PLGA-PEG-PLGA (hydrogel) (LA:GA 7:1) is a biodegradable, thermosensitive hydrogel that undergoes phase transition at specific temperatures. It is widely used in drug delivery systems, tissue engineering, wound dressings, and biosensors. The gelation temperature varies with concentration; as concentration increases, the gelation temperature decreases, ranging from 31-34°C at concentrations between 15-20 wt%.

Gel Preparation Method: (1) Remove solid materials from a frozen environment and allow them to return to room temperature before unwrapping and opening them after removing any condensation on the outer packaging; (2) Depending on the gel's intended application conditions, add phosphate buffer, complete culture medium, or distilled water as a solvent in the container to create a 15-20% (w/w) solution; (3) Stir at room temperature in a cool environment (≤25°C) for 24 hours until the polymer is fully dissolved, resulting in a temperature-sensitive hydrogel; (4) Fully cool the prepared temperature-sensitive hydrogel at 4°C, then filter for sterilization in a sterile environment using a 0.22 µm polyethersulfone needle filter. Note: (1) Gels made with a phosphate buffer, complete culture medium, etc., generally have a gelling temperature 1-2°C lower than those made with distilled water; (2) Repeatedly use tools like a spatula to scrape gel-like solids from the bottle walls and lid during solvent addition and dissolution to ensure they fully contact the solvent, accelerating polymer dissolution.