Biphasic bone-mimicking constructs containing silk fibroin peptide enhanced bone regeneration in segmental defects in...

To advance bone tissue engineering, it is essential to design and integrate biomaterials that can closely mimic the microarchitecture of native tissue and enhance biological functionality. This study presents a biphasic bone-mimicking construct that integrates decellularized extracellular matrix (dECM), calcium phosphate cement (CPC), and tailored silk fibroin (SFp) peptides to synergize with biological and mechanical cues for enhanced regeneration. The dECM/CPC hydrogel (dECM/CPC-Hy) layer provides robust structural support, whereas the inner SFp-functionalized dECM hydrogel drives cellular activity. Dynamic light scattering (DLS) and circular dichroism (CD) spectroscopy measurements confirmed distinct secondary structures and zeta potentials ranging from -8.8 ± 0.13 mV to -1.3 ± 0.09 mV for SFp1 and SFp2, respectively. MTT assays demonstrated nontoxicity for all peptides over a concentration range from 10 μg/ml to 200 μg/ml. SFp1 upregulated the expression of the Col1, Opn, Ocn and CD31 genes after 21 days in the dECM/SFp/CPC construct. In a rat radius defect model, the dECM/SFp/CPC construct resulted in significant bone regeneration after 12 weeks, as evidenced by micro-CT and X-ray imaging. In conclusion, the dECM/SFp/CPC construct shows great potential as an advanced biomaterial for bone tissue engineering, combining the biological cues of dECM and SFp with the mechanical properties of CPC to enhance bone regeneration.