Browsing by Author "Amorim, Irina"
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- Combined Use of Chitosan and Olfactory Mucosa Mesenchymal Stem/Stromal Cells to Promote Peripheral Nerve Regeneration In VivoPublication . Alvites, R. D.; Branquinho, Mariana V.; Sousa, Ana C.; Amorim, Irina; Magalhães, Rui; João, Filipa; Almeida, Diogo; Amado, Sandra; Prada, Justina; Pires, Isabel; Zen, Federica; Raimondo, Stefania; Luís, Ana L.; Geuna, Stefano; Varejão, Artur S. P.; Maurício, Ana C.Peripheral nerve injury remains a clinical challenge with severe physiological and functional consequences. Despite the existence of multiple possible therapeutic approaches, until now, there is no consensus regarding the advantages of each option or the best methodology in promoting nerve regeneration. Regenerative medicine is a promise to overcome this medical limitation, and in this work, chitosan nerve guide conduits and olfactory mucosa mesenchymal stem/stromal cells were applied in different therapeutic combinations to promote regeneration in sciatic nerves after neurotmesis injury. Over 20 weeks, the intervened animals were subjected to a regular functional assessment (determination of motor performance, nociception, and sciatic indexes), and after this period, they were evaluated kinematically and the sciatic nerves and cranial tibial muscles were evaluated stereologically and histomorphometrically, respectively. The results obtained allowed confirming the beneficial effects of using these therapeutic approaches. The use of chitosan NGCs and cells resulted in better motor performance, better sciatic indexes, and lower gait dysfunction after 20 weeks. The use of only NGGs demonstrated better nociceptive recoveries. The stereological evaluation of the sciatic nerve revealed identical values in the different parameters for all therapeutic groups. In the muscle histomorphometric evaluation, the groups treated with NGCs and cells showed results close to those of the group that received traditional sutures, the one with the best final values. The therapeutic combinations studied show promising outcomes and should be the target of new future works to overcome some irregularities found in the results and establish the combination of nerve guidance conduits and olfactory mucosa mesenchymal stem/stromal cells as viable options in the treatment of peripheral nerves after injury.
- Neuro-muscular Regeneration Using Scaffolds with Mesenchymal Stem Cells (MSCs) Isolated from Human Umbilical Cord Wharton's Jelly: Functional and Morphological Analysis Using Rat Sciatic Nerve Neurotmesis Injury ModelPublication . Caseiro, Ana Rita; Pereira, Tiago; Ribeiro, Jorge; Amorim, Irina; Faria, Fátima; Bártolo, Paulo Jorge; Armada, Paulo; Luís, Ana Lúcia; Maurício, Ana ColettePeripheral nerves possess the capacity of self-regeneration after traumatic injury but the extent of regeneration is often poor and may benefit from exogenous factors that enhance growth. Neonatal tissues are routinely discarded at parturition so little ethical controversy attends the harvest of the Mesenchymal Stem Cells (MSCs) which may play an important therapeutic role through the secretion of soluble trophic factors which enhance and assist in repair by paracrine activation of surrounding cells. The use of cellular systems is a rational approach for delivering neurotrophic factors at the nerve lesion site, and in our recent research work we have been evaluating the therapeutic value of MSCs isolated from the Wharton jelly (WJ) in nerve repair associated to different tube-guides made of biodegradable and biocompatible biomaterials. The WJ MSCs in vitro studies included cell characterization by immunocytochemistry, karyotype analysis, tri-lineage differentiation capacity and flow cytometry and also citocompatibility by measuring the intracellular calcium concentration ([Ca2+]i) in the presence of different tube-guides.