Alveolus, a company focused on development of non-vascular stent technology, has another $15 million in the bank.

The Charlotte-based medical device firm, which was launched in 2001, has now raised more than $30 million in three rounds of venture capital.

The funds will be used to “catalyze” the company’s product development, Alveolus said in a statement. It is already selling stent products in Europe.

“The conclusion of this round of financing will enable us to bring successfully to market the remainder of our immediate product portfolio as well as allow us to initiate product development on our newest innovative development initiatives,” said Eric Mangiardi, the company’s chief executive officer, in a statement. “”Alveolus will continue to honor its commitment to provide physicians and
their patients with the latest and most innovative non-vascular stent
technology, by developing and providing those tools necessary to improve the patients’ quality of life.”

Ridgeback Capital Management led the round. MDS Capital and other investors from the previous two rounds also participated.

Alveolus’ stents target patients suffering from pulmonary or gastrointestinal obstructions. The company estimates the market for stents to be used in the lungs, colon, esophagus and elsewhere at $500 million annually.