The Secret Society: Descendants of Crypto-Jews in the San Antonio ...

More documents

Recommendations

Info

Unbound vesicle Free aqueous solution Vesicle Aggregate (a) (b) Figure 4: Freeze-fracture TEM images of the biotinylated vesicles 72 hours after the addition of avidin (notice the scales are different). (a) 0.05% molar ratio of biotin showing no aggregation, the entire replica contained unbound vesicles. (b) 2.0% molar ratio of biotin showing a 1.3 µm aggregate. The dropwise addition of the biotinylated vesicles to an avidin solution was an important factor in ensuring proper exposure of the avidin to the biotin on the vesicles. Trials were performed where the avidin was not added dropwise to the biotinylated vesicles, and the results were skewed with more aggregation occurring in the lowest molar ratio of surface biotin. This may also be influenced by the salt concentration in the PBS buffer solution. Overall, there is a positive correlation between the concentration of surface biotin and extent of aggregation as shown by the characterization methods. 5. Conclusion The optimization of the active targeting component of this drug delivery system relies on the concentration of surface biotin, salt concentration of the PBS solution and methodology of the addition of avidin. The biotin-avidin-biotin series can be used as an exchangeable system for targeting other tissues or cells, ie., tumor cells. The further development of such a system will provide a useful tool for drug delivery. There are other techniques that can be explored to further optimize the biotin-avidin-biotin system. These techniques include using free floating biotin for the random binding of sites on avidin to decrease aggregation and a monomeric avidin column for the removal of biotinylated vesicles that have available binding sites for avidin. As a result of the tetrameric structure of avidin and steric hindrance, if one biotin molecule binds to the trans side (trans to the vesicle), there is one location available for the biotin-peptide to bind on the same side. By adding free floating biotin, this can decrease the extent of aggregation by limiting the number of available binding sites. The monomeric avidin column will bind (reversibly) biotinylated vesicles that have open sites for avidin binding. This will allow the biotinylated vesicles with avidin to elute through, decreasing the aggregation caused by biotin and avidin. 6. Acknowledgements We would like to thank Dr. Brian Prevo and Ben Wong for their input, and Dr. Christine Schmidt for critically reviewing this paper. This work is supported by NSF – DMR-05-20415 and the NIH-PEN grant. 7
7. References [1] T. Minko, S.S. Dharap, R.I. Pakunlu et al. Molecular Targeting of Drug Delivery Systems to Cancer. Current Drug Targets (2004) 5: 389 - 406. [2] T.M. Allen, P. R. Cullis. Drug Delivery Systems: Entering the Mainstream. Science. (2004) 353: 1818-1823. [3] E.T. Kisak. Encapsulation of Vesicles and Colloids via Interdigitated Lipid Bilayer. 2001. Dissertation [4] T.M. Allen, E.H. Moase. Therapeutic opportunities for targeted liposomal drug delivery. Advanced Drug Delivery Reviews. (1996) 21: 117-133. [5] T.M. Allen, C. B. Hansen, D.E. Lopes de Menezes. Pharmacokinetics of long-circulating liposomes. Advanced Drug Delivery Reviews. (1995) 16: 267-284. [6] E.T. Kisak, B. Coldren, CA. Evans et al. The Vesosome – A Mulicompartment Drug Delivery Vehicle. Current Medicinal Chemistry. (2004) 11: 1241-1253. [7] D.A. Noppl-Simon, D. Needham. Avidin-Biotin Interactions at Vesicle Surfaces: Adsorption and Binding, Cross-Bridge Formation and Lateral Interactions. Biophysical Journal. (1996) 70: 1391-1401. [8] N.M. Green. Avidin. Advances in Protein Chemistry (1975) 29: 85 – 130. [9] M. L. Jones, G. P. Kurzban. Noncooperativity of Biotin Binding to Tetrameric Streptavidin. Biochemistry. (1995) 34: 11750 – 11756. [10] A. Gabizon, D. Papahdjopoulos. Liposome formulations with prolonged circulation time in blood and enhanced uptake by tumors. Proceedings of the National Academy of Science (1988) 85: 6949 – 6953. [11] J.A. Zasadzinski, S.M. Bailey. Applications of Freeze-Fracture Replications to Problems in Materials and Colloid Science. Journal of Electron Microscopy Technique. (1989) 13: 309-334. [12] M. Vittaz, D. Bazile, G. Spenlehauer et al. Effect of PEO surface density on longcirculating PLA-PEO nanoparticles which are very low complement activators. Biomaterials. (1996) 17: 1575 – 1581. [13] K. Avgoustakis. Pegylated Poly(Lactide) and Poly(Lactide-Co-Glycolide) Nanoparticles: Preparation, Properties and Possible Applications in Drug Delivery. Current Drug Delivery. (2004) 1: 321-333. [14] J.N. Weinstein. Liposomes as Drug Carriers in Cancer Therapy. Cancer Treatment Reports. (1984) 68: 127-135. 8
Page 1 and 2: The Secret Society: Descendants of
Page 3 and 4: today. Present day traditions inclu
Page 5 and 6: to India so he thought it would be
Page 7 and 8: character. He was responsible for t
Page 9 and 10: had filled his colony with people w
Page 11 and 12: that we did that were not exactly C
Page 13 and 14: events. 43 After a year the family
Page 15 and 16: Another area of Jewish influence is
Page 17 and 18: ignored and left to ruin suggests t
Page 19 and 20: Liebman, Seymour B. The Jews in New
Page 21 and 22: Agnes sees herself as the kitten he
Page 23 and 24: He also takes the children “a-bir
Page 25 and 26: although the memory of his father
Page 27 and 28: Works Consulted Berg, Maggie. "'Hap
Page 29 and 30: components of the vesicle are also
Page 31 and 32: DPPE can diffuse laterally across t
Page 33: The DLS measurements of the biotiny
Page 37 and 38: 2 His sweepingly critical accusatio
Page 39 and 40: 4 Naseem Aziz, protests against her
Page 41 and 42: 6 Her talent and desire for attenti
Page 43 and 44: 8 “I do not propose to offer, pre
Page 45 and 46: 10 given simply the leisure-time ne
Page 47 and 48: Kundera quite vocally defends Rushd
Page 49 and 50: Disordered Eating, Anxiety 2 Abstra
Page 51 and 52: Disordered Eating, Anxiety 4 This u
Page 53 and 54: Disordered Eating, Anxiety 6 Figure
Page 55 and 56: Disordered Eating, Anxiety 8 Each p
Page 57 and 58: Disordered Eating, Anxiety 10 point
Page 59 and 60: Disordered Eating, Anxiety 12 eatin
Page 61 and 62: Disordered Eating, Anxiety 14 Concl
Page 63 and 64: Disordered Eating, Anxiety 16 Stice
Page 65 and 66: The following demographic informati
Page 67 and 68: units in TDCJ. The vocational progr
Page 69 and 70: for public transportation it was su
Page 71 and 72: References Asquith, Christina. (Feb

The Secret Society: Descendants of Crypto-Jews in the San Antonio ...

Create successful ePaper yourself

Delete template?

Save as template?