Rhamnolipid Nano-Micelles versus Alcohol-Based Hand Sanitizer: A Comparative Study for Antibacterial Activity against Hospital-Acquired Infections and Toxicity Concerns

Preparation and characterization of Sorafenib nano-emulsion: impact on pharmacokinetics and toxicity; an in vitro and in vivo study

Hepatocellular carcinoma (HCC) ranks as the third leading cause of cancer-related deaths worldwide. Current treatment strategies include surgical resection, liver transplantation, liver-directed therapy, and systemic therapy. Sorafenib (Sor) is the first systemic drug authorized by the US Food and Drug Administration (FDA) for HCC treatment. Nevertheless, the conventional oral administration of Sor presents several limitations: poor solubility, low bioavailability, drug resistance development, and off-target tissue accumulation, leading to numerous adverse effects. Nano-emulsion, a nano-delivery system, is a viable carrier for poorly water-soluble drugs. It aims to enhance drug bioavailability, target organ accumulation, and reduce off-target tissue exposure, thus improving therapeutic outcomes while minimizing side effects. This study formulated Sor nano-emulsion (Sor NanoEm) using the homogenization technique. The resultant nano-emulsion was characterized by particle size (121.75 ± 12 nm), polydispersity index (PDI; 0.310), zeta potential (-12.33 ± 1.34 mV), viscosity (34,776 ± 3276 CPs), and pH (4.38 ± 0.3). Transmission Electron Microscopy exhibited spherical nano-droplets with no aggregation signs indicating stability. Furthermore, the encapsulation of Sor within the nano-emulsion sustained its release, potentially reducing the frequency of therapeutic doses. Cytotoxicity assessments on the HepG2 cell line revealed that Sor NanoEm had a significantly (P < 0.05) more potent cytotoxic effect compared to Sor suspension. Subsequent tests highlighted superior pharmacokinetic parameters and reduced dosage requirements of Sor NanoEm in mice. It exhibited an enhanced safety profile, particularly in behavior, brain, and liver, compared to its suspended form. These findings underscore the enhanced pharmacological and toxicological attributes of Sor Nano-emulsion, suggesting its potential utility in HCC treatment.

Biological machinery for the production of biosurfactant and their potential applications

The growing biotechnology industry has focused a lot of attention on biosurfactants because of several advantages over synthetic surfactants. These benefits include worldwide public health, environmental sustainability, and the increasing demand from sectors for environmentally friendly products. Replacement with biosurfactants can reduce upto 8% lifetime CO2 emissions avoiding about 1.5 million tons of greenhouse gas released into the atmosphere. Therefore, the demand for biosurfactants has risen sharply occupying about 10% (∼10 million tons/year) of the world production of surfactants. Biosurfactants' distinct amphipathic structure, which is made up of both hydrophilic and hydrophobic components, enables these molecules to perform essential functions in emulsification, foam formation, detergency, and oil dispersion-all of which are highly valued characteristic in a variety of sectors. Today, a variety of biosurfactants are manufactured on a commercial scale for use in the food, petroleum, and agricultural industries, as well as the pharmaceutical and cosmetic industries. We provide a thorough analysis of the body of knowledge on microbial biosurfactants that has been gained over time in this research. We also discuss the benefits and obstacles that need to be overcome for the effective development and use of biosurfactants, as well as their present and future industrial uses.

Bioadhesive Polymeric Films Containing Rhamnolipids, An Innovative Antimicrobial Topical Formulation

Acne affects most of the world's population, causing an impact on the self-esteem of adolescents and young adults. One of the causes is the presence of the bacteria Cutibacterium acnes which are part of the natural microbiota of the skin. Topical treatments consist of anti-inflammatory and antibiotics, which could select resistant strains. Alternatives to the antibiotic are biocomposites that have antimicrobial activity like biosurfactants which are produced by bacteria. An innovative way of applying these compounds is bioadhesive polymeric films that adhere to the skin and release the active principle topically. Rhamnolipids have great potential to be used in the treatment of acne because they present antimicrobial activity against C. acnes in low and safe concentrations (MIC of 15.62 µg/mL, CBM of 31.25 µg/mL and CC50 of 181.93 µg/mL). Four films with different rhamnolipids concentrations (0.0; 0.1; 0.2; and 0.3%, w/w) were obtained as to visual appearance, mass variation, thickness, density, solubility, pH, water vapor transmission, mechanical properties (folding endurance, bioadhesion strength, tensile strength, elongation at break and Young's modulus), scanning electron microscopy and infrared. The results show that these formulations had a homogeneous appearance; elastic mechanical properties; pH similar to human skin and bioadhesive. The polymeric films containing rhamnolipids were effective against C. acnes, in the in vitro test, at the three concentrations tested, the film with the highest concentration (0.3%, w/w) being the most promising for presenting the highest antimicrobial activity. Thus, the polymeric film containing rhamnolipids has the potential to be used in the treatment of acne.

Preparation and characterization of nano-emulsion formulations of Asparagus densiflorus root and aerial parts extracts: evaluation of in-vitro antibacterial and anticancer activities of nano-emulsion versus pure plant extract

OBJECTIVE

Preparation and characterization of nano-emulsion formulations for Asparagus densiflorus aerial and root parts extracts.

SIGNIFICANCE

Genus Asparagus is known for its antimicrobial and anticancer activities, however, freeze dried powder of aqueous - alcoholic extract prepared in this study, exhibited a limited water solubility, limiting its therapeutic application. Thus, encapsulation of its phytochemicals into nano-emulsion is proposed as a solution to improve water solubility, and facilitate its clinical translation.

METHODS

the composition of extracts for both aerial and root parts of Asparagus densiflorus was identified by HPLC and LC-MS analysis. Nano-emulsion was prepared via homogenization where a mixture of Castor oil: phosphate buffered saline (10 mM, pH 7.4): Tween 80: PEG 600 in a ratio of 10: 5: 2.5: 2.5, respectively. Nano-emulsion formulations were characterized for particle size, polydispersity index (PDI), zeta potential, TEM, viscosity and pH. Then, the antibacterial and anticancer activities of nano-emulsion formulations versus their pure plant counterparts was assessed.

RESULTS

The analysis of extracts identified several flavonoids, phenolics, and saponins which were reported to have antimicrobial and anticancer activities. Nano-emulsion formulations were monodispersed with droplet sizes ranging from 80.27 ± 2.05 to 111.16 ± 1.97 nm, and polydispersity index ≤0.3. Nano-emulsion formulations enhanced significantly the antibacterial (multidrug resistant bacteria causing skin and dental soft tissues infections) and anticancer (HuH7, HEPG2, H460 and HCT116) activities compared to their pure plant extract counterparts.

CONCLUSION

Employing a nano-delivery system as a carrier for phytochemicals might be an effective strategy to enhance their pharmacological activity, overcome their limitations, and ultimately increase their potential for clinical applications.

Microbial Biosurfactants: Antimicrobial Activity and Potential Biomedical and Therapeutic Exploits

The rapid emergence of multidrug-resistant pathogens worldwide has raised concerns regarding the effectiveness of conventional antibiotics. This can be observed in ESKAPE pathogens, among others, whose multiple resistance mechanisms have led to a reduction in effective treatment options. Innovative strategies aimed at mitigating the incidence of antibiotic-resistant pathogens encompass the potential use of biosurfactants. These surface-active agents comprise a group of unique amphiphilic molecules of microbial origin that are capable of interacting with the lipidic components of microorganisms. Biosurfactant interactions with different surfaces can affect their hydrophobic properties and as a result, their ability to alter microorganisms' adhesion abilities and consequent biofilm formation. Unlike synthetic surfactants, biosurfactants present low toxicity and high biodegradability and remain stable under temperature and pH extremes, making them potentially suitable for targeted use in medical and pharmaceutical applications. This review discusses the development of biosurfactants in biomedical and therapeutic uses as antimicrobial and antibiofilm agents, in addition to considering the potential synergistic effect of biosurfactants in combination with antibiotics. Furthermore, the anti-cancer and anti-viral potential of biosurfactants in relation to COVID-19 is also discussed.

Hand Sanitizer Gels: Classification, Challenges, and the Future of Multipurpose Hand Hygiene Products

Hand hygiene is a crucial measure in the prevention and control of infections, and there is a growing awareness among individuals who are making a conscious effort to maintain hand cleanliness. With the advent of the SARS-CoV-2 outbreak, the demand for hand hygiene products has also gradually shifted towards those with antimicrobial properties. Among these products, hand sanitizer gels (HSGs) have gained considerable popularity as an efficient method of hand cleaning, due to their rapid drying and sustained antimicrobial efficacy. Concurrently, there has been a growing interest in novel HSGs that offer additional functions such as skin whitening, moisturizing, and anti-inflammatory effects. These novel HSGs effectively address concerns associated with the ingestion of antimicrobial ingredients and demonstrate reduced skin irritation, thereby alleviating hand dermatological issues. This review provides an extensive overview of the application scenarios, classification, and challenges associated with HSGs while emphasizing the emergence of novel components with biological functions, aiming to contribute to the advancement of hand hygiene practices and offer novel insights for the development of novel HSGs with outstanding antimicrobial properties with other multiple biological functions and desirable biosafety profiles.

Antimicrobial Activity of Azithromycin Encapsulated into PLGA NPs: A Potential Strategy to Overcome Efflux Resistance

Antimicrobial resistance represents a public health problem with a major negative impact on health and socioeconomic development, and is one of the biggest threats in the modern era. This requires the discovery of new approaches to control microbial infections. Nanomedicine could be one of the promising strategies to improve the treatment of microbial infections. Polymer nanoparticles (PNPs) were reported to overcome the efflux-resistant mechanism toward chemotherapeutic agents. However, to the best of our knowledge, no studies were performed to explore their ability to overcome the efflux-resistant mechanism in bacteria. In the current study, azithromycin (AZI), a macrolide antibiotic, was encapsulated into a biocompatible polymer, poly (lactic-co-glycolic acid) (PLGA) using the nano-precipitation method. The effect of the drug to polymer ratio, surfactant, and pH of the aqueous medium on particle size and drug loading percentage (DL%) were investigated in order to maximize the DL% and control the size of NPs to be around 100 nm. The antibacterial activity of AZI-PLGA NPs was investigated against AZI-resistant bacteria; Methicillin-resistant Staphylococcus aureus (MRSA) and Enterococcus faecalis (E. faecalis), where the efflux mechanism was demonstrated to be one of the resistant mechanisms. AZI-PLGA NPs were safer than free AZI, as revealed from the cytotoxicity test, and were able to overcome the efflux-resistant mechanism, as revealed by decreasing the MIC of AZI-PLGA NPs by four times than free AZI. The MIC value reduced from 256 to 64 µg/mL and from >1000 to 256 µg/mL for MRSA and E. faecalis, respectively. Therefore, encapsulation of AZI into PNPs was shown to be a promising strategy to overcome the efflux-resistant mechanism towards AZI and improve its antibacterial effect. However, future investigations are necessary to explore the effect (if any) of particle size, surface charge, and material composition of PNPs on antibacterial activity. Moreover, it is essential to ascertain the safety profiles of these PNPs, the possibility of their large-scale manufacture, and if this concept could be extended to other antibiotics.

Investigating the Antibacterial Activity and Safety of Zinc Oxide Nanoparticles versus a Commercial Alcohol-Based Hand-Sanitizer: Can Zinc Oxide Nanoparticles Be Useful for Hand Sanitation?

Hand hygiene is the key factor to control and prevent the spread of infections, for example, hospital-acquired infections (HAIs). People commonly use alcohol-based hand sanitizers to assure hand hygiene. However, frequent use of alcohol-based hand sanitizers in a pandemic situation (e.g., COVID-19) was associated with serious drawbacks such as skin toxicity including irritation, skin dermatitis, and skin dryness or cracking, along with peeling, redness, or itching with higher possibility of infection. This demands the development of alternative novel products that are effective as alcohol-based hand sanitizers but have no hazardous effects. Zinc oxide nanoparticles (ZnO-NPs) are known to have broad-spectrum antimicrobial activity, be compatible with the biological system and the environment, and have applicable and economic industrial-scale production. Thus, ZnO-NPs might be a good candidate for hand sanitation. To the best of our knowledge, the antibacterial activity of ZnO-NPs in comparison to alcohol-based hand sanitizers has not yet been studied. In the present work, a comparative study of the antibacterial activity of ZnO-NPs vs. Sterillium, a commercial alcohol-based hand sanitizer that is commonly used in Egyptian hospitals, was performed against common microorganisms known to cause HAIs in Egypt, including Acinetobacter baumannii, Klebsiella pneumoniae, Methicillin-resistant Staphylococcus aureus (MRSA), and Staphylococcus aureus. The safety profiles of ZnO-NPs and Sterillium were also assessed. The obtained results demonstrated the superior antibacterial activity and safety of ZnO-NPs compared to Sterillium. Therefore, ZnO-NPs could be a promising candidate for hand sanitation in comparison to alcohol-based hand sanitizers; however, several studies related to long-term toxicity and stability of ZnO-NPs and investigations into their antimicrobial activity and safety in healthcare settings are still required in the future to ascertain their antimicrobial activity and safety.

Rhamnolipid Nano-Micelles Inhibit SARS-CoV-2 Infection and Have No Dermal or Eye Toxic Effects in Rabbits

Hand hygiene is considered to be the key factor in controlling and preventing infection, either in hospital care settings or in the community. Alcohol-based hand sanitizers are commonly used due to their rapid action and broad spectrum of microbicidal activity, offering protection against bacteria and viruses. However, their frequent administration during COVID-19 pandemic was associated with serious hazards, such as skin toxicity, including irritation, skin dermatitis, skin dryness or cracking, along with peeling redness or itching, with the higher possibility of getting infections. Thus, there is a need to find alternative and novel approaches for hand sanitation. In our previous publications, we reported that rhamnolipids nano-micelles had a comparable antibacterial activity to alcohol-based hand sanitizer and a lower cytotoxicity against human dermal fibroblast cells. In the current study, we investigated the antiviral activity of rhamnolipids nano-micelles against SARS-CoV-2. There was no cytotoxic effect on Vero cells noted at the tested concentrations of rhamnolipids nano-micelles. The rhamnolipids nano-micelles solution at 20, 78, and 312 µg/mL all demonstrated a significant (p < 0.05) decrease of virus infectivity compared to the virus only and the blank vehicle sample. In addition, an acute irritation test was performed on rabbits to further ascertain the biosafety of rhamnolipids nano-micelles. In the eye and skin irritation tests, no degree of irritation was recorded after topical application of rhamnolipids nano-micelles. In addition, histopathological, biomarker, and hematological analyses from animals treated with rhamnolipids nano-micelles were identical to those recorded for untreated animal. From the above, we can conclude that rhamnolipids nano-micelles are a good candidate to be used as a hand sanitizer instead of alcohol-based hand sanitizers. However, they must still be tested in the future among healthcare workers (HCW) in a health care setting to ascertain their antimicrobial efficacy and safety compared to alcohol-based hand sanitizers.