The inventions provided herein relate to compositions, methods, delivery devices and kits for repairing or augmenting a tissue in a subject. The compositions described herein are injectable such that they can be placed in a tissue to be treated with a minimally-invasive procedure (e.g., by injection) and/or be molded flexibly into a tissue void of any shape and/or size. In some embodiments, the composition described herein comprises a plurality of silk fibroin particles, which can retain their original volume within the tissue for a period of time. The compositions can be used as a filler to replace a tissue void, e.g., for tissue repair and/or augmentation, or as a scaffold to support tissue regeneration and/or reconstruction. In some embodiments, the compositions described herein can be used for soft tissue repair or augmentation.