Liposomes containing biosurfactants isolated from Lactobacillus gasseri exert antibiofilm activity against methicillin resistant Staphylococcus aureus strains.

Staphylococcus aureus is the major causative agent of skin and soft tissue infections, whose prevention and treatment have become more difficult due to the emergence of antibiotic-resistant strains. In this regard, the development of an effective treatment represents a challenge that can be overcome by delivering new antibiofilm agents with appropriate nanocarriers. In this study, a biosurfactant (BS) isolated from Lactobacillus gasseri BC9 and subsequently loaded in liposomes (LP), was evaluated for its ability to prevent the development and to eradicate the biofilm of different methicillin resistant S. aureus (MRSA) strains. BS from L. gasseri BC9 was not cytotoxic and was able to prevent formation and to eradicate the biofilm of different MRSA strains. BS loaded liposomes (BS-LP) presented a mean diameter (lower than 200 nm) suitable for topical administration and a low polydispersity index (lower than 0.2) that were maintained over time for up 28 days. Notably, BS-LP showed higher ability than free BS to inhibit S. aureus biofilm formation and eradication. BS-LP were loaded in lyophilized matrices able to quickly dissolve (dissolution time lower than 5 s) upon contact with exudate, thus allowing vesicle reconstitution. In conclusion, in this work, we demonstrated the antibiofilm activity of Lactobacillus-derived BS and BS-LP against clinically relevant MRSA strains. Furthermore, the affordable production of lyophilized matrices containing BS-LP for local prevention of cutaneous infections was established.

Spanish Broom (Spartium junceum L.) fibers impregnated with vancomycin-loaded chitosan nanoparticles as new antibacterial wound dressing: Preparation, characterization and antibacterial activity.

In this work, we propose as new wound dressing, the Spanish Broom fibers impregnated with vancomycin (VM) loaded chitosan nanoparticles. Spanish Broom fibers were extracted by patented method DiCoDe and the morphological, physical and mechanical properties were investigated. Chitosan nanoparticles were prepared by ionic gelation using different weight ratios between chitosan (CH) and tripolyphosphate (TPP). Nanoparticles were characterized in terms of size, zeta potential, yield, encapsulation efficiency, stability and drug release. Finally, the antibacterial activity against Staphylococcus aureus as well as in vitro cytotoxicity on HaCaT cells were evaluated. The best formulation CH/TPP 4:1 was selected based on the encapsulation efficiency and yield. Spanish Broom fibers impregnated with loaded nanoparticles showed an increased antibacterial activity against S. aureus compared to the same fibers containing VM without nanoparticles. Moreover, these fibers were not toxic to HaCaT keratinocytes cells. In conclusion, Spanish Broom fibers impregnated with VM loaded CH/TPP nanoparticles would appear to be a promising candidate for wound dressing application.

Antiproliferative effect of linalool on RPMI 7932 human melanoma cell line: ultrastructural studies.

Linalool, a small monoterpene molecule, is used widely for its flavoring and fragrant properties in many cosmetic products. In this work, we investigated the antiproliferative effect of two different linalool solutions on RPMI 7932 human melanoma and NCTC 2544 normal keratinocites cell lines using the trypan blue method. Morphological changes in cells were investigated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). In addition, apoptosis was evaluated using caspase 3-antibody. Linalool showed a selective inhibitory effect on the growth of melanoma cells in a concentrationdependent manner, inducing several morphological changes, as revealed by SEM and TEM analysis. Moreover, the labelling for caspase-3 is abundant in the melanoma cells and almost absent in the normal keratinocites cells. The results suggest that linalool could be used as drug and/or as model drug for developing potential therapeutic agents for melanoma.

Spartium junceum aromatic water: chemical composition and antitumor activity.

The purpose of this study was to analyse the chemical composition of Spartium junceum L. (also known as Spanish Broom) aromatic water and to evaluate its cytotoxic activity against a series of human cancer cell lines (melanoma: RPMI 7932; leukemia: K562; breast cancer cell: MCF7-Bart and MCF7-ICLC, colon adenocarcinoma: SW480). The results show that the aromatic water was cytotoxic toward the tumor cell lines analyzed (RPMI 7932, K562, MCF7-Bart, MCF7-ICLC, SW480), while it did not appreciably alter the viability of normal keratinocytes (NCTC 2544) suggesting its potential use as an antitumor agent for cancer treatment and/or prevention.

Freeze-dried chitosan/pectin nasal inserts for antipsychotic drug delivery.

The objective of this investigation was the development of chitosan/pectin based nasal inserts to improve bioavailability of antipsychotic drugs in the treatment of psychotic symptoms. In fact, the nasal route of administration ensures systemic availability avoiding the first-pass metabolism and obtaining more efficacious treatments. Chitosan/pectin polyelectrolyte complexes were prepared at pH 5.0 with different polycation/polyanion molar ratios and lyophilized in small inserts in the presence of chlorpromazine hydrochloride. The results show that higher amount of pectin in the complexes, with respect to higher amount of chitosan, produced a more evident porous structure of the nasal inserts, improving water uptake ability and mucoadhesion capacity. Finally, the presence of increasing amounts of pectin allowed the interaction with chlorpromazine hydrochloride inducing the formation of less hydratable inserts thus limiting drug release and permeation. This investigation verifies the formation of polyelectrolyte complexes between chitosan and pectin at pH values in the vicinity of the pKa interval of the two polymers and confirms the potential of these complexes, capable of achieving antipsychotic drug delivery in the nasal cavity.

Pectin-based microspheres for colon-specific delivery of vancomycin.

OBJECTIVES: The aim of this study was to describe a colon-specific delivery system based on pectin hydrogels formed by complexation with chitosan. METHODS: Hydrogels were prepared at different weight ratios (4:1, 7:1, 10:1; pectin/chitosan), loaded with vancomycin hydrochloride (2:1, 4:1; polymer/drug weight ratio) and collected by spray-drying. The microspheres obtained were characterized in terms of morphology, swelling behaviour, mucoadhesive properties and drug loading efficiency. The influence of different pectin/chitosan hydrogels on the release behaviour of microspheres at pH 2.0, 5.5 and 7.4 were evaluated in vitro with and without pectinolytic enzyme. KEY FINDINGS: The results showed that water uptake was increased by raising the environmental pH (from 2.0 to 7.4) and the pectin/chitosan weight ratio, while drug availability was increased by raising the environmental pH (from 2.0 to 7.4) and decreased by raising the pectin/chitosan weight ratio. In the presence of pectinase, the glycoside bonds of pectin were degraded and a considerable amount of drug was released in a short time. CONCLUSIONS: This study suggested that pectin/chitosan microspheres were able to limit the release of vancomycin under acidic conditions and release it under simulated colonic conditions, confirming their potential for a colon-specific drug delivery system.

Polyvinylalcohol substituted with triethyleneglycolmonoethylether as a new material for preparation of solid dispersions of hydrophobic drugs.

Among the different methods used to increase the aqueous drug solubility, the preparation of a solid dispersion with a soluble carrier represents an interesting formulative approach. We substituted polyvinylalcohol with triethyleneglycolmonoethylether and obtained a suitable material for the formulation of a solid dispersion of progesterone, by spray-drying. In particular, we evaluated the influence of the polyvinylalcohol substitution degree and the polymer-drug weight ratios in the preparative mixture on the progesterone dissolution rate in the aqueous environment.