Compressed collagen gel as the scaffold for skin engineering.
ABSTRACT Collagen gel scaffolds can potentially be utilized as cell seeded systems for skin tissue engineering. However, its dramatic contraction after being mixed with cells and its mechanical weakness are the drawbacks for its application to skin engineering. In this study, a compressed collagen gel scaffold was fabricated through the rapid expulsion of liquid from reconstituted gels by the application of 'plastic compression'(PC) technique. Both compressed and uncompressed gels were characterized with their gel contraction rate, morphology, the viability of seeded cells, their mechanical properties and the feasibility as a scaffold for constructing tissue-engineered skin. The results showed that the compression could significantly reduce the contraction of the collagen gel and improve its mechanical property. In addition, seeded dermal fibroblasts survived well in the compressed gel and seeded epidermal cells gradually developed into a stratified epidermal layer, and thus formed tissue engineered skin. This study reveals the potential of using compressed collagen gel as a scaffold for skin engineering.
- SourceAvailable from: Ahad KhoshzabanComparative Clinical Pathology 12/2011; DOI:10.1007/s00580-011-1394-1
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ABSTRACT: A biodegradable hybrid scaffold consisting of a synthetic polymer, poly(lactic acid-co-caprolactone) (PLACL), and a naturally derived polymer, collagen, was constructed by plastic compressing hyperhydrated collagen gels onto a flat warp-knitted PLACL mesh. The collagen compaction process was characterized, and it was found that the duration, rather than the applied load under the test conditions in the plastic compression, was the determining factor of the collagen and cell density in the cell-carrying component. Cells were spatially distributed in three different setups and statically cultured for a period of 7 days. Short-term biocompatibility of the hybrid construct was quantitatively assessed with AlamarBlue and qualitatively with fluorescence staining and confocal microscopy. No significant cell death was observed after the plastic compression of the interstitial equivalents, confirming previous reports of good cell viability retention. The interstitial, epithelial, and composite tissue equivalents showed no macroscopic signs of contraction and good cell proliferation with a two- to threefold increase in cell number over 7 days. Quantitative analysis showed a homogenous cell distribution and good biocompatibility. The results indicate that viable and proliferating multilayered tissue equivalents can be engineered using the PLACL-collagen hybrid construct in the space of several hours.Tissue Engineering Part A 07/2009; 15(7):1667-75. DOI:10.1089/ten.tea.2008.0194 · 4.64 Impact Factor
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ABSTRACT: Plastic compression (PC) of collagen facilitates the fabrication of dense, tissue-like constructs without the need for cell activity. The process involves rapid expulsion of water from cell-seeded collagen gels, normally in a single axis of flow and takes minutes to perform. However, there has been a need for an improvement in terms of scaling up and reproducibility. We have designed a modified technique to fabricate tissue constructs in a multi well format (currently 12 wells) in less than one hour with good reproducibility using upward fluid flow. It has been shown in our group that compression time directly correlates with the height of the initial gel, for a constant fluid leaving area (in our case 22 mm diameter), so in order to determine a range of PC times we have examined the dynamic of liquid loss for a range of gel heights. This included 5.3 mm (2 ml), 7.9 mm (3 ml), 9.2 mm (3.5 ml), 10.5 mm (4 ml) and 13 mm (5 ml). Liquid loss was calculated as percentage increase in paper roll weight relative to the initial weight of paper and was taken every 5 min until plateau. Based on our results we have determined times of compression as 5 min, 10 min, 15 min, 20 min and 35 min for gels in ascending order. Measurements of wet weight and thickness of constructs showed good reproducibility (SD: ±0.005g and ±1.2 μm respectively). Modification of the method has no effect on cell activity and gives opportunity to fabricate constructs with increased complexity through multilayering. We can conclude that the new modified method of plastic compression allows scaling up of the process, with dramatic savings on time and results in reproducible constructs that allow cell culture. Method also opens new research directions using multilayered constructs. Keywordscollagen I–plastic compression–fluid-flow–multi-well compression03/2011: pages 5-8;