Mechanically and Biologically Tunable Core-Sheath Fiber Scaffolds for Bone Tissue Engineering Using Pressure Gyration

Bone tissue engineering faces significant challenges in developing scaffolds that can effectively mimic the complex structure and function of natural bone tissue. To address these challenges, we have used a novel core-sheath pressurized gyration technique to fabricate polycaprolactone (PCL) fiber-based scaffolds. These scaffolds are incorporated with in situ mineralized hydroxyapatite (HAP) and montmorillonite (MMT) clay, which has been modified with three different unnatural amino acids: 5-aminovaleric acid, (±)-2-aminopimelic acid, and 4-(4-aminophenyl) butyric acid. By varying the type of unnatural amino acid-modified clay at the core and sheath, we were able to fine-tune the mineralization response in the scaffolds. This approach allows for the creation of scaffolds with tunable mechanical and biological properties that closely resemble the bone microenvironment. The design enhances cell adhesion, proliferation, and mineralization, which are essential for effective bone regeneration. Our results show that scaffolds with a PCL sheath and amino valeric acid-modified HAP clay exhibited the highest mineralization and calcium deposition, followed by those modified with amino pimelic acid. Scaffolds modified with amino butyric acid HAP clay at the sheath demonstrated the lowest levels of mineralization. These findings highlight the potential of our scaffold design to improve bone regeneration by providing a bone-mimetic environment that supports new bone tissue formation. This work opens new avenues for the development of scaffolds with customizable properties tailored to meet the specific needs of bone tissue engineering.