Size-Controlled Nanomicelles of Poly(lactic acid)–Poly(ethylene glycol) Copolymers with a Multiblock Configuration

Somekawa, Shota; Masutani, Kazunari; Hsu, Yu‐I; Mahara, Atsushi; Kimura, Yoshiharu; Yamaoka, Tetsuji

doi:10.3390/polym7061177

Cited by 9 publications

(10 citation statements)

References 34 publications

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“…Particular interest has been directed towards the realization of objects with nanometer size which show unique physical properties and can be applied in many fields, from medicine to energy production [49,50]. Their size makes their characterization complicate and requires novel approaches.…”

Section: Discovery and Characterization Of New Materialsmentioning

confidence: 99%

Time Domain NMR in Polymer Science: From the Laboratory to the Industry

2019

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Highly controlled polymers and nanostructures are increasingly translated from the lab to the industry. Together with the industrialization of complex systems from renewable sources, a paradigm change in the processing of plastics and rubbers is underway, requiring a new generation of analytical tools. Here, we present the recent developments in time domain NMR (TD-NMR), starting with an introduction of the methods. Several examples illustrate the new take on traditional issues like the measurement of crosslink density in vulcanized rubber or the monitoring of crystallization kinetics, as well as the unique information that can be extracted from multiphase, nanophase and composite materials. Generally, TD-NMR is capable of determining structural parameters that are in agreement with other techniques and with the final macroscopic properties of industrial interest, as well as reveal details on the local homogeneity that are difficult to obtain otherwise. Considering its moderate technical and space requirements of performing, TD-NMR is a good candidate for assisting product and process development in several applications throughout the rubber, plastics, composites and adhesives industry.

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Section: Discovery and Characterization Of New Materialsmentioning

confidence: 99%

Time Domain NMR in Polymer Science: From the Laboratory to the Industry

2019

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“…The aforementioned aggregates are composed by semicrystalline hydrophobic PLLA blocks and they are smaller than PLA 6 –PEO 8 –PLA 6 , PLA 3 –PEO 8 –PLA 3 , and PLA 7 –PEO 3 –PPO 2 –PEO 3 –PLA 7 copolymers (40–70 wt % of PLA, 1.5–1.8 kg mol −1 ) aggregates ( N agg = 150–560 chains and M W agg = 8.1–11.0 × 10 6 kg mol −1 ). The more compacted PLLA aggregates are favorable by crystalline domains formation inside the core structure, while the aggregates composed by amorphous hydrophobic PLA blocks are not stabilized by crystallization process …”

Section: Resultsmentioning

confidence: 99%

Amphiphilic polylactide‐poly(ethylene oxide)‐poly(propylene oxide) block copolymers: Self‐assembly behavior and cell affinity

Loiola

Farias

Portugal

et al. 2018

J. Polym. Sci. Part A: Polym. Chem.

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Polylactide (PLA) is a biodegradable polyester recognized for its potential use as a biomedical material. Poly(ethylene oxide) (PEO) and copolymers based on PEO and poly(propylene oxide) (PPO) are biocompatible polyethers widely applied in the biomedical field, particularly as macromolecular nonionic surfactants. In this work, PLA blocks were attached to the PEO and to the PEO and PPO‐based triblock copolymer PEO–PPO–PEO, through ring‐opening polymerization of racemic lactide (rac‐LA) to obtain the amphiphilic triblock PLA–PEO–PLA and pentablock PLA–PEO–PPO–PEO–PLA copolymers containing hydrophilic/hydrophobic blocks with variable block mass ratios. The copolymers were evaluated for chemical composition, molar mass, and thermal properties, and they were used to prepare self‐assemble aggregates in water from tetrahydrofuran polymer solutions. The combination of scattering light experiments and microscopy techniques revealed the spherical morphology of the aggregates with diameters around 180–200 nm, which comprises a hydrophobic PLA core and a hydrophilic polyether shell. The aggregates are nontoxic to human cervical cancer cell line — HeLa cells, as determined by MTS assay, and the aggregates are potential candidates to be applied in the encapsulation of hydrophobic compounds. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 2203–2213

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“…The PLLA-PEG and PDLA-PEG block copolymers were prepared as reported previously [23]. In short, a mixture of 90% L-LA (25.0 g) or 90% D-LA (25.0 g), PEG (22.5 g), and SA (0.8 g) was added to SnCl 2 (0.46 g) and TSA (0.46 g) as two-component catalysts and heated to 150°C for dehydrative polycondensation.…”

Section: Synthesis Of Pla-peg Block Copolymersmentioning

confidence: 99%

“…The PLA of the PLLA-PEG and PDLA-PEG block copolymer was crystal and amorphous, respectively. The crystallinity of the block copolymer might affect its block number and molecular weight [23]. The diffraction peaks from the sc crystals appeared at 2h = 12°and 21°in the WAXD profiles of PLLA-PEG/PDLA-PEG, while no diffraction from the sc crystals was observed in the single PLLA-PEG and PDLA-PEG copolymers.…”

Section: Formation Of Plla-peg/pdla-peg and Alginate Gelsmentioning

confidence: 99%

Effect of Thermoresponsive Poly(L-lactic acid)–poly(ethylene glycol) Gel Injection on Left Ventricular Remodeling in a Rat Myocardial Infarction Model

Somekawa

Mahara

Masutani

et al. 2017

Tissue Eng Regen Med

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Some gel types have been reported to prevent left ventricular (LV) remodeling in myocardial infarction (MI) animal models. In this study, we tested biodegradable thermoresponsive gels. Poly(L-lactic acid)-poly(ethylene glycol) (PLLA-PEG) and poly(D-lactic acid)-poly(ethylene glycol) (PDLA-PEG) were synthesized by the polycondensation of Land D-lactic acids in the presence of PEG and succinic acid. Each of these block copolymers was used to prepare particles dispersed in an aqueous medium and mixed together to obtain a PLLA-PEG/PDLA-PEG suspension, which was found to show a sol-to-gel transition around the body temperature by the stereocomplex formation of enantiomeric PLLA and PDLA sequences. In the present study, the G 0 of the PLLA-PEG/PDLA-PEG suspension in the rheological measurement remained as low as 1 Pa at 20°C and increased 2 kPa at 37°C. The sol-gel systems of PLLA-PEG/PDLA-PEG might be applicable to gel therapy. The effect of the PLLA-PEG/PDLA-PEG gel injection was compared with that of a calciumcrosslinked alginate gel and saline in a rat MI model. The percent fractional shortening improved in the PLLA-PEG/ PDLA-PEG (20.8 ± 4.1%) and alginate gel (21.1 ± 4.8%) compared with the saline (14.2 ± 2.8%) with regard to the echocardiograph 4 weeks after the injection (p \ 0.05). There were reduced infarct sizes in both PLLA-PEG/PDLA-PEG gel and alginate gel compared with the saline injection (p \ 0.05). Moreover, a greater reduction in LV cavity area was observed with the PLLA-PEG/PDLA-PEG gel than with the alginate gel (p = 0.06). These results suggest that the PLLA-PEG/PDLA-PEG gel should have high therapeutic potential in gel therapy for LV remodeling after MI.

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Size-Controlled Nanomicelles of Poly(lactic acid)–Poly(ethylene glycol) Copolymers with a Multiblock Configuration

Cited by 9 publications

References 34 publications

Time Domain NMR in Polymer Science: From the Laboratory to the Industry

Time Domain NMR in Polymer Science: From the Laboratory to the Industry

Amphiphilic polylactide‐poly(ethylene oxide)‐poly(propylene oxide) block copolymers: Self‐assembly behavior and cell affinity

Effect of Thermoresponsive Poly(L-lactic acid)–poly(ethylene glycol) Gel Injection on Left Ventricular Remodeling in a Rat Myocardial Infarction Model

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