Programming Colloidal Self-Assembled Patterns (cSAPs) into Thermo-Responsible Hybrid Surfaces for Controlling Human...

Area of Science:

• Biomaterials Science
• Surface Chemistry
• Cell Biology

Background:

• Fabricating hybrid surfaces with controllable topography, chemistry, and stiffness to mimic the extracellular matrix (ECM) and influence cell behavior is challenging.
• Colloidal self-assembly offers a promising approach for creating ordered structures with tailored properties at biointerfaces.

Purpose of the Study:

• To develop and characterize hybrid surfaces using colloidal self-assembly technology for tunable cell culture applications.
• To investigate the influence of these hybrid surfaces on the behavior and gene expression of human adipose-derived mesenchymal stem cells (hASCs), bone marrow-derived mesenchymal stem cells (hBMSCs), and THP-1 macrophages.

Main Methods:

• Fabrication of unary, binary, and ternary colloidal self-assembled patterns (cSAPs) using silicon (Si), polystyrene (PS), and poly(N-isopropylacrylamide) nanogels (PNGs) via coassembly or layer-by-layer (LBL) methods.
• Characterization of binary cSAPs (PS/PNG, PNG/PS) for tunable surface topography and wettability between 25 and 37 °C.
• Culturing hASCs, hBMSCs, and THP-1 macrophages on cSAPs under static and dynamic conditions.

Main Results:

• Hybrid cSAPs significantly influenced stem cell focal adhesions, morphology, migration, and gene expression, generally showing more vinculin puncta, smaller spreading size, and faster migration compared to TCPS.
• Static culture on cSAPs up-regulated focal adhesion kinase (FAK) and chondrogenic (AGG, SOX9) gene expression, while dynamic culture promoted osteogenic (COL1, RUNX2) gene expression.
• THP-1 macrophages exhibited varied M1/M2 gene expression profiles under dynamic culture, depending on cSAP composition, indicating sensitivity to surface properties and culture conditions.

Conclusions:

• Thermoresponsive hybrid cSAPs fabricated via colloidal self-assembly are versatile materials for manipulating stem cell behavior and macrophage responses.
• These dynamic surfaces offer a tunable platform for advanced cell culture and biomaterial applications.