Biomimetic nanofibrous gelatin/apatite composite scaffolds for bone tissue engineering

Abstract

Mimicking certain features (e.g. nanoscale topography and biological cues) of natural extracellular matrix (ECM) is advantageous for the successful regeneration of damaged tissue. In this study, nanofibrous gelatin/apatite (NF-gelatin/apatite) composite scaffolds have been fabricated to mimic both the physical architecture and chemical composition of natural bone ECM. A thermally induced phase separation (TIPS) technique was developed to prepare nanofibrous gelatin (NF-gelatin) matrix. The NF-gelatin matrix mimicked natural collagen fibers and had an average fiber diameter of about 150 nm. By integrating the TIPS method with porogen leaching, three-dimensional NF-gelatin scaffolds with well-defined macropores were fabricated. In comparison to Gelfoam® (a commercial gelatin foam) with similar pore size and porosity, the NF-gelatin scaffolds exhibited a much higher surface area and mechanical strength. The surface area and compressive modulus of NF-gelatin scaffolds were more than 700 times and 10 times higher than that of Gelfoam®, respectively. The NF-gelatin scaffolds also showed excellent biocompatibility and mechanical stability. To further enhance pre-osteoblast cell differentiation as well as improving mechanical strength, bone-like apatite particles (< 2 μm) were incorporated onto the surface of NF-gelatin scaffolds via a simulated body fluid (SBF) incubation process. The NF-gelatin/apatite scaffolds showed significantly higher mechanical strength than NF-gelatin scaffolds 5 days after SBF treatment. Furthermore, the incorporated apatite in the NF-gelatin/apatite composite scaffold enhanced the ostgeogenic differentiation. The expression of BSP and OCN in the osteoblast-(NF-gelatin/apatite composite) constructs was about 5 times and 2 times higher than in the osteoblast-(NF-gelatin) constructs 4 week after cell culture. The biomimetic NF-gelatin/apatite scaffolds are, therefore, excellent for bone tissue engineering.

Polymeric Nanofibers in Tissue Engineering

“…48 Originally, the technique was demonstrated with PLLA or PLGA, but more recently, the technique has been performed with polyhydroxyalkanoate, 49 chitosan, 47 gelatin, 50 and gelatin/apatite composites. 51 The advantages of this method are that it does not require specialized equipment, and there is little variation between batches. Additionally, constructs can be produced in a mold to achieve a specific geometry.…”

Microporous bacterial cellulose as a potential scaffold for bone regeneration

“…However, because bacterial cellulose is hydrogel-like, with a high water holding capacity, it may be possible to incorporate drugs and growth factors in the scaffold. In addition, the deposition of calcium phosphate mineral onto bacteria cellulose [31][32][33] may improve bone formation; model studies have shown that a hydroxyapatite layer increases the expression of mRNA encoding the bone matrix proteins osteocalcin, osteopontin, and bone sialoprotein [34,35].…”

Greener Synthesis of Nano Hydroxyapatite using Fatty acids template for the application of Tissue Engineering Nano Hydroxyapatite: Fatty acids Synthesis and Characterizations

“…The need for bone substitutes to replace/restore the function of damaged/lost bone has become a major clinical challenge [1,2]. Current research, serious advances have been accomplished to treat the difficulty or displeasure of bone implant materials with cell/tissues based tissue engineering.…”