I need a transparent biomaterial for my project... could you suggest a few

Define your terminology.

What is transparent?

What is a biomaterial?

That tells what you need to know.

Web site references:
http://en.wikipedia.org/wiki/Biomaterial

Some that come to mind offhand include the adhesive artificial skin products, they are transparent or nearly so.

Any lotion is water based, but usually cloudy so not transparent.

Syrups are often transparent, and some syrups do deliver drugs, so met the criteria.

Water can be used to deliver drugs, in IV drips at hospitals, so would also qualify,

Basically define your terms, then find objects that conform to all of them at once.