University of Washington spin-out MicroGreen Polymers has raised $10m in a series B to support the development of its plastic technologies.

Confederated Tribes of Grand Ronde, an organisation which represents a number of Native American tribes, led the round, which was also joined by inside investors. The investment comes in addition to a similar round for $5m earlier in the year from the Stillaguamish Tribe of Indians, also a Native American tribe.

In a statement, the clean tech said it…