Biomaterial design is often celebrated as a sustainable alternative to industrial material production, promising to replace extractive processes. Yet, this vision sits uneasily beside critiques that see it reproducing extractive logics through the instrumentalisation of living systems. Drawing on ethnographic research among UK-based biomaterial designers, this paper examines how relationships between biomaterial designers and organisms are lived, negotiated, and ethically charged in practice. It argues that care, far from resolving tensions of exploitation, functions as a mechanism through which hierarchies of value are stabilised, justified, and sometimes unsettled. Through practices of growing, attuning to, and killing organisms, biomaterial designers cultivate what Donna Haraway (2008) calls non-innocent care: an engagement that acknowledges complicity in harm while sustaining responsiveness to more‑than‑human worlds. Attending to these ambivalent, affective, and creative entanglements reveals how care in biodesign operates simultaneously as an ethical aspiration, a condition of production, and a site where ecological promise and capitalist value production intertwine unevenly.