RESUMEN
Ultrasound is gaining attention as an alternative tool to regulate chemical processes due to its advantages such as high cost-effectiveness, rapid response, and contact-free operation. Previous studies have demonstrated that acoustic bubble cavitation can generate energy to synthesize functional materials. In this study, we introduce a method to control the spatial distribution of physical and chemical properties of hydrogels by using an ultrasound-mediated particle manipulation technique. We developed a surface acoustic wave device that can localize micro-hydrogel particles, which are formed during gelation, in a hydrogel solution. The hydrogel fabricated with the application of surface acoustic waves exhibited gradients in mechanical, mass transport, and structural properties. We demonstrated that the gel having the property gradients could be utilized as a cell-culture substrate dictating cellular shapes, which is beneficial for interfacial tissue engineering. The acoustic method and fabricated hydrogels with property gradients can be applied to design flexible polymeric materials for soft robotics, biomedical sensors, or bioelectronics applications.
RESUMEN
The fabrication of functional tissues is essential for clinical applications such as disease treatment and drug discovery. Recent studies have revealed that the mechanical environments of tissues, determined by geometric cell patterns, material composition, or mechanical properties, play critical roles in ensuring proper tissue function. Here, we propose an acoustophoretic technique using surface acoustic waves to fabricate therapeutic vascular tissue containing a three-dimensional collateral distribution of vessels. Co-aligned human umbilical vein endothelial cells and human adipose stem cells that are arranged in a biodegradable catechol-conjugated hyaluronic acid hydrogel exhibit enhanced cell-cell contacts, gene expression, and secretion of angiogenic and anti-inflammatory paracrine factors. The therapeutic effects of the fabricated vessel constructs are demonstrated in experiments using an ischemia mouse model by exhibiting the remarkable recovery of damaged tissue. Our study can be referenced to fabricate various types of artificial tissues that mimic the original functions as well as structures.