Comorbidities and concomitant medications in patients with chronic hepatitis C virus infection receiving second-generation direct-acting antiviral regimens in Belgium: an observational study.

Objective: To describe comorbidities and concomitant medications in patients initiating treatment for hepatitis C virus (HCV) infection with direct-acting antiviral (DAA) regimens in Belgium. Methods: This was a noninterventional, observational, multicenter study of data from patient charts. Adult patients with HCV infection receiving second-generation DAA therapy were included. Comorbidities were assessed at the time of HCV treatment initiation. Concomitant medications were recorded at the time of diagnosis and at treatment initiation. Potential clinically relevant drug-drug interactions (DDIs) were assessed based on information available at www.hep-druginteractions.org. The primary objective was to describe concomitant medication use ; secondary objectives were to describe modifications in concomitant therapies and comorbidities. Results: 405 patients were included. A total of 956 comorbidities were reported by 362 patients (median, 2 ; range, 0-15). The most common comorbidities were hypertension (27.2%) ; HIV coinfection (22.5%), and type 2 diabetes mellitus (14.3%). Overall, 1455 concomitant medications were being taken by 365 patients (90.1% ; median, 3 ; range 0-16). The most common concomitant medications were psycholeptics (28.6%), antiviral agents (24.2%), and medications for acid-related disorders (21.0%) Overall, 74/365 (20.3%) patients receiving a concomitant medication required an adaptation to their concomitant medication. The medications that most frequently required change were drugs for acid-related disorders (n = 14) and antiviral drugs (n = 5) ; those that were most frequently stopped were lipid-modifying drugs (n = 25) and drugs for acid-related disorders (n = 13). Conclusion: Physicians are aware of the potential for DDIs with DAAs, but improved alignment between clinical practice and theoretical recommendations is required.

A Genetic Risk Score for the Estimation of Weight Loss After Bariatric Surgery.

BACKGROUND: Sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGB) are the most frequent bariatric surgery procedures worldwide. In this prospective study, we examined the association of a genetic risk score (GRS) with loss of excess weight after bariatric surgery. METHODS: A total of forty-seven morbidly obese Greek patients who underwent SG (81%) or RYGB were recruited, followed up for 2 years and genotyped. Weight loss after surgery was reported as the percentage of excess weight that was lost (%EWL) at 12 and 24 months after surgery. A GRS was constructed based on previously BMI- and WHR-related single nucleotide polymorphisms (SNPs) that were found significantly correlated with weight loss after bariatric surgery in our population. The level of post-surgery %EWL after 12 and 24 months was estimated through two multiple linear regression models that considered the effects of relevant genetic risk variants. RESULTS: The first proposed model suggested that the predictor variables of GRS, age, and BMI had a significant effect on %EWL12m. GRS was significantly associated with %EWL12m, indicating a 4.618% decrease of %EWL12m per score unit. The second model indicated a positive correlation between %EWL24m and %EWL12m, suggesting that while post-surgery weight loss increased during the first 12 months, an increase was expected in the next 12 months as well. GRS was also significantly associated with %EWL24m, indicating approximately 3% decrease of %EWL24m per score unit. CONCLUSION: GRS can be used in the future together with other preoperative parameters in order to predict the outcome of bariatric surgery.

Who to screen for hepatitis C? A cost-effectiveness study in Belgium of comprehensive hepatitis C screening in four target groups.

BACKGROUND AND STUDY AIMS: Hepatitis C virus (HCV) infection often causes asymptomatic disease and patients are frequently diagnosed at an advanced stage. Oral direct acting antivirals (DAAs) are successful in treating HCV with high sustained virologic response (SVR) and excellent tolerability. The aim of this study is to evaluate cost-effectiveness of a broad screening strategy proposing screening to all undiagnosed members of a population (comprehensive HCV screening), in the general adult population, emergency department (ED) attendees, men who have sex with men (MSM) and people who inject drugs (PWID). PATIENTS AND METHODS: We populated a theoretical model with Belgian data. A decision tree model simulating HCV screening and diagnosis was combined with a Markov state transition model simulating treatment. There was one screening round per year during five years. In the ED population only one screening round was considered. RESULTS: The model calculated that more HCV patients could be detected and treated with comprehensive screening compared to the current situation. Incremental cost per incremental quality adjusted life years (QALY) gained was lower than 10.000€/QALY for one and for five screening rounds in the general population (5.139 and 5.200 respectively), in ED attendees (one screening round 5.967), in MSMs (4.292 and 4.302 respectively) and in PWIDs (3.504 and 3.524 respectively). CONCLUSION: A broad screening strategy combined with treatment is likely to be a cost-effective strategy to detect and treat HCV infected patients and diminish the HCV burden in Belgium.

A multicentre, observational study on demographic and disease characteristics of patients seeking care for chronic hepatitis C in Belgium in 2016.

BACKGROUND AND STUDY AIMS: Direct-acting antivirals provide interferon-free treatments for chronic hepatitis C (CHC) virus infection. In Belgium, in 2016, access to these agents was limited to patients with advanced liver fibrosis stages F3 and F4. This study is the first to describe Belgium's patient population ineligible for interferon-free treatment. PATIENTS AND METHODS: This was an observational, cross-sectional, multicentre study that enrolled adult patients with CHC ineligible for interferon-free treatment. Patient data recorded at a single visit included demographic data, disease characteristics, comorbidities, co-medications, treatment status, and laboratory data. RESULTS: Three hundred and three patients from 16 centres in Belgium were included in the statistical analysis. On average, patients were aged 53.5 years and 50.2% were women ; 94.1% had health insurance and 99.0% resided in Belgium. The current hepatitis C virus (HCV) infection was the first infection for 96.0% of patients and the mean time since infection was 20.0 years. Liver fibrosis stage was F0 for 23.7%, F0/F1 or F1 for 38.3%, F1/F2 or F2 for 25.8%, F3 for 7.1%, and F4 for 5.1% of patients ; 28.4% of patients were CHC treatment-experienced. The main reason for ineligibility for interferon-free treatment was lack of reimbursement (84.8%). Other reasons included no treatment urgency or medical decision to wait (27.1%), waiting for future treatment option (8.3%), and no social insurance coverage (3.6%). CONCLUSIONS: This study provides recent data on the CHC patient population and disease characteristics in Belgium that could help medical communities and government agencies manage CHC disease burden.

Hepatitis C virus (HCV) prevalence estimation in the adult general population in Belgium : a meta-analysis.

BACKGROUND AND STUDY AIMS: Although multiple HCV prevalence studies were recently performed in the general population from Belgium, they suffer from a lack of geographical representativeness, an insufficient number of participants or a lack of inclusion of high prevalence groups. The aim of this study is to provide robust information on the HCV burden. METHODS: Recently performed HCV prevalence studies in the general, adult population were included in this study, based on well-defined selection criteria. A meta-analysis was performed to estimate the seroprevalence, the prevalence of participants with viremia and the prevalence estimation for people with viremia which were unaware of their status. RESULTS: Eight studies fulfilled the criteria for inclusion of the quantitative prevalence estimation. Based on the meta-analysis on these 8 studies, we estimated an HCV seroprevalence of 1.01% [95% CI : 0.66-1.42%], representing a total of 90,722 adult, HCV seropositives of which 64,412 individuals (0.71%) were confirmed seropositive. Based on the RNA presence, an estimated viremic prevalence of 0.33% [95% CI : 0.21-0.47 %] was determined, corresponding with 29,642 individuals. This is 46,0% of the true HCV seropositive residents. Further, based on the availability of patient information in 5 out of the 8 studies, a prevalence of 0.18% [95% CI : 0.07-0.33] representing 16,168 individuals from the adult Belgian population are unaware of their HCV status. CONCLUSIONS: We believe that the quantitative measurement by the meta-analysis will be more reliable for their use in the design of a screening strategy or in the development of prevention campaigns as compared to the prevalence estimations performed at local level.

Development of pectin microparticles by using ionotropic gelation with chlorhexidine as cross-linking agent.

Having previously highlighted the gelation of pectin with chlorhexidine (CX), pectinate microparticles were prepared here by vibrational prilling using CX, not only as an active ingredient encapsulated but also as a cross-linking agent. CX amount required for pectin gelation was smaller than usual dications (Ca2+, Zn2+) used as cross-linking agent for pectin ionotropic gelation: CX seemed to bind more easily to pectin chains that could be explained by its large molecular size. Three batches of CX microparticles with different mean size were prepared. Whatever the droplet mean diameter, similar particle characteristics in terms of encapsulation efficiency, CX encapsulation yield and drug release were observed. The encapsulation efficiency was about 5.5%, the CX encapsulation yield was approximately 44% and the maximal amount of CX released after 6 h was about 7%. Finally, zinc diacetate was added to the formulation as a competitive pectin cross-linking agent in order to limit CX binding to pectin and to improve CX release. The influence of CX and Zn2+ concentrations on the particles properties was studied by the means of a Doehlert design. Results showed the interest of such a mixture since the competition between both cations led to more or less structured and large microparticles, some of them having promoted the quantity of CX released.

Stopping nucleos(t)ide analogue treatment in Caucasian hepatitis B patients after HBeAg seroconversion is associated with high relapse rates and fatal outcomes.

BACKGROUND: Stopping nucleos(t)ide analogues (NA) after hepatitis B e antigen (HBeAg) seroconversion is associated with high relapse rates in Asian patients, but data in Caucasian cohorts are scarce. Clinical course, outcomes and immunological aspects of chronic hepatitis B infections differ substantially between distinct ethnicities. AIM: The aim of this study was to determine relapse rates, factors predicting relapse and clinical outcomes after nucleos(t)ide analogue cessation in a large, predominantly Caucasian cohort of chronic hepatitis B patients with nucleos(t)ide analogue-induced HBeAg seroconversion. METHODS: This is a nationwide observational cohort study including HBeAg positive, mono-infected chronic hepatitis B patients with nucleos(t)ide analogue-induced HBeAg seroconversion from 18 centres in Belgium. RESULTS: A total of 98 patients with nucleo(s)tide analogue-induced HBeAg seroconversion were included in the study. Of the 62 patients who stopped treatment after a median consolidation treatment of 8 months, 30 relapsed. Higher gamma-glutamyl transferase levels at both treatment initiation (HR 1.004; P = 0.001 per unit increment) and HBeAg seroconversion (HR 1.006; P = 0.013 per unit increment) were associated with an increased risk of clinically significant relapse in a multivariate Cox regression model. Treatment cessation led to liver-related death in 2 patients, of whom one showed a severe flare. Of the patients who continued treatment after HBeAg seroconversion, none relapsed or developed severe hepatic outcomes. CONCLUSION: Treatment withdrawal in Caucasian chronic hepatitis B patients after nucleos(t)ide analogue-induced HBeAg seroconversion results in viral relapses in more than half of patients with potential fatal outcomes. These real-world data further lend support to preferentially continue NA treatment after HBeAg seroconversion until HBsAg loss.

The risk of early occurrence and recurrence of hepatocellular carcinoma in hepatitis C-infected patients treated with direct-acting antivirals with and without pegylated interferon: A Belgian experience.

Recently, concerns were raised of high rates of HCC recurrence in patients treated with direct-acting antivirals (DAA) for hepatitis C infection. We investigated the HCC occurrence and recurrence rates within 6 months after treatment with DAA with or without pegylated interferon (PEG-IFN) in real life. This is a retrospective, multicenter cohort trial, executed in 15 hospitals distributed across Belgium. Populations were matched based on fibrosis score (Metavir F3-F4). Patients with a Child-Pugh score ≥ B were excluded. In total, 567 patients were included, of whom 77 were treated with PEG-IFN+DAA between 2008 and 2013 and 490 with DAA without PEG-IFN between 2013 and 2015. Patients treated with PEG-IFN+DAA (53±9y) were younger than patients treated with DAA without PEG-IFN (59±12y) (P=.001). 47% of patients treated with PEG-IFN+DAA were in the F4 stage vs 67% of patients treated with DAA without PEG-IFN (P=.001). Screening was inadequate in 20% of both patient groups (P=.664). The early occurrence rate of HCC was 1.7% and 1.1% in patients treated with DAA with and without PEG-IFN, respectively (P=.540). The early recurrence rate was 0% in patients treated with PEG-IFN+DAA and 15.0% in patients treated with DAA without PEG-IFN (P=.857). There is no difference in early occurrence of new HCC between patients treated with DAA with and without PEG-IFN. We did observe a high early recurrence rate of HCC in patients treated with DAA without PEG-IFN. However, these patients were at baseline more at risk for HCC. Finally, in 20%, screening for HCC was inadequate.

A case of pseudorenal failure - spontaneous rupture of the urinary bladder.

A 64-year old woman was admitted to the hospital for severe abdominal pain and distension after gardening and chopping wood the day before. She had a medical history of superficial transitional cell carcinoma (TCC) of the urinary bladder and a laparoscopic nefro-ureterectomy for an invasive TCC of the upper urothelial tract in 2012. Clinical examination showed an acute abdomen. Laboratory analysis revealed a plasma creatinine level of 4,23 mg/dl. Computed tomography (CT) imaging of the abdomen showed hypodense free intraperitoneal fluid, suspicious for ascites. Serum creatinine level decreased to 1.8 mg/dl after placement of a urinary catheter. Laparoscopic exploration revealed a perforated ulcer in the urinary bladder dome, the intraperitoneal fluid showed abnormally high levels of urea and creatinine, confirming uroperitoneum. This case shows that uroperitoneum must be in-cluded in the differential diagnosis of patients with diffuse/acute abdominal pain, abdominal distension and elevated levels of serum creatinine, and that vigilance is indicated.

Mitigating the burden of hepatitis C virus among people who inject drugs in Belgium.

BACKGROUD AND AIMS: In 2010, there were an estimated 10 100 PWID in Belgium and 43% (34%-57%) were HCV infected. Understanding HCV transmission dynamics in high-risk populations and assessing the potential impact of improved HCV treatment strategies requires robust epidemiological data and mathematical modeling. METHODS: CV transmission was modeled using cohorts to track HCV incidence and prevalence among active PWID in the general PWID population, OST and NSP. Model assumptions were derived from published literature and expert consensus. The relative impact of increasing the number of PWID treated with new oral DAAs was considered. RESULTS: If the current transmission paradigm continues, there will be 2645 HCV-infected PWID in 2030. Annually treating 30 (1% of 2015 population) or 120 (4% of 2015 population) HCV-infected PWID with oral DAAs will result in 5% and 25% reductions, respectively, in HCV-infected PWID by 2030. Treating 370 PWID annually (12.5% of 2015 population) will result in a > 90% reduction by 2030. CONCLUSION: Treating a small number of PWID can result in substantial reduction in HCV prevalence in this population ; however, high levels of treatment are necessary to reduce the viral pool and thus the risk of secondary infections. This analysis supports implementation of a screening and treatment strategy among PWID when combined with an expansion of harm reduction programs.

Achieving WHO recommendations for Hepatitis C Virus Elimination in Belgium.

BACKGROUD: The World Health Organization (WHO) released updated guidelines for the screening, care and treatment of patients with chronic hepatitis C virus (HCV) infection. METHODS: A previously described HCV disease burden model was used to develop a "WHO scenario" to achieve the WHO recommendations of a 90% reduction in incidence and 65% reduction in liver-related deaths. After determining the steps necessary to achieve this goal, the impact of realistic constraints was modeled. RESULTS: In 2015, there were 66.200 viremic infections, with 43% diagnosed and 1.350 treated. In order to reduce new infections, treatment must be extended to ≥ F0 patients, including people who inject drugs and other individuals at risk of transmitting HCV. -Additionally, diagnosis and treatment of 3.030 and 4.060 patients, respectively, would be required. The largest attenuation of the WHO scenario would occur if no new cases were diagnosed after 2018 (300% more viremic infections by 2030). Limiting treatment to ≥ F2 patients or treating fewer patients (3.000) would result in 220% or 140% more viremic cases, respectively, compared with the WHO scenario. CONCLUSION: Achieving the WHO guidelines in Belgium requires a coordinated effort to scale up treatment and prevention efforts and to allow treatment access to patients of all fibrosis stages. A scale-up of treatment, however, requires patients to be both diagnosed and linked to care, suggesting a need for increased awareness and expanded screening efforts. Finally, prevention of new HCV infections requires a comprehensive understanding of the population at risk of transmitting HCV.

Belgian experience with triple therapy with boceprevir and telaprevir in genotype 1 infected patients who inject drugs.

No data have been reported yet on treatment outcome in persons who inject drugs (PWID) infected with hepatitis C virus treated with boceprevir or telaprevir in combination with peginterferon (Peg IFN) and ribavirin (RBV). Additionally, there are concerns about the safety of boceprevir and telaprevir in some subgroups of patients with hepatitis C (HCV). In a cohort of HCV patients infected with genotype 1 in Belgium, treatment outcome of patients infected due to IV drug use was analyzed and compared with patients who have no history of substance use. The study population consisted of 179 patients: 78 PWID and 101 controls treated with boceprevir (n = 79) or telaprevir (n = 100) additional to Peg IFN and RBV; 53 (30%) had advanced disease (F3, F4) and 79 (44%) had an antiviral therapy previously. There were no significant differences in the baseline characteristics between both groups, except that PWID patients were more frequently infected with genotype 1a (67% vs 21%), were younger and were predominantly male. Psychiatric complaints during follow-up occurred more frequently in the PWID patients: 24% versus 11% (P = .02). Treatment failure for other reasons than absence of viral response was 70% and 64% in PWID and non-PWID respectively. The sustained viral response (SVR) rates were similar in both groups (71% in PWID vs 72% in non-PWID); with a non-inferiority test with -5% margin there is a difference of -1% (95% CI [-15%, 13%]) and P = 0.30. There are no reasons to exclude PWID from treatment with boceprevir, telaprevir and novel antiviral therapies.

Characteristics, treatment, and virologic responses of chronic hepatitis C patients treated with peginterferon alfa-2a and ribavirin in belgium: a sub-analysis of the PROPHESYS study.

BACKGROUND AND STUDY AIMS: PROPHESYS was a prospective, international cohort study of monoinfected, treatment-naive chronic hepatitis C patients treated with a combination of peginterferon alfa-2a or alfa-2b and ribavirin.It included worldwide 7,163 patients from 19 countries (including 384 patients from Belgium alone) and demonstrated that sustained virologic response rates in the real world were similar to those achieved in well-controlled clinical trials. The objective of this sub-analysis was to present an overview of the baseline characteristics, anti-hepatitis C drug treatment, and virologic responses of the patients treated in Belgium, infected with HCV genotype 1, 2, 3, or 4, and administered pegin-terferon alfa-2a. Moreover, the impact of ribavirin dosage on the response to treatment was studied. PATIENTS AND METHODS: 356 patients were included in this sub-analysis. All variables were summarized using descriptive statistics. RESULTS: Compared to the published data of the whole study population (1), the Belgian data presented some significant differences in terms of genotype distribution and response to treatment (e.g. lower prevalence of HCV genotype 1 infection, lower virologic response rates in HCV genotype 2 patients). Deviations from existing recommendations were identified (e.g. higher dose of ribavirin in HCV genotype 2 or 3 patients). Patients who received less than 80% of the target dose of ribavirin experienced a significantly weaker response to treatment. CONCLUSION: This sub-analysis provided an interesting profile of the Belgian experience in the treatment of chronic hepatitis C.

A non-interventional phase IV Belgian survey to assess the antiviral effectiveness of pegylated interferon-alpha-2b and ribavirin treatment according to the stage of liver fibrosis in previously untreated patients with genotype 1/4/5/6 chronic hepatitis C (PRACTICE).

BACKGROUND AND STUDY AIMS: This was an observational, non-interventional, multicenter, phase IV study, in patients with genotype 1/4/5/6 chronic hepatitis C (CHC). The primary objectives were to evaluate SVR in patients with no or minimal fibrosis (METAVIR F0-F1) versus well established fibrosis (F2-F4), and to estimate response on Weeks 12, 24 and 48 on treatment in previously untreated patients with genotypes 1/4/5/6 CHC. PATIENTS AND METHODS: 538 patients treated with pegylated interferon alfa 2b 1.5 mcg/kg in combination with ribavirin 800-1200 mg/day were enrolled in 55 sites in Belgium and Luxembourg, 505 being considered for the analysis. 40% of the patients were female and 60% male, the average age was 47.5 years, 10.5% were 65 or older. RESULTS: SVR was observed in 35% of the patients, EVR in 68%, of which pEVR in 33% and cEVR in 35%. SVR was observed in 43% of the low fibrosis group (F0, F1) and 30% of the high fibrosis group (F2, F3, F4) (p = 0.005). SVR rates were 34% for genotype 1, 37% for genotype 4, and 47% for genotype 5 (NS). Multivariate analysis showed that EVR and baseline METAVIR score are independent prognostic factors for SVR. CONCLUSIONS: This trial confirms that fibrosis stage and early viral response are the most important key-factors to predict sustained response, suggesting that the earlier patients are treated, the better the outcome. Non-invasive techniques enable us to closely monitor progression of fibrosis, allowing a better selection of patients for antiviral treatment in the DAA-era.

Intrinsic nature of the excess electron distribution at the TiO2(110) surface.

The gap state that appears upon reduction of TiO2 plays a key role in many of titania's interesting properties but its origin and spatial localization have remained unclear. In the present work, the TiO2(110) surface is reduced in a chemically controlled way by sodium adsorption. By means of resonant photoelectron diffraction, excess electrons are shown to be distributed mainly on subsurface Ti sites strikingly similar to the defective TiO2(110) surface, while any significant contribution from interstitial Ti ions is discarded. In agreement with first principles calculations, these findings demonstrate that the distribution of the band gap charge is an intrinsic property of TiO2(110), independent of the way excess electrons are produced.

Mucoadhesion evaluation of polysaccharide gels for vaginal application by using rheological and indentation measurements.

The influence of hyaluronic acid (HA) and fructooligosaccharides (FOS) addition on low methyl pectin (LMP) gelation has been investigated in order to produce adhesive gel-based microparticles suitable for the development of a vaginal delivery system of pro- and prebiotics. First, dynamic rheological measurements were performed on LMP/Ca(2+) gels with or without FOS and HA in presence or not of porcine stomach mucins. This rheological method is known to translate the interactions between polymer and mucins and then simulate the polymer bioadhesion potential. Nevertheless, as this method is disputed, in vitro and ex vivo indentation test measurements were also achieved in order to correlate the results obtained. Despite some different results, the overall tendency indicates that addition of HA and FOS enhanced the mucoadhesive properties of LMP gels. Moreover, gel-based microparticles obtained according to an emulsification/gelation method and composed by LMP 3% (w/v), FOS 5% (w/v) and HA 0.5% (w/v) displayed a mucoadhesive potential adapted to vaginal delivery system.

Two outbreaks of botulism associated with consumption of green olive paste, France, September 2011.

Two family outbreaks of botulism (a total of nine cases) were identified in south-east and northern France in early September 2011. The source of infection was considered to be a ground green olive paste. Botulinum type A toxin was identified in seven cases and in the incriminated olive paste. Incorrect sterilisation techniques were observed at the artisanal producer's workshop. These episodes highlight the potential public health threat of Clostridium botulinum linked to inadequate sterilisation of food products.

Improvement of an encapsulation process for the preparation of pro- and prebiotics-loaded bioadhesive microparticles by using experimental design.

The purpose of this study was to design a new vaginal bioadhesive delivery system based on pectinate-hyaluronic acid microparticles for probiotics and prebiotics encapsulation. Probiotic strains and prebiotic were selected for their abilities to restore vaginal ecosystem. Microparticles were produced by emulsification/gelation method using calcium as cross-linking agent. In the first step, preliminary experiments were conducted to study the influence of the main formulation and process parameters on the size distribution of unloaded microparticles. Rheological measurements were also performed to investigate the bioadhesive properties of the gels used to obtain the final microparticles. Afterwards an experimental design was performed to determine the operating conditions suitable to obtain bioadhesive microparticles containing probiotics and prebiotics. Experimental design allowed us to define two important parameters during the microencapsulation process: the stirring rate during the emulsification step and the pectin concentration. The final microparticles had a mean diameter of 137µm and allowed a complete release of probiotic strains after 16h in a simulated vaginal fluid at +37°C.

Skin absorption studies of octyl-methoxycinnamate loaded poly(D,L-lactide) nanoparticles: estimation of the UV filter distribution and release behaviour in skin layers.

New formulation strategies have to be developed to limit the skin penetration of UV-filter. Nanoparticles (NP) are very suitable for that purpose. In this study, the skin distribution, at different times (1, 2 and 3 h), of octyl-methoxycinnamate (OMC) from loaded PLA-nanoparticles was compared to a classical formulation containing non-encapsulated OMC, using the Franz cell method. The results showed that the OMC penetration was clearly impeded by stratum corneum and that the major part of the OMC-NP was accumulated at the skin surface (> 80%). A significant lower OMC amount was quantified in viable skin with NP compared to the OMC emulgel. To accurately determine the real OMC amount in close contact with viable skin layers two solvents were used to extract OMC from the skin compartments. Acetone (ACET) allowed quantifying both OMC in NP and OMC released from the particles, while isopropylmyristate (IPM), a non-solvent of the NP polymer (PLA), allowed quantifying only OMC released from the particles. Using IPM as an extraction solvent, it appeared that the OMC released from NP, in contact with viable skin, was 3-fold lower than free OMC diffused from the emulgel. Lastly, a sustained release was observed when nanoparticles were used.

Elaboration and characterization of barium silicate thin films.

Room temperature depositions of barium on a thermal silicon oxide layer were performed in ultra high vacuum (UHV). In-situ X-ray photoelectron spectroscopy (XPS) analyses were carried out as well after exposure to air as after subsequent annealings. These analyses were ex-situ completed by secondary ion mass spectrometry (SIMS) profiles and transmission electron microscopy (TEM) cross-sectional images. The results showed that after air exposure, the barium went carbonated. Annealing at sufficient temperature permitted to decompose the carbonate to benefit of a barium silicate. The silicate layer was formed by interdiffusion of barium with the initial SiO2 layer.