Biomedical Engineering Reference
In-Depth Information
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Figure 5.7
HBP carriers for drug delivery. (Reproduced from Zhou et al.
6
with
permission from Wiley-VCH.)
entrapped inside the nanocavities of dendritic structures for the unimolecular
micelles (type 2). However, the unimolecular micelles of HBPs can only load a
small amount of guest molecules due to the limited volume of the interior
cavities in one molecule. By contrast, multimolecular micelles possess much
larger hydrophobic cores, thus enhancing the amount of encapsulating drug
and the controllability of drug delivery. For the multimolecular micelles like
type 3, the drugs are loaded in the micelle cores or shells according to their
hydrophilicity. For the responsive HBP-based micelles like type 4, the exterior
stimuli can trigger the transformation of the hydrophilic/hydrophobic balance
and further alter the HBP self-assembling morphologies, thus controlling the
release rate of the drugs. Type 5 represents drug conjugates in which drugs are
covalently conjugated to the terminal groups of HBPs. Apart from the
common advantages of the micelles, these HBP-based drug delivery systems
have unique merits, such as better temporal and spatial controllability due to
