Bone healing (IMAGE) Penn State Caption Penn State College of Medicine researchers are studying how cannabinoids may manage pain and promote bone healing in bone fractures. Fluorescence microscopy reveals how periosteal bone progenitors, which later develop into specialized bone cells that help bone tissue for, appear in healing tissue. Credit Reyad Elbarbary, Penn State Usage Restrictions Educational use only License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.