Characterization and emulsifying properties of block copolymers prepared from lactic acid and poly(ethylene glycol)

Siao, Syuan-Yi; Lin, Li-Hsiu; Chen, Weiwen; Huang, Mao-Hsiung; Chong, Pele

doi:10.1002/app.30497

Cited by 9 publications

(7 citation statements)

References 23 publications

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“…On the basis of our knowledge, there has been no previous publication on the synthesis of a PLA‐NR diblock copolymer. The PLA‐based diblock copolymers have included PLA‐poly(ethylene glycol), PLA‐poly(ethylene oxide), PLA‐PS, and PLA‐poly(para‐phenylenevinylene) . NR has been chemically modified to obtain a hydroxyl terminated liquid rubber (a hydroxyl telechelic natural rubber, HTNR).…”

Section: Introductionmentioning

confidence: 99%

Bio‐based diblock copolymers prepared from poly(lactic acid) and natural rubber

Chumeka

Pasetto

Pilard

et al. 2014

J of Applied Polymer Sci

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New bio-based diblock copolymers were synthesized from poly(lactic acid) (PLA) and natural rubber (NR). NR polymer chains were modified to obtain hydroxyl telechelic natural rubber oligomers (HTNR). Condensation polymerization between PLA and HTNR was performed at 110 C during 24 or 48 h. The molecular weight of PLA and HTNR and the molar ratio PLA : HTNR were varied. The new ester linkage in the diblock copolymers was determined by 1 H-NMR. The molecular weight of the diblock copolymers determined from SEC agreed with that expected from calculation. The thermal behavior and degradation temperature were determined by DSC and TGA, respectively. The diblock copolymers were used as a toughening agent of PLA and as a compatibilizer of the PLA/NR blend. PLA blended with the diblock copolymer showed higher impact strength, which was comparable to the one of a PLA/NR blend. The former blend showed smaller dispersed particles as showed by SEM images, indicating the increase in miscibility in the blend due to the PLA block. The compatibilization was effective in the blends containing 10 wt % of rubber. At a higher rubber content (>10 wt %), coalescence of the NR and diblock copolymer was responsible of the larger rubber diameter in the blends, which causes a decrease of the impact strength.

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Section: Introductionmentioning

confidence: 99%

Bio‐based diblock copolymers prepared from poly(lactic acid) and natural rubber

Chumeka

Pasetto

Pilard

et al. 2014

J of Applied Polymer Sci

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“…The step‐growth polymerization of LA and properties of different LA‐based copolymers produced by this method are relatively vastly reported in scientific literature in general 23–26. However, the effects of the type of chain end‐termination on the polymerization processes of LA‐based low molar mass compounds or the production efficiency of dilactide has not been sufficiently reported in the literature.…”

Section: Introductionmentioning

confidence: 99%

Telechelic poly(L‐lactic acid) for dilactide production and prepolymer applications

Inkinen¹,

Nobes²,

Södergård³

2010

J of Applied Polymer Sci

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ABSTRACT:The suitability of different types of telechelic poly(lactic acid) (PLA) copolymers for dilactide production and prepolymer products was evaluated. L-lactic acid (L-LA) was copolymerized with 1,4-butanediol, pentaerythritol, adipic acid, or 1,2,3,4-butanetetracarboxylic acid (1,2,3,4-BTCA). The influence of branching, the choice of catalyst, and the type of terminal groups on the properties and the thermal stability of the end product was determined. Carboxyl-termination of PLA was shown to lead to higher molar masses than hydroxyl-termination. The observed differences in the molar masses were explained by the lower thermal stability of the hydroxyl-terminated PLA, as evidenced by the faster depolymerization rate of the hydroxylterminated polymers and their higher tendency to undergo racemization. Sn(Oct) 2 was found to be a more effective copolymerization catalyst than Fe(OAc) 2 in terms of the final molar masses obtained. It was additionally found that the amount of chains not attached to the comonomers decreased toward longer polymerization times and was typically higher for the hydroxyl-terminated copolymers. The results suggest that predominant carboxyl-termination would increase the thermal stability of PLA polymers, whereas hydroxyl-termination could be utilized to increase the production speed and efficiency of dilactide.

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“…Oil-in-water (O/W) emulsions are oil droplets dispersed into a continuous water phase123. In vaccine formulation, O/W was successfully applied as vaccine adjuvants (from the Latin adjuvare , meaning “to help”) for increasing the antigen-sparing efficacy in pandemic influenza vaccine preparedness and for enhancing the immunogenicity of seasonal influenza vaccines in elderly subjects45.…”

mentioning

confidence: 99%

Degradable emulsion as vaccine adjuvant reshapes antigen-specific immunity and thereby ameliorates vaccine efficacy

Huang

Cheng

et al. 2016

Sci Rep

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This study describes the feasibility and adjuvant mechanism of a degradable emulsion for tuning adaptive immune responses to a vaccine antigen. We featured a mouse model with ovalbumin (OVA) as the antigen to deepen our understanding of the properties of a degradable emulsion-based adjuvant, dubbed PELC, interacting with immune cells and to elucidate their roles in vaccine immunogenicity in vivo. First, we demonstrated that the emulsion, which is stabilized by an amphiphilic bioresorbable polymer, shows degradation in mimic human body conditions and considerable tolerance in vivo. Then, we confirmed the model protein could be loaded into the emulsion and released from the matrix in a sustained manner, subsequently driving the production of antigen-specific antibodies. We also comprehended that PELC not only recruits antigen-presenting cells (APCs) to the injection site but also induces the activation of the recruited APCs and migration to the draining lymph nodes. As an adjuvant for cancer immunotherapy, PELC-formulated OVA could strongly enhance antigen-specific T-cell responses as well as anti-tumor ability with respected to non-formulated OVA, using OVA protein/EG7 cells as a tumor antigen/tumor cell model. Accordingly, our data paved the way for the clinical application of degradable emulsions based on amphiphilic bioresorbable polymers as vaccine adjuvants.

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Characterization and emulsifying properties of block copolymers prepared from lactic acid and poly(ethylene glycol)

Cited by 9 publications

References 23 publications

Bio‐based diblock copolymers prepared from poly(lactic acid) and natural rubber

Bio‐based diblock copolymers prepared from poly(lactic acid) and natural rubber

Telechelic poly(L‐lactic acid) for dilactide production and prepolymer applications

Degradable emulsion as vaccine adjuvant reshapes antigen-specific immunity and thereby ameliorates vaccine efficacy

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