OODBMS <-> RDF

Hello.
I need to make data stored in an object-oriented (ZODB) database 
available as RDF. I've been looking for existing architectures and 
mapping techniques, and eventually found D2RQ 
<http://www4.wiwiss.fu-berlin.de/bizer/D2RQ/spec/>. The problem is that 
D2RQ seems too much oriented towards the relational paradigm.
Is there any research done on this particular area? I've been thinking 
about something similar to D2RQ, but object-oriented. However, I'd like 
to know if there's any work already done about this subject.

Thanks in advance,

Pedro