Ultrasound - assisted microfluidics based microbubble mediated synthesis of nanoparticle - reinforced dual porous scaffolds for tissue regeneration

The development of biomimetic scaffolds with optimized porosity and mechanical properties is critical for tissue regeneration applications. This study aimed at production of nanoparticle reinforced dual porous scaffolds using a combination of ultrasound and microfluidics. Microfluidic T-junction device helped to achieve uniform primary pores through microbubble generation while ultrasound facilitated the fragmentation of microbubbles, resulting in formation of smaller secondary pores. The primary pores helped enhance nutrient and oxygen supply throughout the scaffold while the secondary pores provided a high surface area for cellular adhesion and cell distribution. The hierarchical pore size distribution was confirmed using Confocal microscopy and Scanning electron microscopy (SEM). Mechanical testing performed using a Universal Testing Machine (UTM) confirmed that the mechanical strength of the scaffolds closely matches to that of biological soft tissues. In vitro assays performed on the scaffolds using Human Embryonic Kidney (HEK 293) cells revealed enhanced cellular proliferation and uniform distribution of cells in scaffolds. The results suggested that synthesized scaffolds match physicochemical, mechanical, and biological properties of the native human tissues and can be used for tissue regeneration applications.