Skip to main content Accessibility help
×
Home

Micro- to Nano-scale Structure and Drug Release Behavior of Solutions and Hydrogels of Poly (lactide)-Poly (ethylene oxide)-Poly (lactide) Triblock Copolymers

  • Sarvesh Kumar Agrawal (a1), Naomi Sanabria-DeLong (a2), Pete R. Jemian (a3), Jeannine M. Coburn (a4), Gregory N. Tew (a5) and Surita R. Bhatia (a6)...

Abstract

We have performed for the first time a complete structural characterization of PLA-PEO-PLA in the solution and hydrogel states. Previous studies on hydrogels of these polymers have shown that these gels have excellent mechanical properties suitable for possible application in tissue engineering and drug delivery. We have performed SANS, USAXS and confocal microscopy to relate the change in micro to nano scale self-assembled structure of these polymers in aqueous solution with changes in the block length and stereospecificity of the PLA block. A significant difference in structure and association behavior was seen between the polymers made from amorphous D/L-lactide as compared to those with crystalline L lactide blocks. In the former case spherical micelles were seen to form whereas the latter forms nonspherical polydisperse micellar assemblies. Both polymers form an associative network structure at higher concentrations, leading to gelation. USAXS and confocal microscopy show the presence of large-scale fractal aggregates in the hydrogels of these polymers. The fractal structure was denser for the L lactide series polymers as compared to the D/L-lactide series polymers. These results show that we can tune the microstructure and thereby the mechanical strength of these gels depending upon the specific application we need it for. We also show profiles for release of hydrophobic drug sulindac from 5 weight% solutions of these polymers in phosphate buffer saline. The profiles follows an almost zero order release behavior that continues slowly and steadily over several days and is again found to be strongly dependent on the crystallinity and molecular weight of the PLA block.

Copyright

References

Hide All
(1) Kubies, D.; Rypacek, F.; Kovarova, J.; Lednicky, F. Biomaterials 2000, 21, 529536.
(2) Kricheldorf, H. R.; Meierhaack, J. Makromolekulare Chemie-Macromolecular Chemistry and Physics 1993, 194, 715725.
(3) Li, Y. X.; Volland, C.; Kissel, T. Journal of Controlled Release 1994, 32, 121128.
(4) Kissel, T.; Li, Y. X.; Unger, F. Advanced Drug Delivery Reviews 2002, 54, 99134.
(5) Li, S. M.; Rashkov, I.; Espartero, J. L. et al. Macromolecules 1996, 29, 5762.
(6) Rashkov, I.; Manolova, N.; Li, S. M. et al. Macromolecules 1996, 29, 5056.
(7) Molina, I.; Li, S. M.; Martinez, M. B.; Vert, M. Biomaterials 2001, 22, 363369.
(8) Lee, C. W.; Kang, Y. G.; Jun, K. Korea Polymer Journal 2001, 9, 8491.
(9) Jeong, B.; Kibbey, M. R.; Birnbaum, J. C. et al. Macromolecules 2000, 33, 8317–322.
(10) Aamer, K. A.; Sardinha, H.; Bhatia, S. R.; Tew, G. N. Biomaterials 2004, 25, 10871093.
(11) Agrawal, S. K.; Sanabria-DeLong, N.; Coburn, J. M.; Bhatia, S. R.; Tew, G. N. Journal of Controlled Release Accepted.
(12) Sanabria-DeLong, N.; Agrawal, S. K.; Bhatia, S. R.; Tew, G. N. In preparation.
(13) Xu, J. T.; Fairclough, J. P. A. et al. Journal of Materials Chemistry 2003, 13, 27402748.
(14) Schmidt, P. W. Journal of Applied Crystallography 1991, 24, 414435.
(15) Crichton, M.; Bhatia, S. Journal of Applied Crystallography 2003, 36, 652655.
(16) Pakstis, L. M.; Ozbas, B. et al. Biomacromolecules 2004, 5, 312318.

Keywords

Micro- to Nano-scale Structure and Drug Release Behavior of Solutions and Hydrogels of Poly (lactide)-Poly (ethylene oxide)-Poly (lactide) Triblock Copolymers

  • Sarvesh Kumar Agrawal (a1), Naomi Sanabria-DeLong (a2), Pete R. Jemian (a3), Jeannine M. Coburn (a4), Gregory N. Tew (a5) and Surita R. Bhatia (a6)...

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed