Biomedical subjects

M Daliri

Publications and source records attributed to M Daliri.

4 recordsLinked to original sources

PubMed2001

Cell behavior on laser surface-modified polyethylene terephthalate in vitro.

This work has been undertaken to study the cell behavior of L929 fibroblasts on the laser irradiated polyethylene terephthalate (PET) surface. To modify the surface properties of the PET, CO2 pulsed laser at the wavelength of 9.25 microm and KrF excimer laser at 248 nm with various number of pulses were used. Laser irradiation caused some changes in the chemical and physical properties of the laser-treated film surfaces, which were evaluated using different techniques. These changes may affect the cell adhesion and growth on the laser-treated PET. Therefore, cell attachment and spreading were investigated on the laser-treated PET in vitro. The data from in vitro assays showed the fibroblast cells were attached and proliferated extensively on the CO2 and KrF laser-treated films in comparison with the unmodified PET. The results obtained from the cell behavior studies revealed that surface morphology and wettability affected cell adhesion and spreading on the laser-treated PET.

Animals↗

PubMed2001

Isocyanate-terminated urethane prepolymer as bioadhesive material: evaluation of bioadhesion and biocompatibility, in vitro and in vivo assays.

Attempts have been made to evaluate the degree of bioadhesion and biocompatibility of a synthesized urethane prepolymer with specially tailored microstructure. Wetting behaviour and extent of interfacial adhesion of the prepared prepolymer towards biological substrates were examined by in vitro methods. The former was carried out by measuring the contact angle between drops of the prepolymer liquid and a biological surface, while the latter was determined from the force between the prepolymer and tissue model or mucus. The obtained results exhibited good tissue wettability and bioadhesion by the prepolymer. Preliminary evaluation of biocompatibility for the uncatalytically cured prepolymer films was performed by cytotoxicity and histotoxicity experiments. Results showed a significant growth for the adhered L929 fibroblast cells within a period of 5 days incubation. Also, no severe inflammatory tissue response towards the samples implanted in rabbit for 16 weeks was seen. These observations can support the potentiality of the designed urethane prepolymer to be applied as hemostatic agent.

Adhesiveness↗

PubMed1999

Expression of growth factor ligand and receptor genes in preimplantation stage water buffalo (Bubalus bubalis) embryos and oviduct epithelial cells.

The temporal pattern of expression of genes for several growth factor ligands and receptors was examined in preimplantation water buffalo embryos and oviduct epithelial cells using RT-PCR. The identity of the resulting PCR products was confirmed by their expected size, restriction analysis, Southern blot hybridization and nucleotide sequence analysis. Preimplantation stage embryos from the one-cell to the blastocyst stage were derived after maturation, fertilization and culture of oocytes in vitro. Expression of members of the insulin-like growth factor (IGF) family was observed predominantly in preimplantation stage embryos and oviduct epithelial cells. Similarly, transcripts encoding insulin and IGF-I receptors were detected at each stage of embryonic development. The mRNA transcript of the IGF-I receptor was not detected in oviduct epithelial cells, but a prominent band corresponding to the insulin receptor was observed. Insulin and IGF-II mRNA were expressed as maternal transcripts that were not detected at the two- to four-cell stage but were present as zygotic transcripts at the eight-cell stage. Transcripts encoding IGF-I were detected in oviduct epithelial cells, but were not observed in any of the preimplantation stage embryos. Transforming growth factor (TGF) alpha and beta and epidermal growth factor mRNA transcripts were not detected in any of the preimplantation stage embryos. These results indicate that IGF-I acts via a paracrine mechanism to promote growth and development of preimplantation water buffalo embryos. Similarly, IGF-II appears to act through a heterologous autocrine mechanism via the IGF-I or the insulin receptor. Furthermore, the presence of TGF-alpha in oviduct epithelial cells indicates that it may have a critical role during development.

Amino Acid Sequence↗

PubMed1996

Differential cleavage and developmental rates and their correlation with cell numbers and sex ratios in buffalo embryos generated in vitro.

In vitro matured and fertilized buffalo oocytes were co-cultured with buffalo oviductal epithelial cells (BOEC) in CRlaa medium. Cleaved embryos were separated according to the time of completion of first cleavage (i.e., before 30 h and after 30 h post insemination) and cultured for 5 to 10 d and allowed to develop to the blastocyst stage. Zygotes cleaving before 30 h were termed fast-cleaving while those cleaving after 30 h were termed slow-cleaving. The results indicated that fast-cleaving embryos are more likely to develop into blastocysts (25%) than slow-cleaving embryos (7.8%). The quality and viability of fast-cleaving and fast-developing blastocysts was found to be better than that of slow-cleaving, slow-developing blastocysts as judged by cell numbers (67.7 +/- 3.7 vs 35.2 +/- 2.1). However, the mitotic index was not different between the 2 groups. The sex of fast-developing and slow-developing blastocysts was determined via the polymerase chain reaction (PCR) to correlate the rate of embryonic development with the sex ratio of the embryos. Embryos produced by Bull 293 and Bull M-82, irrespective of their being fast or slow-developing, gave rise to more females and males, respectively. From these results, we suggest that there may be a sire effect on sex ratio of in vitro produced buffalo embryos.

Journal Article↗