Dissolving PLA without harm to cured Polyurethane/Silicone (4 replies)

I am currently undergoing a research project involving the development of a prototype using PLA in combination with a surrounding transparent silicone or polyurethane mold. The goal is to make the core of the prototype out of PLA (preferably) or ABS, cast a polyurethane mold around it, and then dissolve the PLA core without any harm to the silicone/polyurethane once cured using a solvent. The end product would be similar to a boiled egg without the egg yolk (yellow part) with a hole at the top.

Are there any popular solvents used today that break down PLA to a liquid-based solution so that it can easily pour out of the prototype while not affecting the structure of the polyurethane/silicone?