Bone tissue scaffolds

Jose MV et al (2009) Fabrication and characterization of aligned nanofibrous PLGA/Collagen blends as bone tissue scaffolds. Polymer 50(15) 3778-3785... 

There is little difference between the ideal dental and bone tissue scaffolds. They must both be biomimetic to allow for cell interaction, provide sufficient structural support, degrade at a rate that is consistent with bone tissue formation, and able to incorporate various growth factors to aid in regeneration of native tissue. Supramolecular assembling peptide-based scaffolds provide a conduit for cell delivery due to its biomimetic namre. However, as a self-assembled scaffold, these peptide-based constructs often lack the structural capability to provide a stable dental scaffold by itself. To rectify this issue, it would be prudent to develop a composite scaffold capable of providing structural support while at the same time offering a biomimetic environment that degrades at a rate consistent with dental tissue formation. 

J.F. D Oloiveira, A.M. Rossi. Effect of Process Parameters on the Characteristics of Porous Calcium Phosphate Ceramics for Bone Tissue Scaffolds. Artificial Organ. 2004 27(5) 406-411. 

Image is adapted from Cooke, M.N., 2004. Novel Stereolithographic Manufacture of Biodegradable Bone Tissue Scaffolds, Case Western Reserve University. 

Ordered mesoporous silica have already been studied as carriers for drug delivery [1,2] recently, their use has also been proposed in bone tissue engineering [3,4], in combination with bioactive glass-ceramic scaffolds [5,6]. The kinetics of ibuprofen release in SBF [7] from MCM-41 silica with similar pore diameter has shown puzzling discontinuities [3,6,8] aim of the present work is to assess whether these anomalies may be related to structural changes in the MCM-41 mesoporous spheres under the adopted conditions. 

Li Z, Ramay HR, Hauch KD et al (2005) Chitosan-alginate hybrid scaffolds for bone tissue engineering. Biomaterials 26 3919-3928... 

Yilgor, P., Sousa, R.A., Reis, R.L., Hasirci, N. and Hasird, V. (2008) 3D plotted PCL scaffolds for stem cell based bone tissue engineering. Macromolecular Symposia, 269, 92-99. 

Raman spectroscopy can be used for live, in situ, temporal studies on the development of bone-like mineral (bone nodules) in vitro in response to a variety of biomaterials/scaffolds, growth factors, hormones, environmental conditions (e.g. oxygen pressure, substrate stiffness) and from a variety of cell sources (e.g. stem cells, FOBs or adult osteoblasts). Furthermore, Raman spectroscopy enables a detailed biochemical comparison between the TE bone-like nodules formed and native bone tissue. Bone formation by osteoblasts (OB) is a dynamic process, involving the differentiation of progenitor cells, ECM production, mineralisation and subsequent tissue remodelling. 

As well as being used as a scaffold for tissue engineering, Hutchens et al. [64] described the creation of a calcium-deficient hydroxyapatite, the main mineral component of bone. Calcium phosphate particles were precipitated in BC by consecutive incubation of calcium chloride and sodium phosphate solutions. Initial tests with osteoblasts in the in vitro evaluation showed that solid fusion between the material and the bone tissue is possible. Hence, this material is a good candidate for use as a therapeutic implant to regenerate bone and heal osseous damage. 

Kim, H.J., Kim, U.J., Vunjak-Novakovic, G., Min, B.H., and Kaplan, D.L. "Influence of macro-porous protein scaffolds on bone tissue engineering from bone marrow stem cells". Biomaterials 26(21), 4442-4452 (2005a). 

Meinel, L., Karageorgiou, V., Fajardo, R., Snyder, B., Shinde-Patil, V., Zichner, L., Kaplan, D., Langer, R., and Vunjak-Novakovic, G. "Bone tissue engineering using human mesenchymal stem cells Effects of scaffold material and medium flow". Ann. Biorned. Eng. 32(1), 112-122 (2004b). 

CNTs are especially valued as implant materials thanks to their novel mechanical properties and surface functionability.35 They have been found to make an ideal scaffold for the growth of bone tissue.36 Moreover, many tissues and organs require bio-compatible substrates to facilitate tissue growth and implantation. The fabric made fom CNTs serves as an efficient tissue scaffold.36 Several publications demonstrate that CNTs can be used as a substrate for neuronal growth, and that modifications of the CNTs can be employed to modulate the development of neurons. This suggests that it may be possible to employ suitably functionalized CNTs as neural prostheses in neurite regeneration.35 Lipid bilayers have been developed using a nanotube template. 

Rezwan K, Chen QZ, Blaker JJ, Boccaccini AR (2006) Biodegradable and bioactive porous polymer/inorganic composite scaffolds for bone tissue engineering. Biomaterials 27(18) 3413—3431... 

Kretlow JD, Mikos AG (2007) Review mineralization of synthetic polymer scaffolds for bone tissue engineering. Tissue Eng 13(5) 927—938... 

H. Yoshimoto, Y.M. Shin, H. Terai, J.P. Vacanti. 2003. A biodegradable nanofiber scaffold by electrospinning and its potential for bone tissue engineering. Biomaterials, 24. pp. 2077. 

Bokhari, M. Birch, M. Akay, G. Polyhipe polymer a novel scaffold for in vitro bone tissue engineering. Adv. Exp. Med. Biol. 2003, 534, 247-254. 

If a scaffold is transplanted, the rate of biodegradability is important to ensure that the scaffold remains to support a transplant until a natural ECM replaces it. The biodegradation or resorption rate is a function of the scaffold composition, structure, and the mechanical load present at the site of transplantation. The necessary rate at which the scaffold is degraded varies according to the tissue type. For example, slow degradation is allowable in bone tissue, whereas in other tissues chronic inflammation may occur if the rate is too low.f It is important that the degradation by-products are nontoxic to the body. 

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