Laponite Nanoclay-Loaded Microgel Suspensions as Supportive Matrices for Osteogenesis

Microscale carriers have emerged as promising materials for nurturing cell growth and as delivery vehicles for regenerative therapies. Carriers based on granular hydrogels have proved advantageous, where “microgels” can be formulated to have a broad range of properties to guide the behavior of adherent cells. Herein, the fabrication of osteogenic microgel matrices through the incorporation of laponite nanoclays is demonstrated. Forming a jammed suspension provides a scaffolding where cells can adhere to the surface of the microgels, with pathways for migration and proliferation fostered by the interstitial volume. By varying the content and type of laponite—RD and XLG—the degree of osteogenesis can be tuned in embedded populations of adipose-derived stem cells. The nano- and microstructured composite materials enhance osteogenesis at the transcript and protein level, leading to increased deposition of bone minerals and an increase in the compressive modulus of the assembled scaffold. Together, these microgel suspensions are promising materials for encouraging osteogenesis with scope for delivery via injection and stabilization to bone-mimetic mechanical properties after matrix deposition.