Biomedical Engineering Reference
In-Depth Information
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Figure
5.4
Sustained
release
technology
of
thermo-responsive
HBPs
through
controlling the external oscillating magnetic field.
most attractive materials to construct drug and gene delivery systems, because
of the existence of a redox potential gradient between the extra- and
intracellular space. However, most of them fail in preclinical studies because
of their high toxicity. The design of biocompatible materials is of significant
need.
Liu et al. designed and prepared a series of redox-responsive HBPs.
11,41
For
instance, synthesis of an amphiphilic hyperbranched homopolymer with
alternating hydrophobic disulfide and hydrophilic polyphosphate segments
along the highly branched structure by SCROP of the monomer, consisting of
both hydrophobic and hydrophilic moieties, as shown in Figure 5.5. This
hyperbranched polyphosphate (HPHDP) has excellent bioavailability and is
further utilized in the construction of hydrophobic anticancer drug delivery
system, which can be rapidly and efficiently transported into the nuclei of
tumor cells and shows enhanced inhibition of cell proliferation.
Such redox-stimulus biodegradable micelles self-assembled from functional
HBPs are promising biomaterials to improve both drug and gene delivery
efficacy.
5.3.2 Targeting
Chemotherapy is detrimental to both cancer cells and normal cells. Despite
ceaseless and intense efforts to discover highly effective oncology drugs,
conventional chemotherapeutic agents still perform with poor specificity in
arriving at tumor tissues and are often restricted by dose-limiting cytotoxicity.
The functional delivery systems are capable of making drugs accumulate
