Bone tissue regeneration biomaterials

Xie F et al (2006) Effect of shearing on formation of silk fibers from regenerated Bombyx mori silk fibroin aqueous solution. Int J Biol Macromol 38(3-5) 284-288 Li C et al (2006) Electrospun silk-BMP-2 scaffolds for bone tissue engineering. Biomaterials 27(16) 3115-3124... 

Self-assembling Biomaterials for Scaffold Based Bone Tissue Regeneration... 

Besides SAPs, Hartgerink et. al. have developed peptide amphiphiles (PAs) [68], a new class of self-assembling peptide-based biomaterials with potential for bone tissue regeneration. A PA is comprised of three peptide regions, each with different functions, and a hydrophobic aliphatic tail. These components interact with each other, self-assembling to form a cylinder (Figure 7). Particularly, the structure of a PA contains four cysteine amino acids that are adjacent to a hydrophilic aliphatic core. This allows for disulfide bonding, which stabilizes the PA structure when it self-assembles. Furthermore, phosphoserine, which is copious in... 

Cool SM, Kenny B, Wu A, Nurcombe V, Trau M, Cassady Al, et al. Poly (3-hydroxybutyrate-co-3-hydroxyvalerate) composite biomaterials for bone tissue regeneration in vitro performance assessed by osteoblast proliferation, osteoclast adhesion and resorption, and macrophage proinflammatory response. J Biomed Mater Res Part A 2007 599-610. 

Polyphosphoesters are biomaterials composed of phosphorus-incorporated monomers. These polymers consist of phosphates with two R groups, one in the backbone and the other as a side group. They have good biocompatibility and a similarity to biomacromolecules such as DNA and RNA. Polyphosphoesters are divided into two different classes polyphosphonates with an alkyl or aryl R group and polyphosphates with an alkoxy or aryloxy R group. Polyphosphoesters are copolymerized with polyethers and polyesters to enhance their physical properties. They have been studied as scaffolds for bone tissue regeneration [8]. 

Francis, L., Venugopal, J., Prabhakaran, M.P., Thavasi, V., Marsano, E., Ramakrishna, S., 2010. Simultaneous electrospin-electrosprayed biocomposite nanofibrous scaffolds for bone tissue regeneration. Acta Biomaterials 6,4100-4109. 

According to such requirements, the fabrication of an ideal scaffold for bone-tissue regeneration requires three major factors cells, signals and proper biomaterials. 

Biomaterials must be properly selected because their physical, mechanical and biological properties will determine, to a great extent, the properties of the tissue-engineering scaffold. In Section 15.4, the main characteristics of monolithic biomaterials, precisely ceramics and polymers, are depicted, whereas in Section 15.5 the potential of ceramic-polymer nanocomposites in bone-tissue regeneration is illustrated. 

Nanocomposites combined with osteoconductive, osteoinductive factors, and/or osteogenic cells have gained much interest as a new and versatile class of biomaterial suitable for next-generation biomimetic scaffolds. The experimental examples summarized in this chapter represent some of the developments of nanocomposites designed for bone-tissue regeneration. However, further substantial research efforts are required to address some major key challenges. 

Arcos, D. and Vallet-Regi, M. 2010. Sol-gel silica-based biomaterials and bone tissue regeneration. Acta Biomater 6 2874-88. 

Composites made with carbon nanostructures have demonstrated their high performance as biomaterials, basically applied in the field of tissue regeneration with excellent results. For example, P.R. Supronowicz et al. demonstrated that nanocomposites fabricated with polylactic acid and CNTs can be used to expose cells to electrical stimulation, thus promoting osteoblast functions that are responsible for the chemical composition of the organic and inorganic phases of bone [277]. MacDonald et al. prepared composites containing a collagen matrix CNTs and found that CNTs do not affect the cell viability or cell proliferation [278]. 

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