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Fig. 8.2
Incorporation of targeting moiety into AB block copolymer for the preparation of surface
functionalized micelle to active target diseased cells
control of biodistribution and site-specific cellular uptake, in a process referred to as
active targeting (Fig.
8.2
). Due to increased stability in serum provided by PEG, the
strategy used by researchers is the functionalization of the distal end of PEG chain
to introduce the targeting moieties. The moieties studied for active targeting include
lactose (to bind asialoglycoprotein receptors in hepatocytes) [
31,
32
] , cyclic RGD
peptide (to bind a
v
b
3
integrin receptors expressed in several cells including cancer-
ous) [
33,
34
] , transferrin [
35,
36
] , hyaluronic acid [
37
] , and various others [
38,
39
] .
8.4
Formation of Polymeric Micelles
The unique characteristic of amphiphilic block copolymers to form supramolecular
structures of different size and shape due to distinct solvent affinity facilitates the
formation of polymeric micelles. Core-shell architecture is often observed when the
hydrophobic segment is segregated from the aqueous phase to form the core which
is surrounded by a palisade of the hydrophilic segments. This structure provides the
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