The influence of amniotic membrane extracts on cell growth depends on the part of membrane and childbirth mode selected: a proof-of-concept study.

OBJECTIVE: The amniotic membrane (AM) is a rich source of biologically active factors, important for wound healing and is widely used in various clinical applications, including tissue engineering, reconstructive surgery and wound management. The aim of the present proof-of-concept study was to assess the influence of amniotic membrane extracts on in vitro proliferation of main cells involved in tissue regeneration. The assessment was done in regards to the content of selected biologically active factors in amniotic membrane extracts. METHOD: The quantitative analysis of EGF, TGF-ß and TIMP-1 in tested samples was assayed by enzyme-linked immunosorbent assay (ELISA) tests. The influence of amniotic membrane extracts on proliferation of keratinocytes (HaCaT), fibroblasts (Wi-38) and endothelial cell lines (HECa-10) was assessed using a colorimetric tetrazolium salt reduction assay. RESULTS: In all of the amnion samples high amounts of EGF, TGF-ß and TIMP-1 were detected. However, the content of these factors varied between placental and cervical portions of the same membrane. Moreover, various concentrations of biologically active factors between physiological at-term delivery and caesarean section-derived membranes were also observed. All of the assessed amnion extracts stimulated proliferation of HaCaT and Wi-38 cells, although samples prepared from caesarean section-derived cervical portion of amniotic membrane stimulated more proliferation of keratinocytes than of fibroblasts. In contrast to HaCaT and Wi-38 cells, proliferation of HECa-10 cell line was inhibited by all tested extracts. CONCLUSION: The results of our proof-of-concept study confirm that biological dressings prepared from amniotic membrane, especially its placental portion, since they stimulated both fibroblasts and keratinocytes, may provide relevant support for wound healing. On the other hand, dressings prepared from caesarean section-derived cervical portion of amniotic membrane, since they stimulate mainly epidermal cells, may be suitable for some specific applications, where more selective action is required, such as in ocular surgery. However, verification of this observation requires further studies.

The direct inhibition of MMP-2 and MMP-9 by an enzyme alginogel: a possible mechanism of healing support for venous leg ulcers.

Flaminal Forte is an enzyme alginogel,whose activity depends on the absorption and binding of matrix metalloproteinases (MMPs), which are known to play a crucial role in delayed wound healing. The aim of the study was to evaluate the influence of Flaminal on MMP-2/-9 activity in ulcer exudate, ex vivo. Eight patients with bilateral venous leg ulcers were treated for 4 weeks with Flaminal Forte covered by hydrocolloid ('F' wounds), or with hydrocolloid alone ('H' wounds) as a reference control. Clinical assessment did not reveal any differences between F and H wounds regarding surface reduction and general wound condition. Nevertheless, although non-significant, there was a visible difference in peri-wound skin appearance in F wounds, as compared to H wounds. The wound exudate contained high MMP-2/-9 levels, which gradually decreased as wounds healed. The attenuation of MMPs was stronger in F than in H exudate, however, in standard zymography this difference appeared non-significant. Real-time zymography revealed that Flaminal mediated a powerful direct inhibition of gelatinolytic activity of wound exudate and of recombinant MMP-2/-9 in vitro.