Biomedical subjects

M Dadsetan

Publications and source records attributed to M Dadsetan.

3 recordsLinked to original sources

PubMed2003

In vivo biocompatibility and biodegradation of poly(ethylene carbonate).

Biodegradation and biocompatibility of poly(ethylene carbonate) (PEC) was examined using an in vivo cage implant system. Exudate analysis showed that PEC and PEC degradation products were biocompatible and induced minimal inflammatory and wound healing responses. Adherent foreign body giant cells (FBGCs) caused pitting on the PEC surface, which led to extensive degradation over time. Data obtained from molecular weight and examination of film cross-sections in the scanning electron microscope (SEM) indicated that PEC underwent surface erosion with no change to the remaining bulk. Attenuated total reflectance infrared (ATR-FTIR) spectroscopy was used to characterize the chemical degradation. Superoxide anion released from inflammatory cells appeared to initiate an "unzipping" mechanism of degradation by deprotonation of PEC hydroxyl end groups. The resulting alkoxide ion participated in a concerted mechanism involving water and the carbonate carbonyl, leading to elimination of ethylene glycol. Carbonate ions decomposed further with release of carbon dioxide to regenerate alkoxide ion.

Absorbable Implants↗

PubMed2001

In vitro studies of platelet adhesion on laser-treated polyethylene terephthalate surface.

In order to improve blood compatibility, the surfaces of polyethylene terephthalate (PET) were treated using CO2 pulsed and KrF excimer lasers. The physico-chemical characterization of the laser-treated PET surfaces was carried out through attenuated total reflectance infrared spectroscopy and contact-angle measurements. The hemocompatibility of the laser-irradiated PET films was examined in vitro to evaluate their capability of inducing platelet adhesion in comparison with unmodified PET. The number of adhered platelets was determined by lactate dehydrogenase (LDH) activity measurement. Platelet adhesion on the untreated PET was relatively high compared to the laser-treated samples. Laser irradiation of PET surface reduced the number of adherent platelets and prevented platelet spreading on the surface. Reduction of platelet adhesion was attributed to the change in morphology, chemical structure, and crystallinity of the PET surface due to laser irradiation with various numbers of pulses. The morphology of adhered platelets on the PET surfaces was investigated by scanning electron microscopy (SEM). The SEM observations were consistent with the results obtained from LDH activity measurement.

Biocompatible Materials↗

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↗