Programmable, autonomous molecular robot fabricated and fueled with DNA
- PDF / 346,427 Bytes
- 2 Pages / 585 x 783 pts Page_size
- 69 Downloads / 186 Views
R
egeneration of defects in the bone tissue due to disease or trauma continues to be a major challenge in orthopedics and dentistry. Autologous transplants that are commonly used in the clinic suffer from limited availability of harvestable tissue in addition to significant patient discomfort. Engineered tissues offer a promising alternative to transplants and there is a growing need to develop three-dimensional (3D) scaffolds for tissue regeneration. Owing to their excellent osteoconductive properties, calcium phosphate-based materials have emerged as promising candidates for bone tissue regeneration. Typically, these materials require processing at a high temperature (hundreds of degree Celsius) for mechanical integrity which renders them unsuitable for encapsulation of bioactive molecules like drugs and growth factors to enhance the therapeutic effects. In a recent study, researchers from Dankook University in South Korea have prepared ceramic microparticles for sustained delivery of biomolecules at room temperature in an
Programmable, autonomous molecular robot fabricated and fueled with DNA
M
achines constructed from DNA can be made to walk along selfassembled DNA tracks. The simplest devices are controlled by sequential addition of DNA signals (molecules of single-stranded DNA, or oligonucleotides). Signal strands interact by hybridizing with complementary single-stranded DNA to form a double-helical duplex; they can also displace a strand from an existing duplex. For example, a signal strand can hybridize to bind a foot of the walker to its track. A complementary signal strand can then reverse this reaction
246
MRS BULLETIN
•
VOLUME 36 • APRIL 2011
•
aqueous environment that afford easy encapsulation of drugs and proteins. Self-setting calcium phosphate cements (CPCs) are being widely studied as potential injectable biomaterials to fill bone defects of any shape. Reporting in the February issue of the Journal of the AmerScanning electron micrograph of calcium phosphate ican Ceramic Society cements-collagen composite microparticle morphology and surface microstructure (inset) prepared by aqueous (DOI: 10.1111/j.1551emulsification at room temperature. 2916.2010.04314.x; p. 351), J.-H. Park, H.-W. Kim, and their colleagues introduce a trolled delivery of encapsulated drugs technique to fabricate self-hardening or growth factors to enhance cell funcmicrospheres with sizes of hundreds of tion in these scaffolds. Furthermore, the micrometers for use as 3D bone tissue surface of the α-TCP microspheres was matrix prepared by emulsification of covered by nanocrystals of bone minerα-tricalcium phosphate (α-TCP)-based al-like hydroxyapatite phase when the CPC mixed with collagen. CPC-collaparticles incubated in simulated body gen composites constitute the two major fluid. Results from in vitro cell studies components of the calcified bone matrix. indicated that osteoblasts adhere, spread, Biomolecules can be easily incorporated and proliferate on these microsphere into these microparticles by adding them subs
Data Loading...
