Tissue-mimicking composite barrier membranes to prevent abdominal adhesion formation after surgery

Postoperative abdominal adhesions often occur after abdominal surgery; barrier membranes which mimic peritoneal tissue can be constructed to prevent abdominal adhesions. To this end, silk fibroin (SF) sheets were coated with polyvinyl alcohol (PVA) and agarose (AGA) at PVA:AGA ratios of 100:0, 70:30, 50:50, 30:70, and 0:100 to create a composite anti-adhesive barrier and allow us to identify a suitable coating ratio. The membranes were characterized in terms of their molecular organization, structure, and morphology using Fourier transform Infrared spectrometer (FT-IR), differential scanning calorimeter (DSC), and scanning electron microscope (SEM), respectively. The physical and mechanical properties of the membranes and their biological performance (i.e., fibroblast proliferation and invasion) were tested in vitro. Each membrane showed both smooth and rough surface characteristics. Membranes coated with PVA:AGA at ratios of 100:0, 70:30, 50:50, and 30:70 exhibited more -OH and amide III moieties than those coated with 0:100 PVA:AGA, which consequently affected structural organization, degradation, and fibroblast viability. The 0:100 PVA:AGA-coated degraded the fastest. Barrier membranes coated with 100:0 and 70:30 PVA: AGA demonstrated reduced fibroblast proliferation and attachment. The membrane coated with 70:30 PVA:AGA exhibited a stable appearance, and did not curl under wet conditions. Therefore, SF sheets coated with 70:30 PVA:AGA show promise as anti-adhesive barrier membranes for further development.

Biphasic scaffolds of polyvinyl alcohol/gelatin reinforced with polycaprolactone as biomedical materials supporting for bone augmentation based on anatomical mimicking; fabrication, characterization, physical and mechanical properties, and in vitro testing

Reinforced biphasic scaffolds were fabricated with based materials design of anatomical mimicking and evaluated to identify the certain application for maxillofacial surgery. The scaffolds created the polyvinyl alcohol (PVA) with a percentage of gelatin of 5% and were coated with polycaprolactone (PCL) that a different number of cycles 0, 1, 5, 10, and 15 cycles (PCL0, PCL1, PCL5, PCL10, and PCL15 were used to fabricate biphasic scaffolds via bubbling and freeze-thawing before reinforce with immersion coating techniques. The structure and morphology of the scaffolds were characterized and observed by a scanning electron microscope, a differential scanning calorimeter, and a thermogravimetric analyzer, respectively. The performance of the scaffolds was tested in terms of their swelling behavior, degradation, and mechanical properties. They were cultured with MC3T3E1 osteoblast cells and L929 fibroblast cells. The main biological performance of cell proliferation was analyzed, and protein synthesis, calcium synthesis, and alkaline phosphatase activity of the scaffolds were studied. Their morphology demonstrated fewer pores when coated with PCL. Mechanical strength of the modified scaffolds increased followed by the cycles of coating with PCL. The scaffolds with more cycle of PCL coating lower swelling and degradability than without PCL coating. They had more thermal stability than the scaffold without PCL coating. The scaffolds with PCL coating demonstrated better bio-functionality to activate cell response than without coating. Finally, the result exhibited that PCL10 provide a suitably reinforced biphasic scaffold with high promise for maxillofacial surgery.

Microbubble technology for natural rubber latex foam production: The use of various gas-filled microbubbles

In recent years, microbubble technology has attracted great attention in many application fields including water treatment, food processing, oil recovery, surface cleaning, and therapeutic applications. In this paper, microbubbles (MBs) of air, nitrogen, and argon were applied to produce natural rubber latex foams (NRLFs). The bubbles were generated by flowing the gas through a porous diffuser and latex. The effect of gas source on cellular structure, density, elasticity, indentation hardness, and flammability of the bubbled foams was discussed. Argon MBs offered the latex foams with fine cell diameters and uniform cell size distribution resulting in enhanced elasticity and physical properties of the foams. Indentation hardness index and limiting oxygen index value depended significantly on the gas used. By using the microbubble technique, the future prospects in NRLF production can be expected due to its ability in controllable cellular structure.

Constructed microbubble porous scaffolds of polyvinyl alcohol for subchondral bone formation for osteoarthritis surgery

Osteoarthritis (OA) is a disease that leads to the damage of subchondral bone. To treat OA, patients can have surgery to implant biomaterials into the damaged area. In this research, biomaterials of 3D porous scaffolds were fabricated by the use of air microbubbles for subchondral bone formation proposed for OA surgery. Microbubbles were generated in a polyvinyl alcohol solution at various air flow rates of 20 (F20), 100 (F100), 200 (F200), and 300 (F300) cc min^-1. Molecular organization, structure, and morphology of the scaffolds were characterized and observed by Fourier transform infrared spectroscopy, a differential scanning calorimeter, and a scanning electron microscope, respectively. Physical and mechanical properties based on swelling behavior and compressive strength of the scaffolds were also evaluated. Biological performance by means of osteoblast proliferation, protein synthesis, and alkaline phosphatase activity of the scaffolds were studied. The scaffolds showed molecular organization via interaction of -OH and C = O. They had residual water in their structures. The scaffolds exhibited a morphology of a spherical-like cell shape with small pores and a rough surface produced on each cell. Each cell was well connected with the others. The cell size and porous structure of the scaffolds depended significantly on the flow rate used. The molecular organization, structure, and morphology of the scaffolds had an effect on their physical and mechanical properties and biological performance. F100 was found to be an optimum scaffold offering a molecular organization, structure, morphology, physical and mechanical properties, and biological performance which was suitable for subchondral bone formation. This research deduced that the F100 scaffold is promising for OA surgery.

Bioactive surface-modified Ti with titania nanotube arrays to design endoprosthesis for maxillofacial surgery: structural formation, morphology, physical properties and osseointegration

Modification of the surface of titanium into titania (TiO₂) nanotube (TNT) arrays was performed by electrochemical anodization to design an endoprosthesis for maxillofacial surgery. TNT arrays with different surface structures were successfully coated on titanium substrates by varying the anodizing voltages and annealed at 450 °C for 4 h. The phase composition and morphology of the nanotubes were examined by x-ray powder diffraction and field-emission scanning electron microscopy, respectively. The biological functions and water wettability of various surface structures were also investigated. The results demonstrated that the annealed nanotubes were composed of an anatase phase only at all applied voltages. The tube diameters and lengths increased as the voltage increased. The surfaces with modification had more wettability, cell adhesion, proliferation, alkaline phosphatase activity and calcium deposition than the surfaces without modification. Finally, the results demonstrated that a modified surface of titanium to produce TNT arrays as a biomaterial is promising to design an osseointegrated surface of endoprosthesis for maxillofacial surgery.