Enzyme responsive amphiphiles

Bionano Chemistry Lab

Muhammad Ehsan (2013652616)

Literature meeting

Date: 2014-05-02

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

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

Encapsulation and release of hydrophobic guests

Figure . Schematic representation of the encapsulation of hydrophobic guests in the hydrophobic core of a smart micel-lar nanocarrier. Upon enzymatic cleavage of the hydrophobic end groups, the nanocarrier disassembles and the guest molecules are released.

Synthesis of Amphiphilic PEG-Dendron Hybrids

Self-Assemble into Micelles

Self-Assembled Structures

Figure S26: TEM micrographs of micelles formed from PEG-dendron

hybrids 1a-c.

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 unaf-fected in the presence of 0.66μM of Esterase from porcine liver (PLE enzyme) , which is not capable of breaking amide bond .

Micelle Disassembly with Nile Red Fluorescence

Figure . Fluorescence spectra of Nile red (1.25 μM) in the presenceof PEG-dendron hybrid 1b (160 μM) as a function of time after theaddition of the activating enzyme, PGA (0.14 μM). Fluorescenceintensity decreased as Nile red was released into solution.

Enzymatic Degradation of the PEG-Dendron Hybrids

Disassembly and Hydrolysis Rate

Hypothetical Enzymatic Activation Pathways

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.