Tissue Engineering
Farnaz Ghorbani; Ali Zamanian; Hanie Noje Dehian
Volume 8, Issue 4 , February 2015, , Pages 399-409
Abstract
In this study, we fabricated 3-dimentional PLGA-gelatin scaffolds with aligned-oriented pores by freeze casting technique which is similar to Extra Cellular Matrix (ECM), and evaluated its effect on both physical and mechanical features. Dissolving synthetic (PLGA) and natural (Gelatin) polymers in common ...
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In this study, we fabricated 3-dimentional PLGA-gelatin scaffolds with aligned-oriented pores by freeze casting technique which is similar to Extra Cellular Matrix (ECM), and evaluated its effect on both physical and mechanical features. Dissolving synthetic (PLGA) and natural (Gelatin) polymers in common solvent was one of the strengths of this investigation. Scanning electron microscopy (SEM) micrographs indicated that scaffolds contained 95% interconnected pores with diameter about 50-400 µm in horizontal direction and 50-200 µm in vertical direction. Moreover, the results of mercury intrusion porosimetry represented diameter of pores in range of 100–300 µm. According to fourieres transform infrared (FTIR) spectrum there was no inappropriate interactions during processing. Additionally, mechanical analysis (3.2 MPa) of PLGA-gelatin constructs illustrated that polymeric scaffolds can withstand mechanical loads in freezing direction. Based on the water absorption (950%) and biodegradation results, samples can support cellular interactions and prevent their integrity during tissue regeneration. In brief, freeze casted PLGA-gelatin scaffolds can provide unidirectional matrix with desired physical and mechanical characters to regenerate lesions.
Tissue Engineering
Zahra Saghaei Noosh Abadi; Atefe Aghajani; Mohammad Haghpanahi
Volume 7, Issue 1 , June 2013, , Pages 1-11
Abstract
We introduce how we may produce an experimental phantom for modeling the mechanical properties of soft tissue. Gelatin materials are used to construct the phantom. Our phantom comprises of two different types of tissue; tumor and background normal tissue. Weight ratio of the dry gelatin and deionized ...
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We introduce how we may produce an experimental phantom for modeling the mechanical properties of soft tissue. Gelatin materials are used to construct the phantom. Our phantom comprises of two different types of tissue; tumor and background normal tissue. Weight ratio of the dry gelatin and deionized water are obtained for producing the young’s modulus of 21 kPa and 102 kPa for the normal tissue and tumor, respectively. This phantom is used in ultrasound elastography with external excitation less than 5%.
Biomechanics of Bone / Bone Biomechanics
Mahmoud Azami; Fathollah Moztarzadeh; Mohammad Rabiee
Volume 3, Issue 4 , June 2009, , Pages 275-284
Abstract
During past decade, using biomimetic approaches has received much attention by scientists in the field of tissue substitutes preparation. These approaches have been employed for synthesis of bone tissue engineering scaffolds in the case of either materials or synthesis methods. In this study, an apatite ...
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During past decade, using biomimetic approaches has received much attention by scientists in the field of tissue substitutes preparation. These approaches have been employed for synthesis of bone tissue engineering scaffolds in the case of either materials or synthesis methods. In this study, an apatite phase has been synthesized within gelatin hydrogel in biomimetic condition. The obtained composite hydrogel has changed to a porous scaffold with the application of freeze drying technique in order to be used in bone tissue engineering. To characterize the chemical composition and crystal structure of the synthesized precipitate within hydrogel, FTIR, XRD and TEM analysis were used. Surface morphology and porous structure of the scaffold were studied with SEM. SEM analysis was also used to investigate the quality of cultured osteoblast cells activity. Results approved formation of an apatite phase within gelatin hydrogel in biomimetic condition with crystallite size ranging between 7-10 nm. Porosity percentage of the obtained nanocomposite scaffold was about 82% with pores sizes in the range of 100-350μm. Young’s elastic modulus of the scaffold was comparable with that of the spongy bone. The osteoblast cells cultured on the scaffold showed adhesion, immigration and extracellular matrix excretion on the scaffold internal surfaces. Thus, obtained results indicated the potential ability of the prepared biomimetic bone tissue engineering scaffold to be used in bone tissue repair process.
Tissue Engineering
Rana Imani; Parisa Rahnama Moshtaq; Shahriar Hojati Emami; Sasan Jalili; Ali Mohammad Sharifi
Volume 3, Issue 4 , June 2009, , Pages 315-324
Abstract
Cell therapy based on cell encapsulation technology holds out the promise of the treatment of many diseases. The technology of cell encapsulation represents a strategy in which cells that secrete therapeutic products are immobilized and immunoprotected within polymeric and biocompatible carriers. Hydrogels ...
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Cell therapy based on cell encapsulation technology holds out the promise of the treatment of many diseases. The technology of cell encapsulation represents a strategy in which cells that secrete therapeutic products are immobilized and immunoprotected within polymeric and biocompatible carriers. Hydrogels - highly hydrated polymer networks- have ideal characteristics for this application because of good biocompatibility and mimicking natural ECM properties. They can homogeneously incorporate and suspend cells, growth factors, and other bioactive compounds. Temperature-sensitive hydrogels, which can form implants in situ in response to temperature change, from ambient to body temperature, have been extensively used in various cell encapsulation, and tissue repair. The objective of this study was preparation, Characterization and selection the optimum composition of agarose-gelatin blend hydrogel, for cell encapsulation application. In order to obtain hydrogel with appropriate properties, rheological, mechanical, and structural characteristics of obtained hydrogels were examined. Furthermore, the stability of samples was characterized by degradation and gelatin release measurements under physiological condition. Cell attachment and cytotoxicity analysis were also performed. Based on the results, hydrogel containing a 1:1 mixture of gelatin and agarose exhibited sol-to-gel transition near body temperature. Samples contain 50% agarose and more, exhibited mechanical integrity under physiological condition. Indentation test of the mechanical properties demonstrated viscoelastic behavior of the blend gelatin-agarose hydrogels under static load; however by increasing the agarose portion, hydrogel behaved more elastically. In vitro biocompatibility experiments showed undetectable cytotoxicity of the hydrogels. Also adding gelatin to agarose modified cell attachment behavior. The results of this study indicate the possibility of the potential use of prepared thermo-responsive agarose/gelatin conjugate with nearly same portion of two components as cell encapsulation carrier.
Tissue Engineering
Karim Asgarzadeh Tabrizi; Fariba Ourang
Volume -1, Issue 1 , June 2004, , Pages 57-64
Abstract
Gelatin is a protein which is derived from the organic constituent of bone (collagen). Combination of this protein with the inorganic constituent of bone (hydroxyapatite) may provide closer properties to the natural bone. In this study, a biodegradable composite scaffold based on gelatin and hydroxyapatite ...
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Gelatin is a protein which is derived from the organic constituent of bone (collagen). Combination of this protein with the inorganic constituent of bone (hydroxyapatite) may provide closer properties to the natural bone. In this study, a biodegradable composite scaffold based on gelatin and hydroxyapatite was prepared as a substitute for bone tissue. To increase the biocompatibility of this, composite, its fabrication was carried out without using any organic solvent. Porosities obtained were spontaneously achieved without any porogen. The pore morphology indicated a high interconnectivity with diameters ranging from 50 to 200 micrometers, which seems appropriate for bone tissue engineering applications. In order to study the biocompatibility of the scaffolds, mouse fibroblastic cells were used. After 24-hour cell culture period in vitro, suitable cell attachment was observed showing high biocompatibility for all the samples. Further examinations demonstrated that the best biocompatibility is obtained for the composite of 50 wt% hydroxyapatite and 50 wt% gelatin.
