Professor Polak received a DBE for services to medicine and Professor Alan Boobis received an OBE for his services as Deputy Chairman on the Advisory Committee on Pesticides.

Dame Julia heads the centre for tissue engineering and regenerative medicine which she set up with Professor Larry Hench to develop cells and tissues for transplantation into humans.

She became interested in this area of research after she underwent a double heart and lung transplant in 1995 as a result of pulmonary hypertension, a potentially life threatening disease.

Professor Boobis has been at the forefront of research into mechanisms for toxicity at the College's Hammersmith campus, where he is Director of the Department of Health Toxicology Unit.

His particular interest includes understanding factors that contribute to the adverse effects of drugs and environmental chemicals and to applying this knowledge to helping prevent or reduce harm to exposed individuals.

Professor Sir Leszek Borysiewicz, principal of the faculty of medicine, said: "This is great news for both Julia and Alan.

"Both have made fantastic scientific achievements and have contributed enormously in developing Imperial College London as a place renowned for world class science, teaching and clinical advances."