A cohort analysis of residential radon exposure and melanoma incidence in Switzerland.

Radon is a radioactive noble gas found in Earth's crust. It accumulates in buildings, and accounts for approximately half the ionizing radiation dose received by humans. The skin is considerably exposed to ionizing radiation from radon. We aimed to evaluate the association between residential radon exposure and melanoma and squamous cell carcinoma incidence. The study included 1.3 million adults (20 years and older) from the Swiss National Cohort who were residents of the cantons of Vaud, Neuchâtel, Valais, Geneva, Fribourg, and Ticino at the study baseline (December 04, 2000). Cases of primary tumours of skin (melanoma and squamous cell carcinoma) were identified using data from cantonal cancer registries. Long-term residential radon and ambient solar ultraviolet radiation exposures were assigned to each individual's address at baseline. Cox proportional hazard models with age as time scale, adjusted for canton, socioeconomic position, demographic data available in the census, and outdoor occupation were applied. Total and age specific effects were calculated, in the full population and in non-movers, and potential effect modifiers were tested. In total 4937 incident cases of melanoma occurred during an average 8.9 years of follow-up. Across all ages, no increased risk of malignant melanoma or squamous cell carcinoma incidence in relation to residential radon was found. An association was only observed for melanoma incidence in the youngest age group of 20-29 year olds (1.68 [95% CI: 1.29, 2.19] 100 Bq/m3 radon). This association was mainly in women, and in those with low socio-economic position. Residential radon exposure might be a relevant risk factor for melanoma, especially for young adults. However, the results must be interpreted with caution as this finding is based on a relatively small number of melanoma cases. Accumulation of radon is preventable, and measures to reduce exposure and communicate the risks remain important to convey to the public.

Predicting second breast cancer among women with primary breast cancer using machine learning algorithms, a population-based observational study.

Breast cancer survivors often experience recurrence or a second primary cancer. We developed an automated approach to predict the occurrence of any second breast cancer (SBC) using patient-level data and explored the generalizability of the models with an external validation data source. Breast cancer patients from the cancer registry of Zurich, Zug, Schaffhausen, Schwyz (N = 3213; training dataset) and the cancer registry of Ticino (N = 1073; external validation dataset), diagnosed between 2010 and 2018, were used for model training and validation, respectively. Machine learning (ML) methods, namely a feed-forward neural network (ANN), logistic regression, and extreme gradient boosting (XGB) were employed for classification. The best-performing model was selected based on the receiver operating characteristic (ROC) curve. Key characteristics contributing to a high SBC risk were identified. SBC was diagnosed in 6% of all cases. The most important features for SBC prediction were age at incidence, year of birth, stage, and extent of the pathological primary tumor. The ANN model had the highest area under the ROC curve with 0.78 (95% confidence interval [CI] 0.750.82) in the training data and 0.70 (95% CI 0.61-0.79) in the external validation data. Investigating the generalizability of different ML algorithms, we found that the ANN generalized better than the other models on the external validation data. This research is a first step towards the development of an automated tool that could assist clinicians in the identification of women at high risk of developing an SBC and potentially preventing it.

Revisiting carboxylic group functionalization of silica sol-gel materials.

The carboxylic chemical group is a ubiquitous moiety present in amino acids, a ligand for transition metals, a colloidal stabilizer, and a weak acidic ion-exchanger in polymeric resins and given this property, it is attractive for responsive materials or nanopore-based gating applications. As the number of uses increases, subtle requirements are imposed on this molecular group when anchored to various platforms for the functioning of an integrated chemical system. In this context, silica stands as an inert and multipurpose platform that enables the anchoring of multiple chemical entities combined through several orthogonal synthesis methods on the interface. Surface chemical modification relies on the use of organoalkoxysilanes that must meet the demand of tuned chemical properties; this, in turn, urges for innovative approaches for having an improved, but simple, organic toolbox. Starting from commonly available molecular precursors, several approaches have emerged: hydrosilylation, click thiol-ene additions, the use of carbodiimides or the reaction between cyclic anhydrides and anchored amines. In this review, we analyze the importance of the COOH groups in the area of materials science and the commercial availability of COOH-based silanes and present new approaches for obtaining COOH-based organoalkoxide precursors. Undoubtedly, this will attract widespread interest for the ultimate design of highly integrated chemical platforms.

Management and Outcome of Young Women (≤40 Years) with Breast Cancer in Switzerland.

Background: An increase in breast cancer (BC) incidence in young women (YW) as well as disparities in BC outcomes have been reported in Switzerland. We sought to evaluate treatment and outcome differences among YW with BC (YWBC). Methods: YW diagnosed with stage I-III BC between 2000−2014 were identified through nine cancer registries. Concordance with international guidelines was assessed for 12 items covering clinical/surgical management, combined in a quality-of-care score. We compared score and survival outcome between the two linguistic-geographic regions of Switzerland (Swiss-Latin and Swiss-German) and evaluated the impact of quality-of-care on survival. Results: A total of 2477 women were included. The median age was 37.3 years (IQR 34.0−39.4 years), with 50.3% having stage II BC and 70.3% having estrogen receptor positive tumors. The mean quality-of-care score was higher in the Latin region compared to the German region (86.0% vs. 83.2%, p < 0.0005). Similarly, 5- and 10-year overall survival rates were higher in the Latin compared to the German region (92.3% vs. 90.2%, p = 0.0593, and 84.3% vs. 81.5%, p = 0.0025, respectively). There was no difference in survival according to the score. In the univariate analysis, women in the Latin region had a 28% lower mortality risk compared to women in the German region (hazard ratio 0.72; 95% CI 0.59−0.89). In the multivariable analysis, only stage, differentiation, tumor subtype and treatment period remained independently associated with survival. Conclusions: We identified geographic disparities in the treatment and outcome of YWBC in Switzerland. National guidelines for YWBC should be implemented to standardize treatment. Awareness should be raised among YW and clinicians that BC does not discriminate by age.

Does the morphology of cutaneous melanoma help to explain the international differences in survival? Results from 1 578 482 adults diagnosed during 2000-2014 in 59 countries (CONCORD-3).

BACKGROUND: CONCORD-3 highlighted wide disparities in population-based 5-year net survival for cutaneous melanoma during 2000-2014. Clinical evidence suggests marked international differences in the proportion of lethal acral and nodular subtypes of cutaneous melanoma. OBJECTIVES: We aimed to assess whether the differences in morphology may explain global variation in survival. METHODS: Patients with melanoma were grouped into the following seven morphological categories: malignant melanoma, not otherwise specified (International Classification of Diseases for Oncology, third revision morphology code 8720), superficial spreading melanoma (8743), lentigo maligna melanoma (8742), nodular melanoma (8721), acral lentiginous melanoma (8744), desmoplastic melanoma (8745) and other morphologies (8722-8723, 8726-8727, 8730, 8740-8741, 8746, 8761, 8770-8774, 8780). We estimated net survival using the nonparametric Pohar Perme estimator, correcting for background mortality by single year of age, sex and calendar year in each country or region. All-ages survival estimates were standardized using the International Cancer Survival Standard weights. We fitted a flexible parametric model to estimate the effect of morphology on the hazard of death. RESULTS: Worldwide, the proportion of nodular melanoma ranged between 7% and 13%. Acral lentiginous melanoma accounted for less than 2% of all registrations but was more common in Asia (6%) and Central and South America (7%). Overall, 36% of tumours were classified as superficial spreading melanoma. During 2010-2014, age-standardized 5-year net survival for superficial spreading melanoma was 95% or higher in Oceania, North America and most European countries, but was only 71% in Taiwan. Survival for acral lentiginous melanoma ranged between 66% and 95%. Nodular melanoma had the poorest prognosis in all countries. The multivariable analysis of data from registries with complete information on stage and morphology found that sex, age and stage at diagnosis only partially explain the higher risk of death for nodular and acral lentiginous subtypes. CONCLUSIONS: This study provides the broadest picture of distribution and population-based survival trends for the main morphological subtypes of cutaneous melanoma in 59 countries. The poorer prognosis for nodular and acral lentiginous melanomas, more frequent in Asia and Latin America, suggests the need for health policies aimed at specific populations to improve awareness, early diagnosis and access to treatment. What is already known about this topic? The histopathological features of cutaneous melanoma vary markedly worldwide. The proportion of melanomas with the more aggressive acral lentiginous or nodular histological subtypes is higher in populations with predominantly dark skin than in populations with predominantly fair skin. What does this study add? We aimed to assess the extent to which these differences in morphology may explain international variation in survival when all histological subtypes are combined. This study provides, for the first time, international comparisons of population-based survival at 5 years for the main histological subtypes of melanoma for over 1.5 million adults diagnosed during 2000-2014. This study highlights the less favourable distribution of histological subtypes in Asia and Central and South America, and the poorer prognosis for nodular and acral lentiginous melanomas. We found that later stage at diagnosis does not fully explain the higher excess risk of death for nodular and acral lentiginous melanoma compared with superficial spreading melanoma.

Deoxy sugars. General methods for carbohydrate deoxygenation and glycosidation.

Deoxy sugars represent an important class of carbohydrates, present in a large number of biomolecules involved in multiple biological processes. In various antibiotics, antimicrobials, and therapeutic agents the presence of deoxygenated units has been recognized as responsible for biological roles, such as adhesion or great affinity to receptors, or improved efficacy. The characterization of glycosidases and glycosyltranferases requires substrates, inhibitors and analogous compounds. Deoxygenated sugars are useful for carrying out specific studies for these enzymes. Deoxy sugars, analogs of natural substrates, may behave as substrates or inhibitors, or may not interact with the enzyme. They are also important for glycodiversification studies of bioactive natural products and glycobiological processes, which could contribute to discovering new therapeutic agents with greater efficacy by modification or replacement of sugar units. Deoxygenation of carbohydrates is, thus, of great interest and numerous efforts have been dedicated to the development of methods for the reduction of sugar hydroxyl groups. Given that carbohydrates are the most important renewable chemicals and are more oxidized than fossil raw materials, it is also important to have methods to selectively remove oxygen from certain atoms of these renewable raw materials. The different methods for removal of OH groups of carbohydrates and representative or recent applications of them are presented in this chapter. Glycosidic bonds in general, and 2-deoxy glycosidic linkages, are included. It is not the scope of this survey to cover all reports for each specific technique.

Correction to: The relative risk of second primary cancers in Switzerland: a population-based retrospective cohort study.

Following publication of the original article [1], an error was reported in the author group. The correct author group should read as follows.

The relative risk of second primary cancers in Switzerland: a population-based retrospective cohort study.

BACKGROUND: More people than ever before are currently living with a diagnosis of cancer and the number of people concerned is likely to continue to rise. Cancer survivors are at risk of developing a second primary cancer (SPC). This study aims to investigate the risk of SPC in Switzerland. METHODS: The study cohort included all patients with a first primary cancer recorded in 9 Swiss population-based cancer registries 1981-2009 who had a minimum survival of 6 months, and a potential follow-up until the end of 2014. We calculated standardized incidence ratios (SIR) to estimate relative risks (RR) of SPC in cancer survivors compared with the cancer risk of the general population. SIR were stratified by type of first cancer, sex, age and period of first diagnosis, survival period and site of SPC. RESULTS: A total of 33,793 SPC were observed in 310,113 cancer patients. Both male (SIR 1.18, 95%CI 1.16-1.19) and female (SIR 1.20, 95%CI 1.18-1.22) cancer survivors had an elevated risk of developing a SPC. Risk estimates varied substantially according to type of first cancer and were highest in patients initially diagnosed with cancer of the oral cavity and pharynx, Hodgkin lymphoma, laryngeal, oesophageal, or lung cancer. Age-stratified analyses revealed a tendency towards higher RR in patients first diagnosed at younger ages. Stratified by survival period, risk estimates showed a rising trend with increasing time from the initial diagnosis. We observed strong associations between particular types of first and SPC, i.e. cancer types sharing common risk factors such as smoking or alcohol consumption (e.g. repeated cancer of the oral cavity and pharynx (SIRmales 20.12, 95%CI 17.91-22.33; SIRfemales 37.87, 95%CI 30.27-45.48). CONCLUSION: Swiss cancer survivors have an increased risk of developing a SPC compared to the general population, particularly patients first diagnosed before age 50 and those surviving more than 10 years. Cancer patients should remain under continued surveillance not only for recurrent cancers but also for new cancers. Some first and SPCs share lifestyle associated risk factors making it important to promote healthier lifestyles in both the general population and cancer survivors.

Impact of subtypes and comorbidities on breast cancer relapse and survival in population-based studies.

OBJECTIVE: To study the impact of subtypes and comorbidities on breast cancer (BC) relapse and survival in the heterogeneous patients of the real world. METHODS: We identified patients diagnosed with BC between January 2003 and December 2005 from six population-based Swiss cancer registries. Clinicopathologic data was completed with information on locoregional and distant relapse and date and cause of death for over 10-years. We approximated BC subtypes using grade and the immunohistochemical panel for oestrogen, progesterone and human epidermal growth factor 2 (HER2) receptor status. We studied factors affecting relapse and survival. RESULTS: Luminal A-like subtype represented 46% of all newly diagnosed BC (N = 1831), followed by luminal B-like (N = 1504, 38%), triple negative (N = 436, 11%) and HER2 enriched (N = 204, 5%). We observed regional disparities in subtype prevalence that contribute to explain regional differences in survival formerly described. Disease relapse and BC specific mortality differed by subtype and were lower for luminal A like tumours than for other subtypes for any stage at diagnosis. After a median follow-up of 10.9 years, 1311 (33%) had died, half of them 647 (16%) due to another disease, showing the importance of comorbidities. Omission of systemic therapies in selected patients was not associated with poorer BC specific survival, BC subtype and life expectancy playing a role. CONCLUSIONS: Information on tumour subtype is necessary for an adequate interpretation of population-based BC studies. Measures of comorbidity or frailty help in the evaluation of quality of care in the highly heterogeneous patients of the real world.

Quality indicators of clinical cancer care for prostate cancer: a population-based study in southern Switzerland.

BACKGROUND: Quality of cancer care (QoCC) has become an important item for providers, regulators and purchasers of care worldwide. Aim of this study is to present the results of some evidence-based quality indicators (QI) for prostate cancer (PC) at the population-based level and to compare the outcomes with data available in the literature. METHODS: The study included all PC diagnosed on a three years period analysis (01.01.2011-31.12.2013) in the population of Canton Ticino (Southern Switzerland) extracted from the Ticino Cancer Registry database. 13 QI, approved through the validated Delphi methodology, were calculated using the "available case" approach: 2 for diagnosis, 4 for pathology, 6 for treatment and 1 for outcome. The selection of the computed QI was based on the availability of medical documentation. QI are presented as proportion (%) with the corresponding 95% confidence interval. RESULTS: 700 PC were detected during the three-year period 2011-2013: 78.3% of them were diagnosed through a prostatic biopsy and for 72.5% 8 or more biopsy cores were taken. 46.5% of the low risk PC patients underwent active surveillance, while 69.2% of high risk PC underwent a radical treatment (radical prostatectomy, radiotherapy or brachytherapy) and 73.5% of patients with metastatic PC were treated with hormonal therapy. The overall 30-day postoperative mortality was 0.5%. CONCLUSIONS: Results emerging from this study on the QoCC for PC in Canton Ticino are encouraging: the choice of treatment modalities seems to respect the international guidelines and our results are comparable to the scarce number of available international studies. Additional national and international standardisation of the QI and further QI population-based studies are needed in order to get a real picture of the PC diagnostic-therapeutic process progress through the definition of thresholds of minimal standard of care.

Observed rapid bedrock uplift in Amundsen Sea Embayment promotes ice-sheet stability.

The marine portion of the West Antarctic Ice Sheet (WAIS) in the Amundsen Sea Embayment (ASE) accounts for one-fourth of the cryospheric contribution to global sea-level rise and is vulnerable to catastrophic collapse. The bedrock response to ice mass loss, glacial isostatic adjustment (GIA), was thought to occur on a time scale of 10,000 years. We used new GPS measurements, which show a rapid (41 millimeters per year) uplift of the ASE, to estimate the viscosity of the mantle underneath. We found a much lower viscosity (4 × 1018 pascal-second) than global average, and this shortens the GIA response time scale from tens to hundreds of years. Our finding requires an upward revision of ice mass loss from gravity data of 10% and increases the potential stability of the WAIS against catastrophic collapse.

Socioeconomic and demographic inequalities in stage at diagnosis and survival among colorectal cancer patients: evidence from a Swiss population-based study.

Socioeconomic inequalities in cancer stage at diagnosis and survival are important public health issues. This study investigates the association between socioeconomic position (SEP) and colorectal cancer (CRC) stage at diagnosis and survival in Switzerland, a European country with highest level of medical facilities and life expectancy. We used population-based CRC data from seven Swiss cantonal cancer registries 2001-2008 (N = 10,088) linked to the Swiss National Cohort (SNC). Follow-up information was available until the end of 2013. SEP was estimated based on education. The association between cancer stage and SEP was assessed using logistic regression models including cancer localization (colon/rectum), sex, age, civil status, urbanity of residence, language region, and nationality (Swiss/non-Swiss). Survival was analyzed using competing risk regressions reporting subhazard ratios (SHRs) for the risk of dying due to CRC. We observed a social gradient for later stage CRC with adjusted odds ratios (ORs) of 1.11 (95% CI: 0.97-1.19) and 1.28 (95% CI: 1.08-1.50) for middle and low SEP compared to high SEP. Further, single compared to married people had elevated odds of being diagnosed at later stages. Survival was lower in patients with CRC with low SEP in the unadjusted model (SHR: 1.18, 95% CI: 1.07-1.30). After adjustment for stage at diagnosis and further sociodemographic characteristics, significant survival inequalities by SEP disappeared but remained for non-Swiss compared to Swiss citizens and for patients living in nonurban areas compared to their urban counterparts. Swiss public health strategies should facilitate equal access to CRC screening and optimal CRC care for all social groups and in all regions of Switzerland.

Trends in prostate cancer incidence between 1996 and 2013 in two Swiss regions by age, grade, and T-stage.

PURPOSE: To investigate differences in prostate cancer incidence between two distinct Swiss regions from 1996 to 2013 stratified by age group, grade, and T-stage. METHODS: The dataset included 17,495 men living in Zurich and 3,505 men living in Ticino, diagnosed with prostate cancer between 1996 and 2013. We computed age-standardized incidence rates per 100,000 person-years using the European Standard Population. Trends were assessed using JoinPoint regression analysis Software. RESULTS: Age-standardized incidence rates were generally higher in Zurich compared to Ticino but the difference decreased over time. Incidence rates increased significantly up to 2002 in Zurich and 2007 in Ticino and then decreased. A statistically significant increase was observed for men aged < 65 years, for grade 3 tumors, and for T-stage 2 and 3 tumors. The largest decrease was seen for grade 1 tumors. Furthermore, the incidence of tumors of unknown grade or T-stage decreased significantly in both regions. CONCLUSIONS: The trends in prostate cancer incidence rates were similar in both regions, although on a higher level in Zurich compared to Ticino. However, the difference decreased over time. The distribution of T-stage and grade did not explain the difference in incidence rates. Different use of opportunistic screening may play a role.

Quality indicators of colorectal cancer care in southern Switzerland: results from a population-based study.

AIM OF THE STUDY: Assessing the quality of cancer care (QoCC) has become increasingly relevant to providers, regulators and purchasers of healthcare worldwide. The aim of this study was to assess adherence to validated quality indicators (QIs) for colorectal cancer (CRC) in a population-based setting, and to compare results with the available literature. METHODS: All colorectal cancers diagnosed between 1 January 2011 and 31 December 2012 were identified from the files of the population-based Ticino Cancer Registry, southern Switzerland. We computed 12 core QIs, approved by use of the validated Delphi methodology and for which all the necessary medical documentation was available or only minor data collection was still needed to complete the analysis: three for diagnosis, two for pathology and seven for treatment (surgery, oncology and radiotherapy). Each QI was analysed as proportion (%) with 95% confidence interval, following the approach "available case analysis". RESULTS: A total of 474 colorectal cancers were identified: 86.9% patients were diagnosed after they reported symptoms, 90.2% had preoperative colonoscopy, 8.7% underwent emergency surgery, 97.2% had a surgical resection with tumour-free margins, and for 86.6% at least 12 lymph nodes were examined. The overall 30-day postoperative mortality was 3.6% and 66.7% of locally advanced rectal cancers benefited of neoadjuvant radiotherapy ± chemotherapy. CONCLUSIONS: Our study showed the feasibility of assessing QoCC using Cancer Registry population-based data. Results according to the clinical domain of pathology, surgery, oncology and radio-oncology in southern Switzerland are generally positive and encouraging, sometimes more favourable in comparison with other international studies, except the very low proportion of patients with a diagnosis based on opportunistic screening (8.6%). Considering the lack in the literature of population-based studies, further national and international reports are urgently needed for comparative analysis as well as standardisation of QI definition is absolutely necessary for inter-regional comparative goals.

Chemisorption of lanthanide ions on succinate-functionalized mesoporous silica: An in situ characterization by fluorescence.

Chemisorption of Eu3+ and Tb3+ on SBA-15 functionalized with succinic groups has been studied by in situ steady-state fluorescence measurements. The enhancement of the emission sensitive bands indicates that both ions adsorb forming inner-sphere surface complexes. Adsorption is a fast process that attains equilibrium in about 5min. The variation of the peaks maxima (I592 and I616, for europium, and I490 and I545, for terbium) with the total ion concentration is accounted for by the sum of the contributions due to the adsorbed and free ions. The former contribution is langmuirian. At pH 4.5, the respective adsorption constants are 5×105 and 3×105M-1, and the maximum adsorption capacities are 5.10×10-4 and 5.23×10-4molg-1. The mismatch between the latter values and the number of attached carboxylic groups is discussed. Comparison with other functionalized mesoporous silicas indicates that the anchored succinic groups are very efficient for removing lanthanide ions from aqueous solutions.

Evaluation of completeness of case ascertainment in Swiss cancer registration.

This is the first comprehensive evaluation of completeness of case ascertainment in Swiss cancer registration. There is currently no method available that is considered to be the gold standard. Apart from simple measures such as the proportion of cases where registration was initiated by a death certificate and the proportion of diagnoses on the basis of histology or cytology/haematology, we applied two dedicated approaches: (i) the semiquantitative method of comparing the mortality to incidence rate ratio with relative survival (MI-Surv method) and (ii) the Flow method, which provides a quantitative estimate for the completeness depending on time since diagnosis. All 10 Swiss cancer registries in operation since at least 2006 and providing the required parameters were included. Simple and dedicated methods showed high completeness across all cancer registries and for most cancer types tested, with the notable exception of lymphoid leukaemia.

Socioeconomic and demographic disparities in breast cancer stage at presentation and survival: A Swiss population-based study.

We explored socioeconomic and demographic disparities in breast cancer (BC) stage at presentation and survival in a Swiss population-based sample of female BC patients linked to the census-based Swiss National Cohort. Tumor stage was classified according to Surveillance, Epidemiology and End Results Program summary stage (in situ/localized/regional/distant). We used highest education level attained to estimate SEP (low/middle/high). Further demographic characteristics of interest were age at presentation (30-49/50-69/70-84 years), living in a canton with organized screening (yes/no), urbanity of residence (urban/peri-urban/rural), civil status (single/married/widowed/divorced) and nationality (Swiss/non-Swiss). We used ordered logistic regression models to analyze factors associated with BC stage at presentation and competing risk regression models for factors associated with survival. Odds of later-stage BC were significantly increased for low SEP women (odds ratio 1.19, 95%CI 1.06-1.34) compared to women of high SEP. Further, women living in a canton without organized screening program, women diagnosed outside the targeted screening age and single/widowed/divorced women were more often diagnosed at later stages. Women of low SEP experienced an increased risk of dying from BC (sub-hazard ratio 1.22, 95%CI 1.05-1.43) compared to women of high SEP. Notably, these survival inequalities could not be explained by socioeconomic differences in stage at presentation and/or other sociodemographic factors. It is concerning that these social gradients have been observed in a country with universal health insurance coverage, high health expenditures and one of the highest life expectancies in the world.

One-Step Synthesis of Mesoporous Silica Thin Films Containing Available COOH Groups.

Inorganic-organic hybrid mesoporous silica thin films with covalently bonded carboxylic acid groups were synthesized in a one-step procedure, using carboxylic-derivatized alkoxysilanes obtained by photochemical radical thiol-ene addition (PRTEA). The organosilanes were synthesized by clicking mercaptosuccinic or mercaptoacetic thioacids with vinyltrimethoxysilane, using benzophenone as the photoradical initiator. The films were synthesized by evaporation-induced self-assembly of a sol containing a mixture of tetraethoxysilane and different quantities of the organosilanes, without any further treatment after the PRTEA reaction. Two nonionic surfactants were used as templates to produce different pore sizes. Different aging times were also applied. Structural characterization with electron microscopy, porosimetry measurements, and small angle X-ray scattering with two-dimensional detection demonstrated the obtention of mesoporous phases whose degree of ordering depended on the amount of added organosilane. The incorporation of the functional silanes was shown by X-ray photoelectron spectroscopy, and the presence of the COOH groups was confirmed by Fourier transform infrared (FTIR). Finally, the availability of the COOH groups for further chemical modification was demonstrated by FTIR by following the changes in the typical carbonyl IR bands during proton exchange and metal complexation. The proposed simple methodology allows obtaining COOH-modified silica thin films in one step, without the need of hard reaction conditions or deprotection steps. Functionalization with carboxyl groups brings a pH-dependent switch-ability to the pore surface that can be used for multifunctional mesoporous materials design.

A silica supported tricarbocyanine based pH nanosensor with a large Stokes shift and a near infrared fluorescence response: performance in vitro and in live cells.

We report the synthesis of a near-infrared (NIR) fluorescent pH probe with a remarkable Stokes shift (∼135 nm) based on a tricarbocyanine (Cy-PIP). The fluorescent molecule was anchored to SiO2 nanoparticles (Cy-PIP@SiO2) and is capable of monitoring pH changes within the physiological range (pH 6-8). The Cy-PIP@SiO2 nanoparticles were successfully internalized by HeLa cells as shown by fluorescence confocal microscopy, while flow cytometry revealed pH fluctuations during the endocytic pathway.