(590c) Hybrid Membranes Based on the Controlled Assembly of Gelatin-Stabilized Amorphous Calcium Phosphate and Ti3C2Tx Mxene Nanoflakes

Guided bone regeneration (GBR) is an advanced therapy for bone loss, injury, inflammation, and congenital diseases. GBR utilizes flexible free-standing films that cover the defect site preventing the infection and cell invasion while triggering osteogenesis. Besides, these thin films provide mechanical support for healing bone tissue. Here, based on the controlled assembly between gelatin-stabilized amorphous calcium phosphate (Gel-ACP) nanoparticles and two-dimensional titanium carbide nanosheets, Ti₃C₂T_x MXene, we have designed a free-standing film that can be used as a GBR membrane. Amorphous calcium phosphate (ACP) is a critical biological precursor of bone and tooth structure. However, ACP is unstable and easily converts into a stable crystalline phase of calcium phosphate. To control the mineralization of ACP, we use gelatin that can form stable complexes with calcium and phosphate ions. Gel-ACP composite nanoparticles with the size of 200-250 nm are prepared via the precipitation of calcium phosphate from aqueous media in the presence of gelatin. The direct observation of Gel-ACP nanoparticles with transmission electron microscopy confirmed encapsulation of ACP nanoclusters in a gelatin matrix. Vacuum-assisted filtration was used to fabricate self-standing thin films composed of sequential layers of Gel-ACP nanoparticles and MXene. The morphological studies verified the confinement of Gel-ACP nanoparticles in between oriented MXene nanoflakes that facilitate the mineralization of ACP into the oriented hydroxyapatite nanocrystals. The composition of the film was estimated with thermogravimetry analysis. Moreover, the self-standing films are electrically conductive, exhibit good mechanical properties, and remain stable in buffer solution for at least two weeks. The combination of bioactivity, biocompatibility, antimicrobial properties, and electrical conductivity of the individual components in the hybrid MXene/Gel-ACP self-standing film assemblies warrant future research for potentially using them in electrically stimulated guided bone regeneration therapies.