Diamond Castle Partners, the New York-based private equity firm, bought Suture Express Inc., a distributor of disposable medical and surgical products.

Terms were not disclosed and calls seeking comment were not returned by press time.

Linden LLC and CHS Private Equity LP, an investment arm of Code Hennessy & Simmons LLC, exited the company after more than three years of ownership. Initially, the team of PE investors bought the company from its founders. In the time since, the joint PE ownership team has expanded Suture Express’ product offerings and customer base.

Tom Formolo, a partner with CHS, worked on the company and on the deal for the PE firm.

Diamond Castle Partners has made investments across entertainment, advertising and media, Internet and technology, manufacturing and food services industries. Linden, on the other hand, had a history of making investments in healthcare and medical services and technology companies all over the US.

William Blair provided advisory services to Suture Express and Kirkland & Ellis provided legal advice.

Increasingly, private equity firms have looked to make healthcare investments. Spectrum Laboratory Network bought, earlier this week, Carilion Labs, a laboratory testing service; the acquirer was bought late last year by PE firm Welsh Carson Anderson & Stowe. EDG Partners launched its second PE fund earlier this year, and is still picking up contributions en route to its $150 million goal; the private equity firm has made a number of healthcare investments in the past. Finally—still, in 2010—Genstar Capital’s Univita Health, a Phoenix-based healthcare services firm, bought a similar company as part of its expansion plans.