PROBLEM TO BE SOLVED: To provide a composition, a method and a delivery instrument for adjusting bleeding in a surgical procedure.SOLUTION: A composition contains peptide solution having amino acid sequence (e.g. RADA:Arg-Ala-Asp-Ala) which consists of alternate hydrophilic and hydrophobic amino acid. A prefilled syringe contains the composition. The composition is gelatinized when it comes into contact with biological fluid and/or blood of a patient (that is, physiologic condition) and self-organizes into a macroscopic structure of stable β sheet.SELECTED DRAWING: None【課題】外科的手順中の出血を調節するための、組成物、方法および送達器具の提供。【解決手段】交互の親水性および疎水性アミノ酸からなるアミノ酸配列(例えばRADA:Arg-Ala-Asp-Ala)を有するペプチド溶液を含む組成物。前記組成物を含むプレフィルドシリンジ。前記組成物は、患者の体液および/または血液(すなわち、生理学的条件)と接触した際にゲル化し、安定したβシートの巨視的構造に自己組織化する。【選択図】なし