picture: the blood brain barrier
As seen in many of the articles above, Two fundamental difficulties in the delivery of drugs to treat central nervous system (CNS) diseases are the systemic delivery of therapeutics across the bloodbrain-barrier (BBB), and the targeting of drugs to specific tissues or cells within the brain. With the advent and promise of RNA-based therapeutics that utilize RNA interference (RNAi) to trigger specific silencing of genes within diseased tissues, the necessity to surmount such obstacles has become even more urgent. Most pre-clinical and clinical studies on delivery of RNAi to the CNS have utilized invasive, intra-cerebral delivery of RNA to the targeted tissue. Thus, methods need to be developed to facilitate delivery of therapeutically significant quantities of RNA to the CNS via the systemic route, and to elicit clinically significant RNAi effects within the CNS tissues.
One of the approaches developed to overcome this obstacle is using antibody keys to pass through both the blood brain barrier and the tumor cell membrane with the help of liposomes which deposit a genetically engineered non-viral plasmid in the brain cancer cells. The plasmid encodes a short hairpin RNA (shRNA) designed to interfere with the expression of the epidermal growth factor receptor, EGFR, a potent proponent of tumor cell proliferation. This works just like a Trojan horse. The liposome acts as the hollowed horse; the plasmid is the Trojan warrior released inside the cell to combat the cancer.
Pre clinical studies on mice have shown encouraging results. Tumors in the treated mice had reduced EGFR content, and the mice showed an 88 percent increase in survival time. With continued research and new discoveries, it won’t be too long before the problem of delivery is resolved.
For further information check out the article below:
http://www.innovations-report.com/html/reports/medicine_health/report-29779.html
No comments:
Post a Comment