Characterization of the Antibacterial Activity of an SiO2 Nanoparticular Coating to Prevent Bacterial Contamination in Blood Products

Technological innovations and quality control processes within blood supply organizations have significantly improved blood safety for both donors and recipients. Nevertheless, the risk of transfusion-transmitted infection remains non-negligible. Applying a nanoparticular, antibacterial coating at the surface of medical devices is a promising strategy to prevent the spread of infections. In this study, we characterized the antibacterial activity of an SiO2 nanoparticular coating (i.e., the “Medical Antibacterial and Antiadhesive Coating” [MAAC]) applied on relevant polymeric materials (PM) used in the biomedical field. Electron microscopy revealed a smoother surface for the MAAC-treated PM compared to the reference, suggesting antiadhesive properties. The antibacterial activity was tested against selected Gram-positive and Gram-negative bacteria in accordance with ISO 22196. Bacterial growth was significantly reduced for the MAAC-treated PVC, plasticized PVC, polyurethane and silicone (90–99.999%) in which antibacterial activity of ≥1 log reduction was reached for all bacterial strains tested. Cytotoxicity was evaluated following ISO 10993-5 guidelines and L929 cell viability was calculated at ≥90% in the presence of MAAC. This study demonstrates that the MAAC could prevent bacterial contamination as demonstrated by the ISO 22196 tests, while further work needs to be done to improve the coating processability and effectiveness of more complex matrices.

The Effect of Autophagy Induction in Oncolytic Reovirus Replication in Mesenchymal Stem Cells

Background and Aims: Oncolytic reoviruses can infect and kill malignant cells while sparing their normal counterparts. Reoviral infection can induce or activate autophagy, even though metformin can induce autophagy. Identifying and regulating the cellular pathways important for reovirus replication and oncolysis can improve targeted-biological therapies for cancer. Here, the autophagic process was triggered via metformin, and we investigated the effect of autophagy activation on oncolytic reovirus replication in mesenchymal stem cells as primary cells and L929 cell lines. Materials and Methods: Adipose derived mesenchymal stem cells (AD-MSCs) and L929 cells were treated with metformin and reovirus type-3 strain Dearing (T3D). Twenty-four hours after infection, the viability of AD-MSCs and L929 cells were examined by MTT assay. Also, the effect of metformin-induced autophagy in the reovirus replication in these cells was determined by real-time polymerase-chain-reaction. Results: Our results show that treatment with metformin and reovirus reduced the viability of the cells compared to treatment with metformin or reovirus alone in both cells. Also, coadministration of metformin and reovirus significantly decreased the relative expression level of the Beclin-1 gene compared to treatment with metformin in both cells. However, the expression level of the reovirus L3 gene after treatment with metformin and reovirus in L929 cells increased significantly compared to AD-MSCs. Conclusion: Our data suggest that metformin-induced autophagy enhances reoviral replication in AD-MSCs and L929 cells. These findings represent the role of autophagy induction in facilitating reovirus replication and contribute to a better understanding of reovirus-host interactions.

The Effects of Curcumin Nanoparticles Incorporated into Collagen-Alginate Scaffold on Wound Healing of Skin Tissue in Trauma Patients

Wound healing is a biological process that is mainly crucial for the rehabilitation of injured tissue. The incorporation of curcumin (Cur) into a hydrogel system is used to treat skin wounds in different diseases due to its hydrophobic character. In this study, sodium alginate and collagen, which possess hydrophilic, low toxic, and biocompatible properties, were utilized. Collagen/alginate scaffolds were synthesized, and nanocurcumin was incorporated inside them; their interaction was evaluated by FTIR spectroscopy. Morphological studies investigated structures of the samples studied by FE-SEM. The release profile of curcumin was detected, and the cytotoxic test was determined on the L929 cell line using an MTT assay. Analysis of tissue wound healing was performed by H&E staining. Nanocurcumin was spherical, its average particle size was 45 nm, and the structure of COL/ALG scaffold was visible. The cell viability of samples was recorded in cells after 24 h incubation. Results of in vivo wound healing remarkably showed CUR-COL/ALG scaffold at about 90% (p < 0.001), which is better than that of COL/ALG, 80% (p < 0.001), and the control 73.4% (p < 0.01) groups at 14 days/ The results of the samples’ FTIR indicated that nanocurcumin was well-entrapped into the scaffold, which led to improving the wound-healing process. Our results revealed the potential of nanocurcumin incorporated in COL/ALG scaffolds for the wound healing of skin tissue in trauma patients.

Novel 2-Nitroimidazole and imidazooxazole Derivatives and Their Activity Against Trypanosoma cruzi and Mycobacterium tuberculosis

Background: Tuberculosis (TB) is one of the top ten causes of death worldwide, while Chagas disease (CD) is the parasitic disease that kills the largest number of people in the Americas. TB is the leading cause of death for patients with AIDS; it kills 1.5 million people and causes 10 million new cases every year. The lack of newly developed chemotherapeutic agents and insufficient access to health care services for a diagnosis increase the incidence of multidrug-resistant TB (MDRTB) cases. Although CD was identified in 1909, the chronic stages of the disease still lack adequate treatment. Objective: The purpose of this work was to design and synthesize two new series of 2-nitroimidazole 5a-e and imidazooxazoles 6a-e with 1H-1,2,3-triazolil nucleus and evaluate their activities against Tc and Mycobacterium tuberculosis (Mtb). Methods: Two series of five compounds were synthesized in a 3 or 4-step route in moderated yields, and their structures were confirmed by NMR spectral data analyses. The in vitro antitrypanosomal evaluation of products was carried out in an intracellular model using L929 cell line infected with trypomastigotes and amastigote forms of Tc of β-galactosidase-transfected Tulahuen strain. Their antimycobacterial activity was evaluated against Mtb strain H37Rv. Results: In general, 2-nitroimidazolic derivatives proved to be more potent in regard to antitrypanocidal and antimycobacterial activity. The non-cytotoxic 2-nitroimidazole derivative 5b was the most promising with a half maximum inhibitory concentration of 3.2 µM against Tc and a minimum inhibitory concentration of 65.3 µM against Mtb. Conclusion: Our study reinforced the importance of 2-nitroimidazole and 1H-1,2,3-triazole nuclei in antimicrobial activity. In addition, derivative 5b proved to be the most promising, presenting important activity against Tc and Mtb and could be used as a starting point for the development of new agents against these diseases.

Production and characterization of biocompatible nanofibrous scaffolds made of β-sitosterol loaded polyvinyl alcohol/tragacanth gum composites

Electrospun polyvinyl alcohol and Tragacanth Gum were used to develop nanofibrous scaffolds containing poorly water-soluble beta-sitosterol. Different Concentration and Ratio of Polymeric composite: (10%) of β-S concentration in (PVA) 8 %, (TG) 0.5%, and 1% respectively were added, prepared and electrospun. The methods have included four parameters (Solution concentration, feeding rate, voltage, and distance of the collector to the tip of the needle) for designing and compared the nanofibers' average diameters. The nanofibers collected were identified via SEM, FTIR, and XRD measurements. A contact angle measurement described the hydrophilicity of the scaffold. MTT test was assessed for obtained nanofibers by using L929 normal fibroblast cells. The %age of mechanical strength, porosity, and deterioration of the scaffolds was well discussed. The average nanofibre ranged from 63 ± 20 nm to 97 ± 46 nm in diameters. The nanofibers loaded with β-S were freely soluble in water and displayed a short release lag time. The dissolution was related to an immediate dissolution, submicron-level recrystallization of β-S with sufficient conditions for nanofibers for L929 cell culture that could be used in biomedical applications. It concluded that electrospinning is a promising technique for poorly water-soluble β-S formulations that could be used in biomedical applications.

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.

Antibiotic resistance alters through iron-regulating Sigma factors during the interaction of Staphylococcus aureus and Pseudomonas aeruginosa

Iron is a limiting factor in such a condition that usually is sequestered by the host during polymicrobial infections of Pseudomonas aeruginosa and Staphylococcus aureus. This study aimed to investigate the interaction of S. aureus and P. aeruginosa, which alters iron-related sigma factors regulation and antibiotic resistance. The antibiotic resistance of P. aeruginosa and S. aureus was investigated in a L929 cell culture model. The expression level of pvdS, hasI (P. aeruginosa sigma factors), and sigS (S. aureus sigma factor) genes was determined using Quantitative Real-Time PCR. pvdS and hasI were downregulated during co-culture with S. aureus, while the susceptibility to carbapenems increased (p-value < 0.0001). Also, there was a direct significant relationship between resistance to vancomycin with sigS. Regarding the findings of the current study, iron-related sigma factors of P. aeruginosa and S. aureus play a role in induction susceptibility to various antibiotics, including carbapenems and vancomycin.

Topical Nanoemulgel for the Treatment of Skin Cancer: Proof-of-Technology

The present study is a mechanistic validation of ‘proof-of-technology’ for the effective topical delivery of chrysin nanoemulgel for localized, efficient treatment of melanoma-affected skin. Background: Currently available treatments for skin cancer are inefficient due to systemic side effects and poor transcutaneous permeation, thereby presenting a formidable challenge for the development of novel nanocarriers. Methods: We opted for a novel approach and formulated a nanocomplex system composed of hydrophobic chrysin dissolved in a lipid mix, which was further nanoemulsified in Pluronic® F-127 gel to enhance physicochemical and biopharmaceutic characteristics. Chrysin, a flavone extracted from passion flowers, exhibits potential anti-cancer activities; however, it has limited applicability due to its poor solubility. Pseudo-ternary phase diagrams were constructed to identify the best self-nanoemulsifying region by varying the compositions of oil, Caproyl® 90 surfactant, Tween® 80, and co-solvent Transcutol® HP. Chrysin-loaded nanoemulsifying compositions were characterized for various physicochemical properties. Results: This thermodynamically stable, self-emulsifying drug delivery system showed a mean droplet size of 156.9 nm, polydispersity index of 0.26, and viscosity of 9100 cps after dispersion in gel. Mechanical characterization using Texture Analyzer exhibited that the gel had a hardness of 487 g and adhesiveness of 500 g. Ex vivo permeation through rat abdominal skin revealed significant improvement in percutaneous absorption measured as flux, the apparent permeability coefficient, the steady-state diffusion coefficient, and drug deposition. In vitro cytotoxicity on A375 and SK-MEL-2 cell lines showed a significantly improved therapeutic effect, thus ensuring reduction in dose. The safety of the product was established through biocompatibility testing on the L929 cell line. Conclusion: Aqueous, gel-based, topical, nanoemulsified chrysin is a promising technology approach for effective localized transcutaneous delivery that will help reduce the frequency and overall dose usage and ultimately improve the therapeutic index.