Green composites in bone tissue engineering

Abstract

Natural and biodegradable polymers are of particular interest as green sources with low-cost and environmentally friendly features, and have been widely used for polymer composite development. The term "Green Composites" refers to polymer/ filler systems in which polymer, filler, or sometimes both components are green in view of sources from which they are yielded or their biodegradability. Natural fibers obtained from plants, animals, and/or geological processes are a big class of green sources widely applied in green composite development. There has also been continued research on recycling of green composite as well as developing hybrid systems for advanced applications. In view of their outstanding biodegradability and biocompatibility in biological media, green composites are crucial elements in medicine. For instance, chitin, chitosan, alginate, and collagen are green polymers widely used for manufacturing composites for hard tissue repair. Several green composite polymers have been used for development of hard tissue implants such as artificial bone, bone cement, knee hip replacement, and spine instrumentation. This review attempts to classify and discuss applications of green composites in bone tissue engineering. Applications of different types of natural fiber biocomposite scaffolds for fractured bone repair were reviewed; besides, morphological structures of scaffolds were correlated with the mechanical properties of human bone.

Structural Characterization Analyses of Low Brass Filler Biomaterial for Hard Tissue Implanted Scaffold Applications

“…These implanted scaffolds are translational therapeutic approaches [5] using tissue engineering techniques [6] to treat degenerative diseases [7] and improve cartilage regeneration efficiency [8] for osteoarthritis patients. At present, titanium filler [9] is still the most commonly used in metallic scaffolds [10] in advanced combinations with polymer-based biomaterials [11][12][13] during the green composite fabrication processes [14]. However, the existing titanium dioxide filler in these applications [15] was over-strengthened or too hard, resulting in a thin oxide surface layer not being discussed [16].…”

Special Features of Polyester-Based Materials for Medical Applications

“…Usually, materials used to repair bone defects are metallic biomaterials [ 36 , 37 ], bioceramics [ 38 , 39 ], and natural and synthetic polymers [ 40 , 41 ]. Hydroxyapatite (HA; (Ca 10 (PO 4 ) 6 (OH) 2 )) has been used as filler in polymer composites to improve the biocompatibility, mechanical strength, and porosity of biomaterials due to its similarity in structure and composition to bone and enamel, or to create polyester nanografts that impart the biodegradability and bioresorbability of polymers with their osteoconductivity, osteoinductivity, and osteointegration properties [ 42 , 43 ].…”

Green Polymer Nanocomposites for Skin Tissue Engineering

“…20,21 As another example, a group of scientists demonstrated the feasibility of affecting cell differentiation and bioactivity (cell labeling) without growth factor addition using scaffold stiffness optimization. 16,22 Moreover, they can be utilized as wound dressing and tissue reconstruction systems. For example, some keratin-based bionanocomposites are used as implantable biomaterials that can be absorbed to the surrounding tissue as a function of time, which brings about tissue stability.…”

“…The hydrophilicity of bionanocomposites is the golden key, making them a practical option for biomedical applications such as cell and tissue engineering. For instance, their noncorrosiveness, toughness, and renewability have made them a nice option for bone tissue engineering instead of ceramics and alloys. − Studies have shown that green nanocomposites own great advantages in comparison with the traditional ones such as cell permeability, cell/drug/gene/nutrient or growth factor delivery, biocompatibility, and biodegradability , as well as supporting cell adhesion or growth as a scaffold. , As another example, a group of scientists demonstrated the feasibility of affecting cell differentiation and bioactivity (cell labeling) without growth factor addition using scaffold stiffness optimization. , Moreover, they can be utilized as wound dressing and tissue reconstruction systems. For example, some keratin-based bionanocomposites are used as implantable biomaterials that can be absorbed to the surrounding tissue as a function of time, which brings about tissue stability.…”