Preparation, characterization and biocompatible properties of β-chitin/silk fibroin/nanohydroxyapatite composite scaffolds prepared using a freeze-drying method

RSC Advances ◽  
2016 ◽  
Vol 6 (9) ◽  
pp. 7048-7060 ◽  
Author(s):  
Mohammad Azadi ◽  
Abbas Teimouri ◽  
Ghasem Mehranzadeh

β-Chitin/silk fibroin/nanohydroxyapatite (CT/SF/nHAp) composite scaffolds were synthesized using a freeze-drying method by blending β-chitin hydrogel, silk fibroin and nHAp at different inorganic/organic weight ratios.

2013 ◽  
Vol 13 (01) ◽  
pp. 1350020 ◽  
Author(s):  
Y. S. LIU ◽  
Q. L. HUANG ◽  
Q. L. FENG ◽  
N. M. HU ◽  
O. ALBERT

In order to improve the mechanical properties of scaffolds for bone tissue engineering, the present study aims to bring calcium carbonate (CaCO3) with signaling molecules, namely pearl powder, into poly(L-lactic acid) (PLLA). PLLA/aragonite and PLLA/vaterite scaffolds were successfully fabricated by the freeze-drying method. Both composite scaffolds had a similar porous structure but a different saturated content of pearl powders. For both scaffolds, the porosity decreases and yield strength increases as pearl powder content increases. Introducing pearl powders into PLLA can improve the mechanical properties of the scaffolds. The porous structure plays a crucial role in the yield strength of pure PLLA scaffolds, whereas the yield strength of PLLA/pearl powder scaffolds mostly relies on pearl powder content.


2008 ◽  
Vol 368-372 ◽  
pp. 1190-1193 ◽  
Author(s):  
Jing Wang ◽  
Mu Qin Li ◽  
Xiang Cai Meng ◽  
Guang Wu Wen

Porous hydroxyapatite (HA) bioceramic matrix with interconnected ducts was obtained using a porogen burnout technique at 1200°C. The HA/silk fibroin (SF) composite scaffolds were developed with the SF sponges formed inside the pores and ducts of the bioceramics by first introducing HA/SF slurries into the pores and ducts followed by a freeze-drying process. Phase components and morphology of materials were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. Porosity was measured by Archimedean method. Compressive strength was also measured. The simulated body fluids (SBF) experiments were conducted to evaluate bioactivity. The results show that hydroxyapatite is the main phase compositions after sintering at 1200°C. The porosity of composite scaffolds reaches 70%~80%. The sizes of pores and ducts of HA matrix range from 150μm to 400μm and the pore sizes of SF sponges formed inside the macroporous structure of bioceramics are approximately 100μm,a structure favorable for bone tissue in-growth. The compressive strength of the composite scaffolds is greatly improved in comparison with that of HA matrix. In the SBF tests, a layer of randomly oriented apatite crystals form on the scaffold surface after sample immersion in SBF. The cell culture experiments show that the osteoblast cells are attached and proliferated on the surface of the composite scaffold, which suggest good bioactivity and cellular compatibility of the composite material.


Author(s):  
J. Anita Lett ◽  
Suresh Sagadevan ◽  
Bavani Latha ◽  
S. Anandhi ◽  
S. Ravichandran ◽  
...  

2012 ◽  
Vol 529-530 ◽  
pp. 447-452 ◽  
Author(s):  
Yos Phanny ◽  
Mitsugu Todo

Hydroxyapatite (HA) scaffold was fabricated using template method. Secondary phase of poly (ε-caprolactone) (PCL) was then introduced into the porous structure of the HA scaffold by the freeze drying method or the room drying process. Compression test and SEM were done to examine the mechanical properties and the microstructural morphology of the composite scaffolds. It was found that the compressive strength and modulus tend to increase with increasing PCL concentration. HA/PCL scaffolds fabricated under the room drying process exhibited higher compression strength and modulus than HA/PCL scaffolds prepared by the freeze drying method because the porous HA surfaces were completely covered by PCL in the room drying scaffolds. XRD test was also used to study the phase stability of the scaffolds. It was confirmed that there was no chemical reaction between PCL and HA. On overall, the results indicated that the introduction of secondary PCL phases into the porous HA scaffold can improve the low strength and toughness of the pure HA scaffold and the HA/PCL composite scaffolds might be a potential candidate in bone tissue engineering.


Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2644
Author(s):  
Jan Oszmiański ◽  
Sabina Lachowicz ◽  
Paulina Nowicka ◽  
Paweł Rubiński ◽  
Tomasz Cebulak

The present study aimed to evaluate the effect of Jerusalem artichoke processing methods and drying methods (freeze drying, sublimation drying, vacuum drying) on the basic physicochemical parameters, profiles and contents of sugars and polyphenolic compounds, and health-promoting properties (antioxidant activity, inhibition of the activities of α-amylase, α-glucosidase, and pancreatic lipase) of the produced purée. A total of 25 polyphenolic compounds belonging to hydroxycinnamic phenolic acids (LC-PDA-MS-QTof) were detected in Jerusalem artichoke purée. Their average content in the raw material was at 820 mg/100 g dm (UPLC-PDA-FL) and was 2.7 times higher than in the cooked material. The chemical composition and the health-promoting value of the purées were affected by the drying method, with the most beneficial values of the evaluated parameters obtained upon freeze drying. Vacuum drying could offer an alternative to freeze drying, as both methods ensured relatively comparable values of the assessed parameters.


2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Weihua Gu ◽  
Jiaqi Sheng ◽  
Qianqian Huang ◽  
Gehuan Wang ◽  
Jiabin Chen ◽  
...  

Highlights The eco-friendly shaddock peel-derived carbon aerogels were prepared by a freeze-drying method. Multiple functions such as thermal insulation, compression resistance and microwave absorption can be integrated into one material-carbon aerogel. Novel computer simulation technology strategy was selected to simulate significant radar cross-sectional reduction values under real far field condition. . Abstract Eco-friendly electromagnetic wave absorbing materials with excellent thermal infrared stealth property, heat-insulating ability and compression resistance are highly attractive in practical applications. Meeting the aforesaid requirements simultaneously is a formidable challenge. Herein, ultra-light carbon aerogels were fabricated via fresh shaddock peel by facile freeze-drying method and calcination process, forming porous network architecture. With the heating platform temperature of 70 °C, the upper surface temperatures of the as-prepared carbon aerogel present a slow upward trend. The color of the sample surface in thermal infrared images is similar to that of the surroundings. With the maximum compressive stress of 2.435 kPa, the carbon aerogels can provide favorable endurance. The shaddock peel-based carbon aerogels possess the minimum reflection loss value (RLmin) of − 29.50 dB in X band. Meanwhile, the effective absorption bandwidth covers 5.80 GHz at a relatively thin thickness of only 1.7 mm. With the detection theta of 0°, the maximum radar cross-sectional (RCS) reduction values of 16.28 dB m2 can be achieved. Theoretical simulations of RCS have aroused extensive interest owing to their ingenious design and time-saving feature. This work paves the way for preparing multi-functional microwave absorbers derived from biomass raw materials under the guidance of RCS simulations.


2006 ◽  
Vol 514-516 ◽  
pp. 1005-1009 ◽  
Author(s):  
José V. Araújo ◽  
J.A. Lopes da Silva ◽  
Margarida M. Almeida ◽  
Maria Elisabete V. Costa

Porous chitosan/brushite composite scaffolds were prepared by a freeze-drying technique, starting from brushite suspensions in chitosan solutions. The obtained scaffolds showed a regular macroporous and interconnected structure with brushite particles uniformly distributed in the chitosan matrix. The variation of the brushite concentration affected the microstructure of the final freeze-dried scaffold, in particular, its porosity and its average pore size. The yield strengths of the composite scaffolds could also be improved by the increase of the brushite content.


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