ABSTRACT Nanoparticles of biodegradable methoxy poly(ethylene glycol)-b-polyester amphiphilic diblock copolymers have widely investigated for use as controlled release drug delivery carriers. In this work, blend nanoparticles of methoxy poly(ethylene glycol)-b-poly(D,L-lactide) (MPEG-b-PDLL) and methoxy poly(ethylene glycol)-b-poly(ε-caprolactone) (MPEG- b-PCL) were prepared by nano-precipitation method without any surfactants. 1H-NMR spectra showed significant difference in integral peak areas, suggesting the nanoparticles with different MPEG-b-PDLL/MPEG-b-PCL blend ratios can be prepared. Transmission electron microscope revealed the blend nanoparticles had nearly spherical in shape with smooth surface. Average size of the blend nanoparticles obtained from light-scattering analysis slightly decreased with increase in blend ratio of MPEG-b-PCL. The MPEG-b-PDLL and MPEG-b-PCL were amorphous and semi-crystalline, respectively. Thermal transition properties of the blend nanoparticles were studied with differential scanning calorimetry (DSC). The DSC results showed that glass transition temperatures of the blend nanoparticles decreased and heats of melting steadily increased, while the melting temperature did not change as the MPEG-b-PCL blend ratio increased. This indicates the miscibility of MPEG-b-PDLL and MPEG-b-PCL in the amorphous phase of the blend nanoparticles. Thermogravimetric analysis showed that the blend nanoparticles clearly exhibited two thermal decomposition steps due to MPEG-b-PDLL decomposition followed with MPEG-b-PCL. The blend nanoparticles had two temperatures of maximum decomposition rate (Td, max) accorded to each blend component. The Td, max of MPEG-b- PDLL phase significantly decreased, while Td, max of MPEG-b-PCL phase did not change as the MPEG-b-PCL blend ratio increased. These results suggested that the desired thermal properties of blend nanoparticles can be tailored by varying the blend ratio.
Cite this paper
nullNanthakasri, W. , Srisa-Ard, M. and Baimark, Y. (2011) Biodegradable Blend Nanoparticles of Amphiphilic Diblock Copolymers Prepared by Nano-Precipitation Method. Journal of Biomaterials and Nanobiotechnology, 2, 561-566. doi: 10.4236/jbnb.2011.225067.
 S. Y. Kim, Y. M. Lee and J. S. Kang, “Indomethacin-Loaded Methoxy Poly(Ethylene Glycol)/Poly(D,L-Lactide) Amphiphilic Diblock Copolymeric Nanospheres: Pharmacokinetic and Toxicity Studies in Rodents,” Journal of Biomedical Material Research, Vol. 74A, No. 4, 2005, pp. 581-590. doi:10.1002/jbm.a.30342
 E. Pierri and K. Avgoustakis, “Poly(Lactide)-Poly(Ethylene Glycol) Micelles as a Carrier for Griseofulvin,” Journal of Biomedical Material Research, Vol. 75A, No. 3, 2005, pp. 639-647. doi:10.1002/jbm.a.30490
 H. M. Aliabadi, A. Mahmud, A. D. Sharifabadi and A. Lavasanifar, “Micelles of Methoxy Poly(Ethylene Oxide)-b-Poly(ε-Caprolactone) as Vehicles for the Solubilization and Controlled Delivery of Cyclosporine A,” Journal of Controlled Release, Vol. 104, No. 2, 2005, pp. 301-311. doi:10.1016/j.jconrel.2005.02.015
 X. W. Wei, C. Y. Gong, M. Gou, S. Z. Fu, Q. Guo, S. Shi, F. Luo, G. Guo, L. Y. Qiu and Z. Y. Qian, “Biodegradable Poly(ε-Caprolactone)-Poly(Ethylene Glycol) Copolymers as Drug Delivery System,” International Journal of Pharmaceutics, Vol. 381, No. 2, 2009, pp. 1-18.
 R. Gref, Y. Minamitake, M. T. Peracchia, V. Trubetskoy, V. Torchilin and R. Langer, “Biodegradable Long-Circulating Polymeric Nanospheres,” Science, Vol. 263, No. 5153, 1994, pp. 1600-1603.
 S. Stolnik, L. Illum and S. S. Davis, “Long Circulating Microparticulate Drug Carriers,” Advanced Drug Deliverly Review, Vol. 16, No. 2, 1995, pp. 195-214.
 S. Y. Kim, I. L. Shin, Y. M. Lee, C. S. Cho and Y. K. Sung, “Methoxy Poly(Ethylene Glycol) and ε-Caprolactone Amphiphilic Block Copolymeric Micelle Containing Indomethacin. II. Micelle Formation and Drug Release Behaviours,” Journal of Controlled Release, Vol. 51, No. 1, 1998, pp. 13-22.
 A. Lucke, J. Tebmar, E. Schnell, G. Schmeer and A. Gopferich, “Biodegradable Poly(D,L-Lactic Acid)-Poly (Ethylene Glycol)-Monomethyl Ether Copolymers: Structures and Surface Properties Relevant to Their Use as Biomaterials,” Biomaterials, Vol. 21, No. 23, 2000, pp. 2361-2370. doi:10.1016/S0142-9612(00)00103-4
 C. He, J. Sun, C. Deng, T. Zhao, M. Deng, X. Chen and X. Jing, “Study of the Synthesis, Crystallization, and Morphology of Poly(Ethylene Glycol)-Poly(ε-Caprolactone) Diblock Copolymers,” Biomacromolecules, Vol. 5, No. 5, 2004, pp. 2042-2047. doi:10.1021/bm049720e
 H. Hyun, M. S. Kim, S. C. Jeong, Y. H. Kim, S. Y. Lee and H. B. Lee, “Preparation of Diblock Copolymers Consisting of Methoxy Poly(Ethylene Glycol) and Poly(ε- Caprolactone)/Poly(L-Lactide) and Their Degradation Property,” Polymer Engineering and Science, Vol. 46, 2006, pp. 1242-1249. doi:10.1002/pen.20581
 Y. Zhang, C. Wang, W. Yang, B. Shi and S. Fu, “Tri-Component Diblock Copolymers of Poly(Ethylene Glycol)-Poly(ε-Caprolactone-Co-Lactide): Synthesis, Characterization and Loading Camptothecin,” Colloid and Polymer Science, Vol. 283, No. 11, 2005, pp. 1246-1252.
 Y. H. Na, Y. He, X. Shuai, Y. Kikkawa, Y. Doi and Y. Inoue, “Compatibilization Effect of Poly(ε-Caprolactone)-b-Poly(Ethylene Glycol) Block Copolymers and Phase Morphology Analysis in Immiscible Poly(Lactide)/ Poly(ε-Caprolactone) Blends,” Biomacromolecules, Vol. 3, No. 6, 2002, pp. 1179-1186. doi:10.1021/bm020050r
 F. Ahmed and D. E. Discher, “Self-Porating Polymersomes of PEG-PLA and PEG-PCL: Hydrolysis-Triggered Controlled Release Vesicles,” Journal of Controlled Release, Vol. 96, No. 1, 2004, pp. 37-53.
 Y. Dong and S. S. Feng, “Nanoparticles of Poly(D,L- Lactide)/Methoxy Poly(Ethylene Glycol)-Poly(D,L-Lactide) Blends for Controlled Release of Paclitaxel,” Journal of Biomedical Material Research, Vol. 78A, 2006, pp. 12-19. doi:10.1002/jbm.a.30684
 S. A. Casarin, S. M. Malmonge, M. Kobayashi and J. A. M. Agnelli, “Study on in Vitro Degradation of Bioabsorable Polymers Poly(Hydroxybutyrate-Co-Valerate)-PHBV and Poly(Caprolactone)-PCL,” Journal of Biomaterials and Nanobiotechnology, Vol. 2, 2011, pp. 207-215.