1. Bionano Chemistry Lab
Muhammad Ehsan
(2013652616)
Date: 2014-05-02

2. dx.doi.org/10.1021/ja413036q | J. Am. Chem. Soc. XXXX, XXX, XXX−XXX
dx.doi.org/10.1021/ja413036q | J. Am. Chem. Soc. XXXX, XXX, XXX−XXX

3. Introduction
 Stimuli-responsive micelles have gained increasing attention due to their
potential utilization as nanocarriers for drug delivery.
 Responsive materials are inspired
 changes in pH,
 temperature,
 irradiated light,
 or their combination
 Enzymes as stimuli

4. Encapsulation and release of hydrophobic guests
Figure . Schematic representation of the encapsulation of hydrophobic guests in the hydrophobic core of a smart micellar
nanocarrier. Upon enzymatic cleavage of the hydrophobic end groups, the nanocarrier disassembles and the guest
molecules are released.

5. Synthesis of Amphiphilic PEG-Dendron Hybrids

6. Self-Assemble into Micelles

7. Self-Assembled Structures
Figure S26: TEM micrographs of micelles formed from PEG-dendron
hybrids 1a-c.

8. Selectivity of the Enzymatic Activation
Figure : Fluorescence emission intensity of compound 1b is unaffected
in the absence of the activating enzyme penicilin G amidase (PGA )
after 12 hours in buffer
Figure : Fluorescence emission intensity of compound 1b is
unaffected in the presence of 0.66μM of Esterase from porcine
liver (PLE enzyme) , which is not capable of breaking amide
bond .

9. Micelle Disassembly with Nile Red Fluorescence
Figure . Fluorescence spectra of Nile red (1.25 μM) in the presence
of PEG-dendron hybrid 1b (160 μM) as a function of time after the
addition of the activating enzyme, PGA (0.14 μM). Fluorescence
intensity decreased as Nile red was released into solution.

10. Enzymatic Degradation of the PEG-Dendron Hybrids

11. Disassembly and Hydrolysis Rate

12. Hypothetical Enzymatic Activation Pathways

13. Summary
• New family of amphiphilic PEG-dendron hybrids.
• Enzyme-responsive hybrids and their self assembled micelles have great
potential in the field of drug delivery.
• Disassembly and release rates depended on the CMC.