Tunable Chemical and Topographic Patterns Based on Binary Colloidal Crystals (BCCs) to Modulate MG63 Cell Growth

More effective and diversified surface modification strategies are required for materials used in biomedical engineering. Combining surface modification involving bioactive signals or nonfouling polymers with tunable topography has the potential to meet this need. Here, a method is reported to generate bioactive surfaces having tunable topographies based on self-assembled binary colloidal crystals (BCCs), where the colloids are premodified with nonfouling molecules or cell adhesive peptides. The BCCs are fabricated from silica (Si) microspheres and polymer nanospheres. The Si microspheres are either modified with poly(ethylene glycol) (PEG) or with the cell adhesive arginine–glycine–aspartic acid (RGD) peptide prior to BCC fabrication. Four types of BCCs are explored in cell studies using MG63 cells. BCC surfaces coupled with PEG or RGD peptides are found to significantly modulate cell adhesion, spreading, and morphology, which is attributed to the combination of BCC topography and the molecules at the particle surface within the BCC. PEG-modified BCCs are expected to find applications where limited cell adhesion is required, while the RGD-modified BCCs have the potential for enhancing cell growth on medical devices such as bone implants. More advanced cell biology applications such as controlled stem cell differentiation are also anticipated to find use from BCCs.