Biomedical subjects

I Vural

Publications and source records attributed to I Vural.

4 recordsLinked to original sources

PubMed1995

Plug and seal: prevention of hypoxic cardiocyte death by sealing membrane lesions with antimyosin-liposomes.

The hallmark of cell death is the development of cell membrane lesions. Such lesions in the myocardium are usually associated with acute myocardial infarction. Minimizing myocardial necrosis by thrombolytic reperfusion therapy constitutes the only major treatment to date. We envisioned a method to seal these membrane lesions using immunoliposomes as a novel adjunctive approach. An antigen to intracellular cytoskeletal myosin in hypoxic embryonic cardiocytes is used as an anchoring site, and a specific antibody on immunoliposomes as the anchor to plug and to seal the membrane lesions. H9C2 cells were used because they are cardiocytes and are propagated in tissue culture and their viability may be assessed by various methods. Viability assessed by [3H]thymidine uptake in hypoxic cardiocyte cultures (n = 6 each) treated with antimyosin-immunoliposomes (3.26 +/- 0.483 x 10(6) c.p.m.) was similar to that of normoxic cells (3.68 +/- 0.328 x 10(6) c.p.m.), but was greater than those of untreated hypoxic cells (0.115 +/- 0.155 x 10(6) c.p.m.) or hypoxic cells treated with plain liposomes (1.140 +/- 0.577 x 10(6) c.p.m.). These results were reconfirmed by trypan blue exclusion and by fluorescent, confocal and transmission electron microscopy. They indicated that cell death in hypoxic cardiocytes can be prevented by targeted cell membrane sealing. This concept of cell salvage should be applicable in the prevention of cell death in different biological systems.

Animals↗

PubMedDate not supplied

Cyclophosphamide loaded albumin microspheres II. Release characteristics.

The purpose of this investigation was to evaluate the release characteristics of cyclophosphamide (CP) from glutaraldehyde stabilized human serum albumin microspheres, and to study the effect of the extent of cross-linking, the amount of the stabilizing agent and the size of the microspheres on the in vitro release of CP. Microspheres were prepared by emulsion polymerization method using two different volumes (0.1 and 0.7 ml) of glutaraldehyde solution (25 per cent) and two different crosslinking durations (15 min and 1 h). The resulting mean particle size of the microspheres also varied between 2.5 microns and 3.7 microns. The total CP content in microspheres was analysed from the surface drug and the entrapped drug.

Cross-Linking Reagents↗

PubMedDate not supplied

Decrease in the placental transfer of chloramphenicol when administered in albumin microspheres into rats.

Chloramphenicol is an antibiotic which can pass across the human placenta and has teratogenic effects in the foetus. When this antibiotic is entrapped in albumin microspheres and administered to pregnant rats intravenously its placental transport is significantly lowered when compared with that of free drug. Drug modifications such as entrapment are suggested as an alternative way to prevent harmful effects of drugs in case of consumption during pregnancy.

Animals↗

PubMedDate not supplied

Effect of encapsulation of chloramphenicol in albumin microspheres on its in vitro transfer across the human placenta.

The possibility of reducing drug transfer across the placenta was tested in two of our previous studies. The aim of those studies was to demonstrate an alternative method of drug application during pregnancy which we think would yield a dual benefit, i.e. protecting the foetus from the harmful effects of drugs while curing the mother. The present study was planned as a continuation of the testing of the same idea and we tried to see the effect of albumin microsphere encapsulation of chloramphenicol on its transfer across the human placenta in vitro. Microspheres containing chloramphenicol were prepared according to the method previously described. The mean per cent encapsulation of chloramphenicol in albumin microspheres was found to be 42 +/- 4.3 per cent (n = 5) and the mean size of the albumin microspheres was 3.08 +/- 0.6 mm. In vitro stability of the drug-carrying microspheres was measured by dialysing them at 37 degrees C for 24 h. Chloramphenicol was released from the microspheres gradually leaving about 50 per cent of the entrapped drug in the microspheres after 1.5 h. About 20 per cent of the chloramphenicol was retained in the microspheres at 24 h postincubation. The persistence of the antibacterial effect of the released chloramphenicol is confirmed by antibiogramme tests. In the perfusions the initial free drug concentration was kept at 100 mg/ml.(ABSTRACT TRUNCATED AT 250 WORDS)

Albumins↗