There is a significant impact of strain rate on mechanical properties and failure of biocomposites like collagen reinforced alginate. If strain rate increases, stiffer and brittle behaviour with low failure strain would be observed. While, decreased strain rate exhibits more ductile nature of material with high failure strain. Eventually, the rate of collagen-reinforced alginate primarily would depend on the collagen viscoelastic nature and the flow of alginate matrix with time dependency. The interaction of collagen with matrix, hydration level of biocomposite and degree of crosslinking will also influence the mechanical response.

Amreen Khan thanks for your answer

is it true to say that the mechanical properties (tensile strength and stiffness) are mainly affected by the collagen volume fraction, while the failure strain/compliance are affected by the matrix?

Yes, its true to say likewise. The tensile strength and stiffness are primarily determined by collagen volume fraction while failure strain and compliance gets influenced by tissue deformation and energy absorbed before failure so matrix components are involved in governing it. The matrix highly contribute to ductility and flexibility of material. This holds for many biological tissues but looking at the complex interactions between collagen and matrix, the preciseness may depend on the specific tissue and its mechanical loading environment.