Sub-micrometric liposomes as drug delivery systems in the treatment of periodontitis.

Periodontitis is a complex disease and bacterial infection is one of the most common factors involved in this disease. Current strategies for the local delivery of antibiotics do not allow a complete clearance of bacteria filling dentinal tubules and this limits their therapeutic efficacy. Therefore, there is a strong need for the development of new delivery strategies aimed at improving the efficacy of antibiotic therapy for periodontitis with special reference to their ability to penetrate into the tubules. The aim of the present study is to develop liposome-based delivery systems of sub-micron dimension, able to diffuse into the dentinal tubules. A further aim of the research is to develop a protocol for enhanced diffusion based on the use of magnetic liposomes and magnetic fields. Liposomes were produced by hydration of a pre-liposomal formulation. The vesicles were stabilised with PEG and their re-sizing was achieved by extrusion. Magnetite nanoparticles were synthesized inside the vesicles, i.e., the chemical reaction involving FeCl2, FeCl3 and NH3 occurred within the core of the newly formed liposomes. Dynamic light scattering analysis was performed for size characterization. A mathematical model was implemented to predict the diffusion of the liposomes in dentinal tubules. Ex-vivo validation was performed on extracted human teeth. We produced PEG-ylated liposomes (average size 204.3 nm) and PEG-ylated magnetic liposomes (average size 286 nm) and an iron content of 4.2 µg/ml. Through mathematical modelling, we deduced that sub-micrometer vesicles are able to penetrate into dentinal tubules. This penetration is considerably more effective when the vesicles are magnetized and subjected to an external magnetic field which accelerates their movement within the tubules. The liposome-based delivery systems developed by the present study are able to penetrate deeply into the tubules, sometimes reaching their terminal ends.

BNNT-mediated irreversible electroporation: its potential on cancer cells.

Irreversible lethal electroporation (IRE) is a new non-thermal ablation modality that uses short pulses of high amplitude static electric fields (up 1000 V/cm) to create irreversible pores in the cell membrane, thus, causing cell death. Recently, IRE has emerged as a promising clinical modality for cancer disease treatment. Here, we investigated the responses of tumour human HeLa cells when subjected to IRE in the presence of BNNTs. These consist of tiny tubes of B and N atoms (arranged in hexagons) with diameters ranging from a 1 to 3 nanometres and lengths < 2 µm. BNNTs have attracted wide attention because of their unique electrical properties. We speculate that BNNTs, when interacting with cells exposed to static electrical fields, amplify locally the electric field, leading to cell death. In this work, electroporation assays were performed with a commercial electroporator using the cell- specific protocol suggested by the supplier (exponential decay wave, time constant 20 ms) with the specific aim to compare IRE in absence and in presence of BNNTs. We observed that BNNTs have the capacity to decrease substantially the voltage required for IRE. When cells were pulsed at 800 V/cm, we observed a 2,2-fold reduction in cell survival in the presence of BNNTs compared to controls. We conclude that the death of the tumour cells exposed to IRE is strongly enhanced in the presence of BNNTs, indicating their potential therapeutic application.

Progress in nanotechnology for healthcare.

This review based on the Wickham lecture given by AC at the 2009 SMIT meeting in Sinaia outlines the progress made in nano-technology for healthcare. It describes in brief the nature of nano-materials and their unique properties which accounts for the significant research both in scientific institutions and industry for translation into new therapies embodied in the emerging field of nano-medicine. It stresses that the potential of nano-medicine to make significant inroads for more effective therapies both for life-threatening and life-disabling disorders will only be achieved by high-quality life science research. The first generation of passive nano-diagnostics based on nanoparticle contrast agents for magnetic resonance imaging is well established in clinical practice and new such contrast agents are undergoing early clinical evaluation. Likewise active (second generation) nano-therapies, exemplified by targeted control drug release systems are undergoing early clinical evaluation. The situation concerning other nano-materials such as carbon nanotubes (CNTs) and boron nitride nanotubes (BNNTs) is less advanced although considerable progress has been made on their coating for aqueous dispersion and functionalisation to enable carriage of drugs, genes and fluorescent markers. The main problem related to the clinical use of these nanotubes is that there is no consent among scientists on the fate of such nano-materials following injection or implantation in humans. Provided carbon nanotubes are manufactured to certain medical criteria (length around 1 mum, purity of 97-99% and low Fe content) they exhibit no cytotoxicity on cell cultures and demonstrate full bio-compatibility on in vivo animal studies. The results of recent experimental studies have demonstrated the potential of technologies based on CNTs for low voltage wireless electro-chemotherapy of tumours and for electro-stimulation therapies for cardiac, neurodegenerative and skeletal and visceral muscle disorders.

Novel NHLRC1 mutations and genotype-phenotype correlations in patients with Lafora's progressive myoclonic epilepsy.

BACKGROUND: Lafora's progressive myoclonic epilepsy (Lafora's disease) is an autosomal recessive neurodegenerative disorder characterised by the presence of polyglucosan intracellular inclusions called Lafora bodies. Mutations in two genes, EPM2A and NHLRC1, have been shown to cause the disease. A previous study showed mutations in the EPM2A gene in 14 Lafora's disease families and excluded the involvement of this gene in five other families who were biopsy proven to have the disease. OBJECTIVE: To relate the genetic findings to the clinical course of the disease. METHODS: As part of an ongoing mutational study of the Lafora's disease genes, five new families with the disease were recruited and the genetic analysis was extended to screen the entire coding region of the NHLRC1 gene. Genotype-phenotype correlations were carried out. RESULTS: Seven NHLRC1 mutations were identified, including five novel mutations (E91K, D195N, P218S, F216_D233del, and V359fs32), in eight families with Lafora's disease. On relating the genetic findings to the clinical course of the disease it was shown that patients with NHLRC1 mutations had a slower rate of disease progression (p<0.0001) and thus appeared to live longer than those with EPM2A mutations. A simple DNA based test is described to detect the missense mutation C26S (c.76T-->A) in the NHLRC1 gene, which is prevalent among French Canadians. CONCLUSIONS: Patients with NHLRC1 mutations have a slower rate of disease progression than those with EPM2A mutations.

Drenaje percutáneo transglúteo de colecciones pelvianas: investigación anatómica y correlación clínica / CT-guided transgluteal percutaneous drainage: anatomy and clinic correlation

Antecedentes: Las colecciones pelvianas representan dificultades para su drenaje percutáneo, el acceso transglúteo es una alternativa posible pero se han informado complicaciones. Objetivos: Evaluar los resultados del drenaje percutáneo transglúteo guiado por TAC, analizar el dolor postoperatorio y describir la anatomía de la pared posterolateral de la pelvis. Lugar de aplicación: Policlínica Bancaria "9 de Julio". Diseño: Análisis retrospectivo e investigación anatómica. Población: Entre 1998 y 2004, 24 abscesos pelvianos fueron drenados percutáneamente por vía transglútea, guiados mediante TAC. Examinamos dieciseis disecciones cadavéricas y diez preparados anatómicos. Método: Todos los drenajes fueron practicados con anestesia local emplazando catéteres multipropósito mediante la técnica de Seldinger. El dolor fue evaluado mediante escala visual analógica comparándolo con una serie de pacientes drenados por vía anterior aplicando el test de Student. Fueron observados los diferentes planos anatómicos con sus forámenes y las estructuras óseas, musculares y ligamentarias; en ellos se investigaron los elementos nerviosos y vasculares. Resultados: Todos los abscesos pudieron ser drenados percutáneamente. La efectividad fue del 85 por ciento (17 pacientes). Nueve colecciones estaban comunicados con una víscera hueca. No hubo complicaciones. El dolor promedio fue leve, similar al de los pacientes drenados por vía anterior (p=0,77). En los preparados no observamos estructuras vasculonerviosas mayores por dentro del agujero ciático menor. Conclusiones: El drenaje percutáneo transglúteo es un procedimiento factible y eficáz. El procedimiento no es más doloroso que el drenaje por vía anterior. Existe un sector en la pared posterolateral de la pelvis que permite realizar el drenaje percutáneo con seguridad

Drenaje percutáneo transglúteo de colecciones pelvianas: investigación anatómica y correlación clínica / CT-guided transgluteal percutaneous drainage: anatomy and clinic correlation

Antecedentes: Las colecciones pelvianas representan dificultades para su drenaje percutáneo, el acceso transglúteo es una alternativa posible pero se han informado complicaciones. Objetivos: Evaluar los resultados del drenaje percutáneo transglúteo guiado por TAC, analizar el dolor postoperatorio y describir la anatomía de la pared posterolateral de la pelvis. Lugar de aplicación: Policlínica Bancaria "9 de Julio". Diseño: Análisis retrospectivo e investigación anatómica. Población: Entre 1998 y 2004, 24 abscesos pelvianos fueron drenados percutáneamente por vía transglútea, guiados mediante TAC. Examinamos dieciseis disecciones cadavéricas y diez preparados anatómicos. Método: Todos los drenajes fueron practicados con anestesia local emplazando catéteres multipropósito mediante la técnica de Seldinger. El dolor fue evaluado mediante escala visual analógica comparándolo con una serie de pacientes drenados por vía anterior aplicando el test de Student. Fueron observados los diferentes planos anatómicos con sus forámenes y las estructuras óseas, musculares y ligamentarias; en ellos se investigaron los elementos nerviosos y vasculares. Resultados: Todos los abscesos pudieron ser drenados percutáneamente. La efectividad fue del 85 por ciento (17 pacientes). Nueve colecciones estaban comunicados con una víscera hueca. No hubo complicaciones. El dolor promedio fue leve, similar al de los pacientes drenados por vía anterior (p=0,77). En los preparados no observamos estructuras vasculonerviosas mayores por dentro del agujero ciático menor. Conclusiones: El drenaje percutáneo transglúteo es un procedimiento factible y eficáz. El procedimiento no es más doloroso que el drenaje por vía anterior. Existe un sector en la pared posterolateral de la pelvis que permite realizar el drenaje percutáneo con seguridad (AU)

The role of Pseudomonas species in patients treated with ampicillin and Sulbactam for gangrenous and perforated appendicitis.

A prospective, randomized, double-blinded comparison of Sulbactam and ampicillin and clindamycin and gentamicin is described. The combination of ampicillin and Sulbactam was not as effective in the management of perforated appendicitis and gangrenous appendicitis as was clindamycin and gentamicin. While both combinations of antibiotics had good anaerobic activity and failures were not associated with the recovery of Bacteroides fragilis group organisms, infectious complications were seen in patients from whom Pseudomonas were isolated. These pseudomonads were not nosocomially acquired and were found especially in patients with perforated appendicitis. We concluded that the combination of clindamycin and gentamicin, although less convenient to administer to the patient, remains the adjunctive antibiotic management of choice for perforated or gangrenous appendicitis. The epidemiologic factors of Pseudomonas species as a primary pathogen in peritonitis deserves further attention.