CESAR ISAAC
Projetos de Pesquisa
Unidades Organizacionais
LIM/04 - Laboratório de Microcirurgia, Hospital das Clínicas, Faculdade de Medicina - Líder
2 resultados
Resultados de Busca
Agora exibindo 1 - 2 de 2
- Evaluation of Radiosterilized Glyercerolated Amniotic Membranes as a Substrate for Cultured Human Epithelial Cells(2020) PAGGIARO, Andre O.; MATHOR, Monica B.; TEODORO, Walcy R.; ISAAC, Cesar; CAPELOZZI, Vera L.; GEMPERLI, RolfHuman amniotic membrane (HAM) is a biomaterial with biological properties beneficial to tissue repair, serving as a substrate for cell cultivation. Irradiation is used for tissue sterilization, but can damage the HAM structure. The objective of this paper was to construct a skin substitute, composed of human keratinocytes cultured on glycerolated HAMs, and to evaluate the influence radiation on subsequent cell culture growth. Four batches of HAMs were glycerolated, and half of them were radio-sterilzed with 25 kGy. Non-irradiated glycerolated HAM (ni-HAM) and irradiated glycerolated HAM (i-HAM) samples were then de-epithelized and analyzed using optical microscopy (Picrossirius staining), immunofluorescence and electron microscopy. Subsequently, keratinocytes were cultured on ni- and i-HAMs, and either immersed or positioned at the air-liquid interface. The basement membranes of the ni-HAM group remained intact following de-epithelialization, whereas the i-HAM group displayed no evidence or remnant presence of these membranes. Concerning the keratinocyte cultures, the ni-HAM substrate promoted the growth of multi-layered and differentiated epithelia. Keratinocytes cultured on i-HAM formed epithelium composed of three layers of stratification and discrete cell differentiation. The glycerolated HAM was compatible with cultured epithelia, demonstrating its potential as a skin substitute. Irradiation at 25 kGy caused structural damage to the amnion.
- COMPARISONS OF THE RESULTS OF PERIPHERAL NERVE DEFECT REPAIR WITH FIBRIN CONDUIT AND AUTOLOGOUS NERVE GRAFT: AN EXPERIMENTAL STUDY IN RATS(2016) LONGO, Marco Vinicius Losso; FARIA, Jose Carlos Marques De; ISAAC, Cesar; NEPOMUCENO, Andre Coelho; TEIXEIRA, Nuberto Hopfgartner; GEMPERLI, RolfIntroduction: The standard treatment for nerve defects is nerve autograft. There is no conduit available that provides the same regenerative capacity of nerve autograft. This study evaluated the histological and functional recovery of nerve defects treated with fibrin conduit in comparison to the nerve autograft, in a rat model. Method: A sciatic nerve injury model (10-mm defect) was performed in 20 Wistar rats, nerve defect was reconstructed using a fibrin conduit (n=10). A nerve autograft was used as control (n=10). The walking behavior was measured by footprint analysis at 4, 8, and 12 weeks and sciatic function index was determined. After 12 weeks, histological analysis was performed to evaluate the regenerated nerve and measured axonal density. The triceps surae muscle weight was also evaluated. Results: The fibrin conduit group showed less improvement in walking behavior compared to nerve autograft (-53 +/- 2 vs. -36 +/- 2; P<0.001 at 12 weeks). The fibrin conduit group presented axonal density of 40.0 axons/10.995 mu m2 and the nerve autograft group had 67.2 axons/10.995 mu m2 (P<0.001). The triceps surae muscle weight ratio of the fibrin conduit group was 41 +/- 3% versus 71 +/- 4% of the nerve autograft group (P<0.001). Conclusion: The fibrin conduit could be used for nerve reconstruction following peripheral nerve injury in the rat model. However, the functional recovery in the fibrin conduit repair group was worse than that in nerve autograft group and the nerve repair with the fibrin conduit has less myelinated fibers when compared to the repair with nerve autograft. (C) 2015 Wiley Periodicals, Inc.