Scientists recently created nano-scale borate bioactive glass (Nano-HCA@BG) using a steady-state strong magnetic field experimental device. The glass can effectively reduce the biological toxicity of borate bioglass, enhance the biocompatibility of the glass and boost the effect of borate bioglass on skin repair.
The wound healing process of a mouse skin defect model. (A) Different control group and Nano-HCA@BG mice skin wound healing images on days 0, 1, 3, 5, and 7 (the unit scale of the ruler in the photo is 1 mm). (B) Corresponding statistical results of wound healing rate in mice. Image Credit: Hui Ma.
“It is likely to become the next generation of skin wound repair dressings,” noted Prof. Junfeng Wang of the Hefei Institutes of Physical Science (HFIPS) of the Chinese Academy of Sciences (CAS), who worked on the study alongside Prof. Teng Zhang of Fuzhou University. The study was reported in the Chemical Engineer Journal.
Borate bioglass is made out of boron (B) as the glass network matrix. It has a lot of potential in the field of skin tissue healing because of its good dopability and degradability. However, it emits a huge amount of alkaline ions, and the rapid release of these ions alters the acid-base environment of the tissue surrounding the glass, thus preventing cell development.
Furthermore, because the effective surface area of micron-sized borate bioglass in touch with tissues at the wound is tiny, and the ions on the glass surface are not conducive to collagen deposition, scarring at the site is easily developed after healing.
Preparing a nano-scale borate bioglass with minimal biological toxicity and high biological performance is thus a pressing issue that must be addressed.
For the first time, the researchers employed a unique mobile phase to pre-treat micron-sized borate bioglass in vitro using the melting process. They created nanoscale (50 nm) borate bioglass (Nano-HCA@BG) with an amorphous hydroxyapatite (HCA) layer on top.
During the procedure, the ions in the mobile phase (PO43- and CO32-) were deposited on the glass surface to create the HCA layer, which effectively blocked the quick release of boron and calcium in the remaining glass, thereby lowering the biological toxicity of the glass to cells.
Furthermore, being a major inorganic component of bones, HCA has strong biocompatibility and can speed up collagen formation in tissues.
In vitro degradation experiments, cell experiments and animal experiments revealed that Nano-HCA@BG slow-released boron, calcium and other elements can effectively accelerate wound cell migration and further up-regulation of the expression of vascular-related growth factors in the wound when compared to existing commercialized bioactive glass, HCA and micron-sized borate bioglass and other elements.
Moreover, the amorphous HCA layer on the glass surface not only prevents the rapid release of the glass but also encourages the deposition of collagen in the wound, resulting in faster wound healing.
This study was financially supported by the National Natural Science Foundation of China and a major project of the Ministry of Science and Technology.
Journal Reference:
Chen, R., et al. (2021) Nanosized HCA-coated borate bioactive glass with improved wound healing effects on rodent model. Chemical Engineer Journal. doi.org/10.1016/j.cej.2021.130299.