Provided herein are polymers of Formula (I), and pharmaceutically acceptable salts, co-crystals, tautomers, stereoisomers, and isotopically labeled derivatives thereof, compositions, and formulations thereof. The polymers described herein are biocompatible, non-toxic, water compatible, and operationally simple to formulate. Also provided are methods and kits involving the polymers described herein (e.g., methods of using polymers described herein for delivering agents (e.g., for therapeutic, diagnostic, prophylactic, imaging, ophthalmic, intraoperative, or cosmetic use) to a subject, cell, tissue, or biological sample, as part of materials (e.g., biodegradable materials, biocompatible materials, wound dressing (e.g., bandages), drug depots, coatings), or as scaffolds for tissue engineering. Provided are methods for synthesizing the polymers described herein, and polymers described herein synthesized by the synthetic methods described herein.