ROLF GEMPERLI
Projetos de Pesquisa
Unidades Organizacionais
Departamento de Cirurgia, Faculdade de Medicina - Docente
Instituto Central, Hospital das Clínicas, Faculdade de Medicina
LIM/04 - Laboratório de Microcirurgia, Hospital das Clínicas, Faculdade de Medicina - Líder
Instituto Central, Hospital das Clínicas, Faculdade de Medicina
LIM/04 - Laboratório de Microcirurgia, Hospital das Clínicas, Faculdade de Medicina - Líder
3 resultados
Resultados de Busca
Agora exibindo 1 - 3 de 3
- Limited Efficacy of Adipose Stromal Cell Secretome-Loaded Skin-Derived Hydrogels to Augment Skin Flap Regeneration in Rats(2022) VRIEND, Linda; DONGEN, Joris A. van; SINKUNAS, Viktor; BROUWER, Linda A.; BUIKEMA, Henk J.; MOREIRA, Luiz F.; GEMPERLI, Rolf; BONGIOVANNI, Laura; BRUIN, Alain de; LEI, Berend van der; CAMARGO, Cristina P.; HARMSEN, Martin C.Insufficient vascularization is a recurring cause of impaired pedicled skin flap healing. The administration of adipose tissue-derived stromal cells' (ASCs') secretome is a novel approach to augment vascularization. Yet, the secretome comprised of soluble factors that require a sustained-release vehicle to increase residence time. We hypothesized that administration of a hydrogel derived from decellularized extracellular matrix (ECM) of porcine skin with bound trophic factors from ASCs enhances skin flap viability and wound repair in a rat model. Porcine skin was decellularized and pepsin-digested to form a hydrogel at 37 degrees C. Conditioned medium (CMe) of human ASC was collected, concentrated 20-fold, and mixed with the hydrogel. Sixty Wistar rats were included. A dorsal skin flap (caudal based) of 3 x 10 cm was elevated for topical application of DMEM (group I), a prehydrogel with or without ASC CMe (groups II and III), or ASC CMe (group IV). After 7, 14, and 28 days, perfusion was measured, and skin flaps were harvested for wound healing assessment and immunohistochemical analysis. Decellularized skin ECM hydrogel contained negligible amounts of DNA (11.6 +/- 0.6 ng/mg), was noncytotoxic and well tolerated by rats. Irrespective of ASC secretome, ECM hydrogel application resulted macroscopically and microscopically in similar dermal wound healing in terms of proliferation, immune response, and matrix remodeling as the control group. However, ASC CMe alone increased vessel density after 7 days. Porcine skin-derived ECM hydrogels loaded with ASC secretome are noncytotoxic but demand optimization to significantly augment wound healing of skin flaps.
- The influence of adipocyte-derived stem cells (ASCs) on the ischemic epigastric flap survival in diabetic rats(2021) CAMARGO, Cristina Pires; KUBRUSLY, Marcia Saldanha; MORAIS-BESTEIRO, Julio; HARMSEN, Martim Conrad; GEMPERLI, RolfPurpose: To assess the effects of adipocyte-derived stem cell (ASC)-injection on the survival of surgical flaps under ischemia in diabetic rats. Methods: Diabetes was induced in 30 male Wistar rats using streptozotocin (55 mg/kg). After eight weeks, epigastric flap (EF) surgery was performed. The animals were divided into control (CG), medium-solution (MG), and ASC groups. The outcomes were: the survival area (SA), the survival/total area rate (S/TR), and expression levels (EL) of genes: C5ar1, Icam1, Nos2, Vegf-a. Results: In the ASC group, compared to CG, we observed improved flap SA (CG-420 mm(2) vs. ASC-720 mm(2); p=0.003) was observed. The S/TR analysis was larger in the ASC group (78%) than the CG (45%). This study showed an increase in the Vegf-a EL in the ASC group (2.3) vs. CG (0.93, p=0.0008). The Nos2 EL increased four-fold in the ASC group compared to CG, and C5ar1 EL decreased almost two-fold in the ASC group vs. the CG (p=0.02). There was no difference among the groups regarding Icam1 EL. Compared to the MG, the ASC group had a bigger flap SA (720 mm(2) vs. 301 mm(2), respectively), a bigger S/TR (78% vs. 32%, p=0.06, respectively) and increased EL of Vegf-a (2.3 vs. 1.3, respectively). No difference between ASC-group and MG was seen regarding Nos2 (p=0.08) and C5ar1 (p=0.05). Conclusion: This study suggests that ASCs increase the survival of EF under IR in diabetic rats.
- A modified hydrogel production protocol to decrease cellular content(2022) BRAGA, Gabriela Catao Diniz; CAMARGO, Cristina Pires; HARMSEN, Martin Conrad; CORREIA, Aristides Tadeu; SOUZA, Sonia; SEELAENDER, Marilia; NUNES, Viviane Araujo; SANTOS, Jeniffer Farias dos; NERI, Elida Adalgisa; VALADAO, Iuri Cordeiro; MOREIRA, Luiz Felipe Pinho; GEMPERLI, RolfPurpose: To analyze the cytotoxicity and cell in porcine-derived decellularized skin matrix. Methods: We analyzed the effect of multiple decellularization processes by histological analysis, DNA quantification, and flow cytometry. Subsequently, we analyzed the most appropriate hydrogel concentration to minimize cytotoxicity on fibroblast culture and to maximize cell proliferation. Results: After the fourth decellularization, the DNA quantification showed the lowest DNA concentration (< 50 ng/mg). Histological analysis showed no cell components in the hydrogel. Moreover, hematoxylin and eosin showed a heterogeneous structure of collagen fibers. The best hydrogel concentration ranged from 3 to 25%, and there was no significant difference between the 24 hours and seven days. Conclusion: The process of hydrogel production was effective for removing cells and DNA elements. The best hydrogel concentration ranged from 3 to 25%.