|Year : 2016 | Volume
| Issue : 1 | Page : 1-2
Applications of nanotechnology in orthopedics
Mohamed Gouda Montaser
Orthopedic Surgery Department, Faculty of Medicine, Benha University, Benha, Egypt
|Date of Submission||28-Apr-2016|
|Date of Acceptance||29-Apr-2016|
|Date of Web Publication||28-Nov-2016|
Mohamed Gouda Montaser
Orthopedic Surgery Department, Faculty of Medicine, Benha University, Benha, 3221
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Montaser MG. Applications of nanotechnology in orthopedics. Benha Med J 2016;33:1-2
Nanotechnology (nanotech) is the manipulation of matter with at least one dimension sized from 1 to 100 nm ,.
Nanotech can be used in a multitude of medical applications (nanomedicine), and is a novel tool in orthopedics, including for use in the meniscus, in osteochondral defects, in osseointegration of implants, in vertebral disk regeneration and repair, and in targeted drug delivery .
| Osseointegration of implants|| |
Poor osseointegration can be a major contributor to implant loosening and subsequent failure. Modification of implant surfaces using nanotech has great potential for extending the life of the implant. Many nanofiber scaffolds made for tissue engineering have shown increased mesenchymal stem cell (MSC) osteogenic differentiation, as well as increased osteoblast attachment and proliferation onto nanostructured surfaces, including ceramics and metals. Nanocomposites that mimic bone in structure and composition have also been under active investigation. Recently, injectable nanostructured three-dimensional hydrogel scaffolds were developed that showed enhanced osteoblast adhesion and displayed suitable mechanical properties in the range of human cancellous bone, but fabricating scaffolds with mechanical performance close to compact bone remains a challenge .
| Targeted drug therapy|| |
Nanotech is being used in the field of targeted drug therapy for long-term inhibition of bacterial growth. Although earlier studies successfully incorporated large molecules, such as growth factors, into nanostructured materials, more recent studies have created nanofibrous scaffolds that incorporate smaller molecules, such as doxycycline and silver particles. These can be released in a controlled manner with long-term duration. Recently, implant nanocoatings were developed that contain monocyte chemotactic protein-1 and interleukin-12, which prevent infection by enhancement of the recruitment and activation of macrophages. These applications have great potential for use in the treatment of dental, periodontal, and bone infections. Within the field of orthopedics, further investigations into the long-term viability and toxicity of nanomaterials, in addition to direct comparisons of nanostructured materials and traditional materials, will enable a more definitive answer into the utility of the technology .
| Vertebral disk|| |
Nanotech has also been investigated for application in annulus fibrosus (AF) engineering. Electrospun scaffolds were created as a template for new AF tissue formation; however, the tensile moduli of these constructs reached only one-third to half that of a native lamella. Subsequently, a bilamellar construct with opposing collagen orientations of ±30° was created that showed a circumferential tensile modulus that closely replicated that of native AF. These advances in nanostructured scaffolds for vertebral disk engineering also appear promising ,.
Injuries to the articular cartilage remain one of the most challenging issues in orthopedics. Current treatments that focus on recruitment of MSCs generally result in mechanically inferior fibrocartilagenous tissue .
Tissue engineering strategies to develop scaffolds for osteochondral repair procedures are quite desirable, but to date they have not seen widespread clinical success. Biomimetic nanotech was used to develop a multiphase gradient scaffold with the biologic and functional properties of both bone and cartilage. An integrated composite was created with a bone-like layer of scaffold, a tidemark region with less mineralization, and a cartilaginous layer; the composite was shown to differentially support cartilage and bone generation in vivo. Statistically significant improvement in clinical scores was obtained with a 24-month follow-up, with 70% of patients showing complete filling of the osteochondral defect and complete integration of the graft on MRI .
The aligned nanofibrous scaffolds formed by electrospinning contain the microstructural features and nanolength scales of native extracellular matrix components and provide a substrate conducive to MSC expression of fibrous chondrogenic markers. Nonetheless, these constructs ultimately failed to achieve mechanical equivalence with fibrochondrocyte controls. However, when a similar MSV-laden scaffold based on poly (ε-caprolactone) was coupled with cyclic, physiologic tensile loading, increased fibrocartilage gene expression, collagen deposition, and tensile modulus resulted. Nanotech for meniscal repair is still in its infancy, but the initial data appear promising .
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Drexler KE. Engines of creation: the coming era of nanotechnology. Doubleday. ISBN; 2005; 0-385-19973-2
Drexler KE. Nanosystems: molecular machinary, manufacuring, and computation. New York: John Wiley & Sons; 2005. 40471–57547.
Freitas JR. What is nanomedicine? Dis Mon 2005; 51:325–341.
Miller DC, Haberstroh KM, Webster TJ. PLGA nanometer surface features manipulate fibronectin interactions for improved vascular cell adhesion. Biomed Mater Res A. 2007; 81:678–684.
Tsuang YH, Lin YS, Chen LT, Cheng CK, Sun JS. Effect of dynamic compression on in vitro chondrocyte metabolism. Int J Artif Organs 2008; 31:439–449 (SCI).
Zhang L, Ramsaywack S, Fenniri H, Webster TJ. Enhanced osteoblast adhesion on self-assembled nanostructured hydrogel scaffolds. Tissue Eng Part A 2008; 14:1353–1364.
Zhang L, Rodriguez J, Raez J, Myles AJ, Fenniri H, Webster TJ. Biologically inspired rosette nanotubes and nanocrystalline hydroxyapatite hydrogel nanocomposites as improved bone substitutes. Nanotechnology 2009; 20:175101.
Nerurkar NL, Baker BM, Sen S, Wible EE, Elliott DM, Mauck RL. Nanofibrous biologic laminates replicate the form and function of the annulus fibrosus. Nat Mater 2009; 8:986–992.
Kon E, Delcogliano M, Filardo G, Busacca M, Di Martino A, Marcacci M. Novel nano-composite multilayered biomaterial for osteochondral regeneration: a pilot clinical trial. Am J Sports Med 2011; 39:1180–1190.