Some thermally derived proteinoids are known to form hollow microspheres under specific conditions. In this study, oligomers consisting of L-aspartic acid, L-glutamic acid, L-phenylalanine, and L-tyrosine were prepared through the corresponding a-amino acid-N carboxyanhydrides (NCAs). The oligo(amino acids) synthesized by NCA method had better control on the composition as well as molecular weight. These oligo(amino acids) were found to spontaneously form microspheres under acidic conditions. It was also found that is possible to encapsulate a variety of drug entities within these unique self-assembling systems. The microspheres which form spontaneously at low pH's also dissolve in water at neutral pH and consequently have the potential to be used as oral drug delivery systems.
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References
1.
1. Bloch, H.1983. Poly(-y-Benzyl-L-Glutamate) and Other Glutamic Acid Containing Polymers, New York: Gordon and Breach.
2.
2. Bamford, C. H. and H. Block. 1976. The Polymerization of N-Carboxy-a-Amino Acids, C. H. Bamford and C. F. H. Tipper, eds., Elsevier.
3.
3. Bamford, C. H. and H. Block. 1962. Polyamino Acids, Polypeptides and Proteins, M. A. Stahmann, ed., Madison, WI: University of Wisconsin Press.
4.
4. Kohn, J.1990. In Biodegradable Polymers as Drug Delivery Systems, M. Chasin and R. Langer, eds., New York: Marcel Dekker, p. 195-195.
5.
5. Miquel, J., S. Brooke and S. W. Fox. 1971. Currents in Modern Biology, 3:299-299.
6.
6. Hsu, L. L., S. Brooke and S. W. Fox. 1971. Currents in Modern Biology, 4:12-12.
7.
7. Ryan, J. W. and S. W. Fox. 1973. BioSystem, 5:115-115.
8.
8. Fox, S. W.1980. Naturwissenschaften, 67:378-378.
9.
9. Lacey, J. C., Jr., A. Yuki and S. W. Fox. 1979. BioSystem, 11:1-1.
10.
10. Vaughan, G., A. T. Przybylski and S. W. Fox. 1987. BioSystem, 20:219-219.
11.
11. McAlhaney, W. W. and D. L. Rohlfing. 1976. BioSystem, 8:45-45.
12.
12. Snyder, W. D. and S. W. Fox. 1975. BioSystem, 7:222-222.
13.
13. Syren, R. M., A. Sanjur and S. W. Fox. 1985. BioSystem, 17:275-275.
14.
14. Fox, S. W., J. R. Jungck and T. Nakajima. 1974. Origins of Life, 5:227-227.
15.
15. Hsu, L. and S. W. Fox. 1976. BioSystem, 8:89-89.
16.
16. Brooke, S. and S. W. Fox. 1977. BioSystem, 9:1-1.
17.
17. Rohifing, D. L.1975. Origins of Life, 6:203-203.
18.
18. Fox, S. W.1976. Origins of Life, 7:49-49.
19.
19. Kokufuta, E., H. Sakai and K. Harada. 1984. BioSystem, 16:175-175.
20.
20. Steiner, S. and R. Rosen. 1990. U.S. Patent 4,925,673-673.
21.
21. Oya, M. and T. Takahashi. 1981. Bull. Chem. Soc., Jpn., 54:2705-2705.
22.
22. Leuchs, H.1906. Ber Dtsch. Chem. Ges., 39:857-857.
23.
23. Leuchs, H. and W. Geiger. 1908. Ber Dtsch. Che, Ges., 41:1721-1721.
24.
24. Blacklock, T. J., R. Hirschmann and D. F. Veber. 1987. The Peptides, Vol. 9. New York: Academic Press, Inc., pp. 39-102.
25.
25. Katchalski, E.1951. Advances in Protein Chemistry, Vol. 6. New York: Academic Press, Inc., pp. 123-185.
26.
26. Oya, M. and T. Takahashi. 1982. J Polym. Sci., Polym. Chem. Ed., 20:529-529.
27.
27. Bamford, C. H., A. Elliott and W E. Hamby. 1965. Synthetic Polypeptides. New York: Academic Press, p. 62-62.
30. Iwakura, Y., K. Uno, M. Oya and R. Katakai. 1970. Biopolymers, 9:1419-1419.
31.
31. Oya, M., K. Uno and Y. Iwakura. 1973. Progress in Polymer Science Japan, Vol. 6, K. Uno and S. Onogi, eds., Ibkyo: Kodansha, p. 51-51.
32.
32. Rao, V. S., P. Lapointe and D. N. McGregor. 1993. Makromol. Chem., 194:1095-1095.
33.
33. Daly, W. H. and S. Lee. 1988. J Macromol. Sci.-Chem., A25:705-705.
34.
34. Bodanszky, M. and A. Bodanszky. 1984. The Practice of Peptide Synthesis. Berlin: Springer-Verlag, p. 153-153.
35.
35. Krycheldorf, H. R.1987. a-Amino-N-Carboxy-Anhydrides and Related Heterocycles. Synthesis, Properties, Peptide Synthesis, Polymerization. Berlin: Springer-Verlag, Chapters 1 and 2.
36.
36. Fuchs, F.1922. Chem. Ber, 55:2943-2943.
37.
37. Farthing, A. C.1950. J Chem. Soc, p. 3213-3213.
38.
38. Coleman, D. and A. C. Farthing. 1951. J Chem. Soc, p. 3218-3218.
39.
39. Fuller, W. D., M. S. Velander and M. Goodman. 1976. Biopolymers, 15:1869-1869.
