The Experts below are selected from a list of 1689 Experts worldwide ranked by ideXlab platform
Rui L Reis - One of the best experts on this subject based on the ideXlab platform.
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Supercritical Fluid Technology as a tool to prepare gradient multifunctional architectures towards regeneration of osteochondral injuries
2018Co-Authors: Ana Rita C. Duarte, Vitor E Santo, Manuela E Gomes, Rui L ReisAbstract:Platelet lysates (PLs) are a natural source of growth factors (GFs) known for its stimulatory role on stem cells which can be obtained after activation of platelets from blood plasma. The possibility to use PLs as growth factor source for tissue healing and regeneration has been pursued following different strategies. Platelet lysates are an enriched pool of growth factors which can be used as either a GFs source or as a three-dimensional (3D) hydrogel. However, most of current PLs-based hydrogels lack stability, exhibiting significant shrinking behavior. This chapter focuses on the application of Supercritical Fluid Technology to develop three-dimensional architectures of PL constructs, crosslinked with genipin. The proposed Technology allows in a single step operation the development of mechanically stable porous structures, through chemical crosslinking of the growth factors present in the PL pool, followed by Supercritical drying of the samples. Furthermore gradient structures of PL-based structures with bioactive glass are also presented and are described as an interesting approach to the treatment of osteochondral defects.
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green processing of porous chitin structures for biomedical applications combining ionic liquids and Supercritical Fluid Technology
Acta Biomaterialia, 2011Co-Authors: Simone S. Silva, Ana Paula Carvalho, Ana Rita C. Duarte, João Filipe Mano, Rui L ReisAbstract:Abstract The application of green chemistry principles in the processing of materials for advanced technologies is a steadily increasing field of research. In this work porous chitin-based materials were developed by combining the processing of chitin using ionic liquids (ILs) as a green solvent together with the use of Supercritical Fluid Technology (SCF) as clean Technology. Chitin was dissolved in 1-butyl-3-imidazolium acetate, followed by regeneration of the polymer in ethanol in specific moulds. The IL was removed using Soxhlet extraction and successive steps of extraction with SCF using carbon dioxide/ethanol ratios of 50/50 and 70/30. The developed porous chitin-based structures (ChIL) can be classified as mesoporous materials, with very low density and high porosity. The cytotoxicity of ChIL extracts was investigated using L929 fibroblast-like cells, and the results demonstrated that the produced materials have extremely low cytotoxicity levels. Therefore, the findings suggest that the porous chitin structures may be potential candidates for a number of biomedical applications, including tissue engineering.
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Green processing of porous chitin structures for biomedical applications combining ionic liquids and Supercritical Fluid Technology
Acta Biomaterialia, 2011Co-Authors: Simone S. Silva, Ana Paula Carvalho, Ana Rita C. Duarte, João Filipe Mano, Rui L ReisAbstract:The application of green chemistry principles in the processing of materials for advanced technologies is a steadily increasing field of research. In this work porous chitin-based materials were developed by combining the processing of chitin using ionic liquids (ILs) as a green solvent together with the use of Supercritical Fluid Technology (SCF) as clean Technology. Chitin was dissolved in 1-butyl-3-imidazolium acetate, followed by regeneration of the polymer in ethanol in specific moulds. The IL was removed using Soxhlet extraction and successive steps of extraction with SCF using carbon dioxide/ethanol ratios of 50/50 and 70/30. The developed porous chitin-based structures (ChIL) can be classified as mesoporous materials, with very low density and high porosity. The cytotoxicity of ChIL extracts was investigated using L929 fibroblast-like cells, and the results demonstrated that the produced materials have extremely low cytotoxicity levels. Therefore, the findings suggest that the porous chitin structures may be potential candidates for a number of biomedical applications, including tissue engineering. © 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
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enzymatic degradation of 3d scaffolds of starch poly ɛ caprolactone prepared by Supercritical Fluid Technology
Polymer Degradation and Stability, 2010Co-Authors: Ana Rita C. Duarte, João Filipe Mano, Rui L ReisAbstract:Abstract Starch-based polymers have been proposed for different tissue engineering applications due to their inherent properties. In this work, a polymeric blend of starch-poly-(ɛ-caprolactone) (SPCL) was processed using Supercritical Fluid Technology, namely, by Supercritical assisted phase inversion. As SPCL is a biodegradable polymer, the matrices produced are susceptible of undergoing enzymatic degradation upon implantation in the human body. In vitro assessment of the enzymatic degradation of SPCL was carried out in different buffer solutions containing α-amylase and/or lipase. The effect of the presence of these enzymes was studied by monitoring different parameters in order to characterise both bulk and the surface of the scaffolds. As regards to bulk analysis, weight loss of the samples incubated for 1, 3, 7, 14 and 21 days was determined, further differential scanning calorimetry was carried out. The morphology of the scaffolds after these periods was analysed by micro-computed tomography (μ-CT) and surface chemistry was characterised by infra-red spectroscopy and contact angle measurements. Results suggest that SPLC scaffolds undergo bulk degradation, which is typically characterised by hydrolysis of chemical bonds in the polymer chain at the centre of the matrix, resulting in a highly porous material.
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Enzymatic degradation of 3D scaffolds of starch-poly-(ε-caprolactone) prepared by Supercritical Fluid Technology
Polymer Degradation and Stability, 2010Co-Authors: Ana Rita C. Duarte, João Filipe Mano, Rui L ReisAbstract:Starch-based polymers have been proposed for different tissue engineering applications due to their inherent properties. In this work, a polymeric blend of starch-poly-(ε-caprolactone) (SPCL) was processed using Supercritical Fluid Technology, namely, by Supercritical assisted phase inversion. As SPCL is a biodegradable polymer, the matrices produced are susceptible of undergoing enzymatic degradation upon implantation in the human body. In vitro assessment of the enzymatic degradation of SPCL was carried out in different buffer solutions containing a-amylase and/or lipase. The effect of the presence ofthese enzymes was studied by monitoring different parameters in order to characterise both bulk and the surface of the scaffolds. As regards to bulk analysis, weight loss of the samples incubated for 1, 3, 7, 14 and 21 days was determined, further differential scanning calorimetry was carried out. The morphology of the scaffolds after these periods was analysed by micro-computed tomography (μ-CT) and surface chemistry was characterised by infra-red spectroscopy and contact angle measurements. Results suggest that SPLC scaffolds undergo bulk degradation, which is typically characterised by hydrolysis of chemical bonds in the polymer chain at the centre of the matrix, resulting in a highly porous material. © 2010 Elsevier Ltd. All rights reserved.
Uday B. Kompella - One of the best experts on this subject based on the ideXlab platform.
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Supercritical Fluid Technology based large porous celecoxib plga microparticles do not induce pulmonary fibrosis and sustain drug delivery and efficacy for several weeks following a single dose
Journal of Controlled Release, 2013Co-Authors: Devender S Dhanda, Uday B. Kompella, Puneet Tyagi, Sidney S MirvishAbstract:Abstract Although pulmonary dosing of large porous particles has been shown to sustain drug delivery for a few days, there are no reports on safety or long term delivery. In this study we prepared large porous poly(lactide-co-glycolide) (PLGA) microparticles of celecoxib using Supercritical Fluid pressure-quench Technology and demonstrated 4.8-, 15.7-, and 2.1-fold greater drug levels in lung, bronchoalveolar lavage Fluid (BAL), and plasma compared to conventional microparticles on day 21 after a single intratracheal dosing of dry powders in A/J mice. Porous particle based delivery was 50.2-, 95.5-, and 7.7-fold higher compared to plain drug in the lung, BAL, and plasma, respectively. Toxicity of the formulations was assessed on day 21 following a fibrosis assessment protocol in A/J mice. There was no significant change in lactate dehydrogenase (LDH), total protein, and total cell counts in the BAL, and soluble collagen levels in the lung tissue following particle or drug treatments. Lung histology indicated no significant hyperplasia, granuloma, or collagen deposition in the treated groups. Chemopreventive potential of celecoxib porous particles was assessed in a benzo[a]pyrene (B[a]P) induced lung cancer model in A/J mice, on day 60 following a single intratracheal dose with or without single intravenous paclitaxel/carboplatin treatment. The combination group was more effective than individual groups, with the inhibition of tumor multiplicity and reduction of vascular endothelial growth factor in the BAL being 70 and 58%, respectively. Thus, large porous celecoxib–PLGA microparticles prepared using Supercritical Fluid Technology exhibited sustained drug delivery and anti-tumor efficacy, without causing any significant toxicity.
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Supercritical Fluid Technology based large porous celecoxib–PLGA microparticles do not induce pulmonary fibrosis and sustain drug delivery and efficacy for several weeks following a single dose
Journal of Controlled Release, 2013Co-Authors: Devender S Dhanda, Puneet Tyagi, Sidney S Mirvish, Uday B. KompellaAbstract:Abstract Although pulmonary dosing of large porous particles has been shown to sustain drug delivery for a few days, there are no reports on safety or long term delivery. In this study we prepared large porous poly(lactide-co-glycolide) (PLGA) microparticles of celecoxib using Supercritical Fluid pressure-quench Technology and demonstrated 4.8-, 15.7-, and 2.1-fold greater drug levels in lung, bronchoalveolar lavage Fluid (BAL), and plasma compared to conventional microparticles on day 21 after a single intratracheal dosing of dry powders in A/J mice. Porous particle based delivery was 50.2-, 95.5-, and 7.7-fold higher compared to plain drug in the lung, BAL, and plasma, respectively. Toxicity of the formulations was assessed on day 21 following a fibrosis assessment protocol in A/J mice. There was no significant change in lactate dehydrogenase (LDH), total protein, and total cell counts in the BAL, and soluble collagen levels in the lung tissue following particle or drug treatments. Lung histology indicated no significant hyperplasia, granuloma, or collagen deposition in the treated groups. Chemopreventive potential of celecoxib porous particles was assessed in a benzo[a]pyrene (B[a]P) induced lung cancer model in A/J mice, on day 60 following a single intratracheal dose with or without single intravenous paclitaxel/carboplatin treatment. The combination group was more effective than individual groups, with the inhibition of tumor multiplicity and reduction of vascular endothelial growth factor in the BAL being 70 and 58%, respectively. Thus, large porous celecoxib–PLGA microparticles prepared using Supercritical Fluid Technology exhibited sustained drug delivery and anti-tumor efficacy, without causing any significant toxicity.
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Supercritical Fluid Technology for Drug Product Development - Supercritical Fluid Technology for drug product development
2004Co-Authors: Peter York, Uday B. Kompella, Boris Y ShekunovAbstract:Chemistry and Materials Design for Pharmaceutical Applications. Phase Equilibrium in Solid-Liquid-Supercritical Fluid Systems. Mechanisms of Particle Formation Using Supercritical Fluids. Methods of Particle Production. Colloid and Interface Science for CO2-based Pharmaceutical Processes. Production of Powders for Respiratory Drug Delivery. Control of Physical Form of Drug Substances. Supercritical Fluid Impregnation of Polymers for Drug Delivery. Formulation of Controlled Drug Release Systems. Processing of Biological Materials. Asymmetric Catalysis in Supercritical Fluids. Analytical and Semi-Preparative Supercritical Fluid Chromatography in Drug Discovery. Drug Extraction Development and Potential of Critical Fluid Technology in the Neutraceutical Industry. Scale-Up Issues for Supercritical Fluid Processing in Compliance with GMP
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Supercritical Fluid Technology for drug product development
2004Co-Authors: Peter York, Uday B. Kompella, Boris Y ShekunovAbstract:Chemistry and Materials Design for Pharmaceutical Applications. Phase Equilibrium in Solid-Liquid-Supercritical Fluid Systems. Mechanisms of Particle Formation Using Supercritical Fluids. Methods of Particle Production. Colloid and Interface Science for CO2-based Pharmaceutical Processes. Production of Powders for Respiratory Drug Delivery. Control of Physical Form of Drug Substances. Supercritical Fluid Impregnation of Polymers for Drug Delivery. Formulation of Controlled Drug Release Systems. Processing of Biological Materials. Asymmetric Catalysis in Supercritical Fluids. Analytical and Semi-Preparative Supercritical Fluid Chromatography in Drug Discovery. Drug Extraction Development and Potential of Critical Fluid Technology in the Neutraceutical Industry. Scale-Up Issues for Supercritical Fluid Processing in Compliance with GMP
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preparation of drug delivery systems using Supercritical Fluid Technology
Critical Reviews in Therapeutic Drug Carrier Systems, 2001Co-Authors: Uday B. Kompella, Kavitha KoushikAbstract:Small changes in temperature and pressure near the critical region induce dramatic changes in the density and solubility of Supercritical Fluids, thereby facilitating the use of environmentally benign agents such as CO 2 for their solvent and antisolvent properties in processing a wide variety of materials. While Supercritical Fluid technologies have been in commercial use in the food and chromatography industries for several years, only recently has this Technology made inroads in the formulation of drug delivery systems. This review summarizes some of the recent applications of Supercritical Fluid Technology in the preparation of drug delivery systems. Drugs containing polymeric particles, plain drug particles, solute-containing liposomes, and inclusion complexes of drug and carrier have been formulated using this Technology. Also, polymer separation using this Technology is enabling the selection of a pure fraction of a polymer, thereby allowing a more precise control of drug release from polymeric delivery systems.
Ana Rita C. Duarte - One of the best experts on this subject based on the ideXlab platform.
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Supercritical Fluid Technology as a tool to prepare gradient multifunctional architectures towards regeneration of osteochondral injuries
2018Co-Authors: Ana Rita C. Duarte, Vitor E Santo, Manuela E Gomes, Rui L ReisAbstract:Platelet lysates (PLs) are a natural source of growth factors (GFs) known for its stimulatory role on stem cells which can be obtained after activation of platelets from blood plasma. The possibility to use PLs as growth factor source for tissue healing and regeneration has been pursued following different strategies. Platelet lysates are an enriched pool of growth factors which can be used as either a GFs source or as a three-dimensional (3D) hydrogel. However, most of current PLs-based hydrogels lack stability, exhibiting significant shrinking behavior. This chapter focuses on the application of Supercritical Fluid Technology to develop three-dimensional architectures of PL constructs, crosslinked with genipin. The proposed Technology allows in a single step operation the development of mechanically stable porous structures, through chemical crosslinking of the growth factors present in the PL pool, followed by Supercritical drying of the samples. Furthermore gradient structures of PL-based structures with bioactive glass are also presented and are described as an interesting approach to the treatment of osteochondral defects.
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green processing of porous chitin structures for biomedical applications combining ionic liquids and Supercritical Fluid Technology
Acta Biomaterialia, 2011Co-Authors: Simone S. Silva, Ana Paula Carvalho, Ana Rita C. Duarte, João Filipe Mano, Rui L ReisAbstract:Abstract The application of green chemistry principles in the processing of materials for advanced technologies is a steadily increasing field of research. In this work porous chitin-based materials were developed by combining the processing of chitin using ionic liquids (ILs) as a green solvent together with the use of Supercritical Fluid Technology (SCF) as clean Technology. Chitin was dissolved in 1-butyl-3-imidazolium acetate, followed by regeneration of the polymer in ethanol in specific moulds. The IL was removed using Soxhlet extraction and successive steps of extraction with SCF using carbon dioxide/ethanol ratios of 50/50 and 70/30. The developed porous chitin-based structures (ChIL) can be classified as mesoporous materials, with very low density and high porosity. The cytotoxicity of ChIL extracts was investigated using L929 fibroblast-like cells, and the results demonstrated that the produced materials have extremely low cytotoxicity levels. Therefore, the findings suggest that the porous chitin structures may be potential candidates for a number of biomedical applications, including tissue engineering.
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Green processing of porous chitin structures for biomedical applications combining ionic liquids and Supercritical Fluid Technology
Acta Biomaterialia, 2011Co-Authors: Simone S. Silva, Ana Paula Carvalho, Ana Rita C. Duarte, João Filipe Mano, Rui L ReisAbstract:The application of green chemistry principles in the processing of materials for advanced technologies is a steadily increasing field of research. In this work porous chitin-based materials were developed by combining the processing of chitin using ionic liquids (ILs) as a green solvent together with the use of Supercritical Fluid Technology (SCF) as clean Technology. Chitin was dissolved in 1-butyl-3-imidazolium acetate, followed by regeneration of the polymer in ethanol in specific moulds. The IL was removed using Soxhlet extraction and successive steps of extraction with SCF using carbon dioxide/ethanol ratios of 50/50 and 70/30. The developed porous chitin-based structures (ChIL) can be classified as mesoporous materials, with very low density and high porosity. The cytotoxicity of ChIL extracts was investigated using L929 fibroblast-like cells, and the results demonstrated that the produced materials have extremely low cytotoxicity levels. Therefore, the findings suggest that the porous chitin structures may be potential candidates for a number of biomedical applications, including tissue engineering. © 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
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enzymatic degradation of 3d scaffolds of starch poly ɛ caprolactone prepared by Supercritical Fluid Technology
Polymer Degradation and Stability, 2010Co-Authors: Ana Rita C. Duarte, João Filipe Mano, Rui L ReisAbstract:Abstract Starch-based polymers have been proposed for different tissue engineering applications due to their inherent properties. In this work, a polymeric blend of starch-poly-(ɛ-caprolactone) (SPCL) was processed using Supercritical Fluid Technology, namely, by Supercritical assisted phase inversion. As SPCL is a biodegradable polymer, the matrices produced are susceptible of undergoing enzymatic degradation upon implantation in the human body. In vitro assessment of the enzymatic degradation of SPCL was carried out in different buffer solutions containing α-amylase and/or lipase. The effect of the presence of these enzymes was studied by monitoring different parameters in order to characterise both bulk and the surface of the scaffolds. As regards to bulk analysis, weight loss of the samples incubated for 1, 3, 7, 14 and 21 days was determined, further differential scanning calorimetry was carried out. The morphology of the scaffolds after these periods was analysed by micro-computed tomography (μ-CT) and surface chemistry was characterised by infra-red spectroscopy and contact angle measurements. Results suggest that SPLC scaffolds undergo bulk degradation, which is typically characterised by hydrolysis of chemical bonds in the polymer chain at the centre of the matrix, resulting in a highly porous material.
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Enzymatic degradation of 3D scaffolds of starch-poly-(ε-caprolactone) prepared by Supercritical Fluid Technology
Polymer Degradation and Stability, 2010Co-Authors: Ana Rita C. Duarte, João Filipe Mano, Rui L ReisAbstract:Starch-based polymers have been proposed for different tissue engineering applications due to their inherent properties. In this work, a polymeric blend of starch-poly-(ε-caprolactone) (SPCL) was processed using Supercritical Fluid Technology, namely, by Supercritical assisted phase inversion. As SPCL is a biodegradable polymer, the matrices produced are susceptible of undergoing enzymatic degradation upon implantation in the human body. In vitro assessment of the enzymatic degradation of SPCL was carried out in different buffer solutions containing a-amylase and/or lipase. The effect of the presence ofthese enzymes was studied by monitoring different parameters in order to characterise both bulk and the surface of the scaffolds. As regards to bulk analysis, weight loss of the samples incubated for 1, 3, 7, 14 and 21 days was determined, further differential scanning calorimetry was carried out. The morphology of the scaffolds after these periods was analysed by micro-computed tomography (μ-CT) and surface chemistry was characterised by infra-red spectroscopy and contact angle measurements. Results suggest that SPLC scaffolds undergo bulk degradation, which is typically characterised by hydrolysis of chemical bonds in the polymer chain at the centre of the matrix, resulting in a highly porous material. © 2010 Elsevier Ltd. All rights reserved.
João Filipe Mano - One of the best experts on this subject based on the ideXlab platform.
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green processing of porous chitin structures for biomedical applications combining ionic liquids and Supercritical Fluid Technology
Acta Biomaterialia, 2011Co-Authors: Simone S. Silva, Ana Paula Carvalho, Ana Rita C. Duarte, João Filipe Mano, Rui L ReisAbstract:Abstract The application of green chemistry principles in the processing of materials for advanced technologies is a steadily increasing field of research. In this work porous chitin-based materials were developed by combining the processing of chitin using ionic liquids (ILs) as a green solvent together with the use of Supercritical Fluid Technology (SCF) as clean Technology. Chitin was dissolved in 1-butyl-3-imidazolium acetate, followed by regeneration of the polymer in ethanol in specific moulds. The IL was removed using Soxhlet extraction and successive steps of extraction with SCF using carbon dioxide/ethanol ratios of 50/50 and 70/30. The developed porous chitin-based structures (ChIL) can be classified as mesoporous materials, with very low density and high porosity. The cytotoxicity of ChIL extracts was investigated using L929 fibroblast-like cells, and the results demonstrated that the produced materials have extremely low cytotoxicity levels. Therefore, the findings suggest that the porous chitin structures may be potential candidates for a number of biomedical applications, including tissue engineering.
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Green processing of porous chitin structures for biomedical applications combining ionic liquids and Supercritical Fluid Technology
Acta Biomaterialia, 2011Co-Authors: Simone S. Silva, Ana Paula Carvalho, Ana Rita C. Duarte, João Filipe Mano, Rui L ReisAbstract:The application of green chemistry principles in the processing of materials for advanced technologies is a steadily increasing field of research. In this work porous chitin-based materials were developed by combining the processing of chitin using ionic liquids (ILs) as a green solvent together with the use of Supercritical Fluid Technology (SCF) as clean Technology. Chitin was dissolved in 1-butyl-3-imidazolium acetate, followed by regeneration of the polymer in ethanol in specific moulds. The IL was removed using Soxhlet extraction and successive steps of extraction with SCF using carbon dioxide/ethanol ratios of 50/50 and 70/30. The developed porous chitin-based structures (ChIL) can be classified as mesoporous materials, with very low density and high porosity. The cytotoxicity of ChIL extracts was investigated using L929 fibroblast-like cells, and the results demonstrated that the produced materials have extremely low cytotoxicity levels. Therefore, the findings suggest that the porous chitin structures may be potential candidates for a number of biomedical applications, including tissue engineering. © 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
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enzymatic degradation of 3d scaffolds of starch poly ɛ caprolactone prepared by Supercritical Fluid Technology
Polymer Degradation and Stability, 2010Co-Authors: Ana Rita C. Duarte, João Filipe Mano, Rui L ReisAbstract:Abstract Starch-based polymers have been proposed for different tissue engineering applications due to their inherent properties. In this work, a polymeric blend of starch-poly-(ɛ-caprolactone) (SPCL) was processed using Supercritical Fluid Technology, namely, by Supercritical assisted phase inversion. As SPCL is a biodegradable polymer, the matrices produced are susceptible of undergoing enzymatic degradation upon implantation in the human body. In vitro assessment of the enzymatic degradation of SPCL was carried out in different buffer solutions containing α-amylase and/or lipase. The effect of the presence of these enzymes was studied by monitoring different parameters in order to characterise both bulk and the surface of the scaffolds. As regards to bulk analysis, weight loss of the samples incubated for 1, 3, 7, 14 and 21 days was determined, further differential scanning calorimetry was carried out. The morphology of the scaffolds after these periods was analysed by micro-computed tomography (μ-CT) and surface chemistry was characterised by infra-red spectroscopy and contact angle measurements. Results suggest that SPLC scaffolds undergo bulk degradation, which is typically characterised by hydrolysis of chemical bonds in the polymer chain at the centre of the matrix, resulting in a highly porous material.
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Enzymatic degradation of 3D scaffolds of starch-poly-(ε-caprolactone) prepared by Supercritical Fluid Technology
Polymer Degradation and Stability, 2010Co-Authors: Ana Rita C. Duarte, João Filipe Mano, Rui L ReisAbstract:Starch-based polymers have been proposed for different tissue engineering applications due to their inherent properties. In this work, a polymeric blend of starch-poly-(ε-caprolactone) (SPCL) was processed using Supercritical Fluid Technology, namely, by Supercritical assisted phase inversion. As SPCL is a biodegradable polymer, the matrices produced are susceptible of undergoing enzymatic degradation upon implantation in the human body. In vitro assessment of the enzymatic degradation of SPCL was carried out in different buffer solutions containing a-amylase and/or lipase. The effect of the presence ofthese enzymes was studied by monitoring different parameters in order to characterise both bulk and the surface of the scaffolds. As regards to bulk analysis, weight loss of the samples incubated for 1, 3, 7, 14 and 21 days was determined, further differential scanning calorimetry was carried out. The morphology of the scaffolds after these periods was analysed by micro-computed tomography (μ-CT) and surface chemistry was characterised by infra-red spectroscopy and contact angle measurements. Results suggest that SPLC scaffolds undergo bulk degradation, which is typically characterised by hydrolysis of chemical bonds in the polymer chain at the centre of the matrix, resulting in a highly porous material. © 2010 Elsevier Ltd. All rights reserved.
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preparation of chitosan scaffolds for tissue engineering using Supercritical Fluid Technology
Materials Science Forum, 2010Co-Authors: Ana Rita C. Duarte, João Filipe Mano, Rui L ReisAbstract:The aim of this study was to evaluate the possibility of preparing chitosan porous matrixes using Supercritical Fluid Technology. Supercritical immersion precipitation technique was used to prepare scaffolds of a natural biocompatible polymer, chitosan, for tissue engineering purposes. The physicochemical and biological properties of chitosan make it an excellent material for the preparation of drug delivery systems and for the development of new biomedical applications in many fields from skin to bone or cartilage. Immersion precipitation experiments were carried out at different operational conditions in order to optimize the processing method. The effect of different organic solvents on the morphology of the scaffolds was assessed. Additionally, different parameters that influence the process were tested and the effect of the processing variables such as polymer concentration, temperature and pressure in the chitosan scaffold morphology, porosity and interconnectivity was evaluated by micro computed tomography. The preparation of a highly porous and interconnected structure of a natural material, chitosan, using a clean and environmentally friendly Technology constitutes a new processing Technology for the preparation of scaffolds for tissue engineering using these materials.
Tadafumi Adschiri - One of the best experts on this subject based on the ideXlab platform.
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nanoparticles synthesis using Supercritical Fluid Technology towards biomedical applications
Advanced Drug Delivery Reviews, 2008Co-Authors: K. Byrappa, Satoshi Ohara, Tadafumi AdschiriAbstract:Abstract Supercritical Fluid (SCF) Technology has become an important tool of materials processing in the last two decades. Supercritical CO 2 and H 2 O are extensively being used in the preparation of a great variety of nanomaterials. The greatest requirement in the application of nanomaterials is its size and morphology control, which determine the application potential of the nanoparticles, as their properties vary significantly with size. Although significance of SCF Technology has been described earlier by various authors, the importance of this Technology for the fabrication of inorganic and hybrid nanomaterials in biomedical applications has not been discussed thoroughly. This review presents the nanomaterial preparation systematically using SCF Technology with reference to the processing of biomedical materials. The basic principles of each one of the processes have been described in detail giving their merits and perspectives. The actual experimental data and results have been discussed in detail with respect to the selected nanomaterials for biomedical applications. The SCF synthesis of nanoparticles like phosphors, magnetic materials, carbon nanotubes, etc. have been discussed as they have potential applications in bio-imaging, hyperthermia, cancer therapy, neutron capture therapy, targeted drug delivery systems and so on. The more recent approach towards the in situ surface modification, dispersibility, single nanocrystal formation, and morphology control of the nanoparticles has been discussed in detail.
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Nanoparticles synthesis using Supercritical Fluid Technology–towards biomedical applications
Advanced Drug Delivery Reviews, 2008Co-Authors: K. Byrappa, Seiki Ohara, Tadafumi AdschiriAbstract:Supercritical Fluid (SCF) Technology has become an important tool of materials processing in the last two decades. Supercritical CO(2) and H(2)O are extensively being used in the preparation of a great variety of nanomaterials. The greatest requirement in the application of nanomaterials is its size and morphology control, which determine the application potential of the nanoparticles, as their properties vary significantly with size. Although significance of SCF Technology has been described earlier by various authors, the importance of this Technology for the fabrication of inorganic and hybrid nanomaterials in biomedical applications has not been discussed thoroughly. This review presents the nanomaterial preparation systematically using SCF Technology with reference to the processing of biomedical materials. The basic principles of each one of the processes have been described in detail giving their merits and perspectives. The actual experimental data and results have been discussed in detail with respect to the selected nanomaterials for biomedical applications. The SCF synthesis of nanoparticles like phosphors, magnetic materials, carbon nanotubes, etc. have been discussed as they have potential applications in bio-imaging, hyperthermia, cancer therapy, neutron capture therapy, targeted drug delivery systems and so on. The more recent approach towards the in situ surface modification, dispersibility, single nanocrystal formation, and morphology control of the nanoparticles has been discussed in detail.
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Nanoparticles synthesis using Supercritical Fluid Technology - towards biomedical applications
ADVANCED DRUG DELIVERY REVIEWS, 2008Co-Authors: K. Byrappa, Seiki Ohara, Tadafumi AdschiriAbstract:Supercritical Fluid (SCF) Technology has become an important tool of materials processing in the last two decades. Supercritical CO(2) and H(2)O are extensively being used in the preparation of a great variety of nanomaterials. The greatest requirement in the application of nanomaterials is its size and morphology control, which determine the application potential of the nanoparticles, as their properties vary significantly with size. Although significance of SCF Technology has been described earlier by various authors, the importance of this Technology for the fabrication of inorganic and hybrid nanomaterials in biomedical applications has not been discussed thoroughly. This review presents the nanomaterial preparation systematically using SCF Technology with reference to the processing of biomedical materials. The basic principles of each one of the processes have been described in detail giving their merits and perspectives. The actual experimental data and results have been discussed in detail with respect to the selected nanomaterials for biomedical applications. The SCF synthesis of nanoparticles like phosphors, magnetic materials, carbon nanotubes, etc. have been discussed as they have potential applications in bio-imaging, hyperthermia, cancer therapy, neutron capture therapy, targeted drug delivery systems and so on. The more recent approach towards the in situ surface modification, dispersibility, single nanocrystal formation, and morphology control of the nanoparticles has been discussed in detail. (c) 2008 Published by Elsevier B.V.