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Grubbs JB, Arnold RM, Roy A, Durie K, Bilbrey JA, Gao J, Locklin J. Degradable Polycaprolactone and Polylactide Homopolymer and Block Copolymer Brushes Prepared by Surface-Initiated Polymerization with Triazabicyclodecene and Zirconium Catalysts. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:10183-10189. [PMID: 26317405 DOI: 10.1021/acs.langmuir.5b02093] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Surface-initiated ring-opening polymerization (SI-ROP) of polycaprolactone (PCL) and polylactide (PLA) polymer brushes with controlled degradation rates were prepared on oxide substrates. PCL brushes were polymerized from hydroxyl-terminated monolayers utilizing triazabicyclodecene (TBD) as the polymerization catalyst. A consistent brush thickness of 40 nm could be achieved with a reproducible unique crystalline morphology. The organocatalyzed PCL brushes were chain extended using lactide in the presence of zirconium n-butoxide to successfully grow PCL/PLA block copolymer (PCL-b-PLA) brushes with a final thickness of 55 nm. The degradation properties of "grafted from" PCL brush and the PCL-b-PLA brush were compared to "grafted to" PCL brushes, and we observed that the brush density plays a major role in degradation kinetics. Solutions of methanol/water at pH 14 were used to better solvate the brushes and increase the kinetics of degradation. This framework enables a control of degradation that allows for the precise removal of these coatings.
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Affiliation(s)
- Joe B Grubbs
- Department of Chemistry, College of Engineering, and the Center for Nanoscale Science and Engineering, University of Georgia , Athens, Georgia 30602, United States
- Meredian Holdings Group - MHG, 140 Industrial Boulevard, Bainbridge, Georgia 39817, United States
| | - Rachelle M Arnold
- Meredian Holdings Group - MHG, 140 Industrial Boulevard, Bainbridge, Georgia 39817, United States
| | - Anandi Roy
- Department of Chemistry, College of Engineering, and the Center for Nanoscale Science and Engineering, University of Georgia , Athens, Georgia 30602, United States
| | - Karson Durie
- Department of Chemistry, College of Engineering, and the Center for Nanoscale Science and Engineering, University of Georgia , Athens, Georgia 30602, United States
| | - Jenna A Bilbrey
- Department of Chemistry, College of Engineering, and the Center for Nanoscale Science and Engineering, University of Georgia , Athens, Georgia 30602, United States
| | - Jing Gao
- Department of Chemistry, College of Engineering, and the Center for Nanoscale Science and Engineering, University of Georgia , Athens, Georgia 30602, United States
| | - Jason Locklin
- Department of Chemistry, College of Engineering, and the Center for Nanoscale Science and Engineering, University of Georgia , Athens, Georgia 30602, United States
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Novel method to graft chitosan on the surface of hydroxyapatite nanoparticles via “click” reaction. Chem Res Chin Univ 2014. [DOI: 10.1007/s40242-014-4166-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Shokrollahi P, Mehmanchi M, Atai M, Omidian H, Shokrolahi F. Effect of interface on mechanical properties and biodegradation of PCL HAp supramolecular nano-composites. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2014; 25:23-35. [PMID: 24030697 DOI: 10.1007/s10856-013-5039-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2013] [Accepted: 08/27/2013] [Indexed: 06/02/2023]
Abstract
This research explores the correlation between the structural properties of supramolecular biocomposites and their mechanical strength. Hybrid biocomposites composed of surface-modified hydroxyapatite nano-particles and supramolecular polycaprolactone (SP PCL), were prepared at different compositions, and their mechanical, thermal and viscoelastic properties as well as biodegradability, biocompatibility and cytotoxicity were evaluated in vitro. The results were compared with those for SP PCL/naked hydroxyapatite nano-composites. We show that surface modification of hydroxyapatite nanoparticles resulted in outstanding improvement of tensile strength and modulus up to 3.6 and 2.2-fold, respectively. At above 10 wt% HAp and 20 wt% HApUPy, heterogeneous nano-composites with inferior mechanical properties were obtained. Based on rheological (in steady shear mode) and small/wide angle X-ray scattering measurements, unusual improved mechanical properties were ascribed to the formation of supramolecular clusters around nanoparticles. In-vitro degradation of the supramolecular nano-composites was also studied to investigate the overall product biodegradation as well as toxicity of the degradation product(s).
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Affiliation(s)
- Parvin Shokrollahi
- Department of Biomaterials, Iran Polymer and Petrochemical Institute, P.O. Box 14965/159, Tehran, Iran,
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Penczek S, Kaluzynski K, Pretula J. Bisphosphonate units in the main polymer chain: The first synthesis. ACTA ACUST UNITED AC 2012. [DOI: 10.1002/pola.26083] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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