Degradation of thermoresponsive laponite/PEG-b-PLGA nanocomposite hydrogels controlled by blending PEG-b-PLGA diblock copolymers with different PLGA molecular weights. (May 2021)

• Record Type: Journal Article
• Authors: Maeda, Tomoki; Kitagawa, Midori; Hotta, Atsushi
• Is Part Of: Polymer degradation and stability. Volume 187(2021)
• Publication Date: 2021-05
• Subjects: Poly(ethylene glycol) -- Poly(lactic acid-co-glycolic acid) -- Laponite -- Thermoresponsive hydrogel -- Nanocomposite -- Degradation; Polymers -- Deterioration -- Periodicals; Stabilizing agents -- Periodicals; Polymères -- Dégradation -- Périodiques; Stabilisants -- Périodiques; 668.9
• DOI: 10.1016/j.polymdegradstab.2021.109535
• Languages: English
• ISSNs: 0141-3910

Abstract

Highlights: The laponite/PEG- b -PLGA nanocomposites were prepared using the blend of PEG-b-PLGAs. Gelation temperature was in the temperature range between 25°C and 37°C. Degradation rate of the nanocomposites could be effectively regulated by the blend ratio. Abstract: The thermoresponsive gelation behavior and the degradation behavior of the nanocomposites consisting of poly(ethylene glycol)- b -poly(lactic acid- co -glycolic acid) (PEG- b -PLGA) diblock copolymers and clay nanoparticles (laponite) (laponite/PEG- b -PLGA nanocomposites) were studied by changing the blend ratio of the PEG- b -PLGA diblock copolymers using different PLGA molecular weights of 800 g/mol and 1600 g/mol: PEG- b -PLGA (1000-800, Diblock0.8k) and PEG- b -PLGA (1000-1600, Diblock1.6k). It was found that each gelation temperature was in the temperature range between 25°C and 37°C, when the PEG- b -PLGA concentration and the laponite concentration were kept at 3–4 wt% and 1 wt%, respectively. The degradation rate at 37°C was found to be effectively regulated by the Diblock1.6k/Diblock0.8k blend ratio (DR). In detail, after 15 days of the degradation experiments, the weight loss was decreased by ∼14% when DR changed from DR=0/100 to DR=100/0. It was, therefore, confirmed that DR was the key parameter to control the degradation behavior of the laponite/blended PEG- b -PLGA nanocomposites.