Expression of matrix metalloproteinase‐2 and ‐9 in exudates associated with polydimethyl siloxane and gelatin tubes implanted in mice
Bibliographic record
Abstract
The expression of matrix metalloproteinases (MMPs), MMP-2 and -9, during the inflammatory response to two implanted biomaterials was determined. To illustrate this phenomenon, polydimethyl siloxane (PDMS), weakly crosslinked gelatin, and highly crosslinked gelatin tubes were implanted subcutaneously in mice for up to 3 weeks. Latent MMP-2 (pro-MMP-2) was seen in exudates throughout the experimental period and did not show any apparent changes in time or among the three biomaterials. The expression of MMP-9, however, showed a very different pattern. At days 4 and 8, the predominant form of MMP-9 is pro-MMP-9 (the latent form) and its level is much higher for the PDMS tube than either of the gelatin tubes. The active form of MMP-9, initially low, rose progressively over the 3-week period and reached its peak at week 2 for PDMS and highly crosslinked gelatin and at week 3 for the more degradable, weakly crosslinked gelatin. Data from the histological and cytological analysis also showed that the PDMS tube induced a much stronger cellular response than gelatin tubes, although endotoxin contamination precludes a conclusion related to biomaterial effects. We concluded that MMP-9 is a useful marker of the host inflammatory response to the implanted biomaterials and it may be useful in the assessment of biomaterial biocompatibility. Perhaps more importantly, the consequences of MMPs on matrix remodeling may become of concern in biomaterials used for tissue engineering.
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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 | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.001 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
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".