposites based on isophorone diisocyanate (IPDI), and hydroxyl terminated-polybutadiene (HTPB) incorporating clay were modified using hydroxyethyl cellulose (HLAC) to be further assessed for thermal and mechanical properties. Elastomers samples were prepared by blending clay suspension and PU prepolymer to attain clay contents of 0.3, 0.5, and 1% (weight on dry basis) along with butane diol and HLAC chain extenders. Effect of nanofiller aggregation and dispersion on the thermal degradation and surface morphology of the bionanocomposites were studied. Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy/energy dispersive X-ray (SEM/EDX) and thermal gravimetric (TG) techniques were used to investigate the interactions among PU matrix, clay nanofillers, and HLAC. Mechanical testing indicated an increase in tensile strength and a decrease in elongation at break (%) by just adding 0.3 wt% clay. The thermal stability of the bionanocomposites was improved with the addition of clay. The results of the thermal and mechanical studies demonstrated the feasibility of the bionanocomposites as strong and thermally stable elastomers with low filler loading.
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Affiliation(s)
- Fatima Zia
- Department of Applied Chemistry, Government College University, Faisalabad 38030, Pakistan
| | - Zill-I-Huma Nazli
- Department of Chemistry, Government College Women University, Faisalabad 38000, Pakistan
| | - Khalid Mahmood Zia
- Department of Applied Chemistry, Government College University, Faisalabad 38030, Pakistan.
| | - Waseem Aftab
- College of Engineering, Peking University, Beijing 100871, China
| | - Shazia Tabasum
- Department of Applied Chemistry, Government College University, Faisalabad 38030, Pakistan
| | - Muhammad Asrar
- Department of Zoology, Government College University, Faisalabad 38030, Pakistan
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Gulmez F, Yercan A, Kocaaga B, Guner FS. pH-sensitive castor oil/PEG-based polyurethane films for drug delivery. J Drug Deliv Sci Technol 2021. [DOI: 10.1016/j.jddst.2020.102160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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4
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Prieto E, Cardiel MJ, Vispe E, Idoipe M, Garcia-Martin E, Fraile JM, Polo V, Mayoral JA, Pablo LE, Rodrigo MJ. Dexamethasone delivery to the ocular posterior segment by sustained-release Laponite formulation. ACTA ACUST UNITED AC 2020; 15:065021. [PMID: 32647098 DOI: 10.1088/1748-605x/aba445] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
This paper presents a novel nanoformulation for sustained-release delivery of dexamethasone (DEX) to the ocular posterior segment using a Laponite (LAP) carrier-DEX/LAP 1:10 w w-1 formulation; 10 mg ml-1. In vivo ocular feasibility and pharmacokinetics after intravitreal (IV) and suprachoroidal (SC) administration in rabbit eyes are compared against IV administration of a DEX solution (1 mg ml-1). Thirty rabbit eyes were injected with the DEX/LAP formulation (15 suprachoroid/15 intravitreous). Ophthalmological signs were monitored at day 1 and at weeks 1-4-12-24 post-administration. Three eyes per sample time point were used to quantify DEX concentration using high-performance liquid chromatography-mass spectrometry. The ocular tissues' pharmacokinetic parameters (lens, vitreous humour, choroid-retina unit and sclera) were studied. DEX/LAP was well tolerated under both administration methods. Peak intraocular DEX levels from the DEX/LAP were detected in the vitreous humour after both deliveries soon after administration. The vitreous area under the curve was significantly greater after both DEX/LAP deliveries (IV: 205 968.47; SC: 11 442.22 ng g-1 d-1) than after IV administration of the DEX solution (317.17 ng g-1 d-1). Intravitreal DEX/LAP delivery extended higher vitreous DEX levels up to week 24 (466.32 ± 311.15 ng g-1). With SC delivery, DEX levels were detectable in the choroid-retina unit (12.04 ± 20.85 ng g-1) and sclera (25.46 ± 44.09 ng g-1) up to week 24. This study demonstrated the intraocular feasibility of both SC and IV administration of the DEX/LAP formulation. The LAP increased the intraocular retention time of DEX when compared with conventional solutions. DEX/LAP could be considered a biocompatible and useful sustained-release formulation for treating posterior-pole eye diseases.
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Affiliation(s)
- Esther Prieto
- Ophthalmology Department, Miguel Servet University Hospital, Paseo Isabel la Católica 1-3, E-50009, Zaragoza, Spain. Aragon Institute for Health Research (IIS Aragon), GIMSO research group, University of Zaragoza (Spain), Avda. San Juan Bosco 13, Zaragoza E-50009, Spain
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Norouz F, Halabian R, Salimi A, Ghollasi M. A new nanocomposite scaffold based on polyurethane and clay nanoplates for osteogenic differentiation of human mesenchymal stem cells in vitro. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2019; 103:109857. [DOI: 10.1016/j.msec.2019.109857] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 05/12/2019] [Accepted: 06/02/2019] [Indexed: 01/08/2023]
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Safety study of intravitreal and suprachoroidal Laponite clay in rabbit eyes. Graefes Arch Clin Exp Ophthalmol 2018; 256:535-546. [DOI: 10.1007/s00417-017-3893-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Revised: 12/03/2017] [Accepted: 12/28/2017] [Indexed: 10/18/2022] Open
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Zhang J, Woodruff TM, Clark RJ, Martin DJ, Minchin RF. Release of bioactive peptides from polyurethane films in vitro and in vivo: Effect of polymer composition. Acta Biomater 2016; 41:264-72. [PMID: 27245428 DOI: 10.1016/j.actbio.2016.05.034] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Revised: 04/26/2016] [Accepted: 05/03/2016] [Indexed: 12/11/2022]
Abstract
UNLABELLED Thermoplastic polyurethanes (TPUs) are widely used in biomedical applications due to their excellent biocompatibility. Their role as matrices for the delivery of small molecule therapeutics has been widely reported. However, very little is known about the release of bioactive peptides from this class of polymers. Here, we report the release of linear and cyclic peptides from TPUs with different hard and soft segments. Solvent casting of the TPU at room temperature mixed with the different peptides resulted in reproducible efflux profiles with no evidence of drug degradation. Peptide release was dependent on the size as well as the composition of the TPU. Tecoflex 80A (T80A) showed more extensive release than ElastEon 5-325, which correlated with a degree of hydration. It was also shown that the composition of the medium influenced the rate and extent of peptide efflux. Blending the different TPUs allowed for better control of peptide efflux, especially the initial burst effect. Peptide-loaded TPU prolonged the plasma levels of the anti-inflammatory cyclic peptide PMX53, which normally has a plasma half-life of less than 30min. Using a blend of T80A and E5-325, therapeutic plasma levels of PMX53 were observed up to 9days following a single intraperitoneal implantation of the drug-loaded film. PMX53 released from the blended TPUs significantly inhibited B16-F10 melanoma tumor growth in mice demonstrating its bioactivity in vivo. This study provides important findings for TPU-based therapeutic peptide delivery that could improve the pharmacological utility of peptides as therapeutics. STATEMENT OF SIGNIFICANCE Therapeutic peptides can be highly specific and potent pharmacological agents, but are poorly absorbed and rapidly degraded in the body. This can be overcome by using a matrix that protects the peptide in vivo and promotes its slow release so that a therapeutic effect can be achieved over days or weeks. Thermoplastic polyurethanes are a versatile family of polymers that are biocompatible and used for medical implants. Here, the release of several peptides from a range of polyurethanes was shown to depend on the type of polymer used in the polyurethane. This is the first study to examine polyurethane blends for peptide delivery and shows that the rate and extent of peptide release can be fine-tuned using different hard and soft segment mixtures in the polymer.
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Affiliation(s)
- Jing Zhang
- School of Biomedical Sciences, University of Queensland, St Lucia, Queensland 4072, Australia
| | - Trent M Woodruff
- School of Biomedical Sciences, University of Queensland, St Lucia, Queensland 4072, Australia
| | - Richard J Clark
- School of Biomedical Sciences, University of Queensland, St Lucia, Queensland 4072, Australia
| | - Darren J Martin
- Australian Institute for Bioengineering and Nanotechnology, University of Queensland, St Lucia, Queensland 4072, Australia
| | - Rodney F Minchin
- School of Biomedical Sciences, University of Queensland, St Lucia, Queensland 4072, Australia.
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Jafarbeglou M, Abdouss M, Shoushtari AM, Jafarbeglou M. Clay nanocomposites as engineered drug delivery systems. RSC Adv 2016. [DOI: 10.1039/c6ra03942a] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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Rafiemanzelat F, Adli V, Mallakpour S. Effective preparation of clay/waterborne Azo-containing polyurethane nanocomposite dispersions incorporated anionic groups in the chain termini. Des Monomers Polym 2015. [DOI: 10.1080/15685551.2014.999459] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Affiliation(s)
- Fatemeh Rafiemanzelat
- Organic Polymer Chemistry Research Laboratory, Department of Chemistry, University of Isfahan, Isfahan 81746-73441, Islamic Republic of Iran
| | - Vahdat Adli
- Organic Polymer Chemistry Research Laboratory, Department of Chemistry, University of Isfahan, Isfahan 81746-73441, Islamic Republic of Iran
| | - Shadpour Mallakpour
- Organic Polymer Chemistry Research Laboratory, Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111, Islamic Republic of Iran
- Nanotechnology and Advanced Materials Institute, Isfahan University of Technology, Isfahan 84156-83111, Islamic Republic of Iran
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Stathokostopoulou C, Tarantili PA. Preparation, Characterization and Drug Release Studies from Poly(D,L-lactic acid)/organoclay Nanocomposite Films. JOURNAL OF MACROMOLECULAR SCIENCE PART A-PURE AND APPLIED CHEMISTRY 2014. [DOI: 10.1080/10601325.2014.864920] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Kawachi T, Matsuura Y, Iyoda F, Arakawa S, Okamoto M. Preparation and characterization of DNA/allophane composite hydrogels. Colloids Surf B Biointerfaces 2013; 112:429-34. [DOI: 10.1016/j.colsurfb.2013.08.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Revised: 07/05/2013] [Accepted: 08/08/2013] [Indexed: 10/26/2022]
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Fichter M, Baier G, Dedters M, Pretsch L, Pietrzak-Nguyen A, Landfester K, Gehring S. Nanocapsules generated out of a polymeric dexamethasone shell suppress the inflammatory response of liver macrophages. NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE 2013; 9:1223-34. [DOI: 10.1016/j.nano.2013.05.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2012] [Revised: 04/29/2013] [Accepted: 05/13/2013] [Indexed: 01/16/2023]
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Dawson JI, Oreffo ROC. Clay: new opportunities for tissue regeneration and biomaterial design. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2013; 25:4069-4086. [PMID: 23722321 DOI: 10.1002/adma.201301034] [Citation(s) in RCA: 198] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Revised: 04/04/2013] [Indexed: 06/02/2023]
Abstract
Seminal recent studies that have shed new light on the remarkable properties of clay interactions suggest unexplored opportunities for biomaterial design and regenerative medicine. Here, recent conceptual and technological developments in the science of clay interactions with biomolecules, polymers, and cells are examined, focusing on the implications for tissue engineering and regenerative strategies. Pioneering studies demonstrating the utility of clay for drug-delivery and scaffold design are reviewed and areas for future research and development highlighted.
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Affiliation(s)
- Jonathan I Dawson
- Institute of Developmental Sciences University of Southampton Southampton, UK.
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Babanejad N, Nikjeh MMA, Amini M, Dorkoosh FA. A nanoparticulate raloxifene delivery system based on biodegradable carboxylated polyurethane: Design, optimization, characterization, andin vitroevaluation. J Appl Polym Sci 2013. [DOI: 10.1002/app.39668] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Niloofar Babanejad
- Chemistry Department; Faculty of Science, Imam Khomeini International University; Qazvin Iran
| | | | - Mohsen Amini
- Department of Medicinal Chemistry; Faculty of Pharmacy, Tehran University of Medical Sciences; Tehran Iran
| | - Farid A. Dorkoosh
- Department of Pharmaceutics; Faculty of Pharmacy, Tehran University of Medical Sciences; Tehran Iran
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Da Silva GR, Da Silva-Cunha A, Vieira LC, Silva LM, Ayres E, Oréfice RL, Fialho SL, Saliba JB, Behar-Cohen F. Montmorillonite clay based polyurethane nanocomposite as substrate for retinal pigment epithelial cell growth. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2013; 24:1309-1317. [PMID: 23430334 DOI: 10.1007/s10856-013-4885-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2012] [Accepted: 02/04/2013] [Indexed: 06/01/2023]
Abstract
The subretinal transplantation of retinal pigment epithelial cells (RPE cells) grown on polymeric supports may have interest in retinal diseases affecting RPE cells. In this study, montmorillonite based polyurethane nanocomposite (PU-NC) was investigated as substrate for human RPE cell growth (ARPE-19 cells). The ARPE-19 cells were seeded on the PU-NC, and cell viability, proliferation and differentiation were investigated. The results indicated that ARPE-19 cells attached, proliferated onto the PU-NC, and expressed occludin. The in vivo ocular biocompatibility of the PU-NC was assessed by using the HET-CAM; and through its implantation under the retina. The direct application of the nanocomposite onto the CAM did not compromise the vascular tissue in the CAM surface, suggesting no ocular irritancy of the PU-NC film. The nanocomposite did not elicit any inflammatory response when implanted into the eye of rats. The PU-NC may have potential application as a substrate for RPE cell transplantation.
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Affiliation(s)
- Gisele Rodrigues Da Silva
- School of Pharmacy, Federal University of São João Del Rei, Av. Sebastião Gonçalves Coelho 400, Chanadour, Divinópolis, Minas Gerais 35500-296, Brazil.
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Chung JHY, Simmons A, Zeng Q, Poole-Warren LA. Effects of drug chemistry on the dispersion and release behaviour of polyurethane organosilicate nanocomposites. Eur Polym J 2013. [DOI: 10.1016/j.eurpolymj.2012.11.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Rodrigues LADS, Figueiras A, Veiga F, de Freitas RM, Nunes LCC, da Silva Filho EC, da Silva Leite CM. The systems containing clays and clay minerals from modified drug release: A review. Colloids Surf B Biointerfaces 2013; 103:642-51. [DOI: 10.1016/j.colsurfb.2012.10.068] [Citation(s) in RCA: 148] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2012] [Revised: 10/29/2012] [Accepted: 10/31/2012] [Indexed: 11/29/2022]
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Pinto FCH, Da Silva-Cunha Junior A, Oréfice RL, Ayres E, Andrade SP, Lima LDC, Moura SAL, Da Silva GR. Controlled release of triamcinolone acetonide from polyurethane implantable devices: application for inhibition of inflammatory-angiogenesis. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2012; 23:1431-1445. [PMID: 22466817 DOI: 10.1007/s10856-012-4615-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2011] [Accepted: 03/08/2012] [Indexed: 05/31/2023]
Abstract
The purpose of this study was to develop triamcinolone acetonide-loaded polyurethane implants (TA PU implants) for the local treatment of different pathologies including arthritis, ocular and neuroinflammatory disorders. The TA PU implants were characterized by FTIR, SAXS and WAXS. The in vitro and in vivo release of TA from the PU implants was evaluated. The efficacy of TA PU implants in suppressing inflammatory-angiogenesis in a murine sponge model was demonstrated. FTIR results revealed no chemical interactions between polymer and drug. SAXS results indicated that the incorporation of the drug did not disturb the polymer morphology. WAXS showed that the crystalline nature of the TA was preserved after incorporation into the PU. The TA released from the PU implants efficiently inhibited the inflammatory-angiogenesis induced by sponge discs in an experimental animal model. Finally, TA PU implants could be used as local drug delivery systems because of their controlled delivery of TA.
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Affiliation(s)
- Flávia Carmo Horta Pinto
- School of Pharmacy, Federal University of São João Del Rei, Chanadour, Divinópolis, Minas Gerais, Brazil
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Anadão P, Wiebeck H, Valenzuela-Díaz FR. Panorama da Pesquisa Acadêmica Brasileira em Nanocompósitos Polímero/Argila e Tendências para o Futuro. POLIMEROS 2011. [DOI: 10.1590/s0104-14282011005000069] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A pesquisa em nanocompósitos polímero/argila foi iniciada pela Toyota no final dos anos 80. A partir deste marco, a comunidade científica mundial voltou sua atenção para este tipo de material graças às propriedades mecânicas, químicas e térmicas avançadas em comparação com os compósitos tradicionais. Não foi diferente no Brasil, tal atenção pode ser comprovada pelos inúmeros trabalhos científicos sobre nanocompósitos que começaram a despontar no início do século XXI. Assim, o presente artigo objetiva, após discorrer sobre as definições que concernem nanocompósitos polímero/argila, apresentar as pesquisas científicas brasileiras em nanocompósitos de polímeros de uso geral, de polímeros de engenharia e de outros tipos de polímeros, relacionando-os com o método de produção empregado, morfologia final e propriedades decorrentes da formação de nanocompósitos. Por fim, o mapa da pesquisa brasileira em nanocompósitos polímero/argila e sua perspectiva para o futuro são apresentados.
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Polyurethanes as supports for human retinal pigment epithelium cell growth. Int J Artif Organs 2011; 34:198-209. [PMID: 21374562 DOI: 10.5301/ijao.2011.6398] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/02/2010] [Indexed: 11/20/2022]
Abstract
PURPOSE The transplant of retinal pigment epithelium (RPE) cells on supports may well be an effective therapeutic approach to improve the visual results of patients with age-related macular degeneration. In this study, two biodegradable polyurethanes were investigated as supports for human RPE cells (ARPE-19). METHODS Polyurethane aqueous dispersions based on poly(caprolactone) and/or poly(ethylene glycol) as soft segments, and isophorone diisocyanate and hydrazine as hard segments were prepared. Polyurethane films were produced by casting the dispersions and allowing them to dry at room temperature for one week. The ARPE-19 cells were seeded onto the polyurethane films and they were investigated as supports for in vitro adhesion, proliferation, and uniform distribution of differentiated ARPE-19 cells. Additionally, the in vivo ocular biocompatibility of the polyurethane films was evaluated. RESULTS The RPE adhered to and proliferated onto the polyurethane supports, thus establishing cell-PUD surface interactions. Upon confluence, the cells formed an organized monolayer, exhibited a polygonal appearance, and displayed actin filaments which ran along the upper cytoplasm. At 15 days of seeding, the occluding expression was confirmed between adjacent cells, representing the barrier functionality of epithelial cells on polymeric surfaces and the establishment of cell-cell interactions. Results from the in vivo study indicated that polyurethanes exhibited a high degree of short-term intraocular biocompatibility. CONCLUSIONS Biodegradable polyurethane films display the proper mechanical properties for an easy transscleral-driven subretinal implantation and can be considered as biocompatible supports for a functional ARPE-19 monolayer.
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Moura SA, Lima LDC, Andrade SP, Silva-Cunha Junior AD, Órefice RL, Ayres E, Da Silva GR. Local Drug Delivery System: Inhibition of Inflammatory Angiogenesis in a Murine Sponge Model by Dexamethasone-Loaded Polyurethane Implants. J Pharm Sci 2011; 100:2886-95. [DOI: 10.1002/jps.22497] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2010] [Revised: 10/25/2010] [Accepted: 01/03/2011] [Indexed: 11/07/2022]
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Chung JHY, Simmons A, Poole-Warren LA. Non-degradable polymer nanocomposites for drug delivery. Expert Opin Drug Deliv 2011; 8:765-78. [DOI: 10.1517/17425247.2011.574123] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Biodegradable polyurethane nanocomposites containing dexamethasone for ocular route. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2011. [DOI: 10.1016/j.msec.2010.10.019] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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