Optimisation in vitro et application in vivo d'implants injectables lyophilisés à base de chitosane et de thrombine pour la médecine régénératrice orthopédique
Why this work is in the frame
A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.
Bibliographic record
Abstract
RÉSUMÉ: Les blessures musculo-squelettiques touchent chaque année 11 millions de Canadiens, engen-drant des coûts de 37 milliards de dollars. Malgré les progrès en médecine, les traitements standards actuels présentent un taux d’échec postopératoire élevé, atteignant par exemple entre 20% et 60% pour la réparation de la coiffe des rotateurs (en fonction des études). Cette situation met en évidence un besoin médical crucial que les technologies actuelles ne parviennent pas à combler. Pour répondre à ce défi, le Laboratoire des Biomatériaux et du Cartilage (LBC) a mis au point une formulation de chitosane (CS) lyophilisée destinée à être solubilisée dans du plasma riche en plaquettes (PRP). Ce biomatériau injectable présente l’avantage de coaguler in situ, facilitant ainsi son application au site de la blessure. Cepen-dant, l’implant ainsi obtenu se solidifie lentement, spécifiquement avec du PRP d’origine humaine. Cette lente coagulation peut être problématique, spécifiquement pour les chirurgies pendant lesquelles un fluide est utilisé pour irriguer la zone de travail (p. ex. chirurgies ar-throscopiques). L’humidité présente au site de la blessure peut alors empêcher le biomatériau d’adhérer. L’objectif général des trois études décrites dans cette thèse est de faire progresser le domaine de la médecine régénératrice par le développement et l’optimisation in vitro d’un biomatériau à base de chitosane, validé pour son homogénéité, et testé pour son efficacité in vivo, en particulier pour la régénération du tendon supra-épineux de la coiffe des rotateurs chez le lapin. ABSTRACT: Musculoskeletal injuries affect 11 million Canadians each year, resulting in costs of 37 billion dollars. Despite advances in medicine, current standard treatments have a high postoperative failure rate, ranging from 20 to 60% for rotator cuff repairs, for example. This situation high-lights unmet medical needs that current technologies fail to meet. To address this challenge, the Laboratory of Biomaterials and Cartilage (LBC) developed a freeze-dried chitosan formu-lation designed to be solubilized in platelet-rich plasma (PRP). This injectable biomaterial has the advantage of coagulating in situ, thus facilitating its application at site of injury. However, the resulting implant solidifies slowly, particularly with human-derived PRP. This slow coagulation can be problematic, especially for surgeries where a fluid is used to irrigate the work area (e.g., arthroscopic surgeries). The fluid present at the injury site can then prevent the biomaterial from adhering. The overall objective of the three studies described in this thesis is to advance the field of regenerative medicine by the in vitro development and optimization of a chitosan-based biomaterial, validate it for its homogeneity, and then test it in vivo for its efficacy, particularly for the regeneration of the supraspinatus tendon of the rotator cuff in rabbits. The specific objective of the first study is to propose an algorithm to quantify homogeneity in images. Homogeneity is an important parameter for chitosan-PRP implants, as it influences their degradation and the tissue response that follows their implantation. A precise quantifi-cation of homogeneity thus allows comparing different formulations of the biomaterial among themselves, as well as validating that for each batch of biomaterial produced, the chitosan mixes homogeneously with the blood components.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.002 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.002 | 0.002 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.002 | 0.002 |
| Insufficient payload (model declined to judge) | 0.000 | 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 it