Advanced α-CSH/β-TCP-based injectable paste with magnesium hydroxide and vitamin D-incorporated PLGA microspheres for bone repair

With the development of minimally invasive approaches, calcium-based injectable bone paste has attracted attention as a synthetic alternative due to its biodegradability and analogous composition with native bone. However, this approach is associated with the problem of the materials being absorbed before new bone formation has occurred, with a high resorption, and degradation rate. Here, a poly(lactic-co-glycolic acid) (PLGA)/magnesium hydroxide (MH)/vitamin D (Vit D) microsphere-incorporated α-calcium sulfate hemihydrate (α-CSH)/beta-tricalcium phosphate (β-TCP) injectable paste was designed for the regeneration of bone tissue. The combination of the bioceramic particles with α-CSH demonstrated an appropriate setting time for ease of use in clinical practice and enhanced mechanical properties. Additionally, the introduction of a bone paste with the MH and Vit D-incorporated PLGA microsphere induced osteogenic differentiation and alleviated the inflammatory response, which may occur after massive bone surgery. Based on these findings, this paper presents a versatile bone paste that promotes osteogenesis and modulates the osteoimmune microenvironment for effective bone regeneration.