Genotyping of Chlamydia Abortus Using Multiple Loci Variable Number of Tandem Repeats Analysis Technique

Background: The correlation between various factors (geographical region, clinical incidence, and host type) and the genomic heterogeneity has been shown in several bacterial strains including Chlamydia abortus. Methods: The aim of this study was to survey the predominant types of C. abortus strains isolated from ruminants in Iran by the multiple loci variable number of tandem repeats (VNTR) analysis (MLVA) method. C. abortus infection was evaluated in a total of 117 aborted fetuses by real-time PCR. The isolation was done via the inoculation of the positive samples in chicken embryo and the L929 cell line. Genotyping was carried out by MLVA typing technique. Results: Forty samples (34.2%) were detected with C. abortus infection; however, chlamydial infection in ruminants of Charmahal/Bakhtiari (3 bovines and 35 sheep) was higher than that of Khuzestan (2 sheep). All MLVA types (MT1-MT8) were detected in the collected samples from Charmahal/Bakhtiari but only 2 types (MT1 and MT3) were reported in samples from Khuzestan. The main MT type was MT1 (32% of samples). Although in this study only 9 cow samples were investigated, they possessed similar clusters to those obtained from sheep (MT1 and MT6).Variation of type in sheep samples (MT1 to MT8) was more than that of bovine samples (MT1, and MT6); this can be attributed to the fact that more samples of sheep were studied as against the bovine samples. Conclusion: Although the difference between the detected same MT types in several animal species or between 2 geographic areas is significant, comprehensive studies are still needed. In Iran, due to traditional intercourse between animals of different provinces, the spread of other types is typically highly probable.

In Vitro Biocompatibility Evaluation of Nine Dermal Fillers on L929 Cell Line

Objective. Biomaterial research for soft tissue augmentation is an increasing topic in aesthetic medicine. Hyaluronic acid (HA) fillers are widely used for their low invasiveness and easy application to correct aesthetic defects or traumatic injuries. Some complications as acute or chronic inflammation can occur in patients following the injection. Biocompatibility assays are required for medical devices intended for human use, in order to prevent damages or injuries in the host. In this study, nine HA fillers were tested in order to evaluate their cytotoxicity and their effects on L929 cell line, according to the UNI EN ISO 10993 regulation. Methods. Extracts were prepared from nine HA fillers, and MTS viability assay was performed after 24 h, 48 h, and 72 h of exposure of cells to extracts. Cells cultured with HA filler extracts were monitored for up to 72 h, counted, and stained with haematoxylin/eosin in order to evaluate the cell proliferation rate and morphology. Results. None of the filler tested showed a cytotoxic effect. Two samples showed a higher vitality percentage and higher cell number while two samples showed a lower vitality percentage and lower cell number at 72 h. Conclusion. Data obtained suggest that although examined fillers are not cytotoxic, they show different effects on the in vitro cell proliferation rate. In vitro studies of medical devices could lead to important implications since these could aid to predict effects about their in vivo application. These easy and rapid assays could be useful to test new materials intended for human use avoiding animal tests.

Exploring the Gelation Mechanisms and Cytocompatibility of Gold (III)-Mediated Regenerated and Thiolated Silk Fibroin Hydrogels

Accelerating the gelation of silk fibroin (SF) solution from several days or weeks to minutes or few hours is critical for several applications (e.g., cell encapsulation, bio-ink for 3D printing, and injectable controlled release). In this study, the rapid gelation of SF induced by a gold salt (Au3+) as well as the cytocompatibility of Au3+-mediated SF hydrogels are reported. The gelation behaviors and mechanisms of regenerated SF and thiolated SF (tSF) were compared. Hydrogels can be obtained immediately after mixing or within three days depending on the types of silk proteins used and amount of Au3+. Au3+-mediated SF and tSF hydrogels showed different color appearances. The color of Au-SF hydrogels was purple-red, whereas the Au-tSF hydrogels maintained their initial solution color, indicating different gelation mechanisms. The reduction of Au3+ by amino groups and further reduction to Au by tyrosine present in SF, resulting in a dityrosine bonding and Au nanoparticles (NPs) production, are proposed as underlying mechanisms of Au-SF gel formation. Thiol groups of the tSF reduced Au3+ to Au+ and formed a disulfide bond, before a formation of Au+-S bonds. Protons generated during the reactions between Au3+ and SF or tSF led to a decrease of the local pH, which affected the chain aggregation of the SF, and induced the conformational transition of SF protein to beta sheet. The cytocompatibility of the Au-SF and tSF hydrogels was demonstrated by culturing with a L929 cell line, indicating that the developed hydrogels can be promising 3D matrices for different biomedical applications.

Assessment of cytotoxic and antimicrobial activity of selected gingival haemostatic agents – in vitro study

Purpose: The present research aimed to determine whether and how the aluminium chloride – based materials affect the cell line of the bacterial line and fungi. Methods: Cytotoxicity of haemostatic astringents: Alustat (liquid), Alustat (gel), Alustat (foam), Alustin, Hemostat, Racestyptine and Traxodent containing AlCl3 was conducted on L929 cell line with the use of MTT and SRB assays. The antimicrobial activity (CFU and MIC) against C. albicans, S. mutans, L. rhamnosus was determined. Results: In the MTT results, cell viability for all agents were very low. In SRB, the lowest cytotoxicity was demonstrated for Hemostat and Alustat (foam), Traxodent and Racestyptine. Total reduction of the CFU of S. mutans was observed. Alustat (gel) and Alustat (liquid) completely inhibited the growth of C. albicans, S. mutans and L. rhamnosus. Conclusions: The viability of L929 cells obtained in the SRB assay is more reliable than that obtained in the MTT assay, in the case of gingival haemostatic agents.