Poly(β-malic acid): obtaining high molecular weights by improvement of the synthesis route

Cammas, Sandrine; Renard, I.; Langlois, Valérie; Guéri, Philippe

doi:10.1016/0032-3861(96)00204-2

Cited by 88 publications

(107 citation statements)

References 13 publications

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“…As shown in Scheme 1 and 2, the different amphiphilic block copolymers were obtained from three lactones, benzyl malolactonate, butyl malolactonate and butyl 3-methylmalolactonate, which were synthesized by the aspartic acid route 27,28) . Poly(benzyl malate) PMLABe prepolymers were obtained by anionic ring-opening polymerization of MLABe 1 using a potassium pentenoate, 6-crown-18 ether complex as an initiator in a solution of anhydrous THF (Scheme 1).…”

Section: Synthesis and Characterization Of Degradable Block Copolymersmentioning

confidence: 99%

“…Benzyl malolactonate, MLABe 1, and butyl malolactonate, MLABu 4, were synthesized as described before starting from DL-aspartic acid 27) . Butyl 3-methylmalolactonate, MeMLABu 5, was synthesized as reported elsewhere from (2RS,3RS)-3-methylaspartic acid 28) .…”

Section: Synthesis Of the Monomersmentioning

confidence: 99%

“…The synthesis of the three monomers used (benzyl malolactonate, butyl malolactonate and butyl 3-methylmalolactonate) as well as the preparation and characterization of the corresponding homopolymers have been already described 27,28) . The originality of this work is the association of a hydrophilic block of malic acid units with a hydrophobic block of malic acid ester units, leading to an amphiphilic block copolymer which can be used in the preparation of new degradable macromolecular micelles.…”

Section: Introductionmentioning

confidence: 99%

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New macromolecular micelles based on degradable amphiphilic block copolymers of malic acid and malic acid ester

Cammas‐Marion¹,

Bear

Harada

et al. 2000

Macromol. Chem. Phys.

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To study the behaviour of polymeric materials under in‐vivo conditions, degradable macromolecular micelles based on amphiphilic block copolymers of poly(β‐malic acid) as hydrophilic units and poly(β‐malic acid alkyl esters) as hydrophobic blocks are studied. First three β‐substituted β‐lactones, benzyl malolactonate, butyl malolactonate, and butyl 3‐methylmalolactonate were prepared, starting from aspartic acid. A prepolymer based on benzyl malate units was synthesized by anionic ring‐opening polymerization of benzyl malolactonate. Then the carboxylic end groups of this prepolymer were used as initiator for the polymerization of the second lactone, e. g. butyl malolactonate or butyl 3‐methylmalolactonate. The prepolymer and block copolymers have been characterized by 1H NMR and size exclusion chromatography (SEC). Degradable macromolecular micelles were prepared from the block copolymers by two different methods and characterized by dynamic light scattering and fluorescence measurements using pyrene as a fluorescence probe. It was shown that these amphiphilic degradable copolymers form stable micelles under physiological conditions (10–2 M phosphate buffered solution, PBS, pH 7.4 with 0.15 M NaCl). Moreover, it was displayed that the characteristics of these macromolecular micelles, especially the critical micellar concentration (cmc), are depending on the chain length of both blocks and on the chemical structure of the hydrophobic block. A very important conclusion of this study is, that micelle formation is dependent on the pH of the medium. Therefore, besides the fact that such micelles are potentially degradable into non‐toxic low molecular weight molecules, their properties and stability were proven to be pH‐dependent. This property can lead development of an “intelligent” drug carrier able to release the entrapped biologically active molecule depending on the pH values.

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Section: Synthesis and Characterization Of Degradable Block Copolymersmentioning

confidence: 99%

Section: Synthesis Of the Monomersmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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New macromolecular micelles based on degradable amphiphilic block copolymers of malic acid and malic acid ester

Cammas‐Marion¹,

Bear

Harada

et al. 2000

Macromol. Chem. Phys.

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“…Of the whole synthesis process, the synthesis of MLABz was the crucial step. We optimized the reaction time and temperature of MLABz's synthesis, and the yield was raised from 12% 36 to 32%. Accordingly, the yield of PMLA has been improved.…”

Section: Results and Discussion Synthesis Of Pmlamentioning

confidence: 99%

“…36 Briefly, L-aspartic acid and sodium bromide were dissolved in sulfuric acid solution, then sodium nitrite was added. After stirring for 2 hours, trifluoroacetic anhydride was added and stirred for another 2 hours.…”

mentioning

confidence: 99%

Preparation of poly(β-L-malic acid)-based charge-conversional nanoconjugates for tumor-specific uptake and cellular delivery

Zhou¹,

Yang²,

Qiao³

et al. 2015

IJN

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In this study, a multifunctional poly(β-L-malic acid)-based nanoconjugate with a pH-dependent charge conversional characteristic was developed for tumor-specific drug delivery. The short branched polyethylenimine-modified poly(β-L-malic acid) (PEPM) was first synthesized. Then, the fragment HAb18 F(ab′) 2 and 2,3-dimethylmaleic anhydride were covalently attached to the PEPM to form the nanoconjugate, HDPEPM. In this nanoconjugate, the 2,3-dimethylmaleic anhydride, the shielding group, could shield the positive charge of the conjugate at pH 7.4, while it was selectively hydrolyzed in the tumor extracellular space (pH 6.8) to expose the previously-shielded positive charge. To study the anticancer activity, the anticancer drug, doxorubicin, was covalently attached to the nanoconjugate. The doxorubicin-loaded HDPEPM nanoconjugate was able to efficiently undergo a quick charge conversion from −11.62 mV to 9.04 mV in response to the tumor extracellular pH. The electrostatic interaction between the positively charged HDPEPM nanoconjugates and the negatively charged cell membrane significantly enhanced their cellular uptake, resulting in the enhanced anticancer activity. Also, the tumor targetability of the nanoconjugates could be further improved via the fragment HAb18 F(ab′) 2 ligand–receptor-mediated tumor cell-specific endocytosis.

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Influence of structural parameters on the ring-opening polymerization of new alkyl malolactonate monomers and on the biocompatibility of polymers therefrom

Bizzarri

Chiellini

Ober

et al. 2002

Macromol. Chem. Phys.

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The geometry of several alkyl malolactonate monomers was investigated by NMR and semiempirical computational methods. The results obtained by both techniques indicated that the geometry of the malolactone ring is almost independent of the nature of the side ester group. 13C NMR analysis of the polymer backbone stereochemistry ruled out the occurrence of stereoelective processes in the polymerization of racemic monomers. The observed influence of the bulkiness of the alkyl group on the polymerization rate was therefore attributed to steric interactions between this group and the polymer growing‐end. Preliminary in‐vitro investigation of cell adhesion and proliferation on the surface of homopolymers and copolymers of the investigated alkyl malolactonates suggested a possible correlation between polymer hydrophobicity and biocompatibility.

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Poly(β-malic acid): obtaining high molecular weights by improvement of the synthesis route

Cited by 88 publications

References 13 publications

New macromolecular micelles based on degradable amphiphilic block copolymers of malic acid and malic acid ester

New macromolecular micelles based on degradable amphiphilic block copolymers of malic acid and malic acid ester

Preparation of poly(β-L-malic acid)-based charge-conversional nanoconjugates for tumor-specific uptake and cellular delivery

Influence of structural parameters on the ring-opening polymerization of new alkyl malolactonate monomers and on the biocompatibility of polymers therefrom

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Poly(β-malic acid): obtaining high molecular weights by improvement of the synthesis route

Cited by 88 publications

References 13 publications

New macromolecular micelles based on degradable amphiphilic block copolymers of malic acid and malic acid ester

New macromolecular micelles based on degradable amphiphilic block copolymers of malic acid and malic acid ester

Preparation of poly(&beta;-L-malic acid)-based charge-conversional nanoconjugates for tumor-specific uptake and cellular delivery

Influence of structural parameters on the ring-opening polymerization of new alkyl malolactonate monomers and on the biocompatibility of polymers therefrom

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Preparation of poly(β-L-malic acid)-based charge-conversional nanoconjugates for tumor-specific uptake and cellular delivery