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Lee MH, Boettiger D, Composto RJ. Biomimetic Carbohydrate Substrates of Tunable Properties Using Immobilized Dextran Hydrogels. Biomacromolecules 2008; 9:2315-21. [DOI: 10.1021/bm8002094] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Mark H. Lee
- Institute for Medicine and Engineering, Department of Materials Science and Engineering, and Department of Microbiology, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - David Boettiger
- Institute for Medicine and Engineering, Department of Materials Science and Engineering, and Department of Microbiology, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Russell J. Composto
- Institute for Medicine and Engineering, Department of Materials Science and Engineering, and Department of Microbiology, University of Pennsylvania, Philadelphia, Pennsylvania 19104
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152
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Van Tomme SR, van Nostrum CF, Dijkstra M, De Smedt SC, Hennink WE. Effect of particle size and charge on the network properties of microsphere-based hydrogels. Eur J Pharm Biopharm 2008; 70:522-30. [PMID: 18582574 DOI: 10.1016/j.ejpb.2008.05.013] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2007] [Revised: 05/19/2008] [Accepted: 05/28/2008] [Indexed: 11/20/2022]
Abstract
This work describes the tailorability of the network properties of self-assembling hydrogels, based on ionic crosslinking between dextran microspheres. Copolymerization of hydroxyethyl methacrylate-derivatized dextran (dex-HEMA), emulsified in an aqueous poly(ethylene glycol) (PEG) solution, with methacrylic acid (MAA) or dimethylaminoethyl methacrylate (DMAEMA) resulted in negatively or positively charged microspheres, respectively, at physiological pH. The monomer/HEMA ratio ranged between 6 and 57, resulting in microspheres with zeta (zeta)-potentials from -6 to -34mV and +3 to +23mV, for the monomers MAA and DMAEMA, respectively. By altering the emulsification procedure, microsphere batches with various sizes and size distributions were obtained. The aim of the research was to assess the effect of particle size (distribution) and charge on the network properties of the macroscopic hydrogels. The ability to tailor the mechanical properties such as strength and elasticity increases the potential of the hydrogels to be used in a variety of pharmaceutical applications. Additionally, the injectability of these self-assembling hydrogels was investigated. Injectability is an important feature of drug delivery systems, since it allows avoiding surgery. Rheological analysis showed that an increasing surface charge of the microspheres led to stronger hydrogels. Relatively small microspheres (7microm) with a narrow size distribution (99% smaller than 14microm) gave rise to stronger hydrogels when compared to larger microspheres of 20microm with a broad distribution (99% smaller than 50microm). When small microspheres were combined with large microspheres of opposite charge, it was found that the strongest gels were obtained with 75% small and 25% large microspheres, instead of equal amounts (50/50) of positively and negatively charged microspheres. Computer modeling confirmed these findings and showed that the most favorable composition, related to the lowest potential energy, comprised of 75% small microspheres. Taking both charge and size effects into account, the storage moduli (G') of the almost fully elastic hydrogels could be tailored from 400 to 30,000Pa. Injectability tests showed that hydrogels (G' up to 4000Pa) composed of equal amounts of oppositely charged microspheres (-7 and +6mV, average particle size 7microm) could be injected through 25G needles using a static load of 15N, an ISO accepted value. In conclusion, a variety of options to control the network properties of macroscopic hydrogels are provided, related to the charge and particle size of the composing dextran microspheres. Furthermore, it is shown that the hydrogels are injectable, making them attractive candidates for a diversity of pharmaceutical applications.
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Affiliation(s)
- Sophie R Van Tomme
- Department of Pharmaceutics, Utrecht University, Utrecht, The Netherlands.
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153
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Santagapita PR, Brizuela LG, Mazzobre MF, Ramirez HL, Corti HR, Santana RV, Buera MP. Structure/function relationships of several biopolymers as related to invertase stability in dehydrated systems. Biomacromolecules 2008; 9:741-7. [PMID: 18189362 DOI: 10.1021/bm7012108] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Structure/function relationships of different biopolymers (alginate, dextran, or beta-cyclodextrin) were analyzed as single excipients or combined with trehalose in relation to their efficiency as enzyme stabilizers in freeze-dried formulations and compared to trehalose. Particularly, a novel synthesized polymer beta-cyclodextrin-branched alginate (beta-CD-A) was employed as excipient. During freeze-drying, the polymers or their mixtures did not confer better protection to invertase compared to trehalose. Beta-CD-A (with or without trehalose), beta-cyclodextrin (beta-CD), or dextran with trehalose were the best protective agents during thermal treatment, while beta-CD and alginate showed a negative effect on invertase activity preservation. The beta-CD linked alginate combined the physical stability provided by alginate with the stabilization of hydrophobic regions of the enzyme provided by cyclodextrin. Beta-CD-A was effective even at conditions at which trehalose lost its protective effect. A relatively simple covalent combination of two biopolymers significantly affected their functionalities and, consequently, their interactions with proteins, modifying enzyme stability patterns.
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Affiliation(s)
- Patricio R Santagapita
- Departamento de Industrias, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria 1428, Buenos Aires, Argentina
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154
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Biondi M, Ungaro F, Quaglia F, Netti PA. Controlled drug delivery in tissue engineering. Adv Drug Deliv Rev 2008; 60:229-42. [PMID: 18031864 DOI: 10.1016/j.addr.2007.08.038] [Citation(s) in RCA: 271] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2007] [Accepted: 08/09/2007] [Indexed: 11/15/2022]
Abstract
The concept of tissue and cell guidance is rapidly evolving as more information regarding the effect of the microenvironment on cellular function and tissue morphogenesis become available. These disclosures have lead to a tremendous advancement in the design of a new generation of multifunctional biomaterials able to mimic the molecular regulatory characteristics and the three-dimensional architecture of the native extracellular matrix. Micro- and nano-structured scaffolds able to sequester and deliver in a highly specific manner biomolecular moieties have already been proved to be effective in bone repairing, in guiding functional angiogenesis and in controlling stem cell differentiation. Although these platforms represent a first attempt to mimic the complex temporal and spatial microenvironment presented in vivo, an increased symbiosis of material engineering, drug delivery technology and cell and molecular biology may ultimately lead to biomaterials that encode the necessary signals to guide and control developmental process in tissue- and organ-specific differentiation and morphogenesis.
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Affiliation(s)
- Marco Biondi
- Interdisciplinary Research Centre on Biomaterials (CRIB), University of Naples Federico II, Naples, Italy
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155
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Tabata Y. Current status of regenerative medical therapy based on drug delivery technology. Reprod Biomed Online 2008; 16:70-80. [DOI: 10.1016/s1472-6483(10)60558-5] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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156
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Van Tomme SR, Mens A, van Nostrum CF, Hennink WE. Macroscopic Hydrogels by Self-Assembly of Oligolactate-Grafted Dextran Microspheres. Biomacromolecules 2007; 9:158-65. [DOI: 10.1021/bm700931q] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Sophie R. Van Tomme
- Department of Pharmaceutics, Utrecht Institute for Pharmaceutical Sciences (UIPS), Utrecht University, P.O. Box 80082, 3508 TB Utrecht, The Netherlands, Inorganic Chemistry and Catalysis Group, Department of Chemistry, Faculty of Science, Utrecht University, P.O. Box 80083, 3508 TB Utrecht, The Netherlands
| | - Ad Mens
- Department of Pharmaceutics, Utrecht Institute for Pharmaceutical Sciences (UIPS), Utrecht University, P.O. Box 80082, 3508 TB Utrecht, The Netherlands, Inorganic Chemistry and Catalysis Group, Department of Chemistry, Faculty of Science, Utrecht University, P.O. Box 80083, 3508 TB Utrecht, The Netherlands
| | - Cornelus F. van Nostrum
- Department of Pharmaceutics, Utrecht Institute for Pharmaceutical Sciences (UIPS), Utrecht University, P.O. Box 80082, 3508 TB Utrecht, The Netherlands, Inorganic Chemistry and Catalysis Group, Department of Chemistry, Faculty of Science, Utrecht University, P.O. Box 80083, 3508 TB Utrecht, The Netherlands
| | - Wim E. Hennink
- Department of Pharmaceutics, Utrecht Institute for Pharmaceutical Sciences (UIPS), Utrecht University, P.O. Box 80082, 3508 TB Utrecht, The Netherlands, Inorganic Chemistry and Catalysis Group, Department of Chemistry, Faculty of Science, Utrecht University, P.O. Box 80083, 3508 TB Utrecht, The Netherlands
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157
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Mwale F, Wang HT, Petit A, Girard-Lauriault PL, Hunter CJ, Ouellet JA, Wertheimer MR, Antoniou J. The effect of novel nitrogen-rich plasma polymer coatings on the phenotypic profile of notochordal cells. Biomed Eng Online 2007; 6:33. [PMID: 17822560 PMCID: PMC2018722 DOI: 10.1186/1475-925x-6-33] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2007] [Accepted: 09/06/2007] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND The loss of the notochordal cells from the nucleus pulposus is associated with ageing and disc degeneration. However, understanding the mechanisms responsible for the loss of these cells has been hampered in part due to the difficulty of culturing and maintaining their phenotype. Furthermore, little is known about the influence of the substratum on the molecular markers of notochordal cells. METHODS Notochordal cells were isolated from lumbar spine of non-chondrodystrophoid dogs and cultured on N-rich plasma polymer layers, so-called "PPE:N" (N-doped plasma-polymerised ethylene, containing up to 36% [N]) surfaces, for 3, 7 or 14 days. Gene expression of vimentin (VIM), pleiotrophin (PTN), matrix Gla protein (MGP), cartilage oligomeric matrix protein (COMP), keratin 18 (KRT 18), aggrecan (AGG), collagen type 1 (COL1A2), collagen type 2 (COL2A1) was analyzed through semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR). RESULTS Notochordal cells were maintained in culture on PPE:N for up to 14 days with no loss in cell viability. Except for VIM, gene expression varied depending on the culture periods and [N] concentration of the substratum. Generally, PPE:N surfaces altered gene expression significantly when cells were cultured for 3 or 7 days. CONCLUSION The present study has shown that notochordal cells from dogs can attach to and grow on PPE:N surfaces. Analysis of the expression of different genes in these cells cultured on different N-functionalized surfaces indicates that cellular behaviour is gene-specific and time-dependent. Further studies are required to better understand the roles of specific surface functionalities on receptor sites, and their effects on cellular phenotypes.
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Affiliation(s)
- Fackson Mwale
- Division of Orthopaedic Surgery, McGill University, and Lady Davis Institute for Medical Research, 3755, Chemin de la Cote Ste-Catherine, Montreal, QC H3T 1E2, Canada
| | - Hong Tian Wang
- Division of Orthopaedic Surgery, McGill University, and Lady Davis Institute for Medical Research, 3755, Chemin de la Cote Ste-Catherine, Montreal, QC H3T 1E2, Canada
| | - Alain Petit
- Division of Orthopaedic Surgery, McGill University, and Lady Davis Institute for Medical Research, 3755, Chemin de la Cote Ste-Catherine, Montreal, QC H3T 1E2, Canada
| | | | - Christopher J Hunter
- McCaig Centre for Joint Injury and Arthritis Research, Department of Civil Engineering, Department of Cell Biology and Anatomy, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Jean A Ouellet
- Montreal Children Hospital, 2300 Tupper Street, Room C-521, Montréal, QC H3H 1P3, Canada
| | - Michael R Wertheimer
- Department of Engineering Physics, Ecole Polytechnique, Montréal, QC H3T 1J4, Canada
| | - John Antoniou
- Division of Orthopaedic Surgery, McGill University, and Lady Davis Institute for Medical Research, 3755, Chemin de la Cote Ste-Catherine, Montreal, QC H3T 1E2, Canada
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