Bone tissue engineering is one of the most clinical applicable research areas in tissue engineering. Seed cell is the first step and essential element of construction and application of tissue-engineered bone. In recent years, many inspiring achievements have been gained in the field of seed cell study. In this review, current status and the prospects of study of seed cell source in bone tissue engineering are reviewed.

Objective To investigate the clinical outcomes of microwave heliotherapy in situ on the primary or metastatic malignant tumors of the pelvis.Methods From February 2000 to April 2009,18 patients with primary or metastatic malignant tumors of the pelvis were treated with microwave heliotherapy in situ,and followed a total or partial tumor resection.There were 11 males and 7 females with an average age of 45 years(range,16-72).Twelve cases were diagnosed as primary malignant tumor and 6 as metastases.Locations of tumors involved:the Ⅰ region 6 cases.the Ⅱ region 10 cases.and the Ⅲ region 2 cases.The exposures of all tumors were via aTtype or ilioinguinal approach.The lesions were heated at 50℃ for 20 min by 2450 MHz microwave,with surrounding soft tissue protected by copper.mesh.The necrotic tumor tissues were total or partial excised after treatment,with preservation of the anatomical continuity of the pelvic ring.Results The duration of surgery was 60-180 min (110 min on average).The blood loss was 400-800ml(480 ml on average).All patients were followed-up for 0.5-7 years(3.5 years on average).Tumor local recurred in 1 case with chondrosarcoma,and was survival in tumor-bearing after 6 months follow up.One case with malignant fibrous histiocytoma died due to brain,pulmonary,and all body metastases.One case with osteosarcoma died due to pulmonary metastases.Five cases with the metastases died due to non-pelvis metastases.Functions of hip joint in 18 patients were as follows:flexion 80°-130°,extension 0°-10°,abduction 25°-35°,and adduction 18°-23°.Conclusion The clinical result demonstrated that the advantages of microwave heliotherapy in situ were quick increase of temperature,sensitive responses,easy control of temperature,and effective inactivation of tumor cells in the malignant bone tumors of pelvis.