Compositions useful for tissue resection procedures and related methods of preparing the compositions are discussed. The composition may comprise gellan gum, at least one salt, and water. In some aspects, the composition may be prepared by combining the gellan gum, the salt(s), and the water to form a mixture, heating the mixture, introducing the mixture into a reservoir, and allowing the mixture to cool while inside the reservoir to form a gel. The gel may have a continuous, three-dimensional structure, and may be solid or quasi-solid. The composition may be biocompatible and injectable from the reservoir through a needle coupled to the reservoir to the target site of a patient.
