I'm looking for a microsphere about 1 to 10 um. The surface must be net positive charged. It does not matter what is in side the sphere. The material must be FDA approve for human injection or have the potential to be approved. Hopefully, someone know of a commercial supplier because I can not find any. If not please help me with protocol to make such a sphere.
I was thinking of a chitosan microsphere since it is already cationic. It seem that there are a overwhelming amount of information and I'm lost because I know not thing about this field. All of the protocol that I found involves complicated drug delivery application and I'm not trying to add any thing to the in side part. Please help me find a simple protocol that does not require specialized equipment. Maybe, an emulsion method.