Poliglicolic acid neurotube and stem cells in facial nerve regeneration: experimental study in rats

• Grant number: 08/00584-4
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: May 01, 2008
• End date: April 30, 2011
• Field of knowledge: Health Sciences - Medicine
• Principal Investigator: Ricardo Ferreira Bento
• Grantee: Heloísa Juliana Zabeu Rossi Costa
• Host Institution: Faculdade de Medicina (FM). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Facial traumas and tumoral resections may result in lack of facial nerve tissue and difficulties for primary anastomosis. Nerve autograft was an excellent improvement, but the search for better functional results leaded to bioabsorbable conduits. Schwann cells are essential for nerve regeneration, and now it is possible to differentiate bone-marrow stromal cells in Schwann-like cells. Objective: to compare, in rats, the regeneration of bucal segment of the facial nerve through functional evaluation, qualitative and quantitative analysis and morphometry, obtained after: a) interposition of autograft; b) autograft associated with poliglicolic acid tube (tAPG); c) autograft with tAPG plus injection of acelular Matrigel; d) autograft with tAPG plus injection of acelular Matrigel with mesenquimal stem cells without differentiation; e) autograft with tAPG plus injection of acelular Matrigel with mesenquimal stem cells differentiated in schwann-like cells. Material and method: 30 male rats with 2500-3000kg will be used. One rat will be sacrificed and his tibia and fibula were dissected to remove the bone-marrow. The bone marrow-derived cells were differentiated, marked and included in Matrigel. Study groups: 30 rats will be anesthetized and their bucal segment of the facial nerve dissected to create a gap of 5mm. The animals will be divided in 5 groups of 6, according to the treatment employed to correction of the gap. In group A, defects will be corrected by relocation of the nerve fragment in its original position, sutured with nylon 10.0. In group B there will be a tAPG involving the graft. In group C, between autograft and neurotube there will be Matrigel acelular. In group D, between autograft and neurotube there will be marked stem cells without differentiation, included in Matrigel. In group E, cells differentiated in Schwann-like included in Matrigel were injected into tAPG. Functional analysis by electromyography will be performed until sacrifice. Neural regeneration analysis: 4 weeks after the surgical procedure, 6 rats of each group will be sacrificed and the study material will be removed for histological prepare. Qualitative and quantitative (total axonal density) histological analysis will be done, and also the maturation of the myelinated fibers will be evaluated. Statistical analysis: the tests that will be used are Levene, t-Student, Mann-Whitney, Fisher's exact test and qui-square. Significance will be set at p < 0.05. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

ZABEU ROSSI COSTA, HELOISA JULIANA; BENTO, RICARDO FERREIRA; SALOMONE, RAQUEL; AZZI-NOGUEIRA, DEBORAH; ZANATTA, DANIELA B.; COSTA, MARCIO PAULINO; DA SILVA, CIRO FERREIRA; STRAUSS, BRYAN E.; HADDAD, LUCIANA A.. Mesenchymal bone marrow stem cells within polyglycolic acid tube observed in vivo after six weeks enhance facial nerve regeneration. Brain Research, v. 1510, p. 10-21, MAY 13 2013. (08/00584-4, 98/14254-2, 08/00972-4)