| 1. |
|
|
| 2. |
- Feldmann, Eva-Maria, et al.
(author)
-
Description of a novel approach to engineer cartilage with porous bacterial nanocellulose for reconstruction of a human auricle
- 2013
-
In: Journal of Biomaterials Applications. - : SAGE Publications. - 0885-3282 .- 1530-8022. ; 28:4, s. 626-640
-
Journal article (peer-reviewed)abstract
- In this study, we investigated the effects of human primary chondrocytes, derived from routine septorhino- and otoplasties on a novel nondegradable biomaterial. This biomaterial, porous bacterial nanocellulose, is produced by Gluconacetobacter xylinus. Porosity is generated by paraffin beads embedded during the fermentation process. Human primary chondrocytes were able to adhere to bacterial nanocellulose and produce cartilaginous matrix proteins such as aggrecan (after 14 days) and collagen type II (after 21 days) in the presence of differentiation medium. Cells were located within the pores and in a dense cell layer covering the surface of the biomaterial. Cells were able to re-differentiate, as cell shape and extra cellular matrix gene expression showed a chondrogenic phenotype in three-dimensional bacterial nanocellulose culture. Collagen type I and versican expression decreased during three-dimensional culture. Variations in pore sizes of 150-300 mu m and 300-500 mu m did not influence cartilaginous extra cellular matrix synthesis. Varying seeding densities from 9.95x10(2) to 1.99x10(3)cells/mm(2) and 3.98x10(3)cells/mm(2) did not result in differences in quality of extra cellular matrix neo-synthesis. Our results demonstrated that both nasal and auricular chondrocytes are equally suitable to synthesize new extra cellular matrix on bacterial nanocellulose. Therefore, we propose both cell sources in combination with bacterial nanocellulose as promising candidates for the special needs of auricular reconstruction.
|
|
| 3. |
|
|
| 4. |
- Martinez Avila, Hector, 1985, et al.
(author)
-
Biocompatibility evaluation of densified bacterial nanocellulose hydrogel as an implant material for auricular cartilage regeneration
- 2014
-
In: Applied Microbiology and Biotechnology. - : Springer Science and Business Media LLC. - 1432-0614 .- 0175-7598. ; 98:17, s. 7423-7435
-
Journal article (peer-reviewed)abstract
- Bacterial nanocellulose (BNC), synthesized by the bacterium Gluconacetobacter xylinus, is composed of highly hydrated fibrils (99 % water) with high mechanical strength. These exceptional material properties make BNC a novel biomaterial for many potential medical and tissue engineering applications. Recently, BNC with cellulose content of 15 % has been proposed as an implant material for auricular cartilage replacement, since it matches the mechanical requirements of human auricular cartilage. This study investigates the biocompatibility of BNC with increased cellulose content (17 %) to evaluate its response in vitro and in vivo. Cylindrical BNC structures (48 Au 20 mm) were produced, purified in a built-in house perfusion system, and compressed to increase the cellulose content in BNC hydrogels. The reduction of endotoxicity of the material was quantified by bacterial endotoxin analysis throughout the purification process. Afterward, the biocompatibility of the purified BNC hydrogels with cellulose content of 17 % was assessed in vitro and in vivo, according to standards set forth in ISO 10993. The endotoxin content in non-purified BNC (2,390 endotoxin units (EU)/ml) was reduced to 0.10 EU/ml after the purification process, level well below the endotoxin threshold set for medical devices. Furthermore, the biocompatibility tests demonstrated that densified BNC hydrogels are non-cytotoxic and cause a minimal foreign body response. In support with our previous findings, this study concludes that BNC with increased cellulose content of 17 % is a promising non-resorbable biomaterial for auricular cartilage tissue engineering, due to its similarity with auricular cartilage in terms of mechanical strength and host tissue response.
|
|
| 5. |
- Martinez Avila, Hector, 1985, et al.
(author)
-
Novel bilayer bacterial nanocellulose scaffold supports neocartilage formation in vitro and in vivo
- 2015
-
In: Biomaterials. - : Elsevier BV. - 0142-9612 .- 1878-5905. ; 44, s. 122-133
-
Journal article (peer-reviewed)abstract
- Tissue engineering provides a promising alternative therapy to the complex surgical reconstruction of auricular cartilage by using ear-shaped autologous costal cartilage. Bacterial nanocellulose (BNC) is proposed as a promising scaffold material for auricular cartilage reconstruction, as it exhibits excellent biocompatibility and secures tissue integration. Thus, this study evaluates a novel bilayer BNC scaffold for auricular cartilage tissue engineering. Bilayer BNC scaffolds, composed of a dense nanocellulose layer joined with a macroporous composite layer of nanocellulose and alginate, were seeded with human nasoseptal chondrocytes (NC) and cultured invitro for up to 6 weeks. To scale up for clinical translation, bilayer BNC scaffolds were seeded with a low number of freshly isolated (uncultured) human NCs combined with freshly isolated human mononuclear cells (MNC) from bone marrow in alginate and subcutaneously implanted in nude mice for 8 weeks. 3D morphometric analysis showed that bilayer BNC scaffolds have a porosity of 75% and mean pore size of 50±25μm. Furthermore, endotoxin analysis and invitro cytotoxicity testing revealed that the produced bilayer BNC scaffolds were non-pyrogenic (0.15±0.09EU/ml) and non-cytotoxic (cell viability: 97.8±4.7%). This study demonstrates that bilayer BNC scaffolds offer a good mechanical stability and maintain a structural integrity while providing a porous architecture that supports cell ingrowth. Moreover, bilayer BNC scaffolds provide a suitable environment for culture-expanded NCs as well as a combination of freshly isolated NCs and MNCs to form cartilage invitro and invivo as demonstrated by immunohistochemistry, biochemical and biomechanical analyses.
|
|
| 6. |
|
|
| 7. |
|
|
| 8. |
|
|
