Feng-Huei Lin

Director, Institute of Biomed Eng & Nanomed., National Health Research Institutes, Taiwan
Distinguish Professor, Institute of Biomed Eng., National Taiwan University, Taipei, Taiwan

Human tissue depends on blood circulation to transport oxygen, nutrition, carbon dioxide, waste and so forth. If there are problems in transportation of these substances, one’s organ and tissue will be necrotic. When this happened in brain, it may lead to stroke or transient ischemia; in heart, it will probably bring myocardial infarction and stenocardia; in bone, it will cause osteonecrosis. Avascular necrosis of the femoral head is also known as aseptic necrosis of the femoral head or osteonecrosis of the femoral head. According to the literature, 300,000 to 600,000 people have avascular necrosis of the femoral head in the United States. It is a disease of weak osseous blood flow of femoral head. This disease commonly occurs in the people who are thirty to fifty years old. The ultimate purpose of every clinical treatment is to save patient’s femoral head but it’s not an easy work. Making a decision about therapy is related to the patient’s other illness, previous life, living environment and so on.

Poly(propylene fumarate) (PPF) is an unsaturated linear polyester that can be cross-linked through the double bonds along its backbone to form a solid polymer. Cross-linking can be carried out through the addition of N-vinyl pyrrolidinone (NVP, a cross-linker), benzoyl peroxide (BP, an initiator) and N,N-dimethyl-p-toluidine (DMT, an accelerator). An orthopedic composite formulation can be formed through the addition of tetracalcium phosphate (TTCP) / dicalcium phosphate (DCPA) as an osteoconductive agent and ginsenoside (Rg1) as an angiogenic agent. Moreover, TTCP/DCPA can improve the mechanical strength of PPF. This composite forms an injectable paste that can be used to fill skeletal defect, acting both as a biodegradable scaffold with angiogenic agent for cell growth and as a mechanical support at the defect site.

The purpose of study is to fabricate an injectable bone cement with biodegradable and angiogenic functions. We anticipate this bone cement can benefit to supporting mechanical strength immediately after injection. As time goes by, it will be degraded within the body gradually followed by releasing angiogenic agent which can stimulate vascularization of surrounding tissue. With the nutritional supply of new microvessel, bone tissue will regenerate onto this cement. Finally, the cement will be replaced by newly formed bone.