2 research outputs found
Effect of the Surface Charge of Artificial Chaperones on the Refolding of Thermally Denatured Lysozymes
Artificial chaperones are of great
interest in fighting protein misfolding and aggregation for the protection
of protein bioactivity. A comprehensive understanding of the interaction
between artificial chaperones and proteins is critical for the effective
utilization of these materials in biomedicine. In this work, we fabricated
three kinds of artificial chaperones with different surface charges
based on mixed-shell polymeric micelles (MSPMs), and investigated
their protective effect for lysozymes under thermal stress. It was
found that MSPMs with different surface charges showed distinct chaperone-like
behavior, and the neutral MSPM with PEG shell and PMEO<sub>2</sub>MA hydrophobic domain at high temperature is superior to the negatively
and positively charged one, because of the excessive electrostatic
interactions between the protein and charged MSPMs. The results may
benefit to optimize this kind of artificial chaperone with enhanced
properties and expand their application in the future
Fabrication of Conjugated Amphiphilic Triblock Copolymer for Drug Delivery and Fluorescence Cell Imaging
An elegant integration of light-emitting
segments into the structure
of polymeric delivery systems endows the resulting self-assembled
nanovehicles with the diagnostic ability toward an enhanced therapeutic
efficiency. A variety of polyfluorene (PF)-based binary delivery systems
were designed and developed successfully, but PF-based ternary formulations
remain rarely explored, likely due to the synthetic challenge. To
develop a universal synthesis strategy toward linear conjugated amphiphilic
triblock copolymer for cancer theranostics, herein we focused on the
functionalization of the PF terminus for further chain extension and
prepared well-defined PF-based amphiphilic triblock copolymers, PF-<i>b</i>-poly(ε-caprolactone)-<i>b</i>-poly(oligo(ethylene
glycol) monomethyl ether methacrylate) (PF-<i>b</i>-PCL-<i>b</i>-POEGMA), by integrated state-of-the-art polymer chemistry
techniques, including Suzuki reaction, ring-opening polymerization,
atom transfer radical polymerization, and click coupling. The resulting
conjugated amphiphilic triblock copolymers can self-assembe into core–shell-corona
(CSC) micelles with PF block constructing the inner hydrophobic core
for fluorescent tracking, PCL segment forming the hydrophobic middle
shell for drug encapsulation, and POEGMA moiety building the hydrophilic
outer corona for particulate stabilization. Interestingly, the CSC
micelles with hydrophobic PCL middle layer show a greater drug loading
capacity as well as a higher fluorescence quantum yield (Φ)
relative to the core–shell micelles self-assembled from the
control of PF-<i>b</i>-POEGMA diblock copolymers without
PCL sequence due to having more hydrophobic spaces and better separation
of PF sequence provided simultaneously by the PCL central block. The
efficient cellular uptake of the anticancer drug doxorubicin-loaded
CSC micelles together with the in vitro cytotoxicity against the HeLa
cells makes the conjugated amphiphilic triblock copolymers developed
herein a promising platform for simultaneous cell image and drug delivery,
thus offering great potential for cancer theranostics