1
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Lee MC, Lee JS, Kim S, Jamaiyar A, Wu W, Gonzalez ML, Durán TCA, Madrigal-Salazar AD, Bassous N, Carvalho V, Choi C, Kim DS, Seo JW, Rodrigues N, Teixeira SFCF, Alkhateeb AF, Soto JAL, Hussain MA, Leijten J, Feinberg MW, Shin SR. Synergistic effect of Hypoxic Conditioning and Cell-Tethering Colloidal Gels enhanced Productivity of MSC Paracrine Factors and Accelerated Vessel Regeneration. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024:e2408488. [PMID: 39380372 DOI: 10.1002/adma.202408488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2024] [Revised: 09/26/2024] [Indexed: 10/10/2024]
Abstract
Microporous hydrogels have been widely used for delivering therapeutic cells. However, several critical issues, such as the lack of control over the harsh environment they are subjected to under pathological conditions and rapid egression of cells from the hydrogels, have produced limited therapeutic outcomes. To address these critical challenges, cell-tethering and hypoxic conditioning colloidal hydrogels containing mesenchymal stem cells (MSCs) are introduced to increase the productivity of paracrine factors locally and in a long-term manner. Cell-tethering colloidal hydrogels that are composed of tyramine-conjugated gelatin prevent cells from egressing through on-cell oxidative phenolic crosslinks while providing mechanical stimulation and interconnected microporous networks to allow for host-implant interactions. Oxygenating microparticles encapsulated in tyramine-conjugated colloidal microgels continuously generated oxygen for 2 weeks with rapid diffusion, resulting in maintaining a mild hypoxic condition while MSCs consumed oxygen under severe hypoxia. Synergistically, local retention of MSCs within the mild hypoxic-conditioned and mechanically robust colloidal hydrogels significantly increased the secretion of various angiogenic cytokines and chemokines. The oxygenating colloidal hydrogels induced anti-inflammatory responses, reduced cellular apoptosis, and promoted numerous large blood vessels in vivo. Finally, mice injected with the MSC-tethered oxygenating colloidal hydrogels significantly improved blood flow restoration and muscle regeneration in a hindlimb ischemia (HLI) model.
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Affiliation(s)
- Myung Chul Lee
- Division of Engineering in Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Cambridge, MA, 02139, USA
- Medicinal Materials Research Center, Biomedical Research Division, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea
| | - Jae Seo Lee
- Division of Engineering in Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Cambridge, MA, 02139, USA
- Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, Cambridge, MA, 02139, USA
| | - Seongsoo Kim
- Division of Engineering in Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Cambridge, MA, 02139, USA
- Biomaterials Research Center, Biomedical Research Division, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea
| | - Anurag Jamaiyar
- Department of Medicine, Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Winona Wu
- Department of Medicine, Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA
- Division of Vascular and Endovascular Surgery, Beth Israel Deaconess Medical Center, Boston, MA, 02115, USA
| | - Montserrat Legorreta Gonzalez
- Division of Engineering in Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Cambridge, MA, 02139, USA
| | - Tania Carolina Acevedo Durán
- Division of Engineering in Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Cambridge, MA, 02139, USA
| | - Andrea Donaxi Madrigal-Salazar
- Division of Engineering in Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Cambridge, MA, 02139, USA
| | - Nicole Bassous
- Division of Engineering in Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Cambridge, MA, 02139, USA
| | - Violeta Carvalho
- Division of Engineering in Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Cambridge, MA, 02139, USA
- MEtRICs, University of Minho, Campus de Azurém, Guimarães, 4800-058, Portugal
- ALGORITMI/LASI Center, University of Minho, Campus de Azurém, Guimarães, 4800-058, Portugal
- Center for MicroElectromechanical Systems (CMEMS-UMinho), University of Minho, Campus de Azurém, Guimarães, 4800-058, Portugal
- LABBELS-Associate Laboratory, Braga/Guimarães, 4710-057, Portugal
| | - Cholong Choi
- Division of Engineering in Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Cambridge, MA, 02139, USA
| | - Da-Seul Kim
- Division of Engineering in Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Cambridge, MA, 02139, USA
| | - Jeong Wook Seo
- Division of Engineering in Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Cambridge, MA, 02139, USA
| | - Nelson Rodrigues
- MEtRICs, University of Minho, Campus de Azurém, Guimarães, 4800-058, Portugal
- COMEGI-Center for Research in Organizations, Markets and Industrial Management, Lusíada Norte University, Porto, 1349-001, Portugal
| | | | - Abdulhameed F Alkhateeb
- Department of Electrical and Computer Engineering, King Abdulaziz University, Jeddah, 21589, Saudi Arabia
| | - Javier Alejandro Lozano Soto
- Division of Engineering in Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Cambridge, MA, 02139, USA
| | - Mohammad Asif Hussain
- Department of Electrical and Computer Engineering, King Abdulaziz University, Jeddah, 21589, Saudi Arabia
| | - Jeroen Leijten
- Leijten Lab, Department of BioEngineering Technologies, Faculty of Science and Technology, Technical Medical Centre, University of Twente, Drienerlolaan 5, Enschede, 7522 NB, The Netherlands
| | - Mark W Feinberg
- Department of Medicine, Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Su Ryon Shin
- Division of Engineering in Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Cambridge, MA, 02139, USA
- Center for MicroElectromechanical Systems (CMEMS-UMinho), University of Minho, Campus de Azurém, Guimarães, 4800-058, Portugal
- LABBELS-Associate Laboratory, Braga/Guimarães, 4710-057, Portugal
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2
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López-Santiago RF, Delgado J, Castillo R. Competition among physical, chemical, and hybrid gelation mechanisms in biopolymers. SOFT MATTER 2024; 20:2518-2531. [PMID: 38404139 DOI: 10.1039/d3sm01682j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
Depending on how they form their linkages, biopolymer gelatin gels are commonly classified as physical, chemical, or hybrid; in gelatin hybrid gels, the physical and chemical crosslinking mechanisms occur simultaneously. The viscoelastic behavior of gels following different gelation processes was determined around the gel point. Their gel fractal dimensions were obtained using the BST-scaling model from large amplitude oscillatory shear results. The fractal dimension of hybrid gels is between 1.46 and 1.60, depending on the dominant crosslinking process. The main features of the Lissajous-Bowditch curves were determined for maturated gels that follow different gelation processes, and it is possible to observe the dominant gelation mechanism. The gelation kinetics process is followed by measuring the mean squared displacement (MSD) of microspheres embedded in gelatin solutions using diffusion wave spectroscopy, which in turn allows evaluating G'(ω) and G''(ω), the persistence length, and the mesh size as a function of time throughout the gelation process. The MSD, as a function of elapsed time from the start of the gelation process, follows a behavior that depends on the gelation processes. As time elapses after gelation starts, the persistence length of the unstructured, non-bonded flexible polymer sections decreases due to the formation of bonds. In the hybrid case, it is not a mixture of both processes; they are not independent when occurring simultaneously. The time evolution of the gel network's mesh size roughly follows an exponential decay.
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Affiliation(s)
- Ricky F López-Santiago
- Instituto de Física, Universidad Nacional Autónoma de México, P.O. Box 20-364, 01000, Mexico City, Mexico.
| | - Jorge Delgado
- División de Ciencias e Ingenierías, Universidad de Guanajuato, Campus León, León, Guanajuato, Mexico
| | - Rolando Castillo
- Instituto de Física, Universidad Nacional Autónoma de México, P.O. Box 20-364, 01000, Mexico City, Mexico.
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3
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Furmidge R, Jackson CE, Velázquez de la Paz MF, Workman VL, Green NH, Reilly GC, Hearnden V, Claeyssens F. Surfactant-free gelatin-stabilised biodegradable polymerised high internal phase emulsions with macroporous structures. Front Chem 2023; 11:1236944. [PMID: 37681209 PMCID: PMC10481965 DOI: 10.3389/fchem.2023.1236944] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Accepted: 08/10/2023] [Indexed: 09/09/2023] Open
Abstract
High internal phase emulsion (HIPE) templating is a well-established method for the generation of polymeric materials with high porosity (>74%) and degree of interconnectivity. The porosity and pore size can be altered by adjusting parameters during emulsification, which affects the properties of the resulting porous structure. However, there remain challenges for the fabrication of polyHIPEs, including typically small pore sizes (∼20-50 μm) and the use of surfactants, which can limit their use in biological applications. Here, we present the use of gelatin, a natural polymer, during the formation of polyHIPE structures, through the use of two biodegradable polymers, polycaprolactone-methacrylate (PCL-M) and polyglycerol sebacate-methacrylate (PGS-M). When gelatin is used as the internal phase, it is capable of stabilising emulsions without the need for an additional surfactant. Furthermore, by changing the concentration of gelatin within the internal phase, the pore size of the resulting polyHIPE can be tuned. 5% gelatin solution resulted in the largest mean pore size, increasing from 53 μm to 80 μm and 28 μm to 94 µm for PCL-M and PGS-M respectively. In addition, the inclusion of gelatin further increased the mechanical properties of the polyHIPEs and increased the period an emulsion could be stored before polymerisation. Our results demonstrate the potential to use gelatin for the fabrication of surfactant-free polyHIPEs with macroporous structures, with potential applications in tissue engineering, environmental and agricultural industries.
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Affiliation(s)
- Rachel Furmidge
- Materials Science and Engineering, The Kroto Research Institute, University of Sheffield, Sheffield, United Kingdom
- Insigneo Institute for In Silico Medicine, University of Sheffield, Sheffield, United Kingdom
| | - Caitlin E. Jackson
- Materials Science and Engineering, The Kroto Research Institute, University of Sheffield, Sheffield, United Kingdom
- Insigneo Institute for In Silico Medicine, University of Sheffield, Sheffield, United Kingdom
| | - María Fernanda Velázquez de la Paz
- Materials Science and Engineering, The Kroto Research Institute, University of Sheffield, Sheffield, United Kingdom
- Insigneo Institute for In Silico Medicine, University of Sheffield, Sheffield, United Kingdom
| | - Victoria L. Workman
- Materials Science and Engineering, The Kroto Research Institute, University of Sheffield, Sheffield, United Kingdom
- Insigneo Institute for In Silico Medicine, University of Sheffield, Sheffield, United Kingdom
| | - Nicola H. Green
- Materials Science and Engineering, The Kroto Research Institute, University of Sheffield, Sheffield, United Kingdom
- Insigneo Institute for In Silico Medicine, University of Sheffield, Sheffield, United Kingdom
| | - Gwendolen C. Reilly
- Materials Science and Engineering, The Kroto Research Institute, University of Sheffield, Sheffield, United Kingdom
- Insigneo Institute for In Silico Medicine, University of Sheffield, Sheffield, United Kingdom
| | - Vanessa Hearnden
- Materials Science and Engineering, The Kroto Research Institute, University of Sheffield, Sheffield, United Kingdom
- Insigneo Institute for In Silico Medicine, University of Sheffield, Sheffield, United Kingdom
| | - Frederik Claeyssens
- Materials Science and Engineering, The Kroto Research Institute, University of Sheffield, Sheffield, United Kingdom
- Insigneo Institute for In Silico Medicine, University of Sheffield, Sheffield, United Kingdom
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Hasturk O, Sahoo JK, Kaplan DL. Synthesis and characterization of silk-poly(guluronate) hybrid polymers for the fabrication of dual crosslinked, mechanically dynamic hydrogels. POLYMER 2023; 281:126129. [PMID: 37483847 PMCID: PMC10357961 DOI: 10.1016/j.polymer.2023.126129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/25/2023]
Abstract
The rapid ionic crosslinking of alginate has been actively studied for biomedical applications including hydrogel scaffolds for tissue engineering, injectable gels, and 3D bioprinting. However, the poor structural stability of ionic crosslinks under physiological conditions limits the widespread applications of these hydrogels. Moreover, the lack of cell adhesion to the material combined with the inability of proteases to degrade alginate further restrict utility as hydrogel scaffolds. Blends of alginate with silk fibroin have been proposed for improved structural and mechanical properties, but potential phase separation between the hydrophobic protein and the hydrophilic polysaccharide remains an issue. In this study, we demonstrated the synthesis of a hybrid biopolymer composed of a silk backbone with side chains of poly(guluronate) isolated from alginate to introduce rapid ionic crosslinking on enzymatically crosslinked silk-based hydrogels for on-demand and reversible stiffening and softening properties. Dual crosslinked macro- and microgels of silk fibroin-poly(guluronate) (SF-PG) hybrid polymers displayed dynamic morphology with reversible shrinking and swelling behavior. SF-PG hydrogel discs demonstrated dynamic mechanics with compressive moduli ranging from less than 5 kPa to over 80 kPa and underwent proteolytic degradation unlike covalently crosslinked alginate controls. SF-PG gels supplemented with gelatin substituted with tyramine or both tyramine and PG also supported the attachment and survival of murine fibroblasts, suggesting potential uses of these new hydrogels in mammalian cell culture to investigate cellular responses to dynamic mechanics or modeling of diseases defined by matrix mechanics, such as fibrosis and cancer.
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Affiliation(s)
- Onur Hasturk
- Tufts University, Department of Biomedical Engineering, Medford MA, USA
| | | | - David L Kaplan
- Tufts University, Department of Biomedical Engineering, Medford MA, USA
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5
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Chemical Overview of Gel Dosimetry Systems: A Comprehensive Review. Gels 2022; 8:gels8100663. [PMID: 36286165 PMCID: PMC9601373 DOI: 10.3390/gels8100663] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 10/10/2022] [Accepted: 10/12/2022] [Indexed: 11/17/2022] Open
Abstract
Advances in radiotherapy technology during the last 25 years have significantly improved both dose conformation to tumors and the preservation of healthy tissues, achieving almost real-time feedback by means of high-precision treatments and theranostics. Owing to this, developing high-performance systems capable of coping with the challenging requirements of modern ionizing radiation is a key issue to overcome the limitations of traditional dosimeters. In this regard, a deep understanding of the physicochemical basis of gel dosimetry, as one of the most promising tools for the evaluation of 3D high-spatial-resolution dose distributions, represents the starting point for developing new and innovative systems. This review aims to contribute thorough descriptions of the chemical processes and interactions that condition gel dosimetry outputs, often phenomenologically addressed, and particularly formulations reported since 2017.
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6
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Zhu C, Tian Y, Zhang E, Gao X, Zhang H, Liu N, Han X, Sun Y, Wang Z, Zheng A. Semisolid Extrusion 3D Printing of Propranolol Hydrochloride Gummy Chewable Tablets: an Innovative Approach to Prepare Personalized Medicine for Pediatrics. AAPS PharmSciTech 2022; 23:166. [PMID: 35705726 DOI: 10.1208/s12249-022-02304-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2022] [Accepted: 05/02/2022] [Indexed: 01/17/2023] Open
Abstract
The demand for personalized medicine has received extensive attention, especially in pediatric preparations. An emerging technology, extrusion-based 3D printing, is highly attractive in the field of personalized medicine. In this study, we prepared propranolol hydrochloride (PR) gummy chewable tablets tailored for children by semisolid extrusion (SSE) 3D printing technology to meet personalized medicine needs in pediatrics. In this study, the effects of critical formulation variables on the rheological properties and printability of gum materials were investigated by constructing a full-factorial design. In addition, the masticatory properties, thermal stability, and disintegration time of the preparations were evaluated. Bitterness inhibitors were used to mask the bitterness of the preparations. The results of the full-factorial design showed that the amount of gelatin and carrageenan were the key factors in the formulation. Gelatin can improve printability and masticatory properties, carrageenan can improve thermal stability, and accelerate the disintegration of preparations; therefore, a reasonable combination of both could satisfactorily meet the demand for high-quality 3D printing. γ-Aminobutyric acid can reduce the bitterness of gummy chewable tablets to improve medication compliance and the determined formulation (F7) met the quality requirements. In conclusion, the gum material has excellent potential as an extrusion material for 3D printing. The dosage can be adjusted flexibly by the model shape and size. 3D printing has broad prospects in pediatric preparations.
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Affiliation(s)
- Chunxiao Zhu
- Department of Pharmaceutics, School of Pharmacy, Qingdao University, 308th Ningxia Road, Shinan District, Qingdao, 266073, China.,State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, 27th Taiping Road, Haidian District, Beijing, 100850, China
| | - Yang Tian
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, 27th Taiping Road, Haidian District, Beijing, 100850, China
| | - Enhui Zhang
- Pharmacy Department, the 967th Hospital of the Joint Logistic Support Force, DaLian, 116000, China
| | - Xiang Gao
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, 27th Taiping Road, Haidian District, Beijing, 100850, China
| | - Hui Zhang
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, 27th Taiping Road, Haidian District, Beijing, 100850, China
| | - Nan Liu
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, 27th Taiping Road, Haidian District, Beijing, 100850, China
| | - Xiaolu Han
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, 27th Taiping Road, Haidian District, Beijing, 100850, China
| | - Yong Sun
- Department of Pharmaceutics, School of Pharmacy, Qingdao University, 308th Ningxia Road, Shinan District, Qingdao, 266073, China.
| | - Zengming Wang
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, 27th Taiping Road, Haidian District, Beijing, 100850, China
| | - Aiping Zheng
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, 27th Taiping Road, Haidian District, Beijing, 100850, China
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7
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Wu J, Shin H, Lee J, Kim S, Lee H. Preparation of External Stimulus-Free Gelatin-Catechol Hydrogels with Injectability and Tunable Temperature Responsiveness. ACS APPLIED MATERIALS & INTERFACES 2022; 14:236-244. [PMID: 34935360 DOI: 10.1021/acsami.1c19151] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Gelatin is one of the most versatile biopolymers in various biomedical applications. A gelatin derivative gelatin-catechol (Gel-C) was developed in this study to further optimize its chemical and physical properties such as thermal reversibility and injectability. We found that Gel-C remains in a solution state at room temperature, and the temperature-dependent gelation capability of gelatin is well preserved in Gel-C. Its gel-forming temperature decreased to about 10 °C (about 30 °C for gelatin), and a series of gelatin derivatives with different gel-forming temperatures (10-30 °C) were formed by mixing gelatin and Gel-C in different ratios. Additionally, irreversible Gel-C hydrogels could be made without the addition of external stimuli by combining the physical cross-linking of gelatin and the chemical cross-linking of catechol. At the same time, properties of Gel-C hydrogels such as thermal reversibility and injectability could be manipulated by controlling the temperature and pH of the precursor solution. By simulating the formation of an irreversible Gel-C hydrogel in vivo, an in situ gelling system was fabricated by lowering the local temperature of the hydrogel with cold shock, thus realizing targeted and localized molecular delivery with prolonged retention time. This simple system integrated with the temperature responsiveness of gelatin and chemical cross-linking of catechol groups thus provides a promising platform to fabricate an in situ gelling system for drug delivery.
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Affiliation(s)
- Jingxian Wu
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), 291 University Road, Daejeon 34141, Republic of Korea
| | - Honggeun Shin
- R&D Center, InnoTherapy Inc., Seoul 34028, Republic of Korea
| | - Jeehee Lee
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), 291 University Road, Daejeon 34141, Republic of Korea
| | - Soomi Kim
- R&D Center, InnoTherapy Inc., Seoul 34028, Republic of Korea
| | - Haeshin Lee
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), 291 University Road, Daejeon 34141, Republic of Korea
- R&D Center, InnoTherapy Inc., Seoul 34028, Republic of Korea
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8
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Das RP, Gandhi VV, Singh BG, Kunwar A. Balancing loading, cellular uptake, and toxicity of gelatin-pluronic nanocomposite for drug delivery: Influence of HLB of pluronic. J Biomed Mater Res A 2021; 110:304-315. [PMID: 34355509 DOI: 10.1002/jbm.a.37287] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 06/22/2021] [Accepted: 07/22/2021] [Indexed: 11/08/2022]
Abstract
In this study, pluronic stabilized gelatin nanocomposite of varying hydrophilic-lipophilic balance (HLB) were synthesized to study the effect of surface hydrophobicity on their cellular uptake and in turn the delivery of a model hydrophobic bioactive compound, curcumin (CUR). Notably, the variation in HLB from 22 to 8 did not cause much change in morphology (~spherical) and surface charge (~ -6.5 mV) while marginally reducing the size of nanocomposite from 165 ± 097 nm to 134 ± 074 nm. On contrary, nanocomposites exhibited a very significant increase in their numbers, hydrophobicity as well as CUR loading with decreasing HLB values (22-8) of pluronic. Further, the cellular uptake of CUR through pluronic-gelatin nanocomposites was studied in human lung carcinoma (A549) cells. The results indicated that cellular uptake of CUR through nanocomposites followed the order HLB 22 > HLB 18 > HLB 15 > HLB 8. This was also reflected in terms of the decrease in cytotoxicity of CUR through nanocomposite of HLB 8 as compared to that of HLB 22. Interestingly, bare nanocomposite of HLB 8 showed significantly higher cytotoxicity as compared to that of HLB 22. Together these results suggested that although higher hydrophobicity of the gelatin-pluronic nanocomposite facilitated higher entrapment of CUR, the carrier per se became toxic due to its hydrophobic interaction with lipid bilayer of plasma membrane. Thus, HLB parameter is very important in designing hybrid nanocomposite systems involving protein and pluronic to ensure both bio-compatibility of the carrier and the optimum cellular delivery of the pay load.
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Affiliation(s)
- Ram Pada Das
- Radiation and Photochemistry Division, Bhabha Atomic Research Center, Mumbai, India.,Homi Bhabha National Institute, Mumbai, India
| | - Vishwa V Gandhi
- Radiation and Photochemistry Division, Bhabha Atomic Research Center, Mumbai, India.,Homi Bhabha National Institute, Mumbai, India
| | - Beena G Singh
- Radiation and Photochemistry Division, Bhabha Atomic Research Center, Mumbai, India.,Homi Bhabha National Institute, Mumbai, India
| | - Amit Kunwar
- Radiation and Photochemistry Division, Bhabha Atomic Research Center, Mumbai, India.,Homi Bhabha National Institute, Mumbai, India
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9
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Espinosa-Dzib A, Vyazovkin S. Nanoconfined gelation in systems based on stearic and 12-hydroxystearic acids: A calorimetric study. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2021.116191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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10
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Shape memory polyacrylamide/gelatin hydrogel with controllable mechanical and drug release properties potential for wound dressing application. POLYMER 2021. [DOI: 10.1016/j.polymer.2021.123786] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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11
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Agarwal P, Greene DG, Sherman S, Wendl K, Vega L, Park H, Shimanovich R, Reid DL. Structural characterization and developability assessment of sustained release hydrogels for rapid implementation during preclinical studies. Eur J Pharm Sci 2021; 158:105689. [PMID: 33359482 DOI: 10.1016/j.ejps.2020.105689] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2020] [Revised: 11/12/2020] [Accepted: 12/17/2020] [Indexed: 10/22/2022]
Abstract
Sustained-release formulations are important tools to convert efficacious molecules into therapeutic products. Hydrogels enable the rapid assessment of sustained-release strategies, which are important during preclinical development where drug quantities are limited and fast turnaround times are the norm. Most research in hydrogel-based drug delivery has focused around synthesizing new materials and polymers, with limited focus on structural characterization, technology developability and implementation. Two commercially available thermosensitive hydrogel systems, comprised of block copolymers of poly(lactic-co-glycolic acid)-b-poly(ethylene glycol)-b-poly(lactic-co-glycolic acid) (PLGA) and poly(lactide-co-caprolactone)-b-poly(ethyleneglycol)-b-poly(lactide-co-caprolactone) (PLCL), were evaluated during this study. The two block copolymers described in the study were successfully formulated to form hydrogels which delayed the release of lysozyme (> 20 days) in vitro. Characterization of formulation attributes of the hydrogels like Tsol-gel temperature, complex viscosity and injection force showed that these systems are amenable to rapid implementation in preclinical studies. Understanding the structure of the gel network is critical to determine the factors controlling the release of therapeutics out of these gels. The structures were characterized via the gel mesh sizes, which were estimated using two orthogonal techniques: small angle X-ray scattering (SAXS) and rheology. The mesh sizes of these hydrogels were larger than the hydrodynamic radius (size) of lysozyme (drug), indicating that release through these gels is expected to be diffusive at all time scales rather than sub-diffusive. In vitro drug release experiments confirm that diffusion is the dominating mechanism for lysozyme release; with no contribution from degradation, erosion, relaxation, swelling of the polymer network or drug-polymer interactions. PLGA hydrogel was found to have a much higher complex viscosity than PLCL hydrogel, which correlates with the slower diffusivity and release of lysozyme seen from the PLGA hydrogel as compared to PLCL hydrogel. This is due to the increased frictional drag experienced by the lysozyme molecule in the PLGA hydrogel network, as described by the hydrodynamic theory.
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Affiliation(s)
- Prashant Agarwal
- Drug Product Technologies, Process Development, Amgen, Inc., 360 Binney St, Cambridge, MA 02142, United States.
| | - Daniel G Greene
- Drug Product Technologies, Process Development, Amgen, Inc., 360 Binney St, Cambridge, MA 02142, United States
| | - Scott Sherman
- Drug Product Technologies, Process Development, Amgen, Inc., 360 Binney St, Cambridge, MA 02142, United States
| | - Kaitlyn Wendl
- Drug Product Technologies, Process Development, Amgen, Inc., 360 Binney St, Cambridge, MA 02142, United States
| | - Leonela Vega
- Final Product Technologies, Process Development, Amgen Inc., 360 Binney St, Cambridge, MA 02142, United States
| | - Hyunsoo Park
- Drug Product Technologies, Process Development, Amgen, Inc., 360 Binney St, Cambridge, MA 02142, United States
| | - Roman Shimanovich
- Drug Product Technologies, Process Development, Amgen, Inc., 360 Binney St, Cambridge, MA 02142, United States
| | - Darren L Reid
- Drug Product Technologies, Process Development, Amgen, Inc., 360 Binney St, Cambridge, MA 02142, United States
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12
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Liu Y, Lv S, Gao J, Zhang Y, Zhao S, Guo X, Sun G. Study on the stability and cellular affinity of gelatin-polysaccharide composite films. J Biomed Mater Res A 2020; 108:2230-2239. [PMID: 32363671 DOI: 10.1002/jbm.a.36980] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 03/26/2020] [Accepted: 04/04/2020] [Indexed: 12/17/2022]
Abstract
The gelatin film has great potential in biomedical applications, especially in wound healing. The combination of gelatin films and stem cells could further accelerate the skin regeneration. Although polysaccharide modification can improve the mechanical property and biological activity of gelatin films, information about the stability and cellular affinity is still limited. This study investigated the influence of polysaccharides on the stability and cellular affinity of gelatin films. Two kinds of gelatin-polysaccharide composite films, including gelatin-hyaluronic acid (G-HA) and gelatin-chitosan (G-CS), were prepared in this study. It was found that G-HA composite film had better short-term and long-term stability compared with G-CS composite film. And G-HA composite film also had better biological safety than G-CS film. Moreover, the surface of G-HA composite film supported the adhesion and growth of human umbilical cord Wharton's jelly-derived mesenchymal stem cells (WJ MSCs) better than G-CS film surface. These data illustrated that G-HA composite film has better stability and cellular affinity compared with G-CS film, which could be considered a promising delivery system of stem cells for further in vivo studies. Therefore, this work would be very helpful to optimize the preparation of gelatin-polysaccharide composite films.
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Affiliation(s)
- Yang Liu
- Scientific Research Center for Translational Medicine, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, China
| | - Shijie Lv
- Dalian Maternity & Child Healthcare Hospital, Dalian, China
| | - Jun Gao
- Scientific Research Center for Translational Medicine, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, China.,Department of Oral Pathology, College of Stomatology, Dalian Medical University, Dalian, China
| | - Ying Zhang
- Scientific Research Center for Translational Medicine, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, China
| | - Shan Zhao
- Scientific Research Center for Translational Medicine, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, China
| | - Xin Guo
- Scientific Research Center for Translational Medicine, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, China
| | - Guangwei Sun
- Scientific Research Center for Translational Medicine, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, China
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Espinosa-Dzib A, Vyazovkin S. Nanoconfined gelation of polyacrylonitrile, poly(vinyl alcohol), and isotactic polypropylene probed by calorimetry. SOFT MATTER 2020; 16:3285-3293. [PMID: 32167115 DOI: 10.1039/d0sm00004c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Differential scanning calorimetry is used to obtain insights into the kinetics and thermodynamics of nanoconfined gelation. Gels of polyacrylonitrile in propylene carbonate, poly(vinyl alcohol) in ethylene glycol, and isotactic polypropylene in o-dichlorobenzene and decalin are studied in silica nanopores. Two major effects are observed for nanoconfined gels: a decrease in the heat of gelation and an increase in the gelation temperature. The smaller heat indicates that nanoconfinement of polymer chains results in the formation of fewer ordered crosslinks. The increased gelation temperature suggests acceleration of the gelation kinetics. The kinetics has been treated by an advanced isoconversional method and interpreted in terms of the Fisher-Turnbull model. It is found that acceleration of gelation in nanopores is associated with a decrease in the free energy barrier to nucleation, as one would expect for a change in the process mechanism from homogenous to heterogenous nucleation.
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Affiliation(s)
- Alejandra Espinosa-Dzib
- Department of Chemistry, University of Alabama at Birmingham, 901 S. 14th Street, Birmingham, AL 35294, USA.
| | - Sergey Vyazovkin
- Department of Chemistry, University of Alabama at Birmingham, 901 S. 14th Street, Birmingham, AL 35294, USA.
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All You Need to Know about the Kinetics of Thermally Stimulated Reactions Occurring on Cooling. Molecules 2019; 24:molecules24101918. [PMID: 31109036 PMCID: PMC6572213 DOI: 10.3390/molecules24101918] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 05/17/2019] [Accepted: 05/17/2019] [Indexed: 11/16/2022] Open
Abstract
In this tutorial overview article the authors share their original experience in studying the kinetics of thermally stimulated reactions under the conditions of continuous cooling. It is stressed that the kinetics measured on heating is similar to that measured on cooling only for single-step reactions. For multi-step reactions the respective kinetics can differ dramatically. The application of an isoconversional method to thermogravimetry (TGA) or differential scanning calorimetry (DSC) data allows one to recognize multi-step kinetics in the form of the activation energy that varies with conversion. Authors' argument is supported by theoretical considerations as well as by experimental examples that include the reactions of thermal decomposition and crosslinking polymerization (curing). The observed differences in the kinetics measured on heating and cooling ultimately manifest themselves in the Arrhenius plots of the opposite curvatures, which means that the heating kinetics cannot be used to predict the kinetics on cooling. The article provides important background knowledge necessary for conducting successful kinetic studies on cooling. It includes a practical advice on optimizing the parameters of cooling experiments as well as on proper usage of kinetic methods for analysis of obtained data.
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Ikeda S, Murayama D, Tsurumaki A, Sato S, Urashima T, Fukuda K. Rheological characteristics and supramolecular structure of the exopolysaccharide produced by Lactobacillus fermentum MTCC 25067. Carbohydr Polym 2019; 218:226-233. [PMID: 31221325 DOI: 10.1016/j.carbpol.2019.04.076] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 04/17/2019] [Accepted: 04/24/2019] [Indexed: 11/30/2022]
Abstract
Rheological properties and supramolecular structure of the exopolysaccharide (EPS) secreted by Lactobacillus fermentum MTCC 25067 were investigated. The critical concentration representing the lower-limit of the semi-dilute regime was estimated to be 0.71 g/L from the concentration dependence of zero-shear specific viscosity. The storage modulus (G') of a 20 g/L EPS solution was greater than the loss modulus (G″) at 0.1-25 Hz. Approximately linear increases in G' and G″ determined at a frequency of 1 Hz and a strain of 0.01 during cooling from 80 to 25 °C were an indication that the EPS did not undergo thermally-induced cooperative conformational transitions typical of gelling polysaccharides. Atomic force microscopy images revealed that EPS molecules were not completely dissociated into individual molecules in an aqueous solution but remained to form three-dimensional networks. The gel-like dynamic viscoelasticity of the 20 g/L EPS solution was thus attributed to the existence of supramolecular assemblies resulting from significant degrees of intermolecular association of the EPS in the solution.
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Affiliation(s)
- Shinya Ikeda
- Department of Food Science, University of Wisconsin-Madison, Madison, WI 53706, USA.
| | - Daiki Murayama
- Department of Food Science, University of Wisconsin-Madison, Madison, WI 53706, USA.
| | - Akane Tsurumaki
- Department of Life and Food Sciences, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido 080-8555, Japan.
| | - Shoya Sato
- Department of Life and Food Sciences, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido 080-8555, Japan.
| | - Tadasu Urashima
- Department of Life and Food Sciences, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido 080-8555, Japan.
| | - Kenji Fukuda
- Research Center for Global Agromedicine, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido 080-8555, Japan.
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Gelation of Poly(Vinylidene Fluoride) Solutions in Native and Organically Modified Silica Nanopores. Molecules 2018; 23:molecules23113025. [PMID: 30463293 PMCID: PMC6278663 DOI: 10.3390/molecules23113025] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2018] [Revised: 11/08/2018] [Accepted: 11/16/2018] [Indexed: 12/03/2022] Open
Abstract
The purpose of this study is to highlight the surface and size effects of the nanopores on the thermodynamics and kinetics of gelation. The effects have been probed by applying differential scanning calorimetry to poly(vinylidene fluoride) solutions in tetraethylene glycol dimethyl ether (tetraglyme) and γ-butyrolactone. Nanoconfinement has been accomplished by introducing gels into native and organically modified silica nanopores (4–30 nm). Nanoconfinement has produced two major effects. First, the heat of gelation has decreased three to four times compared to that for the bulk systems. Second, the temperature of gelation has increased by ~40 °C (tetraglyme based systems) and ~70 °C (γ-butyrolactone based systems), the increase being stronger in native nanopores. The effects are discussed in terms of acceleration of gelation due to heterogeneous nucleation at the confining surface, and retardation of gelation due to constricted polymer chain mobility in the middle of the pore volume. Calorimetric data have been subjected to isoconversional kinetics analysis. The obtained temperature dependencies of the activation energies of gelation have been interpreted in the frameworks of the nucleation model of Turnbull and Fisher. The results suggest that nanoconfinement leads to a lowering of both the free energy of nucleation and activation energy of diffusion.
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Prado JR, Chen J, Kharlampieva E, Vyazovkin S. Melting of gelatin gels confined to silica nanopores. Phys Chem Chem Phys 2018; 18:29056-29063. [PMID: 27472066 DOI: 10.1039/c6cp03339c] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Nanoconfinement is a way to create materials whose properties differ from the bulk. For the first time, this research explores the effect of nanoconfinement on the thermodynamics and kinetics of gel melting. Differential scanning calorimetry has been employed to study gelatin gels prepared inside 4, 6, 15, and 30 nm pores of a silica matrix. It has been found that with decreasing the pore size the heat of melting decreases from 3.5 J g-1 in bulk to 0.6 J g-1 in 6 nm pores, which is linked to a decrease in crosslinks formed via hydrogen bonding. Despite decreases in crosslink formation, the melting temperature for gels confined to 6 nm pores increased nearly 10 °C compared to bulk gel. In 4 nm pores, no gel melting was observed. Isoconversional kinetic analysis of the melting data has revealed that the increase in thermal stability is associated with a decrease in the pre-exponential factor that occurs upon nanoconfinement. The origins of the effect have been linked to diminished molecular mobility of the gelatin chains confined inside the nanopores, which leads to enhanced restoration of broken crosslinks.
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Affiliation(s)
- J Rachel Prado
- Department of Chemistry, University of Alabama at Birmingham, 901 S. 14th Street, Birmingham, AL 35294, USA.
| | - Jun Chen
- Department of Chemistry, University of Alabama at Birmingham, 901 S. 14th Street, Birmingham, AL 35294, USA.
| | - Eugenia Kharlampieva
- Department of Chemistry, University of Alabama at Birmingham, 901 S. 14th Street, Birmingham, AL 35294, USA.
| | - Sergey Vyazovkin
- Department of Chemistry, University of Alabama at Birmingham, 901 S. 14th Street, Birmingham, AL 35294, USA.
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Guigo N, Sbirrazzuoli N. Thermal Analysis of Biobased Polymers and Composites. RECENT ADVANCES, TECHNIQUES AND APPLICATIONS 2018. [DOI: 10.1016/b978-0-444-64062-8.00002-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Vyazovkin S. Modern Isoconversional Kinetics: From Misconceptions to Advances. RECENT ADVANCES, TECHNIQUES AND APPLICATIONS 2018. [DOI: 10.1016/b978-0-444-64062-8.00008-5] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
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20
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Farjas J, López-Olmedo JP, Roura P. Model-free isoconversional method applied to polymer crystallization governed by the Hoffman-Lauritzen kinetics. POLYMER 2017. [DOI: 10.1016/j.polymer.2017.05.053] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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21
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Vyazovkin S. Isoconversional Kinetics of Polymers: The Decade Past. Macromol Rapid Commun 2016; 38. [PMID: 28009078 DOI: 10.1002/marc.201600615] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Revised: 11/02/2016] [Indexed: 01/17/2023]
Abstract
This article surveys the decade of progress accomplished in the application of isoconversional methods to thermally stimulated processes in polymers. The processes of interest include: crystallization and melting of polymers, gelation of polymer solutions and gel melting, denaturation (unfolding) of proteins, glass transition, polymerization and crosslinking (curing), and thermal and thermo-oxidative degradation. Special attention is paid to the kinetics of polymeric nanomaterials. The article discusses basic principles for understanding the variations in the activation energy and emphasizes the possibility of using models for linking such variations to the parameters of individual kinetic steps. It is stressed that many kinetic effects are not linked to a change in the activation energy alone and may arise from changes in the preexponential factor and reaction model. Also noted is that some isoconversional methods are inapplicable to processes taking place on cooling and cannot be used to study such processes as the melt crystallization.
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Affiliation(s)
- Sergey Vyazovkin
- Department of Chemistry, University of Alabama at Birmingham, 901 S. 14th Street, Birmingham, AL, 35294, USA
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23
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Stanford VL, McCulley CM, Vyazovkin S. Isoconversional Kinetics of Nonisothermal Crystallization of Salts from Solutions. J Phys Chem B 2016; 120:5703-9. [PMID: 27305831 DOI: 10.1021/acs.jpcb.6b03860] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In this study, differential scanning calorimetry (DSC) has been applied to measure the kinetics of nonisothermal crystallization of potassium nitrate and ammonium perchlorate from unsaturated and saturated aqueous solutions. DSC data have been analyzed by an advanced isoconversional method that demonstrates that the process is represented by negative values of the effective activation energy, which varies with the progress of crystallization. The classical nucleation model can be used to predict and understand the experimentally observed variation in the effective activation energy. The saturated and unsaturated solutions have demonstrated distinctly different crystallization kinetics. It is suggested that the unsaturated solutions undergo a change in crystallization mechanism from homogeneous to heterogeneous nucleation.
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Affiliation(s)
- Victoria L Stanford
- Department of Chemistry, University of Alabama at Birmingham , 901 South 14th Street, Birmingham, Alabama 35294, United States
| | - Calla M McCulley
- Department of Chemistry, University of Alabama at Birmingham , 901 South 14th Street, Birmingham, Alabama 35294, United States
| | - Sergey Vyazovkin
- Department of Chemistry, University of Alabama at Birmingham , 901 South 14th Street, Birmingham, Alabama 35294, United States
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24
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Exothermic nonreversing process in the phase transition of poly(N-isopropylacrylamide) studied with stochastic temperature-modulated DSC. ACTA ACUST UNITED AC 2016. [DOI: 10.1002/polb.24089] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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25
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Frazier SD, Srubar WV. Evaporation-based method for preparing gelatin foams with aligned tubular pore structures. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2016; 62:467-73. [DOI: 10.1016/j.msec.2016.01.074] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Revised: 01/08/2016] [Accepted: 01/27/2016] [Indexed: 01/15/2023]
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Wang Y, Wang X, Geng Z, Xiong Y, Wu W, Chen Y. Electrodeposition of a carbon dots/chitosan composite produced by a simple in situ method and electrically controlled release of carbon dots. J Mater Chem B 2015; 3:7511-7517. [DOI: 10.1039/c5tb01051a] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A carbon dots/chitosan composite that can be straightforwardly used for electrodeposition and controlled release was produced by a one-step microwave method.
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Affiliation(s)
- Yifeng Wang
- School of Material Science and Engineering
- Wuhan University of Technology
- Wuhan 430070
- China
| | - Xia Wang
- School of Material Science and Engineering
- Wuhan University of Technology
- Wuhan 430070
- China
| | - Zenghua Geng
- School of Material Science and Engineering
- Wuhan University of Technology
- Wuhan 430070
- China
| | - Yanfei Xiong
- Department of Biological Science and Technology
- Wuhan University of Technology
- Wuhan 430070
- China
| | - Wencheng Wu
- School of Material Science and Engineering
- Wuhan University of Technology
- Wuhan 430070
- China
| | - Yanjun Chen
- School of Material Science and Engineering
- Wuhan University of Technology
- Wuhan 430070
- China
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Vandecasteele J, De Deene Y. On the validity of 3D polymer gel dosimetry: II. Physico-chemical effects. Phys Med Biol 2012; 58:43-61. [DOI: 10.1088/0031-9155/58/1/43] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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28
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Guigo N, Sbirrazzuoli N, Vyazovkin S. Gelation on Heating of Supercooled Gelatin Solutions. Macromol Rapid Commun 2012; 33:698-702. [DOI: 10.1002/marc.201100748] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2011] [Revised: 12/12/2011] [Indexed: 11/10/2022]
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29
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Affiliation(s)
- Sergey Vyazovkin
- Department of Chemistry, University of Alabama at Birmingham, 901S 14th Street, Birmingham, Alabama 35294
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30
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Dranca I, Vyazovkin S. Thermal stability of gelatin gels: Effect of preparation conditions on the activation energy barrier to melting. POLYMER 2009. [DOI: 10.1016/j.polymer.2009.06.070] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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