Sentinel Capital Partners, a private equity firm that invests in smaller middle-market companies, has acquired Massage Envy. Based in Scottsdale, Arizona, Massage Envy is a therapeutic massage services franchise with more than 600 clinics in 42 states, and systemwide sales of more than $450 million. More than 200 Massage Envy franchise licenses are currently in development. For the past 20 years, Sentinel has invested in multi-unit and franchise businesses such as Falcon Holdings (operated by Aslam Khan, subject of Franchise Times’ January 2010 cover story), Border Foods, Castle Dental, Cottman Transmission Systems, Interim Healthcare, Metro Dentalcare and Southern California Pizza Company. Financial terms of the transaction were not disclosed.