Unmodified magnetic nanoparticles (MNPs) lack antibacterial potential. We investigated MNPs surface modifications that can impart antibacterial activity. Six MNPs species were prepared and characterized. Their antibacterial and antibiofilm potentials, surface affinity, and cytotoxicity were evaluated. Prepared MNPs were functionalized with citric acid, amine group, amino-propyl trimethoxy silane (APTMS), arginine, or oleic acid (OA) to give hydrophilic and hydrophobic MNPs with surface charge ranging from −30 to +30 mV. Prepared MNPs were spherical in shape with an average size of 6-15 nm. Hydrophobic (OA-MNPs) and positively charged MNPs (APTMS-MNPs) had significant concentration dependent antibacterial effect. OA-MNPs showed higher inhibitory potential against S. aureus and E. coli (80%) than APTMS-MNPs (70%). Both particles exhibited surface affinity to S. aureus and E. coli. Different concentrations of OA-MNPs decreased S. aureus and E. coli biofilm formation by 50-90%, while APTMS-MNPs reduced it by 30-90%, respectively. Up to 90% of preformed biofilms of S. aureus and E. coli were destroyed by OAMNPs and APTMS-MNPs. In conclusion, surface positivity and hydrophobicity enhance antibacterial and antibiofilm properties of MNPs.

Inactivation of rabies virus is essential for rabies vaccine preparation where the inactivating compound that is currently recommended for rabies vaccine preparation is β-propiolactone (β-PL). This compound is considered better than phenol and formalin but it is expensive and potentially carcinogenic. Data revealed that Ascorbic acid (AA) with cupric ions could yield complete and irreversible inactivation of rabies virus without adversely affecting its antigenicity. Additionally, the results of testing the vaccine potency with the selected inactivating compounds were comparable (P<0.05), and ED50 was higher than the recommended World Health Organization (WHO) limits. The use of HemaGel (plasma substitute) for testing vaccine stabilization was compared with the currently used vaccine stabilizers (human albumin and lactose). HemaGel yielded better stability than the other tested stabilizers. Monitoring of cellular and humoral immune responses indicated that both the total IgG level against rabies vaccine and the IFN and IL5 levels obtained with the HemaGel-stabilized vaccines were higher than those obtained with human albumin- and lactose-stabilized vaccine candidates.

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Purpose One of the essential goals regarding the successful control of rabies infection is the development of a safe, effective, and inexpensive vaccine. the current study aimed to evaluate the inactivation potential of β-propiolactone (βPL), binary ethyleneimine (BEI), and hydrogen peroxide (H 2 O 2 ). Materials and Methods Estimating the inactivation kinetics of βPL, BEI, and H 2 O 2 revealed that the tested inactivants could completely and irreversibly inactivate rabies virus within 2, 12, and 4 hours, respectively while maintaining its viral immunogenicity. The potency of βPL, BEI, and H 2 O 2 inactivated vaccines was higher than the World Health Organization acceptance limit and were in the order of 3.75, 4.21, and 3.64 IU/mL, respectively. Monitoring the humoral and cellular immunity elicited post-immunization using Staphylococcus aureus derived hyaluronic acid (HA) and bacillus Calmette-Guérin purified protein derivative (PPD) adjuvanted rabies vaccine candidates were carried out using enzyme-linked immunosorbent assay. Results Results demonstrated that both adjuvants could progressively enhance the release of anti-rabies total immunoglobulin G as well as the pro-inflammatory mediators (interferon-gamma and interleukin-5) relative to time. However, a higher immune response was developed in the case of HA adjuvanted rabies vaccine compared to PPD adjuvanted one. The harmful consequences of the tested adjuvants were considered via investigating the histopathological changes in the tissues of the immunized rats using hematoxylin and eosin stain. Lower adverse effects were observed post-vaccination with HA and PPD adjuvanted vaccines compared to that detected following administration of the currently used alum as standard adjuvant. Conclusion Our findings suggested that HA and PPD could serve as a promising platform for the development of newly adjuvanted rabies vaccines with elevated immune enhancing potentials and lower risk of health hazards.

Background: Varicella-zoster virus (VZV) is the etiologic agent of two diseases, varicella (chicken pox) and zoster (shingles). Varicella is a self-limited infection, while zoster is mainly a disease of adults. The present study was conducted to isolate VZV from clinically diagnosed children using cell cultures and compare the activity of liquorice powder extract, an alternative herbal antiviral agent, with acyclovir and interferon alpha 2a (IFN-α2a) against the isolated virus. Methods: Forty-eight VZV specimens, 26 from vesicular aspirates and 22 from vesicular swabs, from children clinically diagnosed with varicella were isolated on the Vero cell line. Isolates were propagated and identified with specific antiserum using indirect immunofluorescence and immunodot blotting assays. The growth kinetics of the viral isolates was studied. The antiviral activity of liquorice powder extract, acyclovir (ACV) and IFN-α2a was evaluated against the isolated virus. Results: VZV was successfully isolated in 4 of the 48 specimens, all from vesicular aspirates. The growth kinetics of the viral isolates was time dependent. The inhibitory activity of liquorice powder extract (containing 125 µg/ml glycyrrhizin) when compared to ACV (250 µg/ml) and IFN-α2a is the lowest. Conclusions: VZV isolates were successfully isolated and propagated using Vero cells. Isolates were identified using indirect immunofluorescent and immunodot blotting techniques. Growth kinetics of the isolates revealed an increase in the viral infectivity titer relative to time. Glycyrrhizin in the crude form has low antiviral activity against VZV compared with acyclovir and interferon.