Abstract: Systems, devices, compositions, and methods for treating bleeding, for containing blood that has been lost by a subject due to bleeding, and for treating surfaces contaminated with blood or expected to be contaminated with blood are disclosed. The systems, devices, compositions, and methods utilize platelets, platelet-derived materials, or both. The invention includes sprayers, nebulizers, and equivalents, to deliver platelets and/or platelet-derived materials to desired surfaces. Exemplary embodiments include the use of a pressurized sprayer configured to deliver a topical administration of a lyophilized platelet and/or platelet-derived material to a surface.