Cuttlefish bone scaffold for tissue engineering: a novel hydrothermal transformation, chemical-physical, and biological characterization

Highly ordered CaO from cuttlefish bone calcination for the efficient adsorption of methylene blue from water

The aim of this study is to synthesize cheap and highly ordered CaO from cuttlefish bone (CFB) as a green alternative to conventional adsorbents such as activated carbon. This study focuses on the synthesis of highly ordered CaO via calcination of CFB, at two different temperatures (900 and 1000°C) and two holding times (0.5 and 1 h), as a potential green route for water remediation. The as-prepared highly ordered CaO was tested as an adsorbent using methylene blue (MB) as a model compound for dye contaminants in water. Different CaO adsorbent doses (0.05, 0.2, 0.4, and 0.6 g) were used, keeping the MB concentration fixed at 10 mg/L. The morphology and crystalline structure of the CFB before and after calcination was characterized via scanning electron microscope (SEM) and X-ray diffraction (XRD) analyses, while the thermal behavior and surface functionalities were characterized by thermogravimetric analysis (TGA) and Fourier transform infrared (FTIR) spectroscopy, respectively. Adsorption experiments using different doses of CaO synthesized at 900°C for 0.5 h showed an MB removal efficiency as high as 98% by weight using 0.4 g (adsorbent)/L(solution). Two different adsorption models, the Langmuir adsorption model and the Freundlich adsorption model, along with pseudo-first-order and pseudo-second-order kinetic models, were studied to correlate the adsorption data. The removal of MB via highly ordered CaO adsorption was better modeled by the Langmuir adsorption isotherm giving (R² =0.93), thus proving a monolayer adsorption mechanism following pseudo-second-order kinetics (R²= 0.98), confirming that chemisorption reaction occurs between the MB dye molecule and CaO.

Mechanical design of the highly porous cuttlebone: A bioceramic hard buoyancy tank for cuttlefish

Cuttlefish, a unique group of marine mollusks, produces an internal biomineralized shell, known as cuttlebone, which is an ultra-lightweight cellular structure (porosity, ∼93 vol%) used as the animal's hard buoyancy tank. Although cuttlebone is primarily composed of a brittle mineral, aragonite, the structure is highly damage tolerant and can withstand water pressure of about 20 atmospheres (atm) for the species Sepia officinalis Currently, our knowledge on the structural origins for cuttlebone's remarkable mechanical performance is limited. Combining quantitative three-dimensional (3D) structural characterization, four-dimensional (4D) mechanical analysis, digital image correlation, and parametric simulations, here we reveal that the characteristic chambered "wall-septa" microstructure of cuttlebone, drastically distinct from other natural or engineering cellular solids, allows for simultaneous high specific stiffness (8.4 MN⋅m/kg) and energy absorption (4.4 kJ/kg) upon loading. We demonstrate that the vertical walls in the chambered cuttlebone microstructure have evolved an optimal waviness gradient, which leads to compression-dominant deformation and asymmetric wall fracture, accomplishing both high stiffness and high energy absorption. Moreover, the distribution of walls is found to reduce stress concentrations within the horizontal septa, facilitating a larger chamber crushing stress and a more significant densification. The design strategies revealed here can provide important lessons for the development of low-density, stiff, and damage-tolerant cellular ceramics.

Effects of the Sintering Process on Nacre-Derived Hydroxyapatite Scaffolds for Bone Engineering

A hydroxyapatite scaffold is a suitable biomaterial for bone tissue engineering due to its chemical component which mimics native bone. Electronic states which present on the surface of hydroxyapatite have the potential to be used to promote the adsorption or transduction of biomolecules such as protein or DNA. This study aimed to compare the morphology and bioactivity of sinter and nonsinter marine-based hydroxyapatite scaffolds. Field emission scanning electron microscopy (FESEM) and micro-computed tomography (microCT) were used to characterize the morphology of both scaffolds. Scaffolds were co-cultured with 5 × 104/cm2 of MC3T3-E1 preosteoblast cells for 7, 14, and 21 days. FESEM was used to observe the cell morphology, and MTT and alkaline phosphatase (ALP) assays were conducted to determine the cell viability and differentiation capacity of cells on both scaffolds. Real-time polymerase chain reaction (rtPCR) was used to identify the expression of osteoblast markers. The sinter scaffold had a porous microstructure with the presence of interconnected pores as compared with the nonsinter scaffold. This sinter scaffold also significantly supported viability and differentiation of the MC3T3-E1 preosteoblast cells (p < 0.05). The marked expression of Col1α1 and osteocalcin (OCN) osteoblast markers were also observed after 14 days of incubation (p < 0.05). The sinter scaffold supported attachment, viability, and differentiation of preosteoblast cells. Hence, sinter hydroxyapatite scaffold from nacreous layer is a promising biomaterial for bone tissue engineering.

Cytotoxic and the proliferative effect of cuttlefish bone on MC3T3-E1 osteoblast cell line

Objective:

To evaluate the cytotoxic and the proliferative effect of cuttlefish bone on MC3T3-E1 osteoblast cell line.

Materials and Methods:

MC3T3-E1 cells were treated with 0.5, 1, 5, 25, 50, 100, or 200 μg/ml cuttlefish bone powder (CBP). Cytotoxicity was evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. This assay was also used to determine cell proliferation over 16 days of treatment with 0.5, 25, or 100 μg/ml CBP.

Results:

CBP was not cytotoxic to MC3T3-E1 cells at any concentration. The percentage of cell viability in the 0.5–200 μg/ml CBP groups dose dependently decreased from 107.52 ± 11.03 to 92.48 ± 5.60%; however, the differences between the groups or the negative control group were not significant. At 16 days, 0.5, 25, and 100 μg/ml CBP groups showed 123.19 ± 10.07%, 126.02 ± 15.69%, and 133.33 ± 11.74% proliferation, respectively, that were significantly higher than that of the control group.

Conclusion:

These results indicate that CBP promotes osteoblast proliferation and may be a potential material to increase the number of osteoblasts in a bone defect in the oral cavity.