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Magnetic and Thermal-sensitive PolyN-isopropylacrylamide-based Microgels for Magnetically Triggered Controlled Release
Published on: July 4, 2017
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Temperature-induced molecular transport through polymer multilayers coated with PNIPAM microgels.
A S Vikulina1, S T Aleed, T Paulraj
1Fraunhofer Institute for Cell Therapy and Immunology, Am Mühlenberg 13, 14476 Potsdam-Golm, Germany. Dmitry.Volodkin@izi-bb.fraunhofer.de.
Physical Chemistry Chemical Physics : PCCP
|April 24, 2015
Summary
This study developed temperature-responsive composite films using hyaluronic acid/poly-l-lysine multilayers coated with poly(N-isopropylacrylamide) microgels. These films offer controlled release of molecules, switching from hindered to enhanced diffusion at specific temperatures.
Area of Science:
- Materials Science
- Biomaterials Engineering
- Polymer Chemistry
Background:
- Polyelectrolyte multilayers (PEMs) are effective reservoirs for bioactive molecules but lack controlled release mechanisms.
- Stimuli-responsive release from PEMs is crucial for developing advanced drug delivery systems and cellular applications.
- Existing methods struggle to control molecule release without compromising PEM integrity or biomolecule function.
Purpose of the Study:
- To design and fabricate novel soft composite films with switchable barriers for controlled molecular release.
- To investigate the temperature-dependent behavior of poly(N-isopropylacrylamide) (PNIPAM) microgels integrated into hyaluronic acid/poly-l-lysine (HA/PLL) multilayers.
- To demonstrate the potential of these composite films as stimuli-sensitive planar carriers.
Main Methods:
- Fabrication of HA/PLL multilayers coated with temperature-responsive PNIPAM microgels.
- Immersion of flattened microgels into PEMs to maximize polyelectrolyte contact.
- Utilizing scanning force microscopy (SFM) to analyze film morphology and microgel behavior.
- Investigating poly-l-lysine (PLL) diffusion dynamics at different temperatures relative to PNIPAM's volume phase transition temperature (VPTT).
Main Results:
- PNIPAM microgel coating acted as an efficient, switchable barrier for PLL transport into the HA/PLL multilayers.
- PLL diffusion was significantly hindered at room temperature but dramatically enhanced at 40 °C.
- PNIPAM microgel shrinkage above its VPTT (32 °C) triggered enhanced PLL diffusion.
- SFM revealed distinct volume phase transition mechanisms on soft composite surfaces compared to solid substrates.
Conclusions:
- Soft composite films with PNIPAM microgel coatings provide a novel approach for on-demand, externally stimulated release of molecules from PEMs.
- The temperature-responsive nature of PNIPAM microgels allows for precise control over molecular diffusion barriers.
- These findings pave the way for developing advanced stimuli-sensitive planar carriers for diverse cellular applications.
