Suberin/trans-Cinnamaldehyde Oil Nanoparticles with Antimicrobial Activity and Anticancer Properties When Loaded with Paclitaxel.

Suberin is a biopolyester that can be extracted from bioresources such as cork trees and may find many applications in food packaging, sealing, and biomedical fields. In this work, we describe for the first time the preparation of suberin nanoparticles using the solvent/antisolvent method. Three different suberin extraction methods from cork trees were used to reveal any differences in the production and properties of the nanoparticles. trans-Cinnamaldehyde, a component of cinnamon essential oil, was added to suberin nanoparticles due to its antimicrobial and/or anticancer properties, and its synergistic effect was studied with the inherent biological properties of suberin. Interestingly, both suberin and suberin/trans-cinnamaldehyde nanoparticles showed very good antimicrobial properties against Staphylococcus aureus and Pseudomonas aeruginosa bacteria, and also against Candida albicans (yeast). Suberin nanoparticles containing trans-cinnamaldehyde loaded with 0.1% w/w paclitaxel provided significant anticancer properties against human hepatocellular carcinoma HepG2 cancer cell lines. This study can be used to explore novel biobased polymers as efficient carriers of essential oils and drugs for infection and cancer therapy, by using minimum amount of drugs and therefore reducing their cytotoxicity and side effects.

Cellulose acetate - essential oil nanocapsules with antimicrobial activity for biomedical applications.

This study aimed to obtain bioactive nanosystems by combining cellulose acetate with three selected essential oils (EOs) to create spherical nanocapsules (NCs) using the solvent/anti-solvent technique. The biological activity of the obtained NCs was promoted by the use of some antimicrobial EOs: Peppermint, Cinnamon and lemongrass which were grafted on the cellulose acetate molecules. Due to their chemistry, such as long hydrocarbon tails and heads with functional groups these EOs were playing also the role of surfactant-like substance facilitating the formation of NCs. A dispersion of NCs was obtained in water and various spectroscopy techniques used to examine their size, morphology and chemistry. Dynamic light scattering calculate the size of the NCs whereas scanning electron microscopy showed their morphology. Fluorescent microscopy and Raman spectroscopy proved the attachment of the EOs in the cellulose acetate molecules. The antimicrobial activity of the obtained nanomaterials was tested against four microbial strains (bacteria: Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and a yeast strain of Candida albicans). The obtained results demonstrated that such NCs can be used in a variety of applications including medical, pharmaceutical recipients and in household products for treating or preventing microbial colonization and biofilm development.

Polylactic Acid-Lemongrass Essential Oil Nanocapsules with Antimicrobial Properties.

Polylactic acid was combined with lemongrass essential oil (EO) to produce functional nanocapsules (NCs). The obtained polylactic acid nanoparticles showed antimicrobial activity both with and without the presence of lemongrass oil; however, the presence of EO improved the activity of the NCs. The presence of lemongrass assisted the formation of well-separated NCs and also provided enhanced antimicrobial properties, since lemongrass is known for its antimicrobial character. Fluorescence microscopy was used to optically observe the nanoparticles and NCs and revealed the attachment of lemongrass oil with the polylactic acid NCs. Dynamic light scattering was used to determine their size. UV absorption was used to determine the exact amount of lemongrass oil found in the polylactic acid-lemongrass oil NCs, which was important for understanding the minimum inhibitory concentration for the antimicrobial experiments. A series of clinically important microbial species were used in the study and the obtained NCs proved to have very good antimicrobial properties against all tested strains. Such NCs can be used for the design of ecological strategies, based on natural alternatives, which may be efficient against severe infections, including those that involve resistant pathogens and biofilms or those with difficult to reach localization.

Antimicrobial Lemongrass Essential Oil-Copper Ferrite Cellulose Acetate Nanocapsules.

Cellulose acetate (CA) nanoparticles were combined with two antimicrobial agents, namely lemongrass (LG) essential oil and Cu-ferrite nanoparticles. The preparation method of CA nanocapsules (NCs), with the two antimicrobial agents, was based on the nanoprecipitation method using the solvent/anti-solvent technique. Several physical and chemical analyses were performed to characterize the resulting NCs and to study their formation mechanism. The size of the combined antimicrobial NCs was found to be ca. 220 nm. The presence of Cu-ferrites enhanced the attachment of LG essential oil into the CA matrix. The magnetic properties of the combined construct were weak, due to the shielding of Cu-ferrites from the polymeric matrix, making them available for drug delivery applications where spontaneous magnetization effects should be avoided. The antimicrobial properties of the NCs were significantly enhanced with respect to CA/LG only. This work opens novel routes for the development of organic/inorganic nanoparticles with exceptional antimicrobial activities.

All natural cellulose acetate-Lemongrass essential oil antimicrobial nanocapsules.

Nanocapsules and nanoparticles play an essential role in the delivery of pharmaceutical agents in modern era, since they can be delivered in specific tissues and cells. Natural polymers, such as cellulose acetate, are becoming very important due to their availability, biocompatibility, absence of toxicity and biodegradability. In parallel, essential oils are having continuous growth in biomedical applications due to the inherent active compounds that they contain. A characteristic example is lemongrass oil that has exceptional antimicrobial properties. In this work, nanocapsules of cellulose acetate with lemongrass oil were developed with the solvent/anti-solvent method with resulting diameter tailored between 95 and 185nm. Various physico-chemical and surface analysis techniques were employed to investigate the formation of the nanocapsules. These all-natural nanocapsules found to well bioadhere to mucous membranes and to have very good antimicrobial properties at little concentrations against Escherichia coli and Staphylococcus aureus.

Exposure to major volatile organic compounds and carbonyls in European indoor environments and associated health risk.

This paper summarizes recent data on the occurrence of major organic compounds (benzene, toluene, xylenes, styrene, acetaldehyde, formaldehyde, naphthalene, limonene, α-pinene and ammonia, classified by the European Commission's INDEX strategy report as the priority pollutants to be regulated) and evaluates accordingly cancer and non-cancer risks posed by indoor exposure in dwellings and public buildings in European Union (EU) countries. The review process indicated that significant differences in indoor air quality exist within and among the countries where data were available, indicating corresponding differences in sources and emission strength of airborne chemicals, identified or not. Conservative exposure limits were not exceeded for non-carcinogenic effects, except for formaldehyde; for carcinogenic agents the estimated risks were up to three orders of magnitude higher than the one (10(-6)) proposed as acceptable by risk management bodies. However, the risk assessment evaluation process faces crucial difficulties, either due to the relative paucity of indoor air quality measurements in many EU countries, or by the lack of sampling consistency in the already existing studies, indicating the need for additional measurements of indoor air quality following a harmonized sampling and analytical protocol. Additionally, uncertainties embodied in the cancer potency factors and exposure limit values impose further difficulties in substance prioritization and risk management.