The hemocompatibility of nanoparticles is of critical importance for their systemic administration as drug delivery systems. Formulations of lipid-core nanocapsules, stabilized with polysorbate 80-lecithin and uncoated or coated with chitosan (LNC and LNC-CS), were prepared and characterized by laser diffraction (D[4,3]: 129 and 134 nm), dynamic light scattering (119 nm and 133 nm), nanoparticle tracking (D50: 124 and 139 nm) and particle mobility (zeta potential: -15.1 mV and +9.3 mV) analysis. In vitro hemocompatibility studies were carried out with mixtures of nanocapsule suspensions in human blood at 2% and 10% (v/v). The prothrombin time showed no significant change independently of the nanocapsule surface potential or its concentration in plasma. Regarding the activated partial thromboplastin time, both suspensions at 2% (v/v) in plasma did not influence the clotting time. Even though suspensions at 10% (v/v) in plasma decreased the clotting times (p<0.05), the values were within the normal range. The ability of plasma to activate the coagulation system was maintained after the addition of the formulations. Suspensions at 2% (v/v) in blood showed no significant hemolysis or platelet aggregation. In conclusion, the lipid-core nanocapsules uncoated or coated with chitosan are hemocompatible representing a potential innovative nanotechnological formulation for intravenous administration.

Vegetable oils present important pharmacological properties, which gained ground in the pharmaceutical field. Its encapsulation in nanoemulsions is considered a promising strategy to facilitate the applicability of these natural compounds and to potentiate the actions. These formulations offer several advantages for topical and systemic delivery of cosmetic and pharmaceutical agents including controlled droplet size, protection of the vegetable oil to photo, thermal and volatilization instability and ability to dissolve and stabilize lipophilic drugs. For these reasons, the aim of this review is to report on some characteristics, preparation methods, applications and especially analyze recent research available in the literature concerning the use of vegetable oils with therapeutic characteristics as lipid core in nanoemulsions, specially from Brazilian flora, such as babassu (Orbignya oleifera), aroeira (Schinus molle L.), andiroba (Carapa guaianiensis), casca-de-anta (Drimys brasiliensis Miers), sucupira (Pterodon emarginatus Vogel) and carqueja doce (Stenachaenium megapotamicum) oils.Uniterms: Plant oils/nanoemulsions/preparation. Plant oils/biological applications. INTRODUCTIONThe use of submicrometric colloidal nanocarriers such as nanoparticles (NP) lipid and polymeric, nanoemulsions (NE), microemulsions (ME), liposomes, and polymeric micelles is considered a promising system in the pharmaceutical field, because they have numerous advantages over traditional formulations such as: sustained release of the active element; solubilization of lipophilic molecules; use for different routes of administration; protection from chemical and enzymatic degradation of labile molecules; reduction of vegetable oils (VO) volatilization, side effects and dose (Mäder, Mehnert, 2005;Mehnert, Mäder, 2001;Gref, Couvreour, 2006;Couvreur, Vauthier, 2006; Panyam, Labhasetwar, 2003;Soppimath et al., 2001;Ai et al., 2011; Contri et al., 2012;Contri et al., 2014;Dimer et al., 2014;Severino et al., 2015;Frank et al., 2015;Asbahani et al., 2015). However, all systems differ thermodynamic stability, structure, chemical composition, efficiency encapsulation and types of application (Mäder, Mehnert, 2005;Ai et al., 2011).The development of suitable nanocarriers for pharmaceutical or cosmetic application requires the adequate selection of their adjuvants such as polymers for nanocapsules (NC), surfactants, and oils (Schaffazick et al., 2003;Alvarez-Román et al., 2001;Bouchemal et al., 2004;Friedrich et al., 2008). Recently, special attention has been given to the type of oily phase used as the core in the preparation of NE. VO has been preferred not only due to the concept that it is safe and biocompatible, but mainly because of the diversity of benefits, and the complex composition of fatty acids can exercise under the skin, protecting it against dehydration, solar radiation, inflammation, insect attack, microorganisms, and viruses (Tadros, Kessell, 2004;Bloise, 2003;Oyedeji, Okeke, 2010;Bakkali et. al., 2008;Harris, 2002; Contri et al, ...

The aim of the present study was to develop a transdermal system for controlled delivery of melatonin combining three strategies: nanoencapsulation of melatonin, drying of melatonin-loaded nanocapsules, and incorporation of nanocapsules in a hydrophilic gel. Nanocapsules were prepared by interfacial deposition of the polymer and were spray-dried using water-soluble excipients. In vitro drug release profiles were evaluated by the dialysis bag method, and skin permeation studies were carried out using Franz cells with porcine skin as the membrane. The use of 10% (w/v) water-soluble excipients (lactose or maltodextrin) as spray-drying adjuvants furnished redispersible powders (redispersibility index approximately 1.0) suitable for incorporation into hydrogels. All formulations showed a better controlled in vitro release of melatonin compared with the melatonin solution. The best controlled release results were achieved with hydrogels prepared with dried nanocapsules (hydrogels > redispersed dried nanocapsules > nanocapsule suspension > melatonin solution). The skin permeation studies demonstrated a significant modulation of the transdermal melatonin permeation for hydrogels prepared with redispersible nanocapsules. In this way, the additive effect of the different approaches used in this study (nanoencapsulation, spray-drying, and preparation of semisolid dosage forms) allows not only the control of melatonin release, but also transdermal permeation.

The one pot synthesis, using the ligand-metal-chitosan-lecithin complex to functionalize the surface of the biodegradable nanocapsules, maintained the active site of the antibody fragment making the device interesting for applications in nanomedicine.

In the past two decades the members of the genus Enterococcus have emerged as important nosocomial pathogens worldwide. In the present study, we evaluated the antimicrobial resistance and genotypic characteristics of 203 Enterococcus spp. recovered from different clinical sources from two hospitals in Porto Alegre, Rio Grande do Sul, Brazil. The species were identified by conventional biochemical tests and by an automated system. The genetic diversity of E. faecalis presenting high-level aminoglycoside resistance (HLAR) was assessed by pulsed-field gel electrophoresis of chromosomal DNA after SmaI digestion. The E. faecalis was the most frequent specie (93.6%), followed by E. faecium (4.4%). The antimicrobial resistance profile was: 2.5% to ampicillin, 0.5% to vancomycin, 0.5% teicoplanin, 33% to chloramphenicol, 2% to nitrofurantoin, 66.1% to erythromycin, 66.5% to tetracycline, 24.6% to rifampicin, 30% to ciprofloxacin and 87.2% to quinupristin-dalfopristin. A total of 10.3% of the isolates proved to be HLAR to both gentamicin and streptomycin (HLR-ST/GE), with 23.6% resistant only to gentamicin (HLR-GE) and 37.4% only to streptomycin (HLR-ST). One predominant clonal group was found among E. faecalis HLR-GE/ST. The prevalence of resistance among beta-lactam antibiotics and glycopeptides was very low. However, in this study there was an increased number of HLR Enterococcus which may be spreading intra and inter-hospital.