c# – .NET Question: MEF equivalent for .NET Framework 3.5?

As the title says, is there any MEF equivalent for .NET Framework 3.5?

I’m doing something that requires code to be in .NET Framework 3.5, and I’d like to have a plugin framework that loads DLLs that were made using later versions of .NET or even made in other programming languages. Is there a way to make a .NET 3.5 program/library load DLLs from a specific folder and instantiate them and interact with them?