Controlled drug delivery micelles

ELP-based triblock copolypeptides have also been used to produce stimulus-responsive micelles, and Chaikof and coworkers envisioned the possible application of these micelles as controlled drug delivery vehicles. These amphiphilic triblock copolymers were constructed from two identical hydrophobic ELP endblocks and a hydrophilic ELP midblock. Below the transition temperature, loose and monodispersed micelles were formed that reversibly contracted upon heating, leading to more compact micelles with a reduced size [90]. 

Huh, K.M. Lee, S.C. Lee, J. Cho, Y.W. Park, K. Hydro-tropic polymeric micelle systems for formulation of poorly water-soluble drugs. The 8th European Symposium on Controlled Drug Delivery 2004, 8, 19-21. 

Finally, the presence of surfactant always raises the possibility of micelle formation in the primary continuous phase and the subsequent solubilization of the primary dispersed phase. Solubilization, therefore, represents a convenient mechanism for the transport of primary emulsion components to the secondary continuous phase. Such a solubilization process also represents a convenient mechanism for the transport of material. In the context of a critical application such as controlled drug delivery, in which the mechanism of delivery is diffusion-controlled, such breakdown mechanisms would be very detrimental to the action of the system since they could result in a rapid release of active solute with possibly dangerous effects. 

Concerning the application possibilities, block and graft copolymers micelles and their assemblies as PIC are of great practical importance. Of special interest, as outlined in this review, are amphiphilic copolymers with biocompatible and biodegradable sequences, that have obtained growing attention as controlled drug-delivery systems and as potential carriers in gene therapy. 

Figure 1.7 Micelles of thermo-responsive polymers used as controlled drug delivery vehicle.

DOX and QDs were co-encapsulated into the hydrophobic core of the micelles, the release kinetics was carried out in order to confirm the sustained release of the DOX and the therapeutic efficacy of the obtained micellar formulation was tested in vitro using HeLa cell line. In the aim to evaluate the cellular uptake behavior of the micelles, in vitro imaging studies were also performed. The results indicated the sustained release of the drug and the potential of these micellar systems as efficient optical fluorescence imaging and controlled drug delivery systems. 

Zhang, Q., Ko, N.R., Oh, J.K. Recent advances in stimuh-responsive degradable block copolymer micelles synthesis and controlled drug delivery applications. Chem. Conunun. 48(61), 7542-7552 (2012)... 

Gaucher G, Dufresne MH, Sant VP et al (2005) Block copolymer micelles preparation, characterization and application in drug delivery. J Control Release 109 169-188... 

Liu M, Kono K, Frechet JM. Water-soluble dendritic unimolecular micelles their potential as drug delivery agents. J Control Release 2000 65 121. 

Chung JE, Yokoyama M, Okano T. Inner core segment design for drug delivery control of thermo-responsive polymeric micelles. J Controlled Release 2000 65 93-103. 

Kataoka K, Kwon GS, Yokoyama M, Okano T, Sakurai Y. Block-copolymer micelles as vehicles for drug delivery. J Controlled Release 1993 24 119-132. 

Chung, J. E., M. Yokoyama, M. Yamato, T. Aoyagi, Y. Sakurai, and T. Okano. 1999. Thermo-responsive drug delivery from polymeric micelles constructed using block copolymers of (sbh propylacrylamide) and poly(butylmethacrylate L Control. Rel62 115-127. 

Yu, B. G, T. Okano, K. Kataoka, and G Kwon. 1998. Polymeric micelles for drug delivery solubilization and hemolytic activity of amphotericin BJ. Control. Rel.53 131-136. 

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