Culture of Primary Bovine Chondrocytes on a Continuously Expanding Surface Inhibits Dedifferentiation
Bibliographic record
Abstract
Expansion of autologous chondrocytes in vitro is used to generate adequate populations for cell-based therapies. However, standard (SD) culture methods cause loss of chondrocyte phenotype and dedifferentiation to fibroblast-like cells. Here, we use a novel surface expansion culture system in an effort to inhibit chondrocyte dedifferentiation. A highly elastic silicone rubber culture surface was continuously stretched over a 13-day period to 600% of its initial surface area. This maintained cells at a high density while limiting contact inhibition and reducing the need for passaging. Gene expression analysis, biochemical assays, and immunofluorescence microscopy of follow-on pellet cultures were used to characterize the results of continuous expansion (CE) culture versus SD cultures on rigid polystyrene. CE culture yielded cells with a more chondrocyte-like morphology and higher RNA-level expression of the chondrogenic markers collagen type II, aggrecan, and cartilage oligomeric matrix protein. Furthermore, the expression of collagen type I RNA and α-smooth muscle actin protein were significantly reduced, indicating suppression of fibroblastic features. Pellet cultures from CE chondrocytes contained more sulphated glycosaminoglycan and collagen type II than pellets from SD culture. Additional control cultures on static (unexpanded) silicone (SS culture) indicated that benefits of CE culture were partially due to features of the culture surface itself and partially due to the reduced passaging which that surface enabled through CE. Chondrocytes grown in CE culture may, therefore, be a superior source for cell-based therapies.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".