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Chen Y, Lan Q. Experimental evidence for immiscibility of enantiomeric polymers: Phase separation of high-molecular-weight poly(ʟ-lactide)/poly(ᴅ-lactide) blends and its impact on hindering stereocomplex crystallization. Int J Biol Macromol 2024; 260:129459. [PMID: 38232890 DOI: 10.1016/j.ijbiomac.2024.129459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 01/01/2024] [Accepted: 01/11/2024] [Indexed: 01/19/2024]
Abstract
Although polymers tend not to mix, it remains challenging to characterize the immiscibility of enantiomeric poly(ʟ-lactide) (PLLA) and poly(ᴅ-lactide) (PDLA), particularly with equivalent and high molecular weight (high MW), which frustratingly disfavors the exclusive stereocomplexation. By introducing a random copolymer (PLC) of ʟ-lactide and caprolactone to form binary blends with PLLA and PDLA, the phase behavior of high-MW PLLA/PDLA blends was investigated mainly by using differential scanning calorimetry (DSC) and atomic force microscopy (AFM). DSC results showed that PLLA/PLC blends exhibited a single glass transition temperature (Tg), which depended on the blending ratio and precisely corresponded with the theoretical values calculated from the Fox equation. In comparison, PDLA/PLC blends showed composition-dependent heat-capacity increment at two unchanged Tg values of pure PLC and PDLA. AFM observation revealed that PLC is completely miscible with PLLA at high MW but is immiscible with PDLA, logically suggesting immiscibility of high-MW PLLA and PDLA. Moreover, AFM results demonstrated that high-MW PLLA/PDLA blends exhibited spherical droplets in asymmetric blends and bicontinuous interpenetrating worm-like patterns in symmetric counterparts, showing distinct and well-defined interfaces, confirming the microphase separation. Additionally, different MWs fundamentally led to significant differences in miscibility, which consequently affected the crystallization behaviors of PLLA/PDLA blends. This work provides evidence for (im)miscibility and its crucial impact on the crystallization of PLLA/PDLA blends and has important implications for understanding the stereocomplexation of polymers.
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Affiliation(s)
- Yujing Chen
- Biomaterials Research Center, School of Biomedical Engineering, Southern Medical University, Guangzhou 510515, China
| | - Qiaofeng Lan
- Biomaterials Research Center, School of Biomedical Engineering, Southern Medical University, Guangzhou 510515, China.
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2
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Yamazaki S, Harada M, Watanabe Y, Lang R, Kato T, Haba O, Fukushima K, Kumaki J. Crystallization of Star-Shaped Poly(l-lactide)s with Arm Chains Aligned in the Same Direction in Two-Dimensional Crystals in a Langmuir Monolayer. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:5486-5494. [PMID: 37026866 DOI: 10.1021/acs.langmuir.3c00199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Polylactide (PLA) crystallizes to form extended-chain crystals in a Langmuir monolayer because crystallization is accelerated on the water surface. This is a unique situation where chain packing can be analyzed by simply measuring the lamellar thickness. Herein, star-shaped poly(l-lactide)s (PLLAs) with 2-12 arms were synthesized through the polymerization of l-lactide with various polyols as initiators, and their crystallization behavior in a monolayer was studied via atomic force microscopy. The PLLAs comprising 2-4 arms crystallized with all arms aligned in the same direction and being folded at the central polyol unit. Meanwhile, the PLLAs comprising 6 and 12 arms crystallized with both halves of the arms extended from the center to the opposite directions, most likely due to the steric hindrance of the crowded arms. Considering that the PLLAs crystallized from a once-formed condensed amorphous state during compression, they have a strong tendency to crystallize with the arms aligned in the same direction. The crystallization rate of star-shaped PLAs is known to reduce compared with that of a linear PLA even if the number of arms is as few as 2. This should be closely related to the unique crystallization behavior of the star-shaped PLLAs with the arms aligned in the same direction.
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Affiliation(s)
- Shota Yamazaki
- Department of Organic Materials Science, Graduate School of Organic Materials Science, Yamagata University, Yonezawa, Yamagata 992-8510, Japan
| | - Mahoko Harada
- Department of Organic Materials Science, Faculty of Engineering and Science, Yamagata University, Yonezawa, Yamagata 992-8510, Japan
| | - Yuya Watanabe
- Department of Chemistry and Biotechnology, School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Rongjian Lang
- Department of Chemistry and Biotechnology, School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Takashi Kato
- Department of Chemistry and Biotechnology, School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Osamu Haba
- Department of Organic Materials Science, Graduate School of Organic Materials Science, Yamagata University, Yonezawa, Yamagata 992-8510, Japan
| | - Kazuki Fukushima
- Department of Chemistry and Biotechnology, School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan
- Japan Science and Technology Agency (JST), PRESTO, Honcho, Kawaguchi, Saitama 332-0012, Japan
| | - Jiro Kumaki
- Department of Organic Materials Science, Graduate School of Organic Materials Science, Yamagata University, Yonezawa, Yamagata 992-8510, Japan
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Das A, Noack S, Schlaad H, Reiter G, Reiter R. Exploring Pathways to Equilibrate Langmuir Polymer Films. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:8184-8192. [PMID: 32569470 DOI: 10.1021/acs.langmuir.0c01268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Focusing on the phase-coexistence region in Langmuir films of poly(l-lactide), we investigated changes in nonequilibrated morphologies and the corresponding features of the isotherms induced by different experimental pathways of lateral compression and expansion. In this coexistence region, the surface pressure Π was larger than the expected equilibrium value and was found to increase upon compression, i.e., exhibited a nonhorizontal plateau. As shown earlier by using microscopic techniques [Langmuir 2019, 35, 6129-6136], in this plateau region, well-ordered mesoscopic clusters coexisted with a surrounding matrix phase. We succeeded in reducing Π either by slowing down the rate of compression or through increasing the waiting time after stopping the movement of the barriers, which allowed for relaxations in the coexistence region. Intriguingly, the most significant pressure reduction was observed when recompressing a film that had already been compressed and expanded, if the recompression was started from an area value smaller than the one anticipated for the onset of the coexistence region. This observation suggests a "self-seeding" behavior, i.e., pre-existing nuclei allowed to circumvent the nucleation step. The decrease in Π was accompanied by a transformation of the initially formed metastable mesoscopic clusters into a thermodynamically favored filamentary morphology. Our results demonstrate that it is practically impossible to obtain fully equilibrated coexisting phases in a Langmuir polymer film, neither under conditions of extremely slow continuous compression nor for long waiting times at a constant area in the coexistence region which allow for reorganization.
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Affiliation(s)
- Abhijna Das
- Institute of Physics, University of Freiburg, Hermann-Herder-Str. 3, Freiburg 79104, Germany
- Freiburg Center for Interactive Materials and Bioinspired Technologies (FIT), University of Freiburg, Georges-Köhler-Allee 105, Freiburg 79110, Germany
| | - Sebastian Noack
- Institute of Chemistry, University of Potsdam, Karl-Liebknecht Str. 24-25, Potsdam 14476, Germany
| | - Helmut Schlaad
- Institute of Chemistry, University of Potsdam, Karl-Liebknecht Str. 24-25, Potsdam 14476, Germany
| | - Günter Reiter
- Institute of Physics, University of Freiburg, Hermann-Herder-Str. 3, Freiburg 79104, Germany
- Freiburg Center for Interactive Materials and Bioinspired Technologies (FIT), University of Freiburg, Georges-Köhler-Allee 105, Freiburg 79110, Germany
| | - Renate Reiter
- Institute of Physics, University of Freiburg, Hermann-Herder-Str. 3, Freiburg 79104, Germany
- Freiburg Center for Interactive Materials and Bioinspired Technologies (FIT), University of Freiburg, Georges-Köhler-Allee 105, Freiburg 79110, Germany
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Iwashima K, Yamamoto T, Tezuka Y, Kumaki J. Self-Assembly of Linear and Cyclic Polylactide Stereoblock Copolymers with a Parallel and Antiparallel Chain Arrangement Distinguishing Their Directions on a Water Surface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:6216-6221. [PMID: 32407100 DOI: 10.1021/acs.langmuir.0c00769] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The self-assembly of molecules into a well-ordered structure is one of the most important processes in fabricating sophisticated materials. Here, we show that polymer chains can be self-assembled, distinguishing their direction (parallel or antiparallel), and could be a new useful scaffold for self-assembly in a controlled direction. The system that was used was a stereocomplex (SC) formation of linear and cyclic polylactide (PLA) stereoblock copolymers with a parallel and antiparallel chain arrangement in a Langmuir monolayer. The linear and cyclic stereoblock copolymers with a parallel arrangement formed a well-ordered lamellar SC in the first and second layers upon compression, but the linear and cyclic stereoblock copolymers with an antiparallel arrangement did not form a first-layer lamella and instead formed only the second-layer lamella. These results were only rationally explained by assuming that the enantiomeric PLA chains selectively assembled in a parallel direction, not in an antiparallel direction, in the SC. A simple polymer chain could be self-assembled, distinguishing the direction without a specific interaction group in it.
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Affiliation(s)
- Kenta Iwashima
- Department of Polymer Science and Engineering, Graduate School of Science and Engineering, Yamagata University, Yonezawa, Yamagata 992-8510, Japan
| | - Takuya Yamamoto
- Division of Applied Chemistry, Faculty of Engineering, Hokkaido University, Sapporo, Hokkaido 060-8628, Japan
- Department of Organic and Polymeric Materials, Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8552, Japan
| | - Yasuyuki Tezuka
- Department of Organic and Polymeric Materials, Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8552, Japan
| | - Jiro Kumaki
- Department of Organic Materials Science, Graduate School of Organic Materials Science, Yamagata University, Yonezawa, Yamagata 992-8510, Japan
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Liu J, Qi X, Feng Q, Lan Q. Suppression of Phase Separation for Exclusive Stereocomplex Crystallization of a High-Molecular-Weight Racemic Poly(l-lactide)/Poly(d-lactide) Blend from the Glassy State. Macromolecules 2020. [DOI: 10.1021/acs.macromol.0c00112] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- Jingqun Liu
- School of Biomedical Engineering, Southern Medical University, Guangzhou 510515, China
| | - Xinliang Qi
- School of Biomedical Engineering, Southern Medical University, Guangzhou 510515, China
| | - Qianjin Feng
- School of Biomedical Engineering, Southern Medical University, Guangzhou 510515, China
| | - Qiaofeng Lan
- Biomaterials Research Center, School of Biomedical Engineering, Southern Medical University, Guangzhou 510515, China
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Extended-chain crystallization and stereocomplex formation of polylactides in a Langmuir monolayer. Polym J 2020. [DOI: 10.1038/s41428-020-0312-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Tsuji H, Nakayama K, Arakawa Y. Synthesis and stereocomplex formation of enantiomeric alternating copolymers with two types of chiral centers, poly(lactic acid- alt-2-hydroxybutanoic acid)s. RSC Adv 2020; 10:39000-39007. [PMID: 35518423 PMCID: PMC9057339 DOI: 10.1039/d0ra08351h] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 02/11/2022] [Accepted: 10/01/2020] [Indexed: 11/21/2022] Open
Abstract
Stereocomplex (SC) formation was reported for the first time for enantiomeric alternating copolymers consisting of repeating units with two types of chiral centers, poly(lactic acid-alt-2-hydroxybutanoic acid)s [P(LA-alt-2HB)s]. l,l-Configured poly(l-lactic acid-alt-l-2-hydroxybutanoic acid) [P(LLA-alt-l-2HB)] and d,d-configured poly(d-lactic acid-alt-d-2-hydroxybutanoic acid) [P(DLA-alt-d-2HB)] were amorphous. Blends of P(LLA-alt-l-2HB) and P(DLA-alt-d-2HB) were crystallizable and showed typical SC-type wide-angle X-ray diffraction profiles similar to those reported for stereocomplexed blends of poly(l-lactic acid) and poly(d-lactic acid) homopolymers and of poly(l-2-hydroxybutanoic acid) and poly(d-2-hydroxybutanoic acid) homopolymers, and of l,l-configured poly(l-lactic acid-co-l-2-hydroxybutanoic acid) [P(LLA-co-l-2HB)] and d,d-configured poly(d-lactic acid-co-d-2-hydroxybutanoic acid) [P(DLA-co-d-2HB)] random copolymers. The melting temperature values and melting enthalpy values at 100% crystallinity for stereocomplexed solvent-evaporated and precipitated P(LLA-alt-l-2HB)/P(DLA-alt-d-2HB) blends were correspondingly 187.5 and 187.9 °C, and 98.1 and 91.8 J g−1. Enantiomeric polymer blending of P(LLA-alt-l-2HB) and P(DLA-alt-d-2HB) can confer crystallizability by stereocomplexation and the biodegradable materials with a wide variety of physical properties and biodegradability are highly expected to be prepared by synthesis of alternating copolymers of various combinations of two types of chiral α-substituted 2-hydroxyalkanoic acid monomers and their SC crystallization. Stereocomplex formation was reported for alternating copolymers of chiral α-substituted 2-hydroxyalkanoic acids which can be utilized for preparation of biodegradable materials with a variety of physical properties and biodegradability.![]()
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Affiliation(s)
- Hideto Tsuji
- Department of Applied Chemistry and Life Science
- Graduate School of Engineering
- Toyohashi University of Technology
- Toyohashi
- Japan
| | - Kazuya Nakayama
- Department of Applied Chemistry and Life Science
- Graduate School of Engineering
- Toyohashi University of Technology
- Toyohashi
- Japan
| | - Yuki Arakawa
- Department of Applied Chemistry and Life Science
- Graduate School of Engineering
- Toyohashi University of Technology
- Toyohashi
- Japan
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Das A, El-Tawargy AS, Khechine E, Noack S, Schlaad H, Reiter G, Reiter R. Controlling Nucleation in Quasi-Two-Dimensional Langmuir Poly(l-lactide) Films through Variation of the Rate of Compression. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:6129-6136. [PMID: 30998851 DOI: 10.1021/acs.langmuir.9b00619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We studied morphological changes in a quasi-two-dimensional Langmuir film of low molar mass poly(l-lactide) upon increasing the surface density, starting from randomly distributed molecules to a homogeneous monolayer of closely packed molecules, followed by nucleation and growth of mesoscopic, three-dimensional clusters from an overcompressed monolayer. The corresponding nucleation density of mesoscopic clusters within the monolayer can be tailored through variation of the rate of compression. For a given surface density and temperature, the nucleation probability was found to increase linearly with the rate of compression, allowing to adjust the density of mesoscopic clusters over nearly 2 orders of magnitude.
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Affiliation(s)
- Abhijna Das
- Institute of Physics , University of Freiburg , Hermann-Herder-Str. 3 , Freiburg 79104 , Germany
- Freiburg Center for Interactive Materials and Bioinspired Technologies (FIT) , University of Freiburg , Georges-Köhler-Allee 105 , Freiburg 79110 , Germany
| | - Ahmed S El-Tawargy
- Department of Physics, Faculty of Science , Damietta University , El-Kafrawy Street , Damietta 34517 , Egypt
| | - Emna Khechine
- Institute of Physics , University of Freiburg , Hermann-Herder-Str. 3 , Freiburg 79104 , Germany
- Freiburg Center for Interactive Materials and Bioinspired Technologies (FIT) , University of Freiburg , Georges-Köhler-Allee 105 , Freiburg 79110 , Germany
| | - Sebastian Noack
- Institute of Chemistry , University of Potsdam , Karl-Liebknecht-Str. 24-25 , Potsdam 14476 , Germany
| | - Helmut Schlaad
- Institute of Chemistry , University of Potsdam , Karl-Liebknecht-Str. 24-25 , Potsdam 14476 , Germany
| | - Günter Reiter
- Institute of Physics , University of Freiburg , Hermann-Herder-Str. 3 , Freiburg 79104 , Germany
- Freiburg Center for Interactive Materials and Bioinspired Technologies (FIT) , University of Freiburg , Georges-Köhler-Allee 105 , Freiburg 79110 , Germany
| | - Renate Reiter
- Institute of Physics , University of Freiburg , Hermann-Herder-Str. 3 , Freiburg 79104 , Germany
- Freiburg Center for Interactive Materials and Bioinspired Technologies (FIT) , University of Freiburg , Georges-Köhler-Allee 105 , Freiburg 79110 , Germany
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10
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Nakajima H, Dijkstra P, Loos K. The Recent Developments in Biobased Polymers toward General and Engineering Applications: Polymers that are Upgraded from Biodegradable Polymers, Analogous to Petroleum-Derived Polymers, and Newly Developed. Polymers (Basel) 2017; 9:polym9100523. [PMID: 30965822 PMCID: PMC6418730 DOI: 10.3390/polym9100523] [Citation(s) in RCA: 154] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 09/17/2017] [Accepted: 09/18/2017] [Indexed: 11/23/2022] Open
Abstract
The main motivation for development of biobased polymers was their biodegradability, which is becoming important due to strong public concern about waste. Reflecting recent changes in the polymer industry, the sustainability of biobased polymers allows them to be used for general and engineering applications. This expansion is driven by the remarkable progress in the processes for refining biomass feedstocks to produce biobased building blocks that allow biobased polymers to have more versatile and adaptable polymer chemical structures and to achieve target properties and functionalities. In this review, biobased polymers are categorized as those that are: (1) upgrades from biodegradable polylactides (PLA), polyhydroxyalkanoates (PHAs), and others; (2) analogous to petroleum-derived polymers such as bio-poly(ethylene terephthalate) (bio-PET); and (3) new biobased polymers such as poly(ethylene 2,5-furandicarboxylate) (PEF). The recent developments and progresses concerning biobased polymers are described, and important technical aspects of those polymers are introduced. Additionally, the recent scientific achievements regarding high-spec engineering-grade biobased polymers are presented.
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Affiliation(s)
- Hajime Nakajima
- Macromolecular Chemistry and New Polymeric Materials, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands.
| | - Peter Dijkstra
- Macromolecular Chemistry and New Polymeric Materials, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands.
| | - Katja Loos
- Macromolecular Chemistry and New Polymeric Materials, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands.
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11
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Abstract
Upon blending enantiomeric poly(l-lactide) [i.e., poly(l-lactic acid) (PLLA)] and poly(d-lactide) (PDLA) [i.e., poly(d-lactic acid) (PDLA)] or synthesis of stereo block poly(lactide) [i.e., poly(lactic acid) (PLA)], a stereocomplex (SC) is formed. PLA SC has a higher melting temperature (or heat resistance), mechanical performance, and hydrolysis-resistance compared to those of neat PLLA and PDLA. Because of such effects, PLA SC has been extensively studied in terms of biomedical and pharmaceutical applications as well as commodity, industrial, and environmental applications. Stereocomplexation stabilizes and strengthens PLA-based hydrogel or nanoparticles for biomedical applications. Stereocomplexation increases the barrier property of PLA-based materials and thereby prolongs drug release from PLA based materials. In addition, PLA SC is attracting significant attention because it can act as a nucleating agent for the widely used biobased polymer PLLA and thereby the heat resistance of PLLA-based materials can be enhanced. Interestingly, a wide variety of SCs other than PLA SC are found to have been formed in the enantiomeric substituted PLA blends and stereo block substituted PLA polymers. In the present review article, a decade of progress in investigation of PLA SCs is summarized.
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Affiliation(s)
- Hideto Tsuji
- Department of Environmental and Life Sciences, Graduate School of Engineering, Toyohashi University of Technology, Tempaku-cho, Toyohashi, Aichi 441-8580, Japan.
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Tsuji H. WITHDRAWN: PLA Stereocomplexes: A Decade of Progress. Adv Drug Deliv Rev 2016:S0169-409X(16)30009-6. [PMID: 26785171 DOI: 10.1016/j.addr.2015.12.025] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Accepted: 12/31/2015] [Indexed: 12/16/2022]
Abstract
This article has been withdrawn at the request of the author(s) and/or editor. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.
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Affiliation(s)
- Hideto Tsuji
- Department of Environmental and Life Sciences, Graduate School of Engineering, Toyohashi University of Technology, Tempaku-cho, Toyohashi, Aichi 441-8580, Japan.
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Mechanical and thermal property characterization of poly-l-lactide (PLLA) scaffold developed using pressure-controllable green foaming technology. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2015; 49:612-622. [PMID: 25686990 DOI: 10.1016/j.msec.2015.01.025] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Revised: 12/05/2014] [Accepted: 01/06/2015] [Indexed: 02/04/2023]
Abstract
Poly-l-lactide (PLLA) is one of the most promising biological materials used for tissue engineering scaffolds (TES) because of their excellent biodegradability and tenability. Here, microcellular PLLA foams were fabricated by pressure-controllable green foaming technology. Scanning electron microscopy (SEM), dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC), wide angle X-ray diffraction measurement (WAXRD), thermogravimetric (TG) analysis, reflection-Fourier transform infrared (FTIR) analysis, enzymatic degradation study and MTT assay were used to analyze the scaffolds' morphologies, structures and crystallinities, mechanical and biodegradation properties, as well as their cytotoxicity. The results showed that PLLA foams with pore sizes from 8 to 103μm diameters were produced when the saturation pressure decreased from 7.0 to 4.0MPa. Through a combination of StepScan DSC (SSDSC) and WAXRD approaches, it was observed in PLLA foams that the crystallinity, highly-oriented metastable state and rigid amorphous phase increased with the increasing foaming pressure. It was also found that both the glass transition temperature and apparent enthalpy of PLLA significantly increased after the foaming process, which suggested that the changes of microcellular structure could provide PLLA scaffolds better thermal stability and elasticity. Moreover, MTT assessments suggested that the smaller pore size should benefit cell attachment and growth in the scaffold. The results of current work will give us better understanding of the mechanisms involved in structure and property changes of PLLA at the molecular level, which enables more possibilities for the design of PLLA scaffold to satisfy various requirements in biomedical and green chemical applications.
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Hou X, Li Q, Cao A. In Situ Aggregates of Enantiomeric Poly(styrene)-block
-Poly(lactide) Diblock Copolymers via Stereocomplexation in a Non-selective Solvent. MACROMOL CHEM PHYS 2013. [DOI: 10.1002/macp.201300216] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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15
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Lu D, Duan P, Liu T, Li J, Li T, Lei Z. Synthesis and characterization of biodegradable linear-hyperbranched barbell-like poly(ethylene glycol)-supported poly(lactic-ran
-glycolic acid) copolymers through direct polycondensation. POLYM INT 2013. [DOI: 10.1002/pi.4494] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- Dedai Lu
- Key Laboratory of Polymer Materials of Gansu Province, Key Laboratory of Eco-Environment-Related Polymer Materials, Ministry of Education, College of Chemistry and Chemical Engineering; Northwest Normal University; Lanzhou 730070 People's Republic of China
| | - Pengxue Duan
- Key Laboratory of Polymer Materials of Gansu Province, Key Laboratory of Eco-Environment-Related Polymer Materials, Ministry of Education, College of Chemistry and Chemical Engineering; Northwest Normal University; Lanzhou 730070 People's Republic of China
| | - Tao Liu
- Key Laboratory of Polymer Materials of Gansu Province, Key Laboratory of Eco-Environment-Related Polymer Materials, Ministry of Education, College of Chemistry and Chemical Engineering; Northwest Normal University; Lanzhou 730070 People's Republic of China
| | - Juan Li
- Key Laboratory of Polymer Materials of Gansu Province, Key Laboratory of Eco-Environment-Related Polymer Materials, Ministry of Education, College of Chemistry and Chemical Engineering; Northwest Normal University; Lanzhou 730070 People's Republic of China
| | - Ting'e Li
- Key Laboratory of Polymer Materials of Gansu Province, Key Laboratory of Eco-Environment-Related Polymer Materials, Ministry of Education, College of Chemistry and Chemical Engineering; Northwest Normal University; Lanzhou 730070 People's Republic of China
| | - Ziqiang Lei
- Key Laboratory of Polymer Materials of Gansu Province, Key Laboratory of Eco-Environment-Related Polymer Materials, Ministry of Education, College of Chemistry and Chemical Engineering; Northwest Normal University; Lanzhou 730070 People's Republic of China
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Lu DD, Yang LQ, Shi XL, Chang Y, Zhang H, Lei ZQ. Synthesis and Characterization of Amphiphilic Biodegradable Hyperbranched-linear-hyperbranched Copolymers Based on PEG, PLA, and BHP. INT J POLYM MATER PO 2012. [DOI: 10.1080/00914037.2011.610069] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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17
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Tsuji H, Bouapao L. Stereocomplex formation between poly(L-lactic acid) and poly(D-lactic acid) with disproportionately low and high molecular weights from the melt. POLYM INT 2011. [DOI: 10.1002/pi.3219] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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18
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Wang T, Li D, Lu X, Khmaladze A, Han X, Ye S, Yang P, Xue G, He N, Chen Z. Single Lipid Bilayers Constructed on Polymer Cushion Studied by Sum Frequency Generation Vibrational Spectroscopy. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2011; 115:7613-7620. [PMID: 21712964 PMCID: PMC3122884 DOI: 10.1021/jp200546h] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Planar solid supported single lipid bilayers on mica, glass, or other inorganic surfaces have been widely used as models for cell membranes. To more closely mimic the cell membrane environment, soft hydrophilic polymer cushions were introduced between the hard inorganic substrate and the lipid bilayer to completely avoid the possible substrate-lipid interactions. In this article, sum frequency generation (SFG) vibrational spectroscopy was used to examine and compare single lipid bilayers assembled on the CaF(2) prism surface and on poly (L-lactic acid) (PLLA) cushion. By using asymmetric lipid bilayers composed of a hydrogenated 1,2-dipalmitoyl-sn-glycerol-3-phosphoglycerol (DPPG) leaflet and a deuterated 1,2-dipalmitoyl-(d62)-sn-glycerol-3-phosphoglycerol (d-DPPG) leaflet, it was shown that the DPPG lipid bilayers deposited on the CaF(2) and PLLA surfaces have similar structures. SFG has also been applied to investigate molecular interactions between an antimicrobial peptide Cecropin P(1) (CP1) and the lipid bilayers on the above two different surfaces. Similar results were again obtained. This research demonstrated that the hydrophilic PLLA cushion can serve as an excellent substrate to support single lipid bilayers. We believe that it can be an important cell membrane model for future studies on transmembrane proteins, for which the possible inorganic substrate-bilayer interactions may affect the protein structure or function.
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Affiliation(s)
- Ting Wang
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, 210096, China
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109, USA
| | - Dawei Li
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109, USA
- State Key Laboratory of Coordination Chemistry, Nanjing National Laboratory of Microstructure, Department of Polymer Science and Engineering, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210093, China
| | - Xiaolin Lu
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109, USA
| | | | - Xiaofeng Han
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109, USA
| | - Shuji Ye
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109, USA
| | - Pei Yang
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109, USA
| | - Gi Xue
- State Key Laboratory of Coordination Chemistry, Nanjing National Laboratory of Microstructure, Department of Polymer Science and Engineering, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210093, China
| | - Nongyue He
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, 210096, China
| | - Zhan Chen
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48109, USA
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Aiba N, Sasaki Y, Kumaki J. Strong compression rate dependence of phase separation and stereocomplexation between isotactic and syndiotactic poly(methyl methacrylate)s in a Langmuir monolayer observed by atomic force microscopy. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:12703-12708. [PMID: 20593815 DOI: 10.1021/la1018289] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The stereocomplex formation between isotactic and syndiotactic poly(methyl methacrylate) (it-PMMA, st-PMMA) in a Langmuir monolayer was studied by surface pressure-area isotherms and atomic force microscopy (AFM). We found that the stereocomplex formation was highly sensitive to the compression rate of the monolayer. At a normal compression rate of 0.5 mm/s provided by the moving barrier, the blend monolayer formed a clear phase separation of the it- and st-PMMA domains at 1 mN/m. Further compression to 15 mN/m resulted in a limited degree of stereocomplexation, mainly at the interface between the two domains. However, at a 1/50 slower compression rate of 0.01 mm/s, the blend did not form a clear phase separation at 1 mN/m and quantitatively formed a stereocomplex at 15 mN/m. This apparent immiscibility observed at the faster compression rate was found to be kinetically induced as a result of the rapid compression of the phase-separated mixture at the dilute state because it-PMMA and st-PMMA form expanded and condensed monolayer, respectively. On the other hand, at the slower compression rate, the blend formed a thermodynamically miscible phase, and as a result, the stereocomplex was quantitatively formed. This apparent phase separation of a mixed monolayer composed of an expanded and a condensed monolayer should be a common phenomenon for similar systems and might have caused misjudgment of the miscibility in such cases. The compression rate dependence should be carefully evaluated in order to determine the precise miscibility of blended monolayers in similar systems.
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Affiliation(s)
- Naoyuki Aiba
- Department of Polymer Science and Engineering, Faculty of Engineering, Yamagata University, Yonezawa, Yamagata 992-8510, Japan
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Tsuji H, Yamamoto S, Okumura A, Sugiura Y. Heterostereocomplexation between Biodegradable and Optically Active Polyesters as a Versatile Preparation Method for Biodegradable Materials. Biomacromolecules 2009; 11:252-8. [DOI: 10.1021/bm901113v] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Hideto Tsuji
- Department of Ecological Engineering, Faculty of Engineering, Toyohashi University of Technology, Tempaku-cho, Toyohashi, Aichi 441-8580, Japan
| | - Satomi Yamamoto
- Department of Ecological Engineering, Faculty of Engineering, Toyohashi University of Technology, Tempaku-cho, Toyohashi, Aichi 441-8580, Japan
| | - Ayaka Okumura
- Department of Ecological Engineering, Faculty of Engineering, Toyohashi University of Technology, Tempaku-cho, Toyohashi, Aichi 441-8580, Japan
| | - Yu Sugiura
- Department of Ecological Engineering, Faculty of Engineering, Toyohashi University of Technology, Tempaku-cho, Toyohashi, Aichi 441-8580, Japan
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21
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22
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Molecular recognition of Langmuir–Blodgett polymer films containing uracil groups. Colloids Surf A Physicochem Eng Asp 2008. [DOI: 10.1016/j.colsurfa.2008.01.020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Fukushima K, Chang YH, Kimura Y. Enhanced Stereocomplex Formation of Poly(L-lactic acid) and Poly(D-lactic acid) in the Presence of Stereoblock Poly(lactic acid). Macromol Biosci 2007; 7:829-35. [PMID: 17541929 DOI: 10.1002/mabi.200700028] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Stereoblock poly(lactic acid) (sb-PLA) is incorporated into a 1:1 polymer blend system of poly(L-lactic acid) (PLLA) and poly(D-lactic acid) (PDLA) that has a high molecular weight to study its addition effect on the stereocomplex (sc) formation of PLLA and PDLA. The ternary polymer blend films are first prepared by casting polymer solutions of sb-PLA, PLLA, and PDLA with different compositions. Upon increasing the content of sb-PLA in the blend films the sc crystallization is driven to a higher degree, while the formation of homo-chiral (hc) crystals is decreased. Lowering the molecular weight of the incorporated sb-PLA effectively increases the sc formation. Consequently, it is revealed that sb-PLA can work as a compatibilizer to improve the poor sc formation in the polymer blend of PLLA and PDLA.
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Affiliation(s)
- Kazuki Fukushima
- Department of Biomolecular Engineering, Kyoto Institute of Technology, Matsugasaki, Kyoto, 606-8585, Japan
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