ABSTRACT
Magnesium-doped calcium silicate (CS) bioceramic scaffolds have unique advantages in mandibular defect repair; however, they lack antibacterial properties to cope with the complex oral microbiome. Herein, for the first time, the CS scaffold was functionally modified with a novel copper-containing polydopamine (PDA(Cu2+)) rapid deposition method, to construct internally modified (*P), externally modified (@PDA), and dually modified (*P@PDA) scaffolds. The morphology, degradation behavior, and mechanical properties of the obtained scaffolds were evaluated in vitro. The results showed that the CS*P@PDA had a unique micro-/nano-structural surface and appreciable mechanical resistance. During the prolonged immersion stage, the release of copper ions from the CS*P@PDA scaffolds was rapid in the early stage and exhibited long-term sustained release. The in vitro evaluation revealed that the release behavior of copper ions ascribed an excellent antibacterial effect to the CS*P@PDA, while the scaffolds retained good cytocompatibility with improved osteogenesis and angiogenesis effects. Finally, the PDA(Cu2+)-modified scaffolds showed effective early bone regeneration in a critical-size rabbit mandibular defect model. Overall, it was indicated that considerable antibacterial property along with the enhancement of alveolar bone regeneration can be imparted to the scaffold by the two-step PDA(Cu2+) modification, and the convenience and wide applicability of this technique make it a promising strategy to avoid bacterial infections on implants.
Subject(s)
Animals , Rabbits , Copper/pharmacology , Tissue Scaffolds/chemistry , Bone Regeneration , Anti-Bacterial Agents/pharmacology , Osteogenesis , Calcium , Ions/pharmacologyABSTRACT
Objective: To evaluate the application of mechanically reinforced 45S5 Bioglass®-derived glass ceramic porous scaffolds for repair of bone defect in rabbits. Methods: The BG-ZnB powders were added into the 45S5 Bioglass® powder/paraffin microsphere mixtures and were sintered at 900℃ to obtain porous scaffolds with highly bioactive BG-ZnB of 0%, 2% or 4% of mass fraction (denoted as 45S5/ZnB0, 45S5/ZnB2, 45S5/ZnB4). Phase composition, porosity and compression properties of three kinds of as-sintered scaffolds were characterized by X-ray analysis, mercury porosimetry, and mechanical test. Thirty-six male New Zealand rabbits with critical-sized femoral bone defects were randomly divided into three groups (45S5/ZnB0 group, 45S5/ZnB2 group and 45S5/ZnB4 group, 12 for each), and were implanted with three kinds of porous scaffolds respectively. X-ray, micro-CT three-dimensional reconstruction and tissue slice staining were used to detected the efficiency of bone regeneration at 6 and 16 weeks after operation. The growth of newly formed bone was observed using HE, Masson staining and EnVision method. Results: Phase compositions of 45S5/ZnB2 and 45S5/ZnB4 were the same with 45S5/ZnB0, but the average pore size and porosity of the scaffolds were decreased with the increase of BG-ZnB content. 45S5/ZnB2 and 45S5/ZnB4 scaffolds exhibited higher compressive strength, osteogenesis and trabecular density than those of the 45S5/ZnB0 scaffold (all PConclusion: Low-melt BG-ZnB-assisted sintering is a promising approach to improve the mechanical strength of 45S5 Bioglass®.
Subject(s)
Animals , Male , Rabbits , Bone and Bones , Physiology , Ceramics , Chemistry , Glass , Porosity , Tissue Scaffolds , ChemistryABSTRACT
<p><b>OBJECTIVE</b>To fabricate organic-inorganic composite tissue engineering scaffolds for reconstructing calcified cartilage layer based on three-dimensional (3D) printing technique.</p><p><b>METHODS</b>The scaffolds were developed by 3D-printing technique with highly bioactive calcium-magnesium silicate ultrafine particles of 1%, 3% and 5% of mass fraction, in which the organic phases were composed of type I collagen and sodium hyaluronate. The 3D-printed scaffolds were then crosslinked and solidified by alginate and CaCl₂ aerosol. The pore size and distribution of inorganic phase were observed with scanning electron microscope (SEM); the mechanical properties were tested with universal material testing machine, and the porosity of scaffolds was also measured.</p><p><b>RESULTS</b>Pore size was approximately (212.3 ± 34.2) μm with a porosity of (48.3 ± 5.9)%, the compressive modulus of the scaffolds was (7.2 ± 1.2) MPa, which was irrelevant to the percentage changes of calcium-magnesium silicate, the compressive modulus was between that of cartilage and subchondral bone.</p><p><b>CONCLUSION</b>The porous scaffolds for calcified cartilage layer have been successfully fabricated, which would be used for multi-layered composite scaffolds in osteochondral injury.</p>
Subject(s)
Bioprinting , Cartilage , Materials Testing , Porosity , Printing, Three-Dimensional , Tissue Engineering , Methods , Tissue Scaffolds , ChemistryABSTRACT
Objective: To study the effect of flavonoids from seed residues of Hippophae rhamnoides L.( FSH) and Hippophae rhamnoides L. oil(HRO)on serum lipid in female rats with obesity. Methods Female aged rats with obesity were given FSH and HRO by oral administration for 6 w. Serum triglyceride(TG) and cholesterol(TC) were determined every 2 w. The serum free fatty acid (FFA), high-density lipoprotein cholesterol (HDL-C),body weight and Lee’s index were measured after 6 w. Results: Serum TG and FFA level decreased significantly in rats given FSH. At the same time, FSH could inhibit the increase in body weight and Lee’s index. HRO could regulate the lipid metabolism and decrease serum TG level significantly in female aged rats with obesity. Conclusion: Both FSH and HRO can improve lipid metabolism in female aged rats with obesity.