The presently-disclosed subject matter includes biodegradable scaffolds. Exemplary biodegradable scaffolds comprise a plurality of polythioketal polymers, and a plurality of polyisocyanates, where at least one polyisocyanate is linked to at least one polymer to form the scaffold. Thus, certain embodiments of scaffolds comprise a cross-linked network of the polythioketal polymers and the polyisocyanates. The presently-disclosed subject matter also includes methods for treating tissue, such as skin or bone tissue, in a subject in need thereof. Treatment methods comprise contacting the tissue with an effective amount of the biodegradable scaffold. Furthermore, the presently-disclosed subject matter includes methods for making the present biodegradable scaffolds.