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Paolo A. Netti - One of the best experts on this subject based on the ideXlab platform.
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Morphology modulation of Gas-foamed, micrometric, hollow polystyrene particles
Journal of Applied Polymer Science, 2016Co-Authors: Vincenzo Contaldi, Paolo A. Netti, Ernesto Di Maio, Silvia Orsi, Luigi Imperato, Salvatore IannaceAbstract:In this article, we reports the effects of the processing conditions on the morphological and hollow attributes of polystyrene micrometric hollow particles produced by the use of a recently developed technique based on the Gas Foaming of spherical, dense particles. By modulating the Foaming temperature and saturation pressure, we produced hollow particles with different attributes in terms of hollow dimensions, eccentricity, and open–close features. The results from these small systems were compared, and we found agreement with what is typically observed in bulk polymeric Foaming, for example, an increase in the Foaming efficiency with saturation pressure and the nonmonotonic effect of temperature. Furthermore, we observed an increase in the hollow number when using nucleating agents with respect to the neat polymer and when using nitrogen with respect to carbon dioxide as the blowing agent. The effects of particle manipulation before Foaming to achieve hollow elongated or distorted particles are also reported. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44236.
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Hollow micro- and nano-particles by Gas Foaming
Nano Research, 2014Co-Authors: Silvia Orsi, Salvatore Iannace, Ernesto Di Maio, Paolo A. NettiAbstract:This paper presents the results of a first successful attempt to produce hollow micro- and nano-particles of a large variety of materials, dimensions, shapes and hollow attributes by using an environmentally friendly and cheap technology, common in polymer processing and known as Gas Foaming. The central role played by ad hoc polymeric hollow micro- and nano-particles in a variety of emerging applications such as drug delivery, medical imaging, advanced materials, as well as in fundamental studies in nanotechnology highlights the wide relevance of the proposed method. Our key contribution to overcome the physical lower bound in the micro- and nano-scale Gas Foaming was to embed, prior to Foaming, bulk micro- and nano-particles in a removable and deformable barrier film, whose role is to prevent the loss of the blowing agent, which is otherwise too fast to allow bubble formation. Furthermore, the barrier film allows for non-isotropic deformation of the particle and/or of the hollow, affording non-spherical hollow particles. In comparison with available methods to produce hollow micro- and nano-particles, our method is versatile since it offers independent control over the dimensions, material and shape of the particles, and the number, shape and open/closed features of the hollows. We have Gasfoamed polystyrene and poly-(lactic-co-glycolic) acid particles 200 μm to 200 nm in size, spherical, ellipsoidal and discoidal in shape, obtaining open or closed, single or multiple, variable in size hollows.
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Tailoring the pore structure of PCL scaffolds for tissue engineering prepared via Gas Foaming of multi-phase blends
Journal of Porous Materials, 2012Co-Authors: A. Salerno, Salvatore Iannace, E. Di Maio, Paolo A. NettiAbstract:The aim of this study was the design of poly(ε-caprolactone) (PCL) scaffolds characterized by well controlled pore structures obtained by Gas Foaming of multi-phase blends of PCL and thermoplastic gelatin (TG). Co-continuous blends made of PCL and TG were prepared by melt mixing and, subsequently Gas foamed in an autoclave to induce the formation of the porous network. A mixture of N_2 and CO_2 was used as blowing agent and the Foaming process performed at temperature higher than PCL melting, in the range 70–110 °C. The foams were finally soaked in water at 37 °C to selectively extract the TG and achieve the final pore structure. The results of this study demonstrated that the proposed approach allowed to tailor the micro-structural properties of PCL scaffolds for tissue engineering.
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tailoring the pore structure of pcl scaffolds for tissue engineering prepared via Gas Foaming of multi phase blends
Journal of Porous Materials, 2012Co-Authors: Aurelio Salerno, Salvatore Iannace, Paolo A. Netti, E. Di MaioAbstract:The aim of this study was the design of poly(e-caprolactone) (PCL) scaffolds characterized by well controlled pore structures obtained by Gas Foaming of multi-phase blends of PCL and thermoplastic gelatin (TG). Co-continuous blends made of PCL and TG were prepared by melt mixing and, subsequently Gas foamed in an autoclave to induce the formation of the porous network. A mixture of N2 and CO2 was used as blowing agent and the Foaming process performed at temperature higher than PCL melting, in the range 70–110 °C. The foams were finally soaked in water at 37 °C to selectively extract the TG and achieve the final pore structure. The results of this study demonstrated that the proposed approach allowed to tailor the micro-structural properties of PCL scaffolds for tissue engineering.
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Tuning the microstructure and biodegradation of three-phase scaffolds for bone regeneration made of PCL, Zein, and HA
Journal of Cellular Plastics, 2011Co-Authors: Aurelio Salerno, Salvatore Iannace, E. Di Maio, Paolo A. NettiAbstract:The aim of this study has been the design of novel multi-phase porous scaffolds with bi-modal pore size distributions and controlled biodegradation rate for bone tissue engineering (bTE), via a Gas Foaming—leaching approach. Poly(e-caprolactone) (PCL) has been melt mixed with thermoplastic zein (TZ) and hydroxyapatite particle, to prepare multi-phase PCL—TZ and PCL—TZ—HA composites suitable to be further processed for the fabrication of 3D porous scaffolds. To this aim, these systems have been Gas foamed by using CO2 as blowing agent and, subsequently, soaked in H2O to leach out the plasticizer from the TZ. This combined process allows the formation of an interpenetrated micro- and macro-porosity network within the samples. The effect of the different formulations on the micro-structural properties and in vitro biodegradation of the scaffolds has been investigated, and the results correlated to the mechanisms involved in the formation of the bi-modal pore structure. Results demonstrated that the multi-pha...
Salvatore Iannace - One of the best experts on this subject based on the ideXlab platform.
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A pressure vessel for studying Gas Foaming of thermosetting polymers: sorption, synthesis and processing
Polymer Testing, 2017Co-Authors: Maria Rosaria Di Caprio, Ernesto Di Maio, Daniele Tammaro, Sara Cavalca, Vanni Parenti, Alberto Fangareggi, Salvatore IannaceAbstract:Abstract We herein report the design of an apparatus for studying the concurrent chemo-physical processes occurring during Gas Foaming of thermosetting polymers. In particular, to address the recent interest in combining the Gas (physical) Foaming with the classical (chemical) polyurethane Foaming, a novel instrumented pressure vessel was designed for investigating: i) Gas sorption under high pressure on the different reactants, kept separate; ii) synthesis under high Gas pressure, upon mixing and iii) Foaming upon release of the pressure. The design of the new pressure vessel relies on two key features. From the processing side, we make use of a rubber impeller to keep the two reactants separate during Gas sorption and to allow for an efficient mixing at the end of the sorption stage. From the analytic side, we utilized a sapphire window beneath the sample holder to use diffuse reflectance near-infrared spectroscopy to measure both the amount of sorbed Gas and the reaction kinetics under Gas pressure. Preliminary results are reported for the polyol-isocyanate/CO2 system.
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Morphology modulation of Gas-foamed, micrometric, hollow polystyrene particles
Journal of Applied Polymer Science, 2016Co-Authors: Vincenzo Contaldi, Paolo A. Netti, Ernesto Di Maio, Silvia Orsi, Luigi Imperato, Salvatore IannaceAbstract:In this article, we reports the effects of the processing conditions on the morphological and hollow attributes of polystyrene micrometric hollow particles produced by the use of a recently developed technique based on the Gas Foaming of spherical, dense particles. By modulating the Foaming temperature and saturation pressure, we produced hollow particles with different attributes in terms of hollow dimensions, eccentricity, and open–close features. The results from these small systems were compared, and we found agreement with what is typically observed in bulk polymeric Foaming, for example, an increase in the Foaming efficiency with saturation pressure and the nonmonotonic effect of temperature. Furthermore, we observed an increase in the hollow number when using nucleating agents with respect to the neat polymer and when using nitrogen with respect to carbon dioxide as the blowing agent. The effects of particle manipulation before Foaming to achieve hollow elongated or distorted particles are also reported. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44236.
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Hollow micro- and nano-particles by Gas Foaming
Nano Research, 2014Co-Authors: Silvia Orsi, Salvatore Iannace, Ernesto Di Maio, Paolo A. NettiAbstract:This paper presents the results of a first successful attempt to produce hollow micro- and nano-particles of a large variety of materials, dimensions, shapes and hollow attributes by using an environmentally friendly and cheap technology, common in polymer processing and known as Gas Foaming. The central role played by ad hoc polymeric hollow micro- and nano-particles in a variety of emerging applications such as drug delivery, medical imaging, advanced materials, as well as in fundamental studies in nanotechnology highlights the wide relevance of the proposed method. Our key contribution to overcome the physical lower bound in the micro- and nano-scale Gas Foaming was to embed, prior to Foaming, bulk micro- and nano-particles in a removable and deformable barrier film, whose role is to prevent the loss of the blowing agent, which is otherwise too fast to allow bubble formation. Furthermore, the barrier film allows for non-isotropic deformation of the particle and/or of the hollow, affording non-spherical hollow particles. In comparison with available methods to produce hollow micro- and nano-particles, our method is versatile since it offers independent control over the dimensions, material and shape of the particles, and the number, shape and open/closed features of the hollows. We have Gasfoamed polystyrene and poly-(lactic-co-glycolic) acid particles 200 μm to 200 nm in size, spherical, ellipsoidal and discoidal in shape, obtaining open or closed, single or multiple, variable in size hollows.
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Scaffolds with tubular/isotropic Bi-modal pore structures by Gas Foaming and fiber templating
Materials Letters, 2013Co-Authors: Ernesto Di Maio, Aurelio Salerno, Salvatore IannaceAbstract:The aim of this study was to engineer a scaffold for tissue engineering with double shape pore architecture, with tubular and isotropic pores. A novel method is herein proposed, based on the combination of Gas Foaming and fiber templating. In particular, the tubular pores have been obtained by leaching of melt–spun saccharide fibers (cotton candy) within CO2-foamed poly(e-caprolactone). The optimization of the scaffold has been conducted via the selection of the proper saccharide, its thermal treatment to stabilize the spun fiber (crystallization), the formation of the polymer–fiber composite, the selection of the proper Gas-Foaming processing parameter and the final leaching in water.
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Tailoring the pore structure of PCL scaffolds for tissue engineering prepared via Gas Foaming of multi-phase blends
Journal of Porous Materials, 2012Co-Authors: A. Salerno, Salvatore Iannace, E. Di Maio, Paolo A. NettiAbstract:The aim of this study was the design of poly(ε-caprolactone) (PCL) scaffolds characterized by well controlled pore structures obtained by Gas Foaming of multi-phase blends of PCL and thermoplastic gelatin (TG). Co-continuous blends made of PCL and TG were prepared by melt mixing and, subsequently Gas foamed in an autoclave to induce the formation of the porous network. A mixture of N_2 and CO_2 was used as blowing agent and the Foaming process performed at temperature higher than PCL melting, in the range 70–110 °C. The foams were finally soaked in water at 37 °C to selectively extract the TG and achieve the final pore structure. The results of this study demonstrated that the proposed approach allowed to tailor the micro-structural properties of PCL scaffolds for tissue engineering.
Tae Gwan Park - One of the best experts on this subject based on the ideXlab platform.
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Highly open porous biodegradable microcarriers: in vitro cultivation of chondrocytes for injectable delivery.
Tissue engineering. Part A, 2008Co-Authors: Hyun Jung Chung, In Kyoung Kim, Taek Gyoung Kim, Tae Gwan ParkAbstract:Injectable cell therapy would provide a patient-friendly procedure for treatment of degenerated or wounded tissue. Biodegradable injectable porous microspheres were fabricated to use as dual-purpose microcarriers for cell culture and injectable scaffold for tissue regeneration. Gas Foaming in a water-in-oil-in-water double emulsion was performed for fabricating the well-interconnected porous microcarriers using poly(lactic-co-glycolic acid) (PLGA). The Gas Foaming conditions were finely tuned to control the structural and morphological characteristics. Porous microcarriers with a mean size of approximately 175 microm and an average pore diameter of approximately 29 microm were produced for cell cultivation and injectable delivery. To promote cell seeding, amine-functionalized porous microcarriers were prepared by blending amine-functionalized PLGA with unreacted PLGA. To assess the porous microcarriers for chondrocyte cultivation, bovine articular chondrocytes were seeded and cultured in vitro in spinner flasks for 4 weeks. Visualization and biochemical analyses of the microcarrier-cell constructs were performed to demonstrate cell proliferation and phenotypic expression. Quantification of deoxyribonucleic acid, glycosaminoglycan, and collagen content showed that much greater cell proliferation and expression of cartilage-specific phenotype were observed for cultures in the following order: amine-functionalized porous microcarriers, porous microcarriers, nonporous microcarriers, and monolayer culture.
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Gas foamed open porous biodegradable polymeric microspheres.
Biomaterials, 2006Co-Authors: Taek Kyoung Kim, Jun-jin Yoon, Doo Sung Lee, Tae Gwan ParkAbstract:Abstract Highly open porous biodegradable polymeric microspheres were fabricated for use as injectable scaffold microcarriers for cell delivery. A modified water-in-oil-in-water (W1/O/W2) double emulsion solvent evaporation method was employed for producing the microspheres. The incorporation of an effervescent salt, ammonium bicarbonate, in the primary W1 droplets spontaneously produced carbon dioxide and ammonia Gas bubbles during the solvent evaporation process, which not only stabilized the primary emulsion, but also created well inter-connected pores in the resultant microspheres. The porous microspheres fabricated under various Gas Foaming conditions were characterized. The surface pores became as large as 20 μm in diameter with increasing the concentration of ammonium bicarbonate, being sufficient enough for cell infiltration and seeding. These porous scaffold microspheres could be potentially utilized for cultivating cells in a suspension manner and for delivering the seeded cells to the tissue defect site in an injectable manner.
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immobilization of cell adhesive rgd peptide onto the surface of highly porous biodegradable polymer scaffolds fabricated by a Gas Foaming salt leaching method
Biomaterials, 2004Co-Authors: Jun-jin Yoon, Soon Ho Song, Tae Gwan ParkAbstract:Abstract A cell adhesive peptide moiety, Gly-Arg-Gly-Asp-Tyr (GRGDY), was immobilized onto the surface of highly porous biodegradable polymer scaffolds for enhancing cell adhesion and function. A carboxyl terminal end of poly( d,l -lactic-co-glycolic acid) (PLGA) was functionalized with a primary amine group by conjugating hexaethylene glycol-diamine. The PLGA-NH2 was blended with PLGA in varying ratios to prepare films by solvent casting or to fabricate porous scaffolds by a Gas Foaming/salt leaching method. Under hydrating conditions, the activated GRGDY could be directly immobilized to the surface exposed amine groups of the PLGA-NH2 blend films or scaffolds. For the PLGA blend films, the surface density of GRGDY, surface wettability change, and cell adhesion behaviors were characterized. The extent of cell adhesion was substantially enhanced by increasing the blend ratio of PLGA-NH2 to PLGA. The level of an alkaline phosphatase activity, measured as a degree of cell differentiation, was also enhanced as a result of the introduction of cell adhesive peptides.
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dexamethasone releasing biodegradable polymer scaffolds fabricated by a Gas Foaming salt leaching method
Biomaterials, 2003Co-Authors: Jun-jin Yoon, Jung Hoe Kim, Tae Gwan ParkAbstract:Dexamethasone, a steroidal anti-inflammatory drug, was incorporated into porous biodegradable polymer scaffolds for sustained release. The slowly released dexamethasone from the degrading scaffolds was hypothesized to locally modulate the proliferation and differentiation of various cells. Dexamethasone containing porous poly(D,L-lactic-co-glycolic acid) (PLGA) scaffolds were fabricated by a Gas-Foaming/salt-leaching method. Dexamethasone was loaded within the polymer phase of the PLGA scaffold in a molecularly dissolved state. The loading efficiency of dexamethasone varied from 57% to 65% depending on the initial loading amount. Dexamethasone was slowly released out in a controlled manner for over 30 days without showing an initial burst release. Release amount and duration could be adjusted by controlling the initial loading amount within the scaffolds. Released dexamethasone from the scaffolds drastically suppressed the proliferations of lymphocytes and smooth muscle cells in vitro. This study suggests that dexamethasone-releasing PLGA scaffolds could be potentially used either as an anti-inflammatory porous prosthetic device or as a temporal biodegradable stent for reducing intimal hyperplasia in restenosis.
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Dexamethasone-releasing biodegradable polymer scaffolds fabricated by a Gas-Foaming/salt-leaching method.
Biomaterials, 2003Co-Authors: Jun-jin Yoon, Jung Hoe Kim, Tae Gwan ParkAbstract:Dexamethasone, a steroidal anti-inflammatory drug, was incorporated into porous biodegradable polymer scaffolds for sustained release. The slowly released dexamethasone from the degrading scaffolds was hypothesized to locally modulate the proliferation and differentiation of various cells. Dexamethasone containing porous poly(D,L-lactic-co-glycolic acid) (PLGA) scaffolds were fabricated by a Gas-Foaming/salt-leaching method. Dexamethasone was loaded within the polymer phase of the PLGA scaffold in a molecularly dissolved state. The loading efficiency of dexamethasone varied from 57% to 65% depending on the initial loading amount. Dexamethasone was slowly released out in a controlled manner for over 30 days without showing an initial burst release. Release amount and duration could be adjusted by controlling the initial loading amount within the scaffolds. Released dexamethasone from the scaffolds drastically suppressed the proliferations of lymphocytes and smooth muscle cells in vitro. This study suggests that dexamethasone-releasing PLGA scaffolds could be potentially used either as an anti-inflammatory porous prosthetic device or as a temporal biodegradable stent for reducing intimal hyperplasia in restenosis.
Aurelio Salerno - One of the best experts on this subject based on the ideXlab platform.
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Scaffolds with tubular/isotropic Bi-modal pore structures by Gas Foaming and fiber templating
Materials Letters, 2013Co-Authors: Ernesto Di Maio, Aurelio Salerno, Salvatore IannaceAbstract:The aim of this study was to engineer a scaffold for tissue engineering with double shape pore architecture, with tubular and isotropic pores. A novel method is herein proposed, based on the combination of Gas Foaming and fiber templating. In particular, the tubular pores have been obtained by leaching of melt–spun saccharide fibers (cotton candy) within CO2-foamed poly(e-caprolactone). The optimization of the scaffold has been conducted via the selection of the proper saccharide, its thermal treatment to stabilize the spun fiber (crystallization), the formation of the polymer–fiber composite, the selection of the proper Gas-Foaming processing parameter and the final leaching in water.
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tailoring the pore structure of pcl scaffolds for tissue engineering prepared via Gas Foaming of multi phase blends
Journal of Porous Materials, 2012Co-Authors: Aurelio Salerno, Salvatore Iannace, Paolo A. Netti, E. Di MaioAbstract:The aim of this study was the design of poly(e-caprolactone) (PCL) scaffolds characterized by well controlled pore structures obtained by Gas Foaming of multi-phase blends of PCL and thermoplastic gelatin (TG). Co-continuous blends made of PCL and TG were prepared by melt mixing and, subsequently Gas foamed in an autoclave to induce the formation of the porous network. A mixture of N2 and CO2 was used as blowing agent and the Foaming process performed at temperature higher than PCL melting, in the range 70–110 °C. The foams were finally soaked in water at 37 °C to selectively extract the TG and achieve the final pore structure. The results of this study demonstrated that the proposed approach allowed to tailor the micro-structural properties of PCL scaffolds for tissue engineering.
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Tuning the microstructure and biodegradation of three-phase scaffolds for bone regeneration made of PCL, Zein, and HA
Journal of Cellular Plastics, 2011Co-Authors: Aurelio Salerno, Salvatore Iannace, E. Di Maio, Paolo A. NettiAbstract:The aim of this study has been the design of novel multi-phase porous scaffolds with bi-modal pore size distributions and controlled biodegradation rate for bone tissue engineering (bTE), via a Gas Foaming—leaching approach. Poly(e-caprolactone) (PCL) has been melt mixed with thermoplastic zein (TZ) and hydroxyapatite particle, to prepare multi-phase PCL—TZ and PCL—TZ—HA composites suitable to be further processed for the fabrication of 3D porous scaffolds. To this aim, these systems have been Gas foamed by using CO2 as blowing agent and, subsequently, soaked in H2O to leach out the plasticizer from the TZ. This combined process allows the formation of an interpenetrated micro- and macro-porosity network within the samples. The effect of the different formulations on the micro-structural properties and in vitro biodegradation of the scaffolds has been investigated, and the results correlated to the mechanisms involved in the formation of the bi-modal pore structure. Results demonstrated that the multi-pha...
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processing structure property relationship of multi scaled pcl and pcl ha composite scaffolds prepared via Gas Foaming and nacl reverse templating
Biotechnology and Bioengineering, 2011Co-Authors: Aurelio Salerno, Salvatore Iannace, E. Di Maio, Stefania Zeppetelli, Paolo A. NettiAbstract:In this study, we investigated the processing/ structure/property relationship of multi-scaled porous biodegradable scaffolds prepared by combining the Gas Foaming and NaCl reverse templating techniques. Poly(e-caprolactone) (PCL), hydroxyapatite (HA) nano-particles and NaCl micro-particles were melt-mixed by selecting different compositions and subsequently Gas foamed by a pressure-quench method. The NaCl micro-particles were finally removed from the foamed systems in order to allow for the achievement of the multi-scaled scaffold pore structure. The control of the micro-structural properties of the scaffolds was obtained by the optimal combination of the NaCl templating concentration and the composition of the CO 2 ―N 2 mixture as the blowing agent. In particular, these parameters were accurately selected to allow for the fabrication of PCL and PCL―HA composite scaffolds with multi-scaled open pore structures. Finally, the biocompatibility of the scaffolds has been assessed by cultivating pre-osteoblast MG63 cells in vitro, thus demonstrating their potential applications for bone regeneration.
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Processing/structure/property relationship of multi-scaled PCL and PCL-HA composite scaffolds prepared via Gas Foaming and NaCl reverse templating.
Biotechnology and bioengineering, 2010Co-Authors: Aurelio Salerno, Salvatore Iannace, E. Di Maio, Stefania Zeppetelli, Paolo A. NettiAbstract:In this study, we investigated the processing/ structure/property relationship of multi-scaled porous biodegradable scaffolds prepared by combining the Gas Foaming and NaCl reverse templating techniques. Poly(e-caprolactone) (PCL), hydroxyapatite (HA) nano-particles and NaCl micro-particles were melt-mixed by selecting different compositions and subsequently Gas foamed by a pressure-quench method. The NaCl micro-particles were finally removed from the foamed systems in order to allow for the achievement of the multi-scaled scaffold pore structure. The control of the micro-structural properties of the scaffolds was obtained by the optimal combination of the NaCl templating concentration and the composition of the CO 2 ―N 2 mixture as the blowing agent. In particular, these parameters were accurately selected to allow for the fabrication of PCL and PCL―HA composite scaffolds with multi-scaled open pore structures. Finally, the biocompatibility of the scaffolds has been assessed by cultivating pre-osteoblast MG63 cells in vitro, thus demonstrating their potential applications for bone regeneration.
A.p.m. Antunes - One of the best experts on this subject based on the ideXlab platform.
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the effects of crosslinkers on physical mechanical and cytotoxic properties of gelatin sponge prepared via in situ Gas Foaming method as a tissue engineering scaffold
Materials Science and Engineering: C, 2016Co-Authors: Ali S Poursamar, Alexander N. Lehner, Mahmoud Azami, Somayeh Ebrahimibarough, Ali Samadikuchaksaraei, A.p.m. AntunesAbstract:In this study porous gelatin scaffolds were prepared using in-situ Gas Foaming, and four crosslinking agents were used to determine a biocompatible and effective crosslinker that is suitable for such a method. Crosslinkers used in this study included: hexamethylene diisocyanate (HMDI), poly(ethylene glycol) diglycidyl ether (epoxy), glutaraldehyde (GTA), and genipin. The prepared porous structures were analyzed using Fourier Transform Infrared Spectroscopy (FT-IR), thermal and mechanical analysis as well as water absorption analysis. The microstructures of the prepared samples were analyzed using Scanning Electron Microscopy (SEM). The effects of the crosslinking agents were studied on the cytotoxicity of the porous structure indirectly using MTT analysis. The affinity of L929 mouse fibroblast cells for attachment on the scaffold surfaces was investigated by direct cell seeding and DAPI-staining technique. It was shown that while all of the studied crosslinking agents were capable of stabilizing prepared gelatin scaffolds, there are noticeable differences among physical and mechanical properties of samples based on the crosslinker type. Epoxy-crosslinked scaffolds showed a higher capacity for water absorption and more uniform microstructures than the rest of crosslinked samples, whereas genipin and GTA-crosslinked scaffolds demonstrated higher mechanical strength. Cytotoxicity analysis showed the superior biocompatibility of the naturally occurring genipin in comparison with other synthetic crosslinking agents, in particular relative to GTA-crosslinked samples.
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Potential application of gelatin scaffolds prepared through in situ Gas Foaming in skin tissue engineering
International Journal of Polymeric Materials and Polymeric Biomaterials, 2016Co-Authors: S. Ali Poursamar, Javad Hatami, Alexander N. Lehner, Cláudia Lobato Da Silva, Frederico Castelo Ferreira, A.p.m. AntunesAbstract:ABSTRACTGelatin’s excellent Foaming ability allows the application of in situ Gas Foaming as a preparation technique for porous scaffold development. Here, a new iterative experimental design for in situ Gas Foaming method is reported. The prepared scaffolds were studied for applying the findings to the future skin tissue engineering scaffolds. The thermal stability, mechanical properties, and pore structure of the scaffolds are reported and their degradation resistance by using collagenase enzyme and their cytotoxicity by using fibroblasts were studied. The results of this study demonstrated that Gas Foaming method can be modified to produce an interconnected porous structure with enhanced mechanical properties.
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Gelatin porous scaffolds fabricated using a modified Gas Foaming technique: characterisation and cytotoxicity assessment.
Materials science & engineering. C Materials for biological applications, 2014Co-Authors: S. Ali Poursamar, Javad Hatami, Alexander N. Lehner, Cláudia Lobato Da Silva, Frederico Castelo Ferreira, A.p.m. AntunesAbstract:The current study presents an effective and simple strategy to obtain stable porous scaffolds from gelatin via a Gas Foaming method. The technique exploits the intrinsic Foaming ability of gelatin in the presence of CO2 to obtain a porous structure stabilised with glutaraldehyde. The produced scaffolds were characterised using physical and mechanical characterisation methods. The results showed that Gas Foaming may allow the tailoring of the 3-dimensional structure of the scaffolds with an interconnected porous structure. To assess the effectiveness of the preparation method in mitigating the potential cytotoxicity risk of using glutaraldehyde as a crosslinker, direct and in-direct cytotoxicity assays were performed at different concentrations of glutaraldehyde. The results indicate the potential of the Gas Foaming method, in the preparation of viable tissue engineering scaffolds.
