Biomimetic Mechanically Strong One-Dimensional Hydroxyapatite/Poly( d , l ‑lactide) Composite Inducing Formation of Anisotropic Collagen Matrix

作者：Yonggang Zhang, Jiaping Li, Vivian H. M. Mouser, Nadia Roumans, Lorenzo Moroni, Pamela Habibović · 发表于：ACS Nano · 年份：2021 · DOI：10.1021/acsnano.1c03905 · 被引用次数：70 · 研究领域：Bone Tissue Engineering Materials、biodegradable polymer synthesis and properties、Collagen: Extraction and Characterization

Natural bone is a complex composite, consisting predominantly of collagen and hydroxyapatite (HA), which form a highly organized, hierarchical structure from the nano- to the macroscale. Because of its biphasic, anisotropic, ultrafine structural design, bone tissue possesses excellent mechanical properties. Herein, inspired by the composition and microstructure of natural bone, a biphasic composite consisting of highly aligned strontium/copper-doped one-dimensional hydroxyapatite (Sr/Cu-doped 1D HA) and poly(d,l-lactide) (PDLA) was developed. The presence and alignment of Sr/Cu-doped 1D HA crystals resulted in mechanical reinforcement of the polymer matrix, including compressive and tensile strength and modulus, fracture toughness, swelling resistance, and long-term structural stability. The compressive strength, tensile strength, and Young's modulus of the biomimetic composite were comparable to that of cortical bone. Biologically, the biomimetic composite showed a sustained release of the incorporated Sr and Cu ions, facilitated mineral deposition from simulated body fluid, and supported attachment, proliferation, and alkaline phosphatase activity of human mesenchymal stromal cells (hMSCs). Moreover, the highly aligned Sr/Cu-doped 1D HA crystals in the 3D porous scaffolds induced the alignment of hMSCs and secretion of an anisotropic collagen fiber matrix in 3D. The biomimetic Sr/Cu-doped 1D HA/PDLA composite presented here contributes to the current efforts aiming at the d...