Development of gelatin/carboxymethyl chitosan/nano-hydroxyapatite composite 3D macroporous scaffold for bone tissue engineering applications

Scaffolding polymeric biomaterials: Are naturally occurring biological macromolecules more appropriate for tissue engineering?

Nowadays, tissue and organ failures resulted from injury, aging accounts, diseases or other type of damages is one of the most important health problems with an increasing incidence worldwide. Current treatments have limitations including, low graft efficiency, shortage of donor organs, as well as immunological problems. In this context, tissue engineering (TE) was introduced as a novel and versatile approach for restoring tissue/organ function using living cells, scaffold and bioactive (macro-)molecules. Among these, scaffold as a three-dimensional (3D) support material, provide physical and chemical cues for seeding cells and has an essential role in cell missions. Among the wide verity of scaffolding materials, natural or synthetic biopolymers are the most commonly biomaterials mainly due to their unique physicochemical and biological features. In this context, naturally occurring biological macromolecules are particular of interest owing to their low immunogenicity, excellent biocompatibility and cytocompatibility, as well as antigenicity that qualified them as popular choices for scaffolding applications. In this review, we highlighted the potentials of natural and synthetic polymers as scaffolding materials. The properties, advantages, and disadvantages of both polymer types as well as the current status, challenges, and recent progresses regarding the application of them as scaffolding biomaterials are also discussed.

A ternary doped single matrix material with dual functions of bone repair and multimodal tracking for applications in orthopedics and dentistry

Hydroxyapatite (HA) has been broadly used for the repair of human hard tissues due to its bioactivity and similarity to the mineral of bones and teeth. We prepared a fluorine (F), ytterbium (Yb) and holmium (Ho) ternary doped HA (HYH-F) material and investigated its dual functions of bone repair and multimodal tracking. The results showed that the HYH-F material could display clear X-ray micro-computed tomography (Micro-CT) images based on Yb ions, and Ho ions due to its superparamagnetic properties for magnetic resonance imaging (MRI), while the F ions could enhance the upconversion (UC) fluorescence of the Yb/Ho combination. The ternary doped HYH-F material shows good compatibility with cells and bone tissue. A joint usage of Micro-CT imaging and UC fluorescence imaging distinctly and synergistically demonstrated the distribution state and degradation of the HYH-F material during new bone reconstruction. The single matrix HA material with ternary doping will be beneficial for future biomedical investigation and applications, and it can not only be a bone repair biomaterial, but also provide lifelong multimodal tracking efficacy.

A Review on Properties of Natural and Synthetic Based Electrospun Fibrous Materials for Bone Tissue Engineering

Bone tissue engineering is an interdisciplinary field where the principles of engineering are applied on bone-related biochemical reactions. Scaffolds, cells, growth factors, and their interrelation in microenvironment are the major concerns in bone tissue engineering. Among many alternatives, electrospinning is a promising and versatile technique that is used to fabricate polymer fibrous scaffolds for bone tissue engineering applications. Copolymerization and polymer blending is a promising strategic way in purpose of getting synergistic and additive effect achieved from either polymer. In this review, we summarize the basic chemistry of bone, principle of electrospinning, and polymers that are used in bone tissue engineering. Particular attention will be given on biomechanical properties and biological activities of these electrospun fibers. This review will cover the fundamental basis of cell adhesion, differentiation, and proliferation of the electrospun fibers in bone tissue scaffolds. In the last section, we offer the current development and future perspectives on the use of electrospun mats in bone tissue engineering.