Synthesis and Characterization of Silver-Coated Polymeric Scaffolds for Bone Tissue Engineering: Antibacterial and In Vitro Evaluation of Cytotoxicity and Biocompatibility

In bone tissue engineering, multifunctional composite materials are very challenging. Bone tissue engineering is an innovative technique to develop biocompatible scaffolds with suitable orthopedic applications with enhanced antibacterial and mechanical properties. This research introduces a polymeric nanocomposite scaffold based on arabinoxylan-co-acrylic acid, nano-hydroxyapatite (nHAp), nano-aluminum oxide (nAl₂O₃), and graphene oxide (GO) by free-radical polymerization for the development of porous scaffolds using the freeze-drying technique. These polymeric nanocomposite scaffolds were coated with silver (Ag) nanoparticles to improve antibacterial activities. Together, nHAp, nAl₂O₃, and GO enhance the multifunctional properties of materials, which regulate their physicochemical and biomechanical properties. Results revealed that the Ag-coated polymeric nanocomposite scaffolds had excellent antibacterial properties and better microstructural properties. Regulated morphological properties and maximal antibacterial inhibition zones were found in the porous scaffolds with the increasing amount of GO. Moreover, the nanosystem and the polymeric matrix have improved the compressive strength (18.89 MPa) and Young’s modulus (198.61 MPa) of scaffolds upon increasing the amount of GO. The biological activities of the scaffolds were investigated against the mouse preosteoblast cell lines (MC3T3-E1) and increasing the quantities of GO helps cell adherence and proliferation. Therefore, our findings showed that these silver-coated polymeric nanocomposite scaffolds have the potential for engineering bone tissue

Production and characterization of partially purified thermostable alkaline protease by Bacillus subtilis SFL for blood destaining and dehairing applications

Microbial proteases have been preferred over animal and plant proteases because of their basic properties and ease of production. Bacillus subtilis SFL, an alkaline-thermal protease-producing bacterium was isolated from different sources of wastewater and identified using morphological, biochemical, and molecular methods. The 16S rDNA sequence has been deposited in GenBank with accession number OP714187. Partial purification of alkaline protease was performed by precipitation by 60% ammonium sulfate and ethyl acetate by the ratio (1:1) and column chromatography (gel filtration) by using a sephadex G-100. The optimum temperature and pH of the partially purified alkaline-thermal protease of Bacillus subtilis SFL was at 40°C and pH 8.0. Our results show that 40 g/l of meat extract and 12 g/l of xylose serve as the best nitrogen and carbon sources respectively for the production of this enzyme. The effect of tested metal ions indicated that Mg+2, Ca+2, Na+, Fe+2, Cu+2, Co+2 and Cd+2 inhibited the activity of the protease from Bacillus subtilis SFL. The crude and partially purified protease from B. subtilis SFL substantially degraded red blood cells, distained blood color, dehaired cow skin and decomposed cow hair

Production and characterization of partially purified thermostable alkaline protease by Bacillus subtilis SFL for blood destaining and dehairing applications

Microbial proteases have been preferred over animal and plant proteases because of their basic properties and ease of production. Bacillus subtilis SFL, an alkaline-thermal protease-producing bacterium was isolated from different sources of wastewater and identified using morphological, biochemical, and molecular methods. The 16S rDNA sequence has been deposited in GenBank with accession number OP714187. Partial purification of alkaline protease was performed by precipitation by 60% ammonium sulfate and ethyl acetate by the ratio (1:1) and column chromatography (gel filtration) by using a sephadex G-100. The optimum temperature and pH of the partially purified alkaline-thermal protease of Bacillus subtilis SFL was at 40°C and pH 8.0. Our results show that 40 g/l of meat extract and 12 g/l of xylose serve as the best nitrogen and carbon sources respectively for the production of this enzyme. The effect of tested metal ions indicated that Mg+2, Ca+2, Na+, Fe+2, Cu+2, Co+2 and Cd+2 inhibited the activity of the protease from Bacillus subtilis SFL. The crude and partially purified protease from B. subtilis SFL substantially degraded red blood cells, distained blood color, dehaired cow skin and decomposed cow hair

Synthesis and characterization of silver-coated polymeric scaffolds for bone tissue engineering: antibacterial and in vitro evaluation of cytotoxicity and biocompatibility

In bone tissue engineering, multifunctional composite materials are very challenging. Bone tissue engineering is an innovative technique to develop biocompatible scaffolds with suitable orthopedic applications with enhanced antibacterial and mechanical properties. This research introduces a polymeric nanocomposite scaffold based on arabinoxylan-co-acrylic acid, nano-hydroxyapatite (nHAp), nano-aluminum oxide (nAl2O3), and graphene oxide (GO) by free-radical polymerization for the development of porous scaffolds using the freeze-drying technique. These polymeric nanocomposite scaffolds were coated with silver (Ag) nanoparticles to improve antibacterial activities. Together, nHAp, nAl2O3, and GO enhance the multifunctional properties of materials, which regulate their physicochemical and biomechanical properties. Results revealed that the Ag-coated polymeric nanocomposite scaffolds had excellent antibacterial properties and better microstructural properties. Regulated morphological properties and maximal antibacterial inhibition zones were found in the porous scaffolds with the increasing amount of GO. Moreover, the nanosystem and the polymeric matrix have improved the compressive strength (18.89 MPa) and Young's modulus (198.61 MPa) of scaffolds upon increasing the amount of GO. The biological activities of the scaffolds were investigated against the mouse preosteoblast cell lines (MC3T3-E1) and increasing the quantities of GO helps cell adherence and proliferation. Therefore, our findings showed that these silver-coated polymeric nanocomposite scaffolds have the potential for engineering bone tissue