.
- Abraxane, approved by Food and Drug Administration to treat breast cancer, is the nanoparticle albumin bound paclitaxel.
- In a mice study, scientists from Rice University and University of Texas MD Anderson Cancer Center reported enhanced effectiveness and reduced toxicity of an existing treatment for head and neck cancer when using the nanoparticles to deliver the drug. The hydrophilic carbonic clusters functionalized with polyethylene glycol or PEG-HCC are mixed with the chemotherapeutic drug paclitaxel (Taxol) and the epidermal growth factor receptor (EGFR) targeted Cetuximab and injected intravenously. They found the tumors were killed more effectively with radiation and the healthy tissue suffered less toxicity than without the nanotechnology drug delivery. The standard treatment contains Cremophor EL which allows the hydrophobic paclitaxel to be delivered intravenously. Replacing the toxic Cremophor with carbon nanoparticles eliminated its side effect and improved drug targeting which in turn required a lower dose of the toxic paclitaxel.[17]
- Researchers at Case Western Reserve University reported using nanoparticle chain to deliver doxorubicin to breast cancer cells in a mice study. Three magnetic, iron-oxide nanospheres were chemically linked to one doxorubicin-loaded liposome and formed a 100 nm long nanoparticle chain. After the nanochains penetrated the tumor, radiofrequency field was generated that caused the magnetic nanoparticles to vibrate and rupture the liposome, dispersing the drug in its free form throughout the tumor. The result showed that the nano treatment was more effective in halting tumor growth than the standard treatment with doxorubicin. It is also less harmful to healthy cells since only 5% to 10% of the standard dose of doxorubicin were used.
- Nanoparticles made of polyethylene glycol (PEG) carrying payload of antibiotics at its core could swift charge thus allowing them to target bacterial infection more precisely inside the body, a group of MITresearchers reported. The nanoparticles, containing a sub-layer of pH sensitive chains of the amino acid histidine, carry a slightly negative charge when circulating in the blood stream, can evade detection and clearing by the immune system. When they encounter an infection site the particles gain a positive charge provoked by the slightly acidic environment at the infection sites, allowing them to bind to the negatively charged bacterial cell walls and release antibiotics at locally high concentration. This nano delivery system can potentially destroy bacteria even it has developed resistance to antibiotics because of the targeted high dose and prolonged release of the drug. Although a lot of work is still needed, the researchers believe that it points to a new direction of using nanotechnology to treat infectious disease.
- Using the biomimetic strategy, researchers in the Harvard University Wyss Institute demonstrated in a mouse model that the drug coated nanoparticles can dissolve blood clots by selectively binding to the narrowed regions in the blood vessels – just like the platelets do. Aggregates of biodegradable nanoparticles coated with tissue plasminogen activator (tPA), each about the size of a platelet, were injected intravenously. In the region of vessel narrowing, shear stresses dissociate the aggregates and release the tPA-coated nanoparticles which bind and degrade the blood clots. By précised targeting and concentrating drug at the location of obstruction, the dose used is less than 1/50th of the normal dose. The nanotherapeutics will greatly reduce the severe side effect of bleeding, commonly found in standard treatment of thrombosis.
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