Preparation of Porous Polycaprolactone Scaffolds by Using Freeze-Drying Combined Porogen-Leaching Methods

2008 ◽  
Vol 368-372 ◽  
pp. 1224-1226
Author(s):  
Cheng Yun Ning ◽  
Hai Mei Cheng ◽  
Zhao Yi Yin ◽  
Wen Jun Zhu ◽  
Hao Chen ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Mass Fraction ◽  
Freeze Drying ◽  
Porous Scaffold ◽  
Zero Temperature ◽  
Drying Process ◽  
Key Factors ◽  
3D Microstructure ◽  
Leaching Methods ◽  
Interconnected Pores

The microstructure of scaffold was one of key factors for tissue engineering. Porous polycaprolactone (PCL) scaffolds were fabricated by combination of porogen-leaching and freeze-drying process. Ice particulates were used as porogen material, and PCL solutions in chloroform were mixed with ice particulates for 5minuture at zero temperature. Then the mixture was freezed in liquid nitrogen, and porous scaffold was prepared by freeze - drying finally. The microstructure and properties of the scaffolds were investigated. Porous structure of the scaffolds showed that good 3D microstructure and no porogen remained in the scaffold; pore size and porosity were determined by the size and mass fraction of ice particulates. The results demonstrated that the Scaffolds possessed open and interconnected pores with sizes ranging from several μm to more than 300μm and porosities of 50~80%.

Hydroxyapatite/Biopolymers Composite Scaffolds for Bone Tissue Engineering

2011 ◽  
Vol 493-494 ◽  
pp. 826-831
Author(s):  
A.C.B.M. Fook ◽  
Thiago Bizerra Fideles ◽  
R.C. Barbosa ◽  
G.T.F.S. Furtado ◽  
G.Y.H. Sampaio ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Bone Tissue Engineering ◽  
Bone Tissue ◽  
Freeze Drying ◽  
Three Dimensional ◽  
Porous Scaffolds ◽  
X Ray Diffraction ◽  
X Ray ◽  
Interconnected Pores

The application of a hybrid composite consisting of biopolymer and calcium phosphate, similar morphology and properties of natural bone, may be a way to solve the problem of the fragility of ceramics without reducing its mechanical properties, retaining the properties of biocompatibility and high bioactivity. This work aims at the preparation and characterization of three-dimensional scaffolds composite HA / biopolymers (chitosan and gelatin). The freeze-drying technique was employed in this study to obtain these frameworks and partial results showed the effectiveness of this method. This involved the study of structural, chemical and morphological frameworks, in order to direct the research suggested the application. The X Ray Diffraction (XRD) and infrared spectroscopy and Fourier transform (FTIR) results confirmed the formation of hydroxyapatite (HA) phase and the presence of characteristic bands of HA and biopolymers in all compositions. The microstructure of the scaffolds study conducted by Scanning Electron Microscopy (SEM) revealed the formation of longitudinally oriented microchannels with interconnected pores. In all compositions the porous scaffolds showed varying sizes and mostly larger than 100μm, and is therefore considered materials with potential for application in bone tissue engineering.

Fabrication and characterization of an acellular annulus fibrosus scaffold with aligned porous construct for tissue engineering

2021 ◽  
pp. 088532822110419
Author(s):  
Xiaoyu Jin ◽  
Ran Kang ◽  
Rongrong Deng ◽  
Xu Zhao ◽  
Zihan Wang ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Annulus Fibrosus ◽  
Freeze Drying ◽  
Porous Scaffold ◽  
Three Dimensional ◽  
Supporting Cell ◽  
Host Cells ◽  
Drying Methods ◽  
Freeze Dried

Scaffolds mimicking the native annulus fibrosus (AF) extracellular matrix (ECM) structure are crucial to guide the seeding cells to regenerate aligned tissue, while fabricating such a scaffold by synthetic material is challengeable. Native acellular scaffolds derived from AF tissue certainly possess the advantages of natural structure and composition. Based on previous studies, we modified decellularization procedure and especially compared two drying methods, including gradient dehydration and freeze-drying. The decellularization process can effectively remove the host cells and antigens such as α-Gal, while maintaining the original ECM including GAG and collagen I. Compared with gradient dehydration, freeze-drying not only rendered the decellularized scaffold in dry state for storage but also gave the scaffold more aligned porous structure and hydrophilicity. And, the acellular porous scaffold manifested better capacity of supporting cell ingrowth when seeded human bone marrow mesenchymal stem cells (hBMSCs) or implanted in vivo. Furthermore, this optimized freeze-dried scaffold showed similar mechanical elastic modulus as native AF and demonstrated rare inflammatory granuloma and immune rejection as observed in HE staining and immunohistochemistry staining (IHC) of CD8 and MAC387 epitopes when implanted subcutaneously in vivo. To sum up, through our decellularization and freeze-drying procedure, an aligned porous three-dimensional scaffold derived from the natural AF ECM was successfully fabricated with good retention of ECM components and benign biocompatibility. It will be a promising scaffold for AF tissue engineering.

Development and Characterization of Poly(ε-caprolactone) Reinforced Porous Hydroxyapatite for Bone Tissue Engineering

2012 ◽  
Vol 529-530 ◽  
pp. 447-452 ◽  
Author(s):  
Yos Phanny ◽  
Mitsugu Todo
Keyword(s):  
Tissue Engineering ◽  
Bone Tissue Engineering ◽  
Bone Tissue ◽  
Freeze Drying ◽  
Secondary Phase ◽  
Potential Candidate ◽  
Drying Method ◽  
Drying Process ◽  
Composite Scaffolds ◽  
Porous Hydroxyapatite

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.

Video real-time imaging of artificial membranes during freeze-drying by cryo-electron microscopy

1988 ◽  
Vol 46 ◽  
pp. 16-17
Author(s):  
Alan S. Rudolph ◽  
Ronald R. Price
Keyword(s):  
Real Time ◽  
Self Assembly ◽  
Freeze Drying ◽  
Video Capture ◽  
Drying Process ◽  
Artificial Membranes ◽  
The Past ◽  
Cryo Electron Microscopy ◽  
Spherical Structures ◽  
Capture Techniques

We have employed cryoelectron microscopy to visualize events that occur during the freeze-drying of artificial membranes by employing real time video capture techniques. Artificial membranes or liposomes which are spherical structures within internal aqueous space are stabilized by water which provides the driving force for spontaneous self-assembly of these structures. Previous assays of damage to these structures which are induced by freeze drying reveal that the two principal deleterious events that occur are 1) fusion of liposomes and 2) leakage of contents trapped within the liposome [1]. In the past the only way to access these events was to examine the liposomes following the dehydration event. This technique allows the event to be monitored in real time as the liposomes destabilize and as water is sublimed at cryo temperatures in the vacuum of the microscope. The method by which liposomes are compromised by freeze-drying are largely unknown. This technique has shown that cryo-protectants such as glycerol and carbohydrates are able to maintain liposomal structure throughout the drying process.

scholarly journals Strengthening of Porcine Plasma Protein Superabsorbent Materials through a Solubilization-Freeze-Drying Process

Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 772
Author(s):  
Estefanía Álvarez-Castillo ◽  
Carlos Bengoechea ◽  
Antonio Guerrero
Keyword(s):  
Water Uptake ◽  
Plasma Protein ◽  
Freeze Drying ◽  
Meat Industry ◽  
Drying Process ◽  
Uptake Capacity ◽  
Water Uptake Capacity ◽  
Protein Flour ◽  
Hydrophilic Materials ◽  
By Products

The replacement of common acrylic derivatives by biodegradable materials in the formulation of superabsorbent materials would lessen the associated environmental impact. Moreover, the use of by-products or biowastes from the food industry that are usually discarded would promote a desired circular economy. The present study deals with the development of superabsorbent materials based on a by-product from the meat industry, namely plasma protein, focusing on the effects of a freeze-drying stage before blending with glycerol and eventual injection molding. More specifically, this freeze-drying stage is carried out either directly on the protein flour or after its solubilization in deionized water (10% w/w). Superabsorbent materials obtained after this solubilization-freeze-drying process display higher Young’s modulus and tensile strength values, without affecting their water uptake capacity. As greater water uptake is commonly related to poorer mechanical properties, the proposed solubilization-freeze-drying process is a useful strategy for producing strengthened hydrophilic materials.

scholarly journals Nanocomposite scaffolds for accelerating chronic wound healing by enhancing angiogenesis

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Hamed Nosrati ◽  
Reza Aramideh Khouy ◽  
Ali Nosrati ◽  
Mohammad Khodaei ◽  
Mehdi Banitalebi-Dehkordi ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Wound Healing ◽  
Tissue Regeneration ◽  
Molecular Mechanisms ◽  
Healing Process ◽  
The Body ◽  
Key Factors ◽  
Potential Applications ◽  
Nanocomposite Scaffolds

AbstractSkin is the body’s first barrier against external pathogens that maintains the homeostasis of the body. Any serious damage to the skin could have an impact on human health and quality of life. Tissue engineering aims to improve the quality of damaged tissue regeneration. One of the most effective treatments for skin tissue regeneration is to improve angiogenesis during the healing period. Over the last decade, there has been an impressive growth of new potential applications for nanobiomaterials in tissue engineering. Various approaches have been developed to improve the rate and quality of the healing process using angiogenic nanomaterials. In this review, we focused on molecular mechanisms and key factors in angiogenesis, the role of nanobiomaterials in angiogenesis, and scaffold-based tissue engineering approaches for accelerated wound healing based on improved angiogenesis.

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