Tissue engineering for total meniscal substitution : Animal study in sheep model

Objective: The aim of the study was to investigate the use of a novel hyaluronic acid/polycaprolactone material for meniscal tissue engineering and to evaluate the tissue regeneration after the augmentation of the implant with expanded autologous chondrocytes. Two different surgical implantation techniques in a sheep model were evaluated. Methods: Twenty-four skeletally mature sheep were treated with total medial meniscus replacements, while two meniscectomies served as empty controls. The animals were divided into two groups: cell-free scaffold and scaffold seeded with autologous chondrocytes. Two different surgical techniques were compared: in 12 animals, the implant was sutured to the capsule and to the meniscal ligament; in the other 12 animals, also a transtibial fixation of the horns was used. The animals were euthanized after 4 months. The specimens were assessed by gross inspection and histology. Results: All implants showed excellent capsular ingrowth at the periphery. Macroscopically, no difference was observed between cell-seeded and cell-free groups. Better implant appearance and integrity was observed in the group without transosseous horns fixation. Using the latter implantation technique, lower joint degeneration was observed in the cell-seeded group with respect to cell-free implants. The histological analysis indicated cellular infiltration and vascularization throughout the implanted constructs. Cartilaginous tissue formation was significantly more frequent in the cell-seeded constructs. Conclusion: The current study supports the potential of a novel HYAFF/polycaprolactone scaffold for total meniscal substitution. Seeding of the scaffolds with autologous chondrocytes provides some benefit in the extent of fibrocartilaginous tissue repair

Queries Raised During Oncology Business Pipeline Meetings at the European Medicines Agency:A 5-Year Retrospective Analysis

The European Medicines Agency (EMA) offers guidance and support to pharmaceutical companies through bilateral discussions called business pipeline meetings (BPMs). An analysis of BPMs in oncology over a 5-year period was conducted to identify common topics and recurring queries. The documents of all BPMs available at the EMA regarding the field of oncology from January 1, 2018, to Decemer 31, 2022, were reviewed. For every query, a main category was assigned, and in case of multiple relevant topics, a secondary category was appointed too. For all queries, the follow-up offered by the EMA was documented, and whether the requested information was available. Subsequently, all queries were scanned for overlapping topics between meetings. From 2018 to 2022, 31 BPMs were held between the EMA and pharmaceutical companies to discuss oncology-related questions, for a total of 397 queries raised. They were classified into 24 topics, of which 15 were common topics (n ≥ 10 queries) with regulatory pathways/guidelines and trial design having the most queries. Post-BPM actions were taken or recommended by the EMA for 41.3% of queries, such as referrals to scientific advice or published guidelines. Forty-three queries were raised at more than one BPM. Targeted therapy, companion diagnostics, institutional collaboration, trial design, and regulatory pathways/guidelines were the most discussed topics in oncology BPMs, with molecular developments being the common denominator. Creating Q&amp;A documents, publishing new guidelines, providing a framework for discussions, and questionnaire-based follow-up research can improve the quality of BPMs, and the accessibility of the information requested during the BPMs.</p

Activity-dependent vs neurotrophic modulation of acetylcholine receptor expression: evidence from rat soleus and extensor digitorum longus muscles confirms the exclusive role of activity

Evoked electrical muscle activity suppresses the transcription of mRNAs for acetylcholine receptors in extrajunctional myonuclei. Muscle denervation or disuse release such inhibition and extrajunctional receptors appear. However, in soleus muscles paralyzed with nerve-applied tetrodotoxin, a restricted perijunctional region has been described where myonuclei remain inhibited, a finding attributed to nerve-derived trophic factor(s). Here, we reinvestigate extrajunctional acetylcholine receptor expression in soleus and extensor digitorum longus muscles up to 90 days after denervation or up to 20 days of disuse, to clarify the role of trophic factors, if any. The perijunctional region of soleus muscles strongly expressed acetylcholine receptors during the first 2-3 weeks of denervation. After 2-3 months this expression had disappeared. No perijunctional expression was seen after paralysis by tetrodotoxin or botulinum toxin A. In contrast, the extensor digitorum longus never displayed suppressed perijunctional acetylcholine receptor expression after any treatment, suggesting that it is an intrinsic property of soleus muscles. Soleus denervation only transiently removed the suppression, and its presence in long-term denervated soleus muscles contradicts any contribution from nerve-derived trophic factor(s). In conclusion, our results confirm that evoked electrical activity is the physiological factor controlling the expression of acetylcholine receptors in the entire extrajunctional membrane of skeletal muscles. This article is protected by copyright. All rights reserved