Hybrid Ti6Al4V/Silk Fibroin Composite for Load-Bearing Implants: A Hierarchical Multifunctional Cellular Scaffold

Abstract

Despite the tremendous technological advances that metal additive manufacturing (AM) has made in the last decades, there are still some major concerns guaranteeing its massive industrial application in the biomedical field. Indeed, some main limitations arise in dealing with their biological properties, specifically in terms of osseointegration. Morphological accuracy of sub-unital elements along with the printing resolution are major constraints in the design workspace of a lattice, hindering the possibility of manufacturing structures optimized for proper osteointegration. To overcome these issues, the authors developed a new hybrid multifunctional composite scaffold consisting of an AM Ti6Al4V lattice structure and a silk fibroin/gelatin foam. The composite was realized by combining laser powder bed fusion (L-PBF) of simple cubic lattice structures with foaming techniques. A combined process of foaming and electrodeposition has been also evaluated. The multifunctional scaffolds were characterized to evaluate their pore size, morphology, and distribution as well as their adhesion and behavior at the metal–polymer interface. Pull-out tests in dry and hydrated conditions were employed for the mechanical characterization. Additionally, a cytotoxicity assessment was performed to preliminarily evaluate their potential application in the biomedical field as load-bearing next-generation medical devices.

Nanocomposite Methacrylated Silk Fibroin-Based Scaffolds for Bone Tissue Engineering

“…Furthermore, it has been demonstrated that substrates having elastic moduli within the range of 25-40 kPa promote an upregulation of osteocalcin expression and induce mesenchymal stem cell differentiation towards osteoblasts [66]. Alternatively, SF-based soft materials with good biological properties can be used as fillers in combination with any load-bearing material, i.e., titanium lattice structures [67].…”

Scaffold design considerations for peripheral nerve regeneration

“…As one can picture the strength of spider webs seen in daily life, silk fibroin is a natural protein with outstanding mechanical properties. As a result, it has been popularly used in load-bearing scenarios such as bioresorbable bone fixation devices [148,149], load-bearing scaffolds for dermal tissue regeneration [150] and bone regeneration [151]. In addition, due to its excellent biocompatibility, superb flexural strength, and good elasticity, numerous of SF-based NGCs have been developed and encouraging outcomes have been achieved [54,[152][153][154].…”

Regulation of the Degradation Properties of Tyrosinase-Catalyzed Crosslinking Silk Membranes for Superficial Wound Repair

“…Silk fibroin has emerged as a biopolymer with superior potential application value in tissue engineering and regenerative medicine [ 1 ], owing to its biocompatibility, processability, and relatively mild processing conditions [ 2 , 3 ]. Various types of silk-based materials that undergo reprocessing, modification, and modulation are used in numerous areas, such as tissue engineering [ 4 ], drug delivery [ 5 ], 3D printing [ 6 ], cell coating [ 7 ], microfluidics [ 8 ], biosensors [ 9 ], and blood vessels [ 10 ]. Nevertheless, one of the major challenges for these silk-based biomaterials is safety and efficacy in vivo tissue healing [ 11 ].…”