Bone-mimicking scaffold based on silk fibroin incorporated with hydroxyapatite and titanium oxide as enhanced osteo-conductive material for bone tissue formation: fabrication, characterization, properties, andin vitrotesting.

Bone-mimicking scaffolds based on silk fibroin (SF) mixed with hydroxyapatite nanoparticles (HA NPs) and titanium oxide (TiO2) nanoparticles were created as materials for bone formation. Six scaffold groups were fabricated: S1 (SF), S2 (Silk + (HA: TiO2; 100: 0)), S3 (Silk, (HA: TiO2; 70: 30)), S4 (Silk + (HA NPs: TiO2; 50: 50)), S5 (Silk + (HA: TiO2; 30: 70)), and S6 (Silk + (HA NPs: TiO2; 0:100)). Scaffolds were characterized for molecular formation, structure, and morphology by Fourier transform infrared spectroscopy, element analysis, and X-ray diffraction. They were tested for physical swelling and compressive modulus. Scaffolds were cultured with MC3T3 and testedin vitroto evaluate their biological performance. The results showed that scaffolds with HA and TiO2demonstrated molecular interaction via amide I and phosphate groups. These scaffolds had smaller pore sizes than those without HA and TiO2. They showed more swelling and higher compressive modulus than the scaffolds without HA and TiO2. They exhibited better biological performance: cell adhesion, viability, proliferation, alkaline phosphatase activity, and calcium content than the scaffolds without HA and TiO2. Their porous walls acted as templates for cell aggregation and supported synthesis of calcium secreted from cells. S3 were the most suitable scaffolds. With their enhanced osteo-conductive function, they are promising for bone augmentation for oral and maxillofacial surgery.

Osseointegrated membranes based on electro-spun TiO2/hydroxyapatite/polyurethane for oral maxillofacial surgery.

Membranes which have an osseointegration abilty are often selected as biomaterials in oral and maxillofacial surgery. Although these membranes are often the best option for certain uses, it is a challenge to create functionally attractive membranes. In this research, electro-spun titanium oxide (TiO2)/hydroxyapatite (HA)/polyurethane (PU) membranes were fabricated with different ratios of HA and TiO2: 100: 0, 70:30, 50:50, 30:70 and 0:100 w/w. The morphologies of the different mixtures were assessed with a Scanning Electron Microscope (SEM) and Field Emission Microscope (FESEM). Element analysis was performed with EDX. The physical properties of the water contact angles and mechanical strength were tested and the membranes cultured with osteoblasts to evaluate their biological functions, cell adhesion, viability, proliferation, alkaline phosphatase (ALP) activity, and calcium content. The results showed that the membranes with TiO2 and HA had smaller fibers than those without TiO2 and HA. The TiO2- and HA-including compounds showed the formation of particle aggregation on the surface of the fibers. They also had higher water contact angles, mechanical strength, and stiffness than those without TiO2 and HA, and they had better cell adhesion, viability, proliferation, ALP activity and calcium content. The membrane with a 50:50 TiO2:HA ratio had more unique biological functions than the others. Finally, our research demonstrated that osseointegrated membranes with 50:50 TiO2:HA are promising for oral and maxillofacial surgery.

Layer-by-layer electrospun membranes of polyurethane/silk fibroin based on mimicking of oral soft tissue for guided bone regeneration.

Guided bone regeneration is an effective method that can enhance bone volume at a defect site of the mandible before material implantation. Layer-by-layer electrospun membranes of polyurethane/silk fibroin (SF) were fabricated to mimic oral soft tissue. The electrospun polyurethane fibers were initially fabricated into a membrane. Next, the polyurethane layer was covered with electrospun SF fibers at different thicknesses. Then, the SF layer was covered with electrospun polyurethane fibers. Afterward, the morphologies of the membranes were observed and analyzed by scanning electron microscopy. The physical properties of the membranes were evaluated from the contact angle and mechanical properties. The biological performances were evaluated by observing cell adhesion, viability and proliferation, alkaline phosphatase activity, and calcium content. The results demonstrated that the membrane with a thin SF core showed better physical properties and mechanical performance than the thicker SF cores. Finally, the results deduced that the membrane with a thin SF core was promising for guided bone regeneration.