Nanosized core-shell bio-hybrid microgels and their internal structure

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Nanotechnology

Background:

• Microgels are tunable materials with diverse applications, but their nanoscale internal structure is difficult to characterize.
• Understanding core-shell microgel architecture, including interface properties and guest molecule accessibility, is crucial for designing functional materials.

Purpose of the Study:

• To investigate the core-shell morphology and guest molecule accessibility of bio-hybrid DNA-poly(N-isopropylmethacrylamide) microgels using super-resolution fluorescence microscopy (SRFM).
• To analyze the impact of shell polymerization stages on microgel structure and internal accessibility.

Main Methods:

• Utilized super-resolution fluorescence microscopy (SRFM) to visualize nanoscale structures.
• Employed covalent fluorescence labeling of the core polymer (DNA-poly(N-isopropylmethacrylamide)) and co-polymerization with N,N'-bis(acryloyl)cystamine for shell visualization.
• Examined microgels at three distinct stages of shell polymerization.

Main Results:

• Demonstrated core polymer interpenetration into the shell without structural compromise.
• Quantified the size- and hydrophobicity-dependent accessibility of the microgel core for guest molecules.
• Provided visual insights into core and shell compartmentalization.

Conclusions:

• SRFM offers new perspectives on the internal architecture of core-shell microgels.
• Findings contribute to a deeper understanding of microgel complex behavior.
• This research can guide the rational design of microgel-based drug delivery systems by considering guest molecule properties.