Navegando por Palavras-chave "Parylene"

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    A Novel Approach for Subretinal Implantation of Ultrathin Substrates Containing Stem Cell-Derived Retinal Pigment Epithelium Monolayer
    (Karger, 2012-01-01) Hu, Yuntao; Liu, Laura; Lu, Bo; Zhu, Danhong; Ribeiro, Ramiro; Diniz, Bruno [UNIFESP]; Thomas, Padmaja B.; Ahuja, Ashish K.; Hinton, David R.; Tai, Yu-Chong; Hikita, Sherry T.; Johnson, Lincoln V.; Clegg, Dennis O.; Thomas, Biju B.; Humayun, Mark S.; Univ So Calif; CALTECH; Univ Calif Santa Barbara; Peking Univ; Chang Gung Mem Hosp; Hosp Evangel Curitiba; Universidade Federal de São Paulo (UNIFESP)
    Objective: To evaluate the feasibility of a new technique for the implantation of ultrathin substrates containing stem cell-derived retinal pigment epithelium (RPE) cells into the subretinal space of retina-degenerate Royal College of Surgeon (RCS) rats. Methods: A platform device was used for the implantation of 4-mu m-thick parylene substrates containing a monolayer of human embryonic stem cell-derived RPE (hESC-RPE). Normal Copenhagen rats (n = 6) and RCS rats (n = 5) were used for the study. Spectral-domain optical coherence tomography (SD-OCT) scanning and histological examinations were performed to confirm placement location of the implant. hESC- RPE cells attached to the substrate before and after implantation were evaluated using standard cell counting techniques. Results: SD-OCT scanning and histological examination revealed that the substrates were precisely placed in the rat's subretinal space. the hESC-RPE cell monolayer that covered the surface of the substrate was found to be intact after implantation. Cell counting data showed that less than 2% of cells were lost from the substrate due to the implantation procedure (preimplantation count 2,792 +/- 74.09 cells versus postimplantation count 2,741 +/- 62.08 cells). Detailed microscopic examination suggested that the cell loss occurred mostly along the edges of the implant. Conclusion: With the help of this platform device, it is possible to implant ultrathin substrates containing an RPE monolayer into the rat's subretinal space. This technique can be a useful approach for stem cell-based tissue bioengineering techniques in retinal transplantation research. Copyright (c) 2012 S. Karger AG, Basel
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    Parylene scaffold for cartilage lesion
    (Springer, 2017) da Silveira Franciozi, Carlos Eduardo [UNIFESP]; Vangsness, Carleton Thomas, Jr.; Martinez, Juan Carlos; Rodger, Damien; Chou, Tzu-Chieh; Tai, Yu-Chong; Brant, Rodrigo [UNIFESP]; Wu, Ling; Abdalla, Rene Jorge [UNIFESP]; Han, Bo; Evseenko, Denis; Humayun, Mark
    Evaluate parylene scaffold feasibility in cartilage lesion treatment, introducing a novel paradigm combining a reparative and superficial reconstructive procedure. Fifteen rabbits were used. All animals had both knees operated and the same osteochondral lesion model was created bilaterally. The parylene scaffold was implanted in the right knee, and the left knee of the same animal was used as control. The animals were euthanized at different time points after surgery: four animals at three weeks, three animals at six weeks, four animals at nine weeks, and four animals at 12 weeks. Specimens were analyzed by International Cartilage Repair Society (ICRS) macroscopic evaluation, modified Pineda histologic evaluation of cartilage repair, and collagen II immunostaining. Parylene knees were compared to its matched contra-lateral control knees of the same animal using the Wilcoxon matched-pairs signed rank. ICRS mean +/- SD values for parylene versus control, three, six, nine and twelve weeks, respectively: 7.83 +/- 1.85 versus 4.42 +/- 1.08, p = 0.0005