Title:Advances in Micelle-based Drug Delivery: Cross-linked Systems
Volume: 17
Issue: 13
Author(s): Ismail Alper Isoglu, Yıldız Ozsoy and Sevil Dincer Isoglu*
Affiliation:
- Bioengineering Department, Faculty of Life and Natural Sciences, Abdullah Gül University, Kayseri,Turkey
Keywords:
Biodegradable micelles, Cleavable micelles, Core cross-linking, Cross-linked micelles, Reducible micelles, Shell
cross-linking.
Abstract: There are several barriers that drug molecules encounter in body beginning from kidney
filtration and reticulo-endothelial system (RES) clearance to cellular trafficking. Multifunctional
nanocarriers have a great potential for the delivery of drugs by enhancing therapeutic activity of existing
methodologies. A variety of nanocarriers are constructed by different material types, which have
unique physicochemical properties for drug delivery applications. Micelles formed by amphiphilic
polymers are one of the most important drug/nanocarrier formulation products, in which the core part
is suitable for encapsulation of hydrophobic agent whereas the outer shell can be utilized for targeting
the drug to the disease area. Micelles as self-assembled nanostructures may encounter difficulties in
biodistribution of encapsulated drugs because they have a tendency to be dissociated in dilution or
high ionic strength. Therefore, therapeutic efficiency is decreased and it requires high amount of drug
to be administered to achieve more efficient result. To overcome this problem, covalently stabilized
structures produced by cross-linking in core or shell part, which can prevent the micelle dissociation
and regulate drug release, have been proposed. These systems can be designed as responsive systems
in which cross-links are degradable or hydrolysable under specific conditions such as low pH or reductive
environment. These are enhancing characteristics in drug delivery because their cleavage allows
the release of bioactive agent encapsulated in the carrier at a certain site or time. This review describes
the chemical methodologies for the preparation of cross-linked micelles, and reports an update
of latest studies in literature.
