This synthetic material is completely acellular and doesn't trigger any immune response.

acellular 由前缀 a-（表示"无、非"）和 cellular（细胞的）组成。cellular 来自 cell（细胞）加形容词后缀 -ular。acellular 字面意思是"无细胞的"，指不含任何细胞结构。