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Rui L. Reis - One of the best experts on this subject based on the ideXlab platform.
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Evaluation of Cartilage Regeneration in Gellan Gum/agar Blended Hydrogel with Improved Injectability
Macromolecular Research, 2019Co-Authors: Jong Seon Baek, Cristiano Carlomagno, Jeong Eun Song, Antonella Motta, Thangavelu Muthukumar, David Kim, Claudio Migliaresi, Rui L. Reis, Jong Ho Park, Gilson KhangAbstract:Gellan Gum is known to be one of the biocompatible materials that resemble living tissues, continuously delivering stem cells or general cells, and filling voids in the wound. In spite of the many advantages of Gellan Gum, it has difficulty in the application by inserting the scaffolds into the body. In order to generalize Gellan Gum for medical purpose, it is necessary to increase the injectability of Gellan Gum. In this study, Gellan Gum solutions with 0.2, 0.4, 0.6, 0.8 wt% of agar were prepared. The obtained hydrogels were tested for rheological properties and chondrocytes adhesion, morphology and proliferation. Results showed that the addition of agar, in the starting GG solution, allows extruding the material producing micro-porous scaffolds. The biological evaluation demonstrated that the adhesion and proliferation of chondrocytes increase with the presence of agar in the final structure. The solutions composed of GG and agar represent an efficient, fast and high reproducible methodology with the potential to be used as an injectable hydrogel for cartilage regeneration purposes.
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Differentiation of osteoclast precursors on Gellan Gum-based spongy-like hydrogels for bone tissue engineering
Biomedical Materials, 2018Co-Authors: F. Raquel Maia, Rui L. Reis, Joaquim M. Oliveira, David S. Musson, Dorit Naot, Lucília P. Da Silva, Ana Raquel Fernandes Bastos, João B. Costa, Vitor M. Correlo, Jillian CornishAbstract:Bone tissue engineering with cell-scaffold constructs has been attracting a lot of attention, in particular as a tool for the efficient guiding of new tissue formation. However, the majority of the current strategies used to evaluate novel biomaterials focus on osteoblasts and bone formation, while osteoclasts are often overlooked. Consequently, there is limited knowledge on the interaction between osteoclasts and biomaterials. In this study, the ability of spongy-like Gellan Gum and hydroxyapatite-reinforced Gellan Gum hydrogels to support osteoclastogenesis was investigated in vitro. First, the spongy-like Gellan Gum and hydroxyapatite-reinforced Gellan Gum hydrogels were characterized in terms of microstructure, water uptake and mechanical properties. Then, bone marrow cells isolated from the long bones of mice and cultured in spongy-like hydrogels were treated with 1,25-dihydroxyvitamin D3 to promote osteoclastogenesis. It was shown that the addition of HAp to spongy-like Gellan Gum hydrogels enables the formation of larger pores and thicker walls, promoting an increase in stiffness. Hydroxyapatite-reinforced spongy-like Gellan Gum hydrogels support the formation of the aggregates of tartrate-resistant acid phosphatase-stained cells and the expression of genes encoding DC-STAMP and Cathepsin K, suggesting the differentiation of bone marrow cells into pre-osteoclasts. The hydroxyapatite-reinforced spongy-like Gellan Gum hydrogels developed in this work show promise for future use in bone tissue scaffolding applications.
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Recent progress in Gellan Gum hydrogels provided by functionalization strategies
Journal of Materials Chemistry B, 2016Co-Authors: Ana Helena Dias Bacelar, Joana Silva-correia, Joaquim M. Oliveira, Rui L. ReisAbstract:Gellan Gum, a microbial exopolysaccharide fermentation product of Pseudomonas elodea, is a natural biomaterial that has shown promise for tissue engineering and regenerative medicine applications. Although this exopolysaccharide possesses many advantages, such as interesting physicochemical properties and non-cytotoxicity, the mechanical properties and processability of Gellan Gum are not totally satisfactory in different tissue engineering contexts, i.e. Gellan Gum hydrogels are mechanically weak and the high gelling temperature is also unfavourable. An additional critical limitation is the lack of specific attachment sites for anchorage-dependent cells. However, the multiple hydroxyl groups and the free carboxyl per repeating unit of Gellan Gum can be used for chemical modification and functionalization in order to optimize its physicochemical and biological properties. A number of physical modification approaches have also been employed. This review outlines the recent progress in Gellan Gum hydrogels and their derivatives, and identifies the new challenges in tissue engineering, provided by blending and/or chemical modification.
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Gellan Gum based hydrogels for intervertebral disc tissue engineering applications
Journal of Tissue Engineering and Regenerative Medicine, 2011Co-Authors: Joana Silvacorreia, João Filipe Mano, R. A. Sousa, Joaquim M. Oliveira, João Tiago Oliveira, Sofia G Caridade, Rui L. ReisAbstract:Intervertebral disc (IVD) degeneration is a challenging clinical problem that urgently demands viable nucleus pulposus (NP) implant materials. The best suited biomaterial for NP regeneration has yet to be identified, but it is believed that biodegradable hydrogel-based materials are promising candidates. In this work, we have developed ionic- and photo-crosslinked methacrylated Gellan Gum (GG-MA) hydrogels to be used in acellular and cellular tissue-engineering strategies for the regeneration of IVDs. The physicochemical properties of the developed hydrogels were investigated by Fourier-transform infrared spectroscopy, (1) H nuclear magnetic resonance and differential scanning calorimetry. The swelling ability and degradation rate of hydrogels were also analysed in phosphate-buffered saline solution at physiological pH for a period of 30 days. Additionally, the morphology and mechanical properties of the hydrogels were assessed under a scanning electron microscope and dynamic compression, respectively. An in vitro study was carried out to screen possible cytotoxicity of the Gellan Gum-based hydrogels by culturing rat lung fibroblasts (L929 cells) with hydrogel leachables up to 7 days. The results demonstrated that Gellan Gum was successfully methacrylated. We observed that the produced GG-MA hydrogels possess improved mechanical properties and lower water uptake ability and degradation rate as compared to Gellan Gum. This work also revealed that GG-MA hydrogels are non-cytotoxic in vitro, thus being promising biomaterials to be used in IVD tissue-engineering strategies.
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Injectable Gellan Gum hydrogels with autologous cells for the treatment of rabbit articular cartilage defects.
Journal of Orthopaedic Research, 2010Co-Authors: João Tiago Oliveira, Leandro S. Gardel, Tommaso Rada, Luís Martins, Manuela E. Gomes, Rui L. ReisAbstract:In this work, the ability of Gellan Gum hydrogels coupled with autologous cells to regenerate rabbit full-thickness articular cartilage defects was tested. Five study groups were defined: (a) Gellan Gum with encapsulated chondrogenic predifferentiated rabbit adipose stem cells (ASC + GF); (b) Gellan Gum with encapsulated nonchondrogenic predifferentiated rabbit adipose stem cells (ASC); (c) Gellan Gum with encapsulated rabbit articular chondrocytes (AC) (standard control); (d) Gellan Gum alone (control); (e) empty defect (control). Full-thickness articular cartilage defects were created and the Gellan Gum constructs were injected and left for 8 weeks. The macroscopic aspect of the explants showed a progressive increase of similarity with the lateral native cartilage, stable integration at the defect site, more pronouncedly in the cell-loaded constructs. Tissue scoring showed that ASC + GF exhibited the best results regarding tissue quality progression. Alcian blue retrieved similar results with a better outcome for the cell-loaded constructs. Regarding real-time PCR analyses, ASC + GF had the best progression with an upregulation of collagen type II and aggrecan, and a downregulation of collagen type I. Gellan Gum hydrogels combined with autologous cells constitute a promising approach for the treatment of articular cartilage defects, and adipose derived cells may constitute a valid alternative to currently used articular chondrocytes.
Dipankar Chattopadhyay - One of the best experts on this subject based on the ideXlab platform.
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effect of Gellan Gum on the thermogelation property and drug release profile of poloxamer 407 based ophthalmic formulation
International Journal of Biological Macromolecules, 2017Co-Authors: Mitali Dewan, Gunjan Sarkar, Manas Bhowmik, Atis Kumar Chattoapadhyay, Dipak Rana, Dipankar ChattopadhyayAbstract:The effect of Gellan Gum on the gelation behavior and in-vitro release of a specific drug named pilocarpine hydrochloride from different ophthalmic formulations based on poloxamer 407 is examined. The mixture of 0.3 wt% Gellan Gum and 18 wt% poloxamer (PM) solutions show a considerable increase in gel strength in physiological condition. Gel dissolution rate from PM based formulation is significantly decreased due to the addition of Gellan Gum. FTIR spectra analysis witnesses an interaction in between OH groups of two polymers which accounts for lowering in gelation temperature of PM-Gellan Gum based formulations. It is also observed from the cryo-SEM study that the pore size of PM gel decreases with an addition of Gellan Gum and in-vitro release studies indicate that PM-Gellan Gum based formulation retain drug better than the PM solution alone. Therefore, the developed formulation has the potential to be utilized as an in-situ ophthalmic drug carrier.
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Effect of Gellan Gum on the thermogelation property and drug release profile of Poloxamer 407 based ophthalmic formulation.
International Journal of Biological Macromolecules, 2017Co-Authors: Mitali Dewan, Gunjan Sarkar, Manas Bhowmik, Atis Kumar Chattoapadhyay, Dipak Rana, Beauty Das, Dipankar ChattopadhyayAbstract:The effect of Gellan Gum on the gelation behavior and in-vitro release of a specific drug named pilocarpine hydrochloride from different ophthalmic formulations based on poloxamer 407 is examined. The mixture of 0.3 wt% Gellan Gum and 18 wt% poloxamer (PM) solutions show a considerable increase in gel strength in physiological condition. Gel dissolution rate from PM based formulation is significantly decreased due to the addition of Gellan Gum. FTIR spectra analysis witnesses an interaction in between OH groups of two polymers which accounts for lowering in gelation temperature of PM-Gellan Gum based formulations. It is also observed from the cryo-SEM study that the pore size of PM gel decreases with an addition of Gellan Gum and in-vitro release studies indicate that PM-Gellan Gum based formulation retain drug better than the PM solution alone. Therefore, the developed formulation has the potential to be utilized as an in-situ ophthalmic drug carrier.
Mitali Dewan - One of the best experts on this subject based on the ideXlab platform.
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effect of Gellan Gum on the thermogelation property and drug release profile of poloxamer 407 based ophthalmic formulation
International Journal of Biological Macromolecules, 2017Co-Authors: Mitali Dewan, Gunjan Sarkar, Manas Bhowmik, Atis Kumar Chattoapadhyay, Dipak Rana, Dipankar ChattopadhyayAbstract:The effect of Gellan Gum on the gelation behavior and in-vitro release of a specific drug named pilocarpine hydrochloride from different ophthalmic formulations based on poloxamer 407 is examined. The mixture of 0.3 wt% Gellan Gum and 18 wt% poloxamer (PM) solutions show a considerable increase in gel strength in physiological condition. Gel dissolution rate from PM based formulation is significantly decreased due to the addition of Gellan Gum. FTIR spectra analysis witnesses an interaction in between OH groups of two polymers which accounts for lowering in gelation temperature of PM-Gellan Gum based formulations. It is also observed from the cryo-SEM study that the pore size of PM gel decreases with an addition of Gellan Gum and in-vitro release studies indicate that PM-Gellan Gum based formulation retain drug better than the PM solution alone. Therefore, the developed formulation has the potential to be utilized as an in-situ ophthalmic drug carrier.
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Effect of Gellan Gum on the thermogelation property and drug release profile of Poloxamer 407 based ophthalmic formulation.
International Journal of Biological Macromolecules, 2017Co-Authors: Mitali Dewan, Gunjan Sarkar, Manas Bhowmik, Atis Kumar Chattoapadhyay, Dipak Rana, Beauty Das, Dipankar ChattopadhyayAbstract:The effect of Gellan Gum on the gelation behavior and in-vitro release of a specific drug named pilocarpine hydrochloride from different ophthalmic formulations based on poloxamer 407 is examined. The mixture of 0.3 wt% Gellan Gum and 18 wt% poloxamer (PM) solutions show a considerable increase in gel strength in physiological condition. Gel dissolution rate from PM based formulation is significantly decreased due to the addition of Gellan Gum. FTIR spectra analysis witnesses an interaction in between OH groups of two polymers which accounts for lowering in gelation temperature of PM-Gellan Gum based formulations. It is also observed from the cryo-SEM study that the pore size of PM gel decreases with an addition of Gellan Gum and in-vitro release studies indicate that PM-Gellan Gum based formulation retain drug better than the PM solution alone. Therefore, the developed formulation has the potential to be utilized as an in-situ ophthalmic drug carrier.
Atis Kumar Chattoapadhyay - One of the best experts on this subject based on the ideXlab platform.
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effect of Gellan Gum on the thermogelation property and drug release profile of poloxamer 407 based ophthalmic formulation
International Journal of Biological Macromolecules, 2017Co-Authors: Mitali Dewan, Gunjan Sarkar, Manas Bhowmik, Atis Kumar Chattoapadhyay, Dipak Rana, Dipankar ChattopadhyayAbstract:The effect of Gellan Gum on the gelation behavior and in-vitro release of a specific drug named pilocarpine hydrochloride from different ophthalmic formulations based on poloxamer 407 is examined. The mixture of 0.3 wt% Gellan Gum and 18 wt% poloxamer (PM) solutions show a considerable increase in gel strength in physiological condition. Gel dissolution rate from PM based formulation is significantly decreased due to the addition of Gellan Gum. FTIR spectra analysis witnesses an interaction in between OH groups of two polymers which accounts for lowering in gelation temperature of PM-Gellan Gum based formulations. It is also observed from the cryo-SEM study that the pore size of PM gel decreases with an addition of Gellan Gum and in-vitro release studies indicate that PM-Gellan Gum based formulation retain drug better than the PM solution alone. Therefore, the developed formulation has the potential to be utilized as an in-situ ophthalmic drug carrier.
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Effect of Gellan Gum on the thermogelation property and drug release profile of Poloxamer 407 based ophthalmic formulation.
International Journal of Biological Macromolecules, 2017Co-Authors: Mitali Dewan, Gunjan Sarkar, Manas Bhowmik, Atis Kumar Chattoapadhyay, Dipak Rana, Beauty Das, Dipankar ChattopadhyayAbstract:The effect of Gellan Gum on the gelation behavior and in-vitro release of a specific drug named pilocarpine hydrochloride from different ophthalmic formulations based on poloxamer 407 is examined. The mixture of 0.3 wt% Gellan Gum and 18 wt% poloxamer (PM) solutions show a considerable increase in gel strength in physiological condition. Gel dissolution rate from PM based formulation is significantly decreased due to the addition of Gellan Gum. FTIR spectra analysis witnesses an interaction in between OH groups of two polymers which accounts for lowering in gelation temperature of PM-Gellan Gum based formulations. It is also observed from the cryo-SEM study that the pore size of PM gel decreases with an addition of Gellan Gum and in-vitro release studies indicate that PM-Gellan Gum based formulation retain drug better than the PM solution alone. Therefore, the developed formulation has the potential to be utilized as an in-situ ophthalmic drug carrier.
Dipak Rana - One of the best experts on this subject based on the ideXlab platform.
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effect of Gellan Gum on the thermogelation property and drug release profile of poloxamer 407 based ophthalmic formulation
International Journal of Biological Macromolecules, 2017Co-Authors: Mitali Dewan, Gunjan Sarkar, Manas Bhowmik, Atis Kumar Chattoapadhyay, Dipak Rana, Dipankar ChattopadhyayAbstract:The effect of Gellan Gum on the gelation behavior and in-vitro release of a specific drug named pilocarpine hydrochloride from different ophthalmic formulations based on poloxamer 407 is examined. The mixture of 0.3 wt% Gellan Gum and 18 wt% poloxamer (PM) solutions show a considerable increase in gel strength in physiological condition. Gel dissolution rate from PM based formulation is significantly decreased due to the addition of Gellan Gum. FTIR spectra analysis witnesses an interaction in between OH groups of two polymers which accounts for lowering in gelation temperature of PM-Gellan Gum based formulations. It is also observed from the cryo-SEM study that the pore size of PM gel decreases with an addition of Gellan Gum and in-vitro release studies indicate that PM-Gellan Gum based formulation retain drug better than the PM solution alone. Therefore, the developed formulation has the potential to be utilized as an in-situ ophthalmic drug carrier.
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Effect of Gellan Gum on the thermogelation property and drug release profile of Poloxamer 407 based ophthalmic formulation.
International Journal of Biological Macromolecules, 2017Co-Authors: Mitali Dewan, Gunjan Sarkar, Manas Bhowmik, Atis Kumar Chattoapadhyay, Dipak Rana, Beauty Das, Dipankar ChattopadhyayAbstract:The effect of Gellan Gum on the gelation behavior and in-vitro release of a specific drug named pilocarpine hydrochloride from different ophthalmic formulations based on poloxamer 407 is examined. The mixture of 0.3 wt% Gellan Gum and 18 wt% poloxamer (PM) solutions show a considerable increase in gel strength in physiological condition. Gel dissolution rate from PM based formulation is significantly decreased due to the addition of Gellan Gum. FTIR spectra analysis witnesses an interaction in between OH groups of two polymers which accounts for lowering in gelation temperature of PM-Gellan Gum based formulations. It is also observed from the cryo-SEM study that the pore size of PM gel decreases with an addition of Gellan Gum and in-vitro release studies indicate that PM-Gellan Gum based formulation retain drug better than the PM solution alone. Therefore, the developed formulation has the potential to be utilized as an in-situ ophthalmic drug carrier.