Michelle Obama in a Maria Pinto dress for the final primaries. Photo: Chip Somodevilla, Getty Images

Even designing dresses that turned Michelle Obama into a fashion trendsetter couldn't keep Maria Pinto in business.

The designer has closed the doors to her Chicago boutique, reports the Chicago Sun-Times, and she is expected to seek bankruptcy protection this week.

Pinto tells the Sun-Times "economic challenges and soft buying trends at the top end of the apparel market" contributed to her business woes.

''I am confident that the 'Maria Pinto' name will not go away, but will merely take a break, before emerging in a new form," she tells the newspaper.

"I plan on using the next several months to explore different avenues and opportunities for business, as economic conditions improve."

In addition to dressing Obama (see the purple sleeveless sheath dress she wore for the final primaries?), Pinto's customers also included Oprah Winfrey and several Chicago socialites and civic leaders.

Pinto studied at the School of the Art Institute of Chicago and New York's Parsons School of Design and Fashion Institute of Technology, and worked for Geoffrey Beene in her first fashion job. In 1991, she launched her own line, which was carried in stores including Bergdorf Goodman, then she opened her Chicago boutique in 2008, according to the paper.

And, if there's any debate on Michelle Obama's style power, here's a look at her first 100 days of fashion.