MedProperties Realty Advisors LLC and Catalyst Healthcare Real Estate have teamed to develop a 35,000-square-foot medical office building in the new 55-acre Founders Square retail and residential mixed-use development under construction on the southeast corner of Collier Boulevard and Immokalee Road. The partnership closed on the property on June 17. The office space is already 100 percent pre-leased for a 15-year initial term by Naples-based Physicians Regional Healthcare, said Darryl Freling, managing principal of MedProperties, a Dallas-based healthcare real estate private equity firm. The building will be developed by Pensacola-based Catalyst, which has had a long-standing business relationship with MedProperties.  Founders Square also will include more than 400 luxury multifamily units and more than 270,000 square feet of retail space, including multiple restaurants, stores and a high-end spa, according to a news release.