OBJECTIVE: To investigate the most effective method to promote human embryonic lung fibroblast proliferation, we established several novel local fibrin-gel delivery systems, which could continuously release multiple growth factors in vitro. METHODS: Multiple growth factors, including platelet-derived growth factor (PDGF), vascular endothelial growth factor (VEGF), transforming growth factor (TGF) and epidermal growth factor (EGF) were added to fibrinogen solutions. These multiple growth-factor-containing fibrinogen solutions were converted to fibrin gel using thrombin to establish a delivery system. The kinetics and dissolution curves of the different fibrin-gel delivery systems were determined by daily measurement of the dissolved collagen volume. Human embryonic lung fibroblasts were randomly divided into 2 groups: the growth-factors (group A) and the non-growth-factors groups (group B). Based on the fibrin-gel shape, groups A and B were both randomly divided into 4 sub-groups; the fully-covered fibrin-gel, island fibrin-gel, scattered punctiform fibrin-gel and medium without fibrin-gel control groups. Cell proliferation was determined by cell counting and cell viability using the methyl thiazolyl tetrazolium (MTT) assay. Cell proliferation rate was measured by MTT. RESULTS: (1) The peak of growth factors releasing from gel of island group was 8.2 ± 0.8 days, while that of scattered punctiform group was 8.0 ± 1.0 days, and that of the fully-covered fibrin-gel group was 9.8 ± 0.4 days. The trend of growth factor releasing was significantly different among groups (F = 31.054, P < 0.05). There was no statistical difference in the release kinetics between the island group and the scattered punctiform group ( t = 1. 000, P > 0. 05). The peak of growth factors releasing from gel of the fully-covered fibrin-gel group was later than that of the island groups and the scattered punctiform fibrin-gel group (t = 6.820, P < 0.01). (2) The cell proliferation rate of island gel containing growth factors subgroup (107.6 ± 1.1) % grew more rapidly than island gel without growth factors subgroup (73.2 ± 2.2) % (F = 375.29, P < 0.01). The cell proliferation rate of the scattered punctiform gel containing growth factors subgroup (141.2 ± 1.8) % grew more rapidly than the scattered punctiform gel without growth factors subgroup (106.0 ± 2.8)% (F = 2274.48, P < 0.01). (3) The trend of growth factor releasing of the scattered punctiform group was significantly faster than that of the island group (F = 12.392, P < 0.01). CONCLUSION: (1) Multiple growth factors, including PDGF, TGF, VEGF and EGF, stimulate human embryonic lung fibroblast growth and proliferation. (2) The enhancement effect of the scattered punctiform fibrin-gel multiple growth-factor-releasing system on cell growth and proliferation was greater compared with the island fibrin-gel multiple growth-factor-releasing system.
RCT Entities:
OBJECTIVE: To investigate the most effective method to promote humanembryonic lung fibroblast proliferation, we established several novel local fibrin-gel delivery systems, which could continuously release multiple growth factors in vitro. METHODS: Multiple growth factors, including platelet-derived growth factor (PDGF), vascular endothelial growth factor (VEGF), transforming growth factor (TGF) and epidermal growth factor (EGF) were added to fibrinogen solutions. These multiple growth-factor-containing fibrinogen solutions were converted to fibrin gel using thrombin to establish a delivery system. The kinetics and dissolution curves of the different fibrin-gel delivery systems were determined by daily measurement of the dissolved collagen volume. Humanembryonic lung fibroblasts were randomly divided into 2 groups: the growth-factors (group A) and the non-growth-factors groups (group B). Based on the fibrin-gel shape, groups A and B were both randomly divided into 4 sub-groups; the fully-covered fibrin-gel, island fibrin-gel, scattered punctiform fibrin-gel and medium without fibrin-gel control groups. Cell proliferation was determined by cell counting and cell viability using the methyl thiazolyl tetrazolium (MTT) assay. Cell proliferation rate was measured by MTT. RESULTS: (1) The peak of growth factors releasing from gel of island group was 8.2 ± 0.8 days, while that of scattered punctiform group was 8.0 ± 1.0 days, and that of the fully-covered fibrin-gel group was 9.8 ± 0.4 days. The trend of growth factor releasing was significantly different among groups (F = 31.054, P < 0.05). There was no statistical difference in the release kinetics between the island group and the scattered punctiform group ( t = 1. 000, P > 0. 05). The peak of growth factors releasing from gel of the fully-covered fibrin-gel group was later than that of the island groups and the scattered punctiform fibrin-gel group (t = 6.820, P < 0.01). (2) The cell proliferation rate of island gel containing growth factors subgroup (107.6 ± 1.1) % grew more rapidly than island gel without growth factors subgroup (73.2 ± 2.2) % (F = 375.29, P < 0.01). The cell proliferation rate of the scattered punctiform gel containing growth factors subgroup (141.2 ± 1.8) % grew more rapidly than the scattered punctiform gel without growth factors subgroup (106.0 ± 2.8)% (F = 2274.48, P < 0.01). (3) The trend of growth factor releasing of the scattered punctiform group was significantly faster than that of the island group (F = 12.392, P < 0.01). CONCLUSION: (1) Multiple growth factors, including PDGF, TGF, VEGF and EGF, stimulate humanembryonic lung fibroblast growth and proliferation. (2) The enhancement effect of the scattered punctiform fibrin-gel multiple growth-factor-releasing system on cell growth and proliferation was greater compared with the island fibrin-gel multiple growth-factor-releasing system.