The present invention relates devices capable of continuous and simultaneous expression of components of a multi-part biomedical composition with variable mixing ratios. The device has at least two syringes that contain the inter-reactive components of the multi-part biomedical composition. At least the barrel of the first syringe has a first retention compartment having a cross-sectional area dimension that is larger than the cross-sectional area of a second retention compartment. The first piston has a cross-sectional dimension that matches the inside cross-sectional dimension of the small dimensioned retention compartment, while a ring-shaped gasket is located within the large dimensioned retention compartment and has an outside cross-sectional dimension that matches an interior dimension of the large dimension retention compartment.