Air Plasma Functionalization of Electrospun Nanofibers for Skin Tissue Engineering.

Nowadays, gelatin, a molecular derivative of collagen, has gained increasing interest in tissue engineering applications due to excellent biocompatibility, biodegradability, availability, process simplicity, and low costs. In this study, we fabricated tannic acid-crosslinked gelatin nanofibers by electrospinning method. In order to increase the bio-functionality of scaffolds, they were exposed to the atmospheric air plasma. Several analytical tools were used for evaluation of nanofibers including scanning electron microscopy (SEM), atomic force microscopy (AFM), attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy, X-ray diffraction (XRD), and water contact angle equipment (CA) together with biocompatibility study using fibroblast cells. Results demonstrated that atmospheric air plasma is not only able to improve the hydrophilicity of nanofibers but it also improves the bio-functionality against human skin fibroblast cells. Hence, we recommend atmospheric air plasma pre-treatment approach for the surface functionalization of gelatin nanofibers for skin tissue engineering applications.

Argon and Argon-Oxygen Plasma Surface Modification of Gelatin Nanofibers for Tissue Engineering Applications.

In the present study, we developed a novel approach for functionalization of gelatin nanofibers using the plasma method for tissue engineering applications. For this purpose, tannic acid-crosslinked gelatin nanofibers were fabricated with electrospinning, followed by treatment with argon and argon-oxygen plasmas in a vacuum chamber. Samples were evaluated by using scanning electron microscopy (SEM), atomic force microscopy (AFM), attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy, contact angle (CA) and X-ray diffraction (XRD). The biological activity of plasma treated gelatin nanofibers were further investigated by using fibroblasts as cell models. SEM studies showed that the average diameter and the surface morphology of nanofibers did not change after plasma treatment. However, the mean surface roughness (RMS) of samples were increased due to plasma activation. ATR-FTIR spectroscopy demonstrated several new bands on plasma treated fibers related to the plasma ionization of nanofibers. The CA test results stated that the surface of nanofibers became completely hydrophilic after argon-oxygen plasma treatment. Finally, increasing the polarity of crosslinked gelatin after plasma treatment resulted in an increase of the number of fibroblast cells. Overall, results expressed that our developed method could open new insights into the application of the plasma process for functionalization of biomedical scaffolds. Moreover, the cooperative interplay between gelatin biomaterials and argon/argon-oxygen plasmas discovered a key composition showing promising biocompatibility towards biological cells. Therefore, we strongly recommend plasma surface modification of nanofiber scaffolds as a pretreatment process for tissue engineering applications.

Prevalence of asthma in children of chemical warfare victims.

OBJECTIVE: Exposure of DNA to sulfur mustard gas may increase the inheritance of asthma in chemical warfare victims' (CWV) offspring. The objective of this study was to determine the prevalence of asthma in children of CWV and compare it to asthmatic children in the general population. METHODS: Four hundred and nine children from 130 CWV fathers and 440 children from 145 asthmatic parents from two cities in Iran participated in this study. The prevalence of asthma was determined by standard questionnaire released for epidemiological survey of asthma in children and compared between two groups. FINDINGS: The prevalence of asthma in the CWV group was 15%; this was not significantly different from the control group (12.5%). The children of the CWV group reported a significantly greater incidence of wheezing (1.2±3.1 attacks) per year, but the control group reported more severe attacks leading to speech difficulties (3%) and coughing (7%). Regression analysis showed that with increasing family size in the control group, the number of subjects suffering from asthmatic symptoms decreases significantly (r=0.86, P=0.001). CONCLUSION: Chemical agents may increase the prevalence of asthma in the offspring of CWV.