Traitement des néovaisseaux cornéens par injections sous-conjonctivales de bevacizumab

LIMOGES-BU Médecine pharmacie (870852108) / SudocSudocFranceF

Combined intra-tendinous injection of Platelet Rich Plasma and bevacizumab accelerates and improves healing compared to Platelet Rich Plasma in tendinosis: comprehensive assessment on a rat model

Purpose: the aim of our study was to assess the potential of combined intratendinous injection of an anti-angiogenic drug: bevacizumab (AA) and Platelet Rich Plasma (PRP) to treat tendinopathy in a murine model of patellar and Achilles tendinopathy, and to evaluate its local toxicity. Material and method: twenty rats (80 patellar and Achilles tendons) were used for the study. We induced tendinosis (T+) in 80 tendons (patellar=40 and Achilles=40) by injecting under ultrasonography (US) guidance Collagenase 1® (day 0 = D0). Clinical examination was performed at D3, immediately followed by either PRP and AA (AAPRPT+, n=40) or PRP (PRPT+ n=40, control) US-guided intratendinous injection. Follow-up at D6, D18 and D25 using clinical, US and histology, and comparison between the 2 groups were performed. To study AA+PRP toxicity, we looked for necrosis or rupture on the 40 AAPRPT+. Results: all AAPRPT+ showed better joint mobilization compared to PRPT+ at D6 (p=0.03), D18 (p=0.04) and D25 (p=0.02). Similar results were found regarding US and histology, with smaller collagen fiber diameters (D6, p≤0.017, D25, p≤0.015), less disorganization and fewer neovessels (D25, p=0.004) in AAPRPT+ compared to PRPT+. No AA+PRP local toxicity was discovered in histology assessment. Conclusion: our study suggests that combined injection of AA and PRP in tendinosis accelerates and improves tendon’s healing compared PRP used alone, with no local toxicity

Focus on cell therapy to treat corneal endothelial diseases

International audienceThe cornea is a multi-layered structure which allows fine refraction and provides both resistance to external insults and adequate transparency. The corneal endothelium ensures stromal hydration, failure of which, such as in Fuchs endothelial corneal dystrophy, after trauma or in aging, may lead to loss of corneal transparency and induce blindness. Currently, no efficient therapeutic alternatives exist except for corneal grafting. Thus corneal tissue engineering represents a valuable alternative approach, which may overcome cornea donor shortage. Several studies describe protocols to isolate, differentiate, and cultivate corneal endothelial cells (CEnCs) in vitro. Two main in vitro strategies can be described: expansion of eye-native cell populations, such as CEnCs, or the production and expansion of CEnCs from non-eye native cell populations, such as induced Pluripotent Stem Cells (iPSCs). The challenge with these cells is to obtain a monolayer of CEnCs on a biocompatible carrier, with a specific morphology (flat hexagonal cells), and with specific functions such as programmed cell cycle arrest. Another issue for this cell culture methodology is to define the adapted protocol (media, trophic factors, timeframe) that can mimic physiological development. Additionally, contamination by other cell types still represents a huge problem. Thus, purification methods, such as Fluorescence Activated Cell Sorting (FACS), Magnetic Ativated Cell Sorting (MACS) or Sedimentation Field Flow Fractionation (SdFFF) are useful. Animal models are also crucial to provide a translational approach for these therapies, integrating macro- and microenvironment influences, systemic hormonal or immune responses, and exogenous interactions. Non-eye native cell graft protocols are constantly improving both in efficacy and safety, with the aim of being the most suitable candidate for corneal therapies in future routine practice. The aim of this work is to review these different aspects with a special focus on issues facing CEnC culture in vitro, and to highlight animal graft models adapted to screen the efficacy of these different protocols