Biomedical Engineering Reference
In-Depth Information
of dry-blended bioceramic-polymer powders as raw materials
for SLS is adopted. A commercial SLS machine is modified to
reduce the consumption of raw materials in scaffold fabrica-
tion. Based on designed scaffold models, nanocomposite scaf-
folds with well-defined architecture and pore structure can be
fabricated via SLS. For using SLS-formed nanocomposite scaf-
folds as vehicles for the controlled release of biomolecules such
as growth factors, both entrapment and attachment strategies
are investigated. As a demonstration of the entrapment strat-
egy, Ca-P/PHBV microspheres loaded with bovine serum albu-
min (BSA) are fabricated and sintered into 3D porous scaffolds.
BSA-loaded nanocomposite scaffolds display controlled in vitro
release behavior. However, there are problems in this biomolecule
entrapment approach for SLS-formed scaffolds. Using the attach-
ment strategy, recombinant human bone morphogenetic protein-
2 (rhBMP-2) can be loaded onto surface-modified scaffolds
through non-covalent binding. The scaffold surface modification
byheparinnotonlyprovidesameanstoprotecttheloadedrhBMP-
2 but also improves the sustained release behavior of rhBMP-2.
The integration of advanced scaffold fabrication technology and
nanocompositeandgrowthfactordeliverytoformmultifunctional
tissue engineering scaffolds holds promises for successful bone
tissue regeneration.
45.1 Introduction
Orthopedic disorders and trauma are a serious and costly health
issueandaffectalargepopulationofpeoplearoundtheworld.Inthe
United States alone, the cost for orthopedic health care exceeds US
$28 billion per year, and this number is increasing due to an aging
population. 1 Currently, various strategies are investigated by many
researchers to maintain, repair, or improve bone tissue functions.
Although bone can regenerate itself, when it comes to critical-size
bone defects or bone tissue loss, bone grafts or bone graft substi-
tutesarenecessaryforthereplacementandregenerationofthefrac-
turedormissingbone.Currentclinicaltreatmentsinvolvetheuseof
autologous bone grafts, allogenous bone grafts, and bone graft sub-
stitutes such as biomedical polymers, bioceramics, and implantable
 
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