Over the next 18 years , he rose to the rank of Professor .
His laboratory developed an international reputation both the areas of cholesterol and membrane biophysics as well as enzyme replacement therapy and the development of novel approaches to drug delivery .
Over the next 18 years , he rose to the rank of Professor and his laboratory developed an international reputation both the areas of cholesterol and membrane biophysics as well as enzyme replacement therapy and the development of novel approaches to drug delivery .