Cancer treatment also benefits from quantum dots in other ways. Nanomedicine has parented and fostered a new approach over the years - silencing of specific genes with the aid of quantum dots. Through passive targeting, quantum dot probes are delivered to tumor cells where they permeate the cell membrane and help withhold further activity of the parasitic cell.
Quantum dots have replaced inorganic fluorophore in fluorescence spectroscopy. Due to their small scale and ability to emit colors of light, quantum dots have been used as "dye" for intra-operative detections of tumors as the doctor traces the path of quantum dots and their absorbtion rate to determine the concentration and location of a tumor in a body.
NANOMEDICINE APPLICATIONS
QUANTUM DOTS
Fighting Cancer
Quantum beads - tiny polymer beads filled with distinctly colored quantum dots and assigned to react with a certain antibody or peptide - enable scientists to identify specific genetic markers, gene sequences, or protein sequences within a sample. Once released, the beads detect and bind to their assigned targets - in cancer, to cells containing the mutated gene, and indicate to researchers the cancerous cell.
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In the future, scientists hope to extend the compatability of quantum dots and utilize them to track the growth of a living cell in a human body or to label numerous molecules at the same time and follow their intracellular signaling cascade during cellular transformation.
NANOPARTICLES
Antioxidants
Cerium oxide nanoparticles have been observed to complete the function of antioxidants: remove oxygen free radicals from a patient's bloodstream following from a daunting injury. Scientists at Rice University have conducted extensive research to further learn how nanoparticles may be used in nanomedicine. Their reserach demonstrated that nanopartcles are capable of absorbing oxygen free radicals from the bloodstream, transporting them and releasing them once the oxygen reached a less dangerous state. One nanoparticle may repeat the process as many times as necessary.
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Bone Growth
Cerium oxide nanoparticles have been observed to complete the function of antioxidants: remove oxygen free radicals from a patient's bloodstream following from a daunting injury. Scientists at Rice University have conducted extensive research to further learn how nanoparticles may be used in nanomedicine. Their reserach demonstrated that nanopartcles are capable of absorbing oxygen free radicals from the bloodstream, transporting them and releasing them once the oxygen reached a less dangerous state. One nanoparticle may repeat the process as many times as necessary.
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Cellular Imaging
Quantum dots offer a new substitute for organic dyes in the process of cellular imaging. Organic dyes are often unable to meet the demand; quantum dots offer a brighter solution. Due to their minute size, quantum dot probes exhibit great potential in the "real-time tracking" of molecules and cellular components - such as DNA, antibodies, and nucleuc acid aptamers. In addition, by infusing a cell with certain colored quantum dots, a researcher will be able to track the cell's movement and migration simply by following the color emitted by the quantum dot! Such applications introduce nanomedicine into other sectors of the medical field, such as cancer diagnosis and treatment, lymphocyte immunology, and stem cell therapeutics.
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NANOPARTICLES (IMAGE 21)
Diagnosing Diseases
Researchers at the University of Missouri-Columbia have found a new and faster way to diagnose diseases. By lacing nanoparticles with specific antibodies, which react and bond with proteins produced by cancerous lung cells, the researchers created a "nano-hound" which will follow the "scent" and lead them to the cancerous areas. In their study, the antibody-infused nanoparticles were injected into a test subject - a pig. The pig was then a subject to a CAT scan, which revealed the cancerous areas as the nanoparticles surrounded the cancerous lung cells. This method provides an easier and faster way of diagnosing cancer than ever before!
Drug Delivery
Prevously, nanoparticles have served as drug delivery systems with a single repugnance - they had to be directly injected into the patient, a process which limited their usefulless and availability. Now, however, reserachers at the Massachusettes Institute of Technology (MIT) and Birgham and Women's Hospital (BWH) have synthesized a new species of oral nanoparticles. Now instead of an injection, a patient was faced with a less threatening pill!
Any drug, encapsulated in a nanoparticle may be swallowed to deliver the medicine to the bloodstream. Each nanoparticle is coated with anitbodies which act as "keys" to unlock the receptors of the cells of intestinal walls, permitting the nanoparticle to break through and enter the bloodstream.
MIT and BWH research has shown that such methods do indeed work; orally acquired insulin was sucessfully delivered in mice as it entered the bloodstream of the animals.
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Another soldier of nanomedicine and drug delivery is the nanodiamond. Relatively new, the nanodiamonds have only experienced postulated possiblities of their use in drug delivery. Some reserachers are testing the use of nanodiamonds, surrounded with chemotherapy drugs, in the treatment of brain tumors; others are testing a similar method for the treatment of leukemia.
Gene Therapy Applications
Nanoparticles have introduced an alternative to viral vectors in terms of transfer of genetic material. Viral vectors have proven to be efficient in their transportatino job, however side effects such as the lethal case of a high school student who was enrolled in a gene therapy course at the University of Pennsylvania motivate further inquiries in nanomedicine.
The process of gene delivery through nanoparticles is simple:
1) The nanoparticle is infused with polymers and DNA material.
2) The nanoparticle is then injected into the body of the patient, where they locate the targeted cells.
3) Through the process of endocytosis, the nanoparticle is engulfed by the target cell.
4) Once inside, the nanopartcile automatically releases its DNA material within the cell, where the DNA may be activated by natural means (gene therapy).
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Tissue Regeneration
NANOROBOTS
Tissue regeneration procedures currently proposed by medicine employ measures, such as chemotherapy, wreak havoc on the human body in their quest to rid the patient off cancerous cells. Surgical procedures also yeild a low survival rate, often murdering the patient rather than healing, not to mention cases in which a new organ is rejected or the body may be infected.
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Victims of forceful trauma will experience less pain during their recovery as the nanobots dispose of dead flesh at the wound site and regrow the lost tissue - quickly, efficiently, and without scarring.
Nanomedicine presents an innovative way of repairing damaged tissue - with the help of tiny nanobots. Since nanobots are only approximately six atoms wide, they are capable of interacting with the human body on the same level as bacteria and viruses, constructing the necessary tissue with native particles - molecules and atoms - to synthesize a new tissue layer.
Unlike most drugs, nanobots are neutral in terms of human body biochemistry, and thus will not be perceived as enemies by the immune system. Such identity will permit nanobots to freely float through the patient's bloodstream and clear up cholesterol, perform microsurgery, and even replace helper-T cells in a weakened inmmune system - which may also aid AIDS patients as well.
Diabetes
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Diabetes is mainly caused due to elevated sugar levels in the blood. In the human body, the protein hSGLT3 monitors extracellular glucose levels, while insulin stimulates the uptake of glucose within the body by muscle and liver cells.
Studies conducted by Adriano Calvancati propose a way to enlist nanomedicine into the war against diabetes. Nanobot's minute size will allow them to travel through the bloodstream of a diabetes patient without interference and measure Blood Glucose Levels at specific time intervals; thus, the glucose levels may be constrantly monitered and kept in check, quickly notifying the patient or the doctor of any critical glucose levels. This way, the patient will be able to take the prescribed medication at the correct time, effectively combating diabetes.
With the use of medical nanobots for such task, the necessity for blood sampling will be eliminated, or at least minimized; in turn, the possibility of acquiring a blood infection will also be minimized, limiting the extend of side effects for diabetes monitoring and treatment.