In vitro evaluation ofin situ gels as short term vitreous substitutes

One promising skin substitutes in the wound healing are the bacterial cellulose membranes (BCM). These biomaterials present nanostructures composed of microfibrils capable of forming three-dimensional pores that allow cell. In association with these biopolymers, several treatments are used, such as enrichment by growth factors and/or the application of photobiomodulation (PBM). Therefore, the aim of this study was to investigate the viability, proliferation and cytotoxicity of a BCM (culturing of Komagataeibacter xylinus), with or without FGF-2 in association with PBM therapy. In the characterization of BCM we saw that the membrane does not show great variations in pH and with the scanning electron microscopy it was possible to observe that the BCM has a denser and a porous side that allows the adhesion of fibroblasts, confirmed by histological staining and DAPI/Phalloidin. In vitro evaluation showed that the immunofluorescence (CaAM/EthD-1) for live and dead cells presented, in the groups with combined treatment at long-term of PBM and FGF-2, a greater quantity of live cells than with these isolated treatments and/or at short-term. However, in the short-term of combined treatment PBM and FGF-2 supplementation, fibroblasts and macrophages were more viable by Alamar Blue, in direct and indirect contact respectively. The comet assay did not show cytotoxicity for DNA damage in fibroblasts indirect contact with membrane extract. The results highlight the potential of association of FGF-2 supplementation with the application of PBM for use with BCM, due to its promoted increased cell density at long-term and improved viability in fibroblasts and macrophages at short-term.

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Ultrastructural investigations of MDL 19,660-induced effects on the canine platelet and megakaryocyte

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100159412 ◽

1990 ◽

Vol 48 (3) ◽

pp. 374-375

Author(s):

D.E. Loudy ◽

J. Sprinkle-Cavallo ◽

J.T. Yarrington ◽

F.Y. Thompson ◽

J.P. Gibson

Keyword(s):

Antidepressant Drug ◽

Beagle Dogs ◽

Long Term Effects ◽

Short Term ◽

Platelet Counts ◽

Toxicological Studies ◽

Induced Aggregation ◽

Internal Architecture

Previous short term toxicological studies of one to two weeks duration have demonstrated that MDL 19,660 (5-(4-chlorophenyl)-2,4-dihydro-2,4-dimethyl-3Hl, 2,4-triazole-3-thione), an antidepressant drug, causes a dose-related thrombocytopenia in dogs. Platelet counts started to decline after two days of dosing with 30 mg/kg/day and continued to decrease to their lowest levels by 5-7 days. The loss in platelets was primarily of the small discoid subpopulation. In vitro studies have also indicated that MDL 19,660: does not spontaneously aggregate canine platelets and has moderate antiaggregating properties by inhibiting ADP-induced aggregation. The objectives of the present investigation of MDL 19,660 were to evaluate ultrastructurally long term effects on platelet internal architecture and changes in subpopulations of platelets and megakaryocytes.Nine male and nine female beagle dogs were divided equally into three groups and were administered orally 0, 15, or 30 mg/kg/day of MDL 19,660 for three months. Compared to a control platelet range of 353,000- 452,000/μl, a doserelated thrombocytopenia reached a maximum severity of an average of 135,000/μl for the 15 mg/kg/day dogs after two weeks and 81,000/μl for the 30 mg/kg/day dogs after one week.

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