Targeting Rgd-Integrins In U87 Cells To Enhance The Delivery Of Micelle-Encapsulated Temozolomide

Hannah Mitchum

School Name

Governor's School for Science and Math

Grade Level

12th Grade

Presentation Topic

Biochemistry

Presentation Type

Mentored

Mentor

Mentor: Dr. Broome; Department of Radiology and Radiological Science, Medical University of South Carolina

Written Paper Award

3rd Place

Abstract

The Blood Brain Barrier (BBB) is a major obstacle when treating brain diseases. Glioblastoma tumor have been particularly devastating as they are nearly impossible to treat with surgery and/or chemotherapy. The FDA approved drug, Temozolomide (TMZ), is effective at destroying U87 brain tumor cell lines in vitro. But in vivo, TMZ is unable to access the tumor efficiently due to charge, size and lipophilicity. Patients administered TMZ have a 10% chance of surviving two years while suffering severe side effects. Clinical research has proven micelle packages are capable of delivering encapsulated drugs across the BBB. The aims of this research is to enhance TMZ delivery and reducing off site side effects using cRGD conjugated micelles. The micelle, composed of PEG-PE-amine and PHC are conjugated with the peptide cRGD and dylite 680 to the amine group by sonication. The cRGD peptide is specific for the RGD integrin seen in U87 tumor cell lines. The micelles showed TMZ encapsulation with dylite 680 tagging using Ultra-Violet Visible Spectroscopy and Dynamic Light Scattering confirmed particle size. U87 cells were treated for varying times, with targeted micelle (RMTMZ) and non-targeted (MTMZ) in the presence or absence of Brefeldin A (BA), an inhibitor of receptor mediated endocytosis. Epi-florescent microscopy showed that RMTMZ without BA had a 77% greater intensity compared to RMTMZ with BA, and 56% greater intensity than MTMZ. Cytotoxicity assay indicated RMTMZ was 71% more proficient at killing U87 cell lines. RMTMZ can now be tested in vivo followed by a pH stability assay.

Location

Owens 203

Start Date

4-16-2016 11:00 AM

COinS
 
Apr 16th, 11:00 AM

Targeting Rgd-Integrins In U87 Cells To Enhance The Delivery Of Micelle-Encapsulated Temozolomide

Owens 203

The Blood Brain Barrier (BBB) is a major obstacle when treating brain diseases. Glioblastoma tumor have been particularly devastating as they are nearly impossible to treat with surgery and/or chemotherapy. The FDA approved drug, Temozolomide (TMZ), is effective at destroying U87 brain tumor cell lines in vitro. But in vivo, TMZ is unable to access the tumor efficiently due to charge, size and lipophilicity. Patients administered TMZ have a 10% chance of surviving two years while suffering severe side effects. Clinical research has proven micelle packages are capable of delivering encapsulated drugs across the BBB. The aims of this research is to enhance TMZ delivery and reducing off site side effects using cRGD conjugated micelles. The micelle, composed of PEG-PE-amine and PHC are conjugated with the peptide cRGD and dylite 680 to the amine group by sonication. The cRGD peptide is specific for the RGD integrin seen in U87 tumor cell lines. The micelles showed TMZ encapsulation with dylite 680 tagging using Ultra-Violet Visible Spectroscopy and Dynamic Light Scattering confirmed particle size. U87 cells were treated for varying times, with targeted micelle (RMTMZ) and non-targeted (MTMZ) in the presence or absence of Brefeldin A (BA), an inhibitor of receptor mediated endocytosis. Epi-florescent microscopy showed that RMTMZ without BA had a 77% greater intensity compared to RMTMZ with BA, and 56% greater intensity than MTMZ. Cytotoxicity assay indicated RMTMZ was 71% more proficient at killing U87 cell lines. RMTMZ can now be tested in vivo followed by a pH stability assay.