Non-invasive tissue regeneration solutions are desired to replace certain invasive surgeries. These alternative methods should provide a protective, porous environment for cells, and injectable scaffolds may be the solution.
In their article in Advanced Materials, Prof. Guo-Qiang Chen and colleagues from Tsinghua University present highly porous microspheres as injectable scaffolds for tissue regeneration.
A gas-assisted double emulsion yielded a highly biocompatible, degradable porous scaffold, produced using polyhydroxyalkanoate (PHA), a family of natural biopolyesters.
The open and stable porous microspheres support the uniform proliferation of human mesenchymal stem cells throughout their structure, and the high internal porosity results in high cell survival.
In vivo experiments of bone regeneration in mice showed that open porous PHA microspheres outperform hollow spheres of PHA, polylactide, and a hyaluronic acid gel. PHA microspheres also exhibited stronger osteoblast regeneration.
To understand the effect of injection pressure on cell viability, injection pressure experiments were completed. The microspheres were found to elicit a cushion-like effect on cells, which enables safe administration of the cells to the desired site with minimal cell death.