| 1. |
- Andersson, Jessica, et al.
(författare)
-
Behavior of human chondrocytes in engineered porous bacterial cellulose scaffolds
- 2010
-
Ingår i: Journal of Biomedical Materials Research - Part A. - : Wiley. - 1552-4965 .- 1549-3296. ; 94A:4, s. 1124-1132
-
Tidskriftsartikel (refereegranskat)abstract
- Regeneration of articular cartilage damage is an area of great interest due to the limited ability of cartilage to self-repair. The latest cartilage repair strategies are dependent on access to biomaterials to which chondrocytes can attach and in which they can migrate and proliferate, producing their own extracellular matrix. In the present study, engineered porous bacterial cellulose (BC) scaffolds were prepared by fermentation of Acetobacter xylinum (A. xylinum) in the presence of slightly fused wax particles with a diameter of 150-300 mu m, which were then removed by extrusion. This porous material was evaluated as a scaffold for cartilage regeneration. Articular chondrocytes from young adult patients as well as neonatal articular chondrocytes were seeded with various seeding techniques onto the porous BC scaffolds. Scanning electron microscopy (SEM) analysis and confocal microscopy analysis showed that cells entered the pores of the scaffolds and that they increasingly filled out the pores over time. Furthermore, DNA analysis implied that the chondrocytes proliferated within the porous BC. Alcian blue van Gieson staining revealed glycosaminoglycan (GAG) production by chondrocytes in areas where cells were clustered together. With some further development, this novel biomaterial can be a suitable candidate for cartilage regeneration applications.
|
|
| 2. |
- Stenhamre, Hanna, 1978
(författare)
-
Chondrocytes Differentiation- Biological and Biomaterial Perspectives
- 2010
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Articular cartilage is an avascular tissue and once injured it does not heal spontaneously. A successful tissue engineering approach for cartilage reconstruction is autolougus chondrocyte implantation (ACI). In ACI a biopsy is harvested from the knee joint and the chondrocytes are isolated, expanded in vitro and subsequently implanted into the defect to regenerate new hyaline tissue. During the ACI procedure the chondrocytes undergo a process of de- and re-differentiation. To improve cartilage cell therapy, knowledge of how we can control and modulate the chondrocytes behavior is essential. The general aim of this thesis was to give insight in how we can influence the differentiation of chondrocytes. To accomplish this we examined whether and to what extent the redifferentiation capacity of articular chondrocytes was affected by the cell source, in vitro cultivation, and the scaffolds used.We found that human chondrocytes behaviour in vitro was depending on the harvesting site in the knee joint. The chondrocytes from femur had a better attachment, proliferation and post-expansion redifferentiation capacity than chondrocytes from tibia. Focusing on the cell source we further found that some degree of dedifferentiation is needed to obtain high quality redifferentiation in vitro. To further study how we could affect the behavior of in vitro expanded chondrocytes the cells were cultured in scaffolds with defined architecture during the redifferentiation. The effect of scaffolds with varied pore size as well as fiber size was examined. The results revealed that the pore size of the scaffold influenced the redifferentiation capacity whereas the size of the fibers did not. The size of the fiber showed to affect the proliferation of the cells and thus different biological processes can be manipulated by the design of the scaffolds. Furthermore, we found that scaffold mediated chondrogenesis in vitro is a process mimicking the fetal cartilage development. Moreover, we found that that redifferentiation of in vitro expanded articular chondrocytes is needed at the time of implantation for neocartilage formation to take place in vivo.The result presented in this thesis thus show that the outcome of articular cartilage tissue engineering in cartilage reconstruction will depend on harvesting site, degree of differentiation of the chondrocytes as well as the scaffold architecture. This information adds additional knowledge into the field of cartilage tissue engineering to be used for further improvement of the treatment of cartilage repair.
|
|
| 3. |
- Thorvaldsson, Anna, 1981, et al.
(författare)
-
Electrospinning of Highly Porous Scaffolds for Cartilage Regeneration
- 2008
-
Ingår i: Biomacromolecules. - : American Chemical Society (ACS). - 1525-7797 .- 1526-4602. ; 9:3, s. 1044-1049
-
Tidskriftsartikel (refereegranskat)abstract
- This study presents a new innovative method where electrospinning is used to coat single microfibers with nanofibers. The nanofiber-coated microfibers can be formed into scaffolds with the combined benefits of tailored porosity for cellular infiltration and nanostructured surface morphology for cell growth. The nanofiber coating is obtained by using a grounded collector rotating around the microfiber, to establish an electrical field yet allow collection of nanofibers on the microfiber. A Teflon tube surrounding the fibers and collector is used to force the nanofibers to the microfiber. Polycaprolactone nanofibers were electrospun onto polylactic acid microfibers and scaffolds of 95 and 97% porosities were made. Human chondrocytes were seeded on these scaffolds and on reference scaffolds of purely nanofibers and microfibers. Thereafter, cellular infiltration was investigated. The results indicated that scaffold porosity had great effects on cellular infiltration, with higher porosity resulting in increased infiltration, thereby confirming the advantage of the presented method. © 2008 American Chemical Society.
|
|
| 4. |
- Thorvaldsson, Anna, 1981, et al.
(författare)
-
Electrospinning of nanofibers for biomedical applications
- 2008
-
Ingår i: 8th World Biomaterials Congress 2008, WBC 2008; Amsterdam; Netherlands; 28 May 2008 through 1 June 2008. - 9781615670802 ; 3, s. 1197-
-
Konferensbidrag (refereegranskat)
|
|
