Effects of EGF and bFGF on irradiated parotid glands.
Radiotherapy is common treatment for head-and-neck cancer, during which the salivary glands are often included within the radiation field. The most common side effect of this treatment is the development of oral dryness (xerostomia). This study considers the administration of epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF or FGF2) at physiological concentrations before and after irradiation in order to repair radiation-induced damage in salivary gland cells. As a preliminary examination of the efficacy of this approach we have characterized the effects of EGF and bFGF on the apoptotic response of 15-Gy irradiated rat salivary glands in vitro. Also, we have developed a controlled-release delivery system to effectively administer the growth factor to the gland since local delivery is essential to avoid unwanted protection of cancer cells. In vitro administration of bFGF prior to and immediately after irradiation partially protected (44%) the rat parotid gland. EGF did not show any significant radioprotective effect on parotid glands after a single 15-Gy irradiation dose. Encapsulation, storage and release of bFGF from biodegradable 50/50 PLGA microspheres did not affect the functionality of the growth factor in vitro.
Thula
Taili T
TT
Biomedical Engineering Department, University of Florida, Gainesville, Florida, USA. tthula@gmail.com
Schultz
Gregory
G
Tran-Son-Tay
Roger
R
Batich
Christopher
C
D000818:Animals; D017209:Apoptosis / Q000187:drug effects* / Q000528:radiation effects*; D002478:Cells, Cultured; D003692:Delayed-Action Preparations / Q000008:administration & dosage* / Q000737:chemistry; D004058:Diffusion; D004815:Epidermal Growth Factor / Q000008:administration & dosage*; D016222:Fibroblast Growth Factor 2 / Q000008:administration & dosage*; D066298:In Vitro Techniques; D010306:Parotid Gland / Q000187:drug effects* / Q000473:pathology / Q000503:physiopathology / Q000528:radiation effects*; D010316:Particle Size; D011832:Radiation Injuries / Q000473:pathology / Q000517:prevention & control*; D011837:Radiation-Protective Agents / Q000008:administration & dosage; D051381:Rats; D017207:Rats, Sprague-Dawley
D003692:Delayed-Action Preparations; D011837:Radiation-Protective Agents; D016222:Fibroblast Growth Factor 2; D004815:Epidermal Growth Factor