Estudo comparativo da inibição da proliferação de fibroblastos in vitro na conjuntiva utilizando mitomicina C e ciclofosfamida / Comparative study of inhibition of fibroblasts proliferation in vitro in the conjunctiva using mitomycin and ciclophosphamide

RESUMO Objetivo: Avaliar a inibição da proliferação de fibroblastos in vitro das conjuntivas obtidas através de exérese de pterígios de pacientes utilizando mitomicina C (MMC) e ciclofosfamida (CF). Métodos: Os pterígios foram retirados de 7 pacientes e submetidos a cultivo celular. Após o cultivo, 3 fragmentos de dimensões iguais deste material foram colhidos de áreas adjacentes do pterígio removido de cada paciente. Eles foram randomicamente selecionados de tal forma que: um fragmento de cada paciente foi exposto: ao meio de cultura (grupo controle), a MMC e a CF por igual período de tempo nas concentrações de 0,4 mg/ml e 10 mg/ml respectivamente. Após este período realizou-se a contagem celular de fibroblastos destes 3 grupos. Cada grupo continha 7 fragmentos. Resultados: Com a utilização da MMC tivemos uma taxa de 95% da inibição da proliferação dos fibroblastos, enquanto com a CF 100%. Conclusões: Ambas as drogas apresentaram elevada taxa da inibição da proliferação de fibroblastos, porém a CF apresentou inibição maior que a MMC.

Abstract Objective: To evaluate the inhibition of fibroblast proliferation in vitro of conjunctiva obtained by excision of pterygium from patients using mitomycin (MMC) and cyclophosphamide (CF). Methods: Pterygiums were removed from 7 patients and subjected to cell culture. After cell cultivation, 3 fragments of equal dimensions of these tissues were collected from adjacent areas of each patient removed pterygium. They were randomly selected in such a way that one fragment of each patient was exposed to: the culture medium (group control), to MMC and to CF for an equal period of time at concentrations of 0,4 mg/dl and 10 mg/dl respectively. After this period, the fibroblast cell count of these groups were performed. Each group had seven fragments. Results: With the use of MMC we had a 95% rate of inhibition of fibroblast proliferation, while with CF 100%. Conclusion: Both drugs showed a high rate of inhibition of fibroblast proliferation, but CF showed greater inhibition than MMC.

The Effect of Hyaluronic Acid on Fibroblast Proliferation in Vitro and Skin Wound Healing in Vivo

It is not determined yet whether hyaluronic acid up- regulates or down-regulates wound healing. This study was designed to define the effect of hyaluronic acid on proliferation of human dermal fibroblasts in vitro and on skin wound closing in vivo. Fibroblasts were isolated from the dermis of adults and cultivated in the presence of either one of 6 concentrations of hyaluronic acid(0, 0.1, 0.2, 0.5, 1.0, 2.0 mg/ml). The fibroblasts were seeded at 2.0 x 10(4) cells/well in Dulbecco's Modified Eagle's Medium/Ham's F-12 nutrient including 10% fetal bovine serum with either one of 6 different concentrations of hyaluronic acid in 24-well plates. The cells were incubated for 6 days. All concentrations of hyaluronic acid stimulated the proliferation of fibroblasts. The best proliferation was seen at 0.2 mg/ml of hyaluronic acid concentration(p = 0.01). For in vivo study, 10 white rats were used. A 5 mm round punch was employed to excise skin and subcutaneous tissue at eight sites on the back. After creating 8 open wounds, 8 concentrations(0, 0.1, 0.2, 0.5, 1.0, 2.0, 5.0, 10.0 mg/ml) of hyaluronic acid were applied. The degrees of wound closing were compared the 6th day under light microscope. Low concentration of hyaluronic acid(0 - 2.0 mg/ml) stimulated the wound closing. However, high concentration of hyaluronic acid(5.0 -10.0 mg/ml) delayed the wound closing. The best wound closing was seen at 0.5 mg/ml of hyaluronic acid (p = 0.032). These results demonstrated that hyaluronic acid influenced human dermal fibroblast proliferation and the skin wound closing in rats, and its concentration was critically important factor.