In today’s finest medical pavilions, where therapies are touted as cutting edge, the treatment of breast cancer still involves going under the knife. With luck, the tumor can be cut out without sacrificing the whole breast.
Using advanced modern medicine, it’s not possible to get at a diseased area without affecting the entire body. Surgery and radiation kill good cells along with bad, and chemotherapy and antibiotics infiltrate the whole body, producing unwanted side effects on normal organs. Even if we direct a drug to influence one part of the body, modern medicine can’t transport a drug precisely to the diseased area. Treatments today are still blunt weapons.
The promise of nanomedicine is to completely revolutionize treatment by transporting the medicine directly to the diseased site without compromising the rest of the body.
The body has developed partitions to protect itself and its critical organs. The central nervous system is the best-defended sites in the body and it encased in bone and has its own circulatory system. The “blood-brain barrier” makes that circulation impermeable to larger antibiotic molecules, which makes it difficult to treat central nervous system infections.
Injuries to the head develops meningitis or abscesses - destructive brain lesions , even if successfully treated, result in permanent neurological problems.
The rapidly evolving science of nanotechnology has provided us with novel techniques to achieve this goal in the form of tiny nanoparticles that can be injected into the blood stream, where they will locate an objective and accomplish a mission.
A nanoparticle that is designed to treat a disease inside the brain must be small enough to cross the blood-brain barrier. It has to elude the antibodies of the immune system that seek to destroy all things foreign in the body. It has to pass through the walls of the brain’s blood vessels.
We’ve been hearing about nanomedicine for many years, and the media has heralded its power many times over. As with various other technologies, hype preceded the real, often obstacle-ridden, work necessary to achieve success. But we are now seeing nanoparticles in real medical diagnoses and treatments. Some truly novel nanoparticle treatments, like those envisioned by DARPA, are now in human trials and showing positive results.
Nanoparticles are made out of biological materials and readily-available element that assimilates easily with human tissue, it is actually critical to bone and connective tissue health—and has the added bonus of being biodegradable.
The advantage of using silicon is that it is a common, crystalline material, and scientists have developed techniques to create uniform holes, or pores, in the crystal by exposure to acid—think dental cavity - or an electrical current. These particles are referred to as mesoporous silicon nanoparticles (MSNP’s).
The pores in the particle may be loaded, variously, with drugs designed to release within the target cell or with nucleic acids (DNA or RNA) for gene therapy. It is even possible to create molecular ‘nanogates’ to act as doors and prevent release of the entrapped cargo until it is exactly where it needs to be to do its work most efficiently. The outer coat of the particle will be interacting with other cells in the blood and must be able to elude the immune system.
Most cells have distinctive surface proteins, like product logos or lapel pins that distinguish one from another - this is how the immune system distinguishes friend from foe. The surface proteins are embedded in a lipid membrane and are used by the nanoparticle to identify the target cell. When the two come into contact, the particle’s “targeting” protein interacts with the targeted cell’s surface. This is the critical moment in which the diseased cell decides whether to allow the particle to bind to it. It requires the proteins to be a specific match.
To find discrete surface characteristics on the bacteria that infect the brain so the nanoparticles can home in on and attach to only those targets. Once attached, the particles will be absorbed into the bacteria and release a peculiar form of RNA that nature has already designed to control normal cell function, but that humans have just begun to co-opt for therapeutic purposes.
It is even possible to create molecular ‘nanogates’ to act as doors and prevent release of the entrapped cargo until it is exactly where it needs to be.
The messenger of the cell, RNA regulates the expression of genes, meaning that it can turn them off. Scientists first discovered RNA-based gene silencing in plants - purple petunias to be precise. They turned the flowers partially white by silencing the gene that produced the purple color. The same mechanism was later found to operate in primitive roundworms.
There are siRNAs in every cell, selectively turning off certain protein manufacturing functions, be it the cell of an animal or plant, human or manatee, bacteria or even virus.
Early work in this area showed that merely injecting “naked siRNA,” into the bloodstream wouldn’t work for the treatment of human disease. But more recent research has showed that when it’s tucked into a silicon mesopore vehicle, siRNA can be protected from scavenging immune cells and circulating nucleases, the enzymes that break down old DNA and RNA, until it has done its job.
The treatment envisaged by the DARPA team will likely be a dose of particles held in a liquid suspension and injected into the body. The particles will then be transported passively in the blood, floating from the veins, through the heart, into the arteries, and eventually to the capillaries of thebrain, where they’ll bind to surface proteins on the bacteria of the brain infection. The job completed, the particles will then be disassembled by housekeeping cells and the component parts - bits of silicon and nucleic acids - recycled or excreted.
There are clinical trials already underway for nanoparticle approaches to the treatment of cancer, obesity, and viral infections. We might target the overactive fat cells in obesity, the tumor cells in cancer, the virus in hepatitis, or the bacteria in traumatic brain infections. While we may never eliminate the damage done by a bullet passing through a limb or a brain, we’re coming closer to a future where there is no longer any need for surgery, radiation, chemotherapy, or antibiotics - a future where we can reach the diseased cells directly.
Using advanced modern medicine, it’s not possible to get at a diseased area without affecting the entire body. Surgery and radiation kill good cells along with bad, and chemotherapy and antibiotics infiltrate the whole body, producing unwanted side effects on normal organs. Even if we direct a drug to influence one part of the body, modern medicine can’t transport a drug precisely to the diseased area. Treatments today are still blunt weapons.
The promise of nanomedicine is to completely revolutionize treatment by transporting the medicine directly to the diseased site without compromising the rest of the body.
The body has developed partitions to protect itself and its critical organs. The central nervous system is the best-defended sites in the body and it encased in bone and has its own circulatory system. The “blood-brain barrier” makes that circulation impermeable to larger antibiotic molecules, which makes it difficult to treat central nervous system infections.
Injuries to the head develops meningitis or abscesses - destructive brain lesions , even if successfully treated, result in permanent neurological problems.
The rapidly evolving science of nanotechnology has provided us with novel techniques to achieve this goal in the form of tiny nanoparticles that can be injected into the blood stream, where they will locate an objective and accomplish a mission.
A nanoparticle that is designed to treat a disease inside the brain must be small enough to cross the blood-brain barrier. It has to elude the antibodies of the immune system that seek to destroy all things foreign in the body. It has to pass through the walls of the brain’s blood vessels.
We’ve been hearing about nanomedicine for many years, and the media has heralded its power many times over. As with various other technologies, hype preceded the real, often obstacle-ridden, work necessary to achieve success. But we are now seeing nanoparticles in real medical diagnoses and treatments. Some truly novel nanoparticle treatments, like those envisioned by DARPA, are now in human trials and showing positive results.
Nanoparticles are made out of biological materials and readily-available element that assimilates easily with human tissue, it is actually critical to bone and connective tissue health—and has the added bonus of being biodegradable.
The advantage of using silicon is that it is a common, crystalline material, and scientists have developed techniques to create uniform holes, or pores, in the crystal by exposure to acid—think dental cavity - or an electrical current. These particles are referred to as mesoporous silicon nanoparticles (MSNP’s).
The pores in the particle may be loaded, variously, with drugs designed to release within the target cell or with nucleic acids (DNA or RNA) for gene therapy. It is even possible to create molecular ‘nanogates’ to act as doors and prevent release of the entrapped cargo until it is exactly where it needs to be to do its work most efficiently. The outer coat of the particle will be interacting with other cells in the blood and must be able to elude the immune system.
Most cells have distinctive surface proteins, like product logos or lapel pins that distinguish one from another - this is how the immune system distinguishes friend from foe. The surface proteins are embedded in a lipid membrane and are used by the nanoparticle to identify the target cell. When the two come into contact, the particle’s “targeting” protein interacts with the targeted cell’s surface. This is the critical moment in which the diseased cell decides whether to allow the particle to bind to it. It requires the proteins to be a specific match.
To find discrete surface characteristics on the bacteria that infect the brain so the nanoparticles can home in on and attach to only those targets. Once attached, the particles will be absorbed into the bacteria and release a peculiar form of RNA that nature has already designed to control normal cell function, but that humans have just begun to co-opt for therapeutic purposes.
It is even possible to create molecular ‘nanogates’ to act as doors and prevent release of the entrapped cargo until it is exactly where it needs to be.
The messenger of the cell, RNA regulates the expression of genes, meaning that it can turn them off. Scientists first discovered RNA-based gene silencing in plants - purple petunias to be precise. They turned the flowers partially white by silencing the gene that produced the purple color. The same mechanism was later found to operate in primitive roundworms.
There are siRNAs in every cell, selectively turning off certain protein manufacturing functions, be it the cell of an animal or plant, human or manatee, bacteria or even virus.
Early work in this area showed that merely injecting “naked siRNA,” into the bloodstream wouldn’t work for the treatment of human disease. But more recent research has showed that when it’s tucked into a silicon mesopore vehicle, siRNA can be protected from scavenging immune cells and circulating nucleases, the enzymes that break down old DNA and RNA, until it has done its job.
The treatment envisaged by the DARPA team will likely be a dose of particles held in a liquid suspension and injected into the body. The particles will then be transported passively in the blood, floating from the veins, through the heart, into the arteries, and eventually to the capillaries of thebrain, where they’ll bind to surface proteins on the bacteria of the brain infection. The job completed, the particles will then be disassembled by housekeeping cells and the component parts - bits of silicon and nucleic acids - recycled or excreted.
There are clinical trials already underway for nanoparticle approaches to the treatment of cancer, obesity, and viral infections. We might target the overactive fat cells in obesity, the tumor cells in cancer, the virus in hepatitis, or the bacteria in traumatic brain infections. While we may never eliminate the damage done by a bullet passing through a limb or a brain, we’re coming closer to a future where there is no longer any need for surgery, radiation, chemotherapy, or antibiotics - a future where we can reach the diseased cells directly.