For the localized treatment of tumors
Bone implants with the ability to carry chemotherapeutical drugs in conception in CICECO
Chemotherapy, followed by the surgical removal of the affected tissue is the treatment usually adapted to bone tumors. An implant which can fill the areas of subtraction, while releasing chemotherapeutical agents locally, in a controlled manner, during the treatment period, is the aim of a research led by the Research Centre in Ceramic Material and Composites (CICECO/UA). In these experiences, specialists are using potential "anti-tumor" drugs coated by nanocapsules.
The osteosarcoma is the most common malignant primary bone tumor. Its major incidence is in children and youngsters and usually involves the amputation of arms and legs. The treatment for this type of tumor implies chemotherapy, followed by the surgical removal of the affected tissue with a safety area, in order to avoid the tumor's reappearance. This area is then filled with a bone or synthetic biomaterial implant.
Considering how important it is to avoid repeating new chemo or radiotherapy treatments in these cases when neutralizing possible residual focus, 11 researchers from the Universities of Aveiro and Coimbra intend to develop an implant which can contain chemotherapeutical agents of specific ranges of action, and also release these components in a controlled manner for a specific and adequate period of time.
"The bone implants we are studying will serve as a support and releasing agent of capsulated drugs in a ciclodextrin nanocapsule. We are currently experimenting with an active molecule with anti-cancer properties specifically directed to osteosarcomas. Nevertheless, it is intended to broaden its application to other types of cancer".
For this person, and as explained by Prof. Rui Correia, project coordinator, there is the need to proceed with the study of its mechanic and biological characteristics. "When we develop projects for these purposes, we must bear in mind their mechanic resistance, as well as other characteristics which must be taken in consideration when performing its implant in the bone. In this specific case, we are working with porous supports that contain a silica gel, manipulated to function both as a nanocapsule deposit and releaser. Its physical form will vary according to the bone area to fill.
The gel matrix will receive the anti-tumor compost (cisplatin and metallic composts), capsulated at a molecular level with ciclodextrin, coloured gello capsules which are nothing more and nothing less that sugar rings.
Prof. Ana Gil explains this innovative technique:
"A subgroup within our team, lead by researcher Susana Braga, is by the one hand, developing new metallic composts with a therapeutic potential and, by the other hand, promoting its capsulation in ciclodextrins. The use of the ciclodextrin on the coating of the medicinal molecule increases the efficiency of the drug and reduces the necessary amount. To work at a nanometric scale allows us to improve the properties, both concerning its solubility and its range of activity, allowing us to make it more specific".
The nanocapsule protects the therapeutic agent from the contact with proteins which are irrelevant to the treatment and makes its located application simpler. The use of ciclodextrins as nanocapsules should protect the organism from the expected high toxicity of the new agents to the healthy cells.