Ultrasonic Enhancement Of The Porosity Of Alginate Scaffold

Human cartilage disease has become more and more popular in recent years and is hard to self-healing. Tissue engineering is a new method that provides good artificial scaffold to support cell growth. Three-dimensional (3-D) cell scaffold system can be a promising way to produce functional chondrocytes for repairing damaged cartilage, which can bring great development for bone surgeries and enhance the treatment effect for cartilage disease. Alginate scaffold with 3-D porous structure can provide sufficient space for the cell adhesion, and has good biocompatibility and mechanical strength. In the present work, low-intensity pulsed ultrasound (LIPUS) was applied to enhance the porosity of 3-D alginate scaffold based on the acoustic-induced microbubble microstreaming. In the experiment, the alginate-calcium-based 3-D scaffold culture system was fabricated with the optimum CaC12/sodium alginate ratio of 3:5. The mechanical properties of alginate scaffold were measured and a scanning electron microscopy was used to analyze the porosity of the scaffold. In addition, microscopy observation of green fluorescent protein expression and CCK-8 assessment were adapted to analyze the cell proliferation effect. The experimental results showed that, with LIPUS treatment under appropriate driving parameters (e.g., the acoustic driving pressure of 0.055 MPa and the exposure time of 20 min), both the porosity of the 3-D scaffold and cell proliferation rate in the scaffold can be significantly improved. This work is helpful for bettering understanding the mechanism underlying the enhanced porosity and permeability of the 3-D alginate scaffolds by using LIPUS, which could in turn benefit the improvement and optimization of the advanced 3-D tissue engineering scaffold technology.