Development of a Defined Approach for Eye hazard identification of chemicals having surfactant properties according to the three UN GHS categories

The purpose of this study was to develop a defined approach (DA) for eye hazard identification according to the three UN GHS categories for surfactants (DASF). The DASF is based on a combination of Reconstructed human Cornea-like Epithelium test methods (OECD TG 492; EpiOcular™ EIT and SkinEthic™ HCE EIT) and the modified Short Time Exposure (STE) test method (0.5% concentration of the test substance after a 5-min exposure). DASF performance was assessed by comparing the prediction results with the historical in vivo data classification and against the criteria established by the OECD expert group on eye/skin. The DASF yielded a balanced accuracy of 80.5% and 90.9% of Cat. 1 (N = 22), 75.0% of Cat. 2 (N = 8), and 75.5% of No Cat. (N = 17) surfactants were correctly predicted. The percentage of mispredictions was below the established maximum values except for in vivo No Cat. surfactants that were over-predicted as Cat. 1 (5.6%, N = 17), with a maximum value set at 5%. The percentage of correct predictions did meet the minimum performance values of 75% Cat. 1, 50% Cat. 2, and 70% No Cat. established by the OECD experts. The DASF has shown to be successful for eye hazard identification of surfactants.

Integrated approaches to testing and assessment for grouping nanomaterials following dermal exposure

Exposure to different nanoforms (NFs) via the dermal route is expected in occupational and consumer settings and thus it is important to assess their dermal toxicity and the contribution of dermal exposure to systemic bioavailability. We have formulated four grouping hypotheses for dermal toxicity endpoints which allow NFs to be grouped to streamline and facilitate risk assessment. The grouping hypotheses are developed based on insight into how physicochemical properties of NFs (i.e. composition, dissolution kinetics, size, and flexibility) influence their fate and hazard following dermal exposure. Each hypothesis is accompanied by a tailored Integrated Approach to Testing and Assessment (IATA) that is structured as a decision tree and tiered testing strategies (TTS) for each relevant question (at decision nodes) that indicate what information is needed to guide the user to accept or reject the grouping hypothesis. To develop these hypotheses and IATAs, we gathered and analyzed existing information on skin irritation, skin sensitization, and dermal penetration of NFs from the published literature and performed experimental work to generate data on NF dissolution in sweat simulant fluids. We investigated the dissolution of zinc oxide and silicon dioxide NFs in different artificial sweat fluids, demonstrating the importance of using physiologically relevant conditions for dermal exposure. All existing and generated data informed the formulation of the grouping hypotheses, the IATAs, and the design of the TTS. It is expected that the presented IATAs will accelerate the NF risk assessment for dermal toxicity via the application of read-across.

AB1211 DOES BODY MASS INDEX AND METABOLIC SYNDROME IMPACT ON FIBROMYALGIA?

Background

Fibromyalgia (FBM), obesity and the metabolic syndrome (MTB) are common conditions with significant impact on health and quality of life, producing relevant economic burden for healthcare systems. Although obesity represents a negative prognostic factor for FBM, the relation between body mass index (BMI) or MTB and FBM severity is still unclear.

Objectives

The aim of our ongoing study was to evaluate the relationship between BMI or prevalent MTB and FBM severity, estimated with 3 different severity scores.

Methods

We included the first 100 women presenting with FBM, defined according to the ACR2016 diagnostic criteria, consecutively evaluated during the period of 1 year in 2 Clinic in Italy. On enrolment were assessed/recorded demographic, clinical and pharmacological characteristics, weight, height, physical activity, tenderness, pain and symptoms. The following scores were calculated: tender points count (TP), Widespread Pain Index (WPI), Polysymptomatic Distress Scale (PDS), Fibromyalgia Impact Questionnaire (FIQ) and modified Fibromyalgia Assessment Status (mFAS). BMI was calculated, and the presence of MTB was evaluated according to current definition. Patients were categorized as presenting with severe disease or moderate/mild disease according to recent definition validated in an Italian population. The prevalence of MTB and the mean ± standard deviation (SD) BMI in subgroups defined according to severity were estimated.

Results

Mean age ±SD was 57.5±12.7 years, mean BMI ±SD was 25.3±5.1, and 9.5% presented with MTB. FBM severity (mean±SD) calculated by PDS, FIQ and mFAS was respectively 25.3±9.3, 63.2±23.1, and 30.1±7.7. Patients with the highest FBM severity according to PDS (>25) were less likely to present with MTB (2.4%) compared to those with a PDS of 0-25 (20.0%, P=.026), with an adjusted (age and BMI) OR (95%CI) for presenting with MTB in patients with less severe FBM of 8.2 (0.962-69.925, P=.054). Similar results were found when the specific conditions characterizing the MTB were considered separately, except for excessive body fat around the waist (not related to severity). The BMI ±SD was comparable between patients with severe disease (25.8±5.8) according to PDS and those with less severe FBM (24.8±4.4, P=.388), with no correlation between BMI and PDS (Rho: 0.083, P=.454). Considering all other characteristics of the two groups defined according to PDS categories (PDS >25 versus PDS 0-25) a significant difference was found in mean age ±SD, greater in patients with less severe FBM (60.2±13.2) compared to those with highest FBM severity (54.8±11.6, P=.046). Similar but less significant findings were found also with FIQ and mFAS. The prevalence of MTB according to the FIQ was 7.3% for highest severity versus 14.3% for less severe FBM (P=.200), with a comparable BMI ±SD between the two groups (respectively 26.2±6.1 versus 24.4±3.7, P=.125). Corresponding figures for MTB or BMI and FBM severity according to the mFAS were respectively: prevalence of MTB in highest severity 3.0% versus 16.3% in the less severe FBM (P=.078); mean ±SD BMI in highest severity 26.4±6.2 versus 24.6±4.2 in less severe patients (P=.121).

Conclusion

The preliminary results of our ongoing analysis demonstrated a slightly inverse relationship between FBM severity and the prevalence of MTB, trending to significance, while no relationship was found between severity and BMI.

References

[1]Salaffi F. Fibromyalgia Criteria and Severity Scales for Clinical and Epidemiological Studies: A Modification of the ACR Preliminary Diagnostic Criteria for Fibromyalgia. Rheumatology. Volume 60, Issue 2, February 2021, Pages 728–736,

[2]Migliorini F. BMI but not age and sex negatively impact on the outcome of pharmacotherapy in fibromyalgia: a systematic review. Expert Rev Clin Pharmacol. 2021 Aug;14:1029-1038.

[3]D’Onghia M. Fibromyalgia and obesity: A comprehensive systematic review and meta-analysis. Semin Arthritis Rheum. 2021 Apr;51:409-424.

[4]Aparicio VA. Fibromyalgia’s key symptoms in normal-weight, overweight, and obese female patients. Pain Manag Nurs. 2013 Dec;14:268-276.

Disclosure of Interests

None declared

Determining nanoform similarity via assessment of surface reactivity by abiotic and in vitro assays

Grouping of substances is a method used to streamline hazard and risk assessment. Assessment of similarity provides the scientific evidence needed for formation of groups. This work reports on justification of grouping of nanoforms (NFs) via similarity of their surface reactivity. Four reactivity assays were used for concentration dependent detection of reactive oxygen species (ROS) generated by NFs: abiotic assays FRAS, EPR and DCFH2-DA, as well as the in vitro assay of NRF2/ARE responsive luciferase reporter activation in the HEK293 cell line. Representative materials (CuO, Mn₂O₃, BaSO₄, CeO₂ and ZnO) and three case studies of each several NFs of iron oxides, Diketopyrrolopyrroles (DPP)-based organic pigments and silicas were assessed. A novel similarity assessment algorithm was applied to quantify similarities between pairs of NFs, in a four-step workflow on concentration-response curves, individual concentration and response ranges, and finally the representative materials. We found this algorithm to be applicable to all abiotic and in vitro assays that were tested. Justification of grouping must include the increased potency of smaller particles via the scaling of effects with specific surface, and hence quantitative similarity analysis was performed on concentration-response in mass-metrics. CuO and BaSO₄ were the most and least reactive representative materials respectively, and all assays found BaSO₄/CuO not similar, as confirmed by their different NOAECs of in vivo studies. However, similarity outcomes from different reactivity assays were not always in agreement, highlighting the need to generate data by one assay for the representative materials and the candidate group of NFs. Despite low similarity scores in vitro some pairs of case study NFs can be accepted as sufficiently similar because the in vivo NOAECs are similar, highlighting the conservative assessment by the abiotic assays.

Development of a standard operating procedure for the DCFH2-DA acellular assessment of reactive oxygen species produced by nanomaterials

Improved strategies are required for testing nanomaterials (NMs) to make hazard and risk assessment more efficient and sustainable. Including reduced reliance on animal models, without decreasing the level of human health protection. Acellular detection of reactive oxygen species (ROS) may be useful as a screening assay to prioritize NMs of high concern. To improve reliability and reproducibility, and minimize uncertainty, a standard operating procedure (SOP) has been developed for the detection of ROS using the 2',7'-dichlorodihydrofluorescein diacetate (DCFH₂-DA) assay. The SOP has undergone an inter- and intra-laboratory comparison, to evaluate robustness, reliability, and reproducibility, using representative materials (ZnO, CuO, Mn₂O₃, and BaSO₄ NMs), and a number of calibration tools to normalize data. The SOP includes an NM positive control (nanoparticle carbon black (NPCB)), a chemical positive control (SIN-1), and a standard curve of fluorescein fluorescence. The interlaboratory comparison demonstrated that arbitrary fluorescence units show high levels of partner variability; however, data normalization improved variability. With statistical analysis, it was shown that the SIN-1 positive control provided an extremely high level of reliability and reproducibility as a positive control and as a normalization tool. The NPCB positive control can be used with a relatively high level of reproducibility, and in terms of the representative materials, the reproducibility CuO induced-effects was better than for Mn₂O₃. Using this DCFH₂-DA acellular assay SOP resulted in a robust intra-laboratory reproduction of ROS measurements from all NMs tested, while effective reproduction across different laboratories was also demonstrated; the effectiveness of attaining reproducibility within the interlaboratory assessment was particle-type-specific.

AB0379 BARICITINIB IN POLYMYALGIA RHEUMATICA AND GIANT CELL ARTERITIS: REPORT OF SIX CASES

Background:

Glucocorticoids (GC) are the cornerstone of the treatment of polymyalgia rheumatica (PMR) and giant cell arteritis (GCA), but they are associated with several adverse events (AEs). Moreover, a considerable proportion of patients relapse during GC tapering.

Objectives:

To describe the efficacy and safety of the JAK-inhibitor baricitinib (BARI) in a group of patients with PMR and/or GCA.

Methods:

Case series of patients with PMR and/or GCA with a refractory disease course, despite several lines of therapy, including methotrexate (MTX) and tocilizumab (TCZ), started treatment with BARI. All patients underwent periodic, standardised clinical and laboratory examinations, and also FDG-PET/CT. PMR-activity score (AS) was calculated at each visit except in patients with isolated large vessel vasculitis (LVV) or GCA.

Results:

A total of six patients (five females and one male, median age 64 years, range 50-83) were treated with BARI. Two of them had isolated PMR (patients #1 and #6), two had PMR with associated LVV (patients #2 and #5), and one (patient #3) had cranial-GCA. Demographic and clinical characteristics are provided in Table 1. At the time of starting BARI, patients were taking a median prednisone dose of 8.75 mg/day (range 0-25), and the 4 patients with PMR±LVV had a median PMR-activity score (PMR-AS) of 23.3 (indicating high disease activity), which decreased to 1.58 after 6 months of treatment with BARI. Two of them could stop GC and continued BARI monotherapy (in one case, BARI was tapered down to 2 mg/day after 12 months).

After starting BARI, patient #3 (GCA) could gradually taper prednisone from 25 mg/day to 10 mg/day in six months, without reporting fever or headache. After one year of treatment, she feels well while taking prednisone 7.5 mg/day.

Patient #4 (LVV) remained clinically stable during the treatment with BARI, but a follow-up FDG-PET/CT showed LVV, and we decided to stop BARI and restart TCZ. After 4 months of treatment with BARI, patient #5 suffered from pneumonia, while she was also taking prednisone 15 mg/day. BARI was therefore stopped. No other AEs attributable to BARI were detected.

Conclusion:

BARI appears as an appealing option for treating patients with PMR and/or GCA. Although these preliminary results should be confirmed by a RCT, BARI lowered rapidly disease activity and exerted a significant steroid-sparing effect, allowing GC withdrawal in 2 out of 6 patients.

Table 1.

Demographic and clinical characteristics of patients.

Patient #SexAgeDiagnosisPrevious treatmentDisease duration (months)PMR-AS1F66PMRMTX, HCQ, SSZ25.540.52F78PMR+LVVTCZ, MTX41.828.83F61GCACYC, MMF, TCZ119.8N/A4F60LVVTCZ16.4N/A5F83PMR+LVVMTX, TCZ24.415.26M50PMRMTX24.617.8

CYC: cyclophosphamide, GCA: giant cell arteritis, HCQ: hydroxychloroquine, LVV: large vessel vasculitis, MMF: mycophenolate mofetil, MTX: methotrexate, N/A: not applicable, PMR: polymyalgia rheumatica, PMR-AS: PMR-activity score, SSZ: sulfasalazine, TCZ: tocilizumab.

Disclosure of Interests:

Dario Camellino Speakers bureau: Medac, Eli Lilly, Paid instructor for: Mylan, Consultant of: Accord, Celgene, Novartis, Sanofi, Christian Dejaco Speakers bureau: Eli Lilly (<10.000€), Andrea Giusti Speakers bureau: UCB, Amgen, Kyowa Kirin, Abiogen Pharma, and Eli Lilly, Consultant of: EffRx, Abiogen Pharma, FRANCO MARTINI: None declared, Renzo Cosso: None declared, Giuseppe Girasole: None declared, Gerolamo Bianchi Speakers bureau: Amgen, MSD, Novartis, Pfizer, Roche, Sanofi, Genzyme, and Servier, Consultant of: Abbvie, Abiogen Pharma, BMS, Celgene, Eli Lilly, GSK, Janssen-Cilag, Medac

POS1105 EFFECTS OF CHOLECALCIFEROL AND CALCIFEDIOL IN OSTEOPOROTIC WOMEN WITH SECONDARY HYPERPARATHYROIDISM DUE TO SEVERE VITAMIN D DEFICIENCY UNDERGOING ZOLEDRONIC ACID TREATMENT: A RANDOMIZED-CONTROLLED TRIAL

Background:

Secondary hyperparathyroidism (sHPTH) due to vitamin D deficiency impairs the bone mineral density (BMD) response to alendronate,1-2 but the optimal strategy for its correction in postmenopausal osteoporotic women (PMO) about to start zoledronic acid (ZOL) therapy is still unknown.

Objectives:

To evaluate the effects of cholecalciferol (D3) and calcifediol (25OHD) on serum 25-OH-vitamin D (s25OHD), parathyroid hormone (PTH) and BMD in PMO presenting with sHPTH due to vitamin D deficiency.

Methods:

PMO with s25OHD <20 ng/ml, sHPTH (PTH >65 pg/ml) and BMD T-score at the lumbar spine (LS), femoral neck (FN) or total hip (TH) < -2.5, or between -1 and -2.5 plus one vertebral/femoral fracture, were randomly assigned to receive a therapeutic dose of D3 (300.000 IU bolus) followed by 175 mcg/weekly of D3, or 175 mcg/weekly of 25OHD alone, 2 months before receiving a single intravenous infusion of ZOL (5 mg). BMD at the LS, FN and TH was assessed at baseline and after one year from ZOL. Serum calcium, PTH and s25OHD were measured at baseline, and 6- and 12-month after ZOL. Adverse and clinical events were ascertained by 3-and 9-month telephone interviews, and by 6- and 12-month clinical evaluation.

Results:

45 PMO (25OHD N=23, D3 N=22) were enrolled over one year and 32 subjects (mean age ±SD 75±10 years, range 51-91) completed the 1-year of treatment/follow-up (25OHD N=17, D3 N=15). Most PMO discontinued for protocol violation, while three deceased before study ending (25OHD N=1, D3 N=2) for reasons not related to the agents investigated. The baseline characteristics were comparable in both groups. At baseline mean s25OHD (±SE) was 8±1 ng/ml in the 25OHD group and 8±1 ng/ml in the D3 group. The corresponding figures for PTH were 111±6 pg/ml (25OHD) and 117±5 pg/ml (D3). Mean s25OHD (±SE) increased in both groups at 6- and 12-month, being significantly greater in the 25OHD group (12-month, 56±2 ng/ml) compared to the D3 group (12-month, 34±2 ng/ml, P<.001) at both time points (Figure 1). PTH (mean ±SE) decreased in both groups, being significantly lower in the 25OHD group at 12-month (25OHD 46±6 pg/ml versus D3 70±6 pg/ml, P=.007), as shown in Figure 1. BMD at the LS, FN and TH increased in both groups (with significant increases versus baseline only at the FN) without significant differences between s25OHD and D3. In PMO receiving D3 serum calcium remained stable over time, while those receiving s25OHD demonstrated a significant increase of serum calcium, with 2 PMO presenting a value close to the upper limit of the reference range at 12-month. No patient reported incident fractures or adverse events.

Conclusion:

Calcifediol 175 mcg weekly appears more potent in improving s25OHD and decreasing PTH concentrations compared to cholecalciferol therapeutic dose (300’000 IU) plus 175 mcg weekly in PMO presenting with sHPTH due to severe vitamin D deficiency about to start ZOL therapy. Further studies are warranted to clarify implications on BMD improvements on the long-term of similar 25OHD and D3 regimens.

References:

[1]Barone A et al., J Am Geriatr Soc 2007.

[2]Kincse G et al., BMC Musculoskelet Disord 2012.

Disclosure of Interests:

Giulia Botticella: None declared, Monica Pizzonia: None declared, Barbara Cossu: None declared, Roberta Bruno: None declared, Dario Camellino Speakers bureau: AbbVie, Celgene, Janssen-Cilag, Eli Lilly, Medac, Mylan, Novartis, and Sanofi, outside the submitted work, Giuseppe Girasole Speakers bureau: Abiogen Pharma and Novartis, outside the submitted work, Andrea Giusti Speakers bureau: UCB, Amgen, Kyowa Kirin, Abiogen Pharma, and Eli Lilly, outside the submitted work, Consultant of: EffRx and Abiogen Pharma, outside the submitted work, Mario Pedrazzoni: None declared, Simona Alexovits: None declared, Franco Pleitavino: None declared, Federico Santolini: None declared, Alessio Nencioni: None declared, Gerolamo Bianchi Speakers bureau: Abbvie, Abiogen Pharma, Amgen, BMS, Celgene, Eli Lilly, GSK, Janssen-Cilag, Medac, MSD, Novartis, Pfizer, Roche, Sanofi, Genzyme, and Servier, outside the submitted work.

Towards FAIR nanosafety data

Nanotechnology is a key enabling technology with billions of euros in global investment from public funding, which include large collaborative projects that have investigated environmental and health safety aspects of nanomaterials, but the reuse of accumulated data is clearly lagging behind. Here we summarize challenges and provide recommendations for the efficient reuse of nanosafety data, in line with the recently established FAIR (findable, accessible, interoperable and reusable) guiding principles. We describe the FAIR-aligned Nanosafety Data Interface, with an aggregated findability, accessibility and interoperability across physicochemical, bio-nano interaction, human toxicity, omics, ecotoxicological and exposure data. Overall, we illustrate a much-needed path towards standards for the optimized use of existing data, which avoids duplication of efforts, and provides a multitude of options to promote safe and sustainable nanotechnology.

POS1447 LOW-INTENSITY PULSED ELECTROMAGNETIC FIELDS IMPROVE PHYSICAL PERFORMANCE IN A DOSE-DEPENDENT MANNER: AN OBSERVATIONAL STUDY IN OLDER ADULTS WITH RHEUMATIC DISEASES

Background:

Low-intensity pulsed electromagnetic fields (PEMF) have been shown to improve gait parameters in frail older adults.1 Furthermore, the continuous exposure to PEMF (up to 1 year) have been demonstrated to produce progressive improvements in self-selected gait speed in older adults at risk of falling.2

Objectives:

To investigate the effects of two different treatment regimens of PEMF on physical performances in older adults presenting with rheumatoid arthritis (RA), osteoarthritis (OA) or severe osteoporosis (OP).

Methods:

Older adults presenting with RA, OA or OP, at increased risk of falls, evaluated in our Falls Prevention Clinic, were considered for a prospective observational study investigating the effects of PEMF on physical performances. PEMF were supplied by the THS 280 E device (THS-Therapeutic Solutions Srl, Milan, Italy). It provides a new therapeutic approach, named TEPS (Triple Energy Postural Stabilization), that represents an evolution of physical therapy.1,2 On the basis of the physician judgment, PEMF were administered following an intensive protocol, every 45 days (PEMF-45), or a standard validated protocol1,2, every 60 days (PEMF-60). All subjects were assessed at baseline and every 3 months with the following tests: 4 meters gait speed test [4MGS, seconds (sec)], timed up and go test (TUG, sec), chair stand test (CST, sec), short physical performance battery (SPPB, score), and hand grip strength (HGS) by hand dynamometer (Kg). Demographic, anthropometric and clinical characteristics, including pharmacological treatments and functional status were evaluated at baseline. Clinical and adverse events were assessed every 45 or 60 days after PEMF administration.

Results:

Overall, 94 patients were enrolled between January and December 2020. Of these, 43 subjects (N=33 PEMF-45, N=11 PEMF-60) with a valid 6-month follow-up assessment were considered for the current analysis. The two groups were comparable regarding the main baseline characteristics, and similar % of patients presented with RA, OA or OP. Mean age (±SE) was 78±7 in PEMF-45 and 77±7 in PEMF-60. As expected, all physical performance tests improved significantly from baseline to 6 months in both groups. Mean (±SE) 4MGS increased significantly more in PEMF-45 (from 3.24±0.12 sec to 2.83±0.18 sec) compared to PEMF-60 (from 3.22±0.21 sec to 3.02±0.30 sec, p=.018). Likewise, mean (±SE) CST improved more in PEMF-45 (from 12.4±0.9 sec to 8.7±0.4 sec) compared to PEMF-60 (from 11.1±1.5 sec to 9.8±0.7 sec, p=.002). No significant difference between groups was found for the other tests, although a trend toward better results in PEMF-45 was manifest: SPPB improved by 6.4% in PEMF-45 and by 3.0% in PEMF-60, and TUG decreased by 7.8% in PEMF-45 and by 6.1% in PEMF-60. During the 6 months observation period no adverse event was observed.

Conclusion:

Preliminary results of our ongoing prospective observational study suggest that a more frequent administration of PEMF produces greater improvements in some but not all physical performance parameters compared to a standard validated regimen1,2.

References:

[1]Giusti A et al., Geriatr Gerontol Int 2013. 2Giusti A et al., J Am Geriatr Soc 2014.

Disclosure of Interests:

Massimo Giovale: None declared, Giuseppina Tramontano: None declared, Rossana Galli: None declared, Simone Rando: None declared, Andrea Giusti Speakers bureau: UCB, Amgen, Kyowa Kirin, Abiogen Pharma, and Eli Lilly, outside the submitted work, Consultant of: EffRx and Abiogen Pharma, outside the submitted work, Lorenzo Bandi: None declared, Francesca Russo: None declared, Stefano Rampoldi Employee of: THS Therapeutic Solutions SRL, Luigi Carlo Bottaro: None declared, Gerolamo Bianchi Speakers bureau: Abbvie, Abiogen Pharma, Amgen, BMS, Celgene, Eli Lilly, GSK, Janssen-Cilag, Medac, MSD, Novartis, Pfizer, Roche, Sanofi, Genzyme and Servier, outside the submitted work

Evolution of spray and aerosol from respiratory releases: theoretical estimates for insight on viral transmission

By modelling the evaporation and settling of droplets emitted during respiratory releases and using previous measurements of droplet size distributions and SARS-CoV-2 viral load, estimates of the evolution of the liquid mass and the number of viral copies suspended were performed as a function of time from the release. The settling times of a droplet cloud and its suspended viral dose are significantly affected by the droplet composition. The aerosol (defined as droplets smaller than 5 μm) resulting from 30 s of continued speech has O(1 h) settling time and a viable viral dose an order-of-magnitude higher than in a short cough. The time-of-flight to reach 2 m is only a few seconds resulting in a viral dose above the minimum required for infection, implying that physical distancing in the absence of ventilation is not sufficient to provide safety for long exposure times. The suspended aerosol emitted by continuous speaking for 1 h in a poorly ventilated room gives 0.1-11% infection risk for initial viral loads of 10 8 - 10 10   copies ml l - l , respectively, decreasing to 0.03-3% for 10 air changes per hour by ventilation. The present results provide quantitative estimates useful for the development of physical distancing and ventilation controls.

A review to support the derivation of a worst-case dermal penetration value for nanoparticles

Data on dermal penetration of nanoparticles (NPs) was reviewed with the goal to establish a worst-case dermal penetration value for NPs. To this aim, the main focus was on studies providing quantitative dermal penetration data (29 studies). In vivo dermal penetration studies and ex vivo studies based on skin explants were included. These studies used NPs with different compositions, dimensions, and shapes. The overall results showed that skin is an efficient barrier for NPs, indistinctly of their properties. However, some studies reported that a small percentage of the applied NP dose penetrated the skin surface and reached deeper skin layers. The integrity of the skin layer and the product formulation were more critical determinants of dermal penetration than the NP properties. Most quantitative studies were based on elemental analysis such that it cannot be concluded if detected levels are attributable to a dissolved fraction or to the penetration of particles as such. Results of qualitative imaging studies suggest that at least a fraction of the levels reported in quantitative studies could be due to particle penetration. Altogether, based on the data compiled, we propose that 1% could be used as a worst-case dermal penetration value for nanoparticles within the boundaries of the properties of those included in our analysis.

The emerging issue of cognitive disorders and dementia among migrants

Background

Due to population aging, people with a migration background are (and will be) increasingly exposed to the burden of chronic, age-related diseases. Specifically, the occurrence of dementia and cognitive disorders in this population of individuals can assume special clinical and public health relevance. The ImmiDem project (GR-2016-02364975) is aimed at characterizing the emerging phenomenon of cognitive disorders in migrants in Italy.

Methods

The number of dementia and mild cognitive impairment (MCI) cases among migrants living in the extended European Union was calculated by applying the age- and gender-specific prevalence rates of these conditions to the population data of international migrants provided by Eurostat. A pilot survey was addressed to a representative sample of Italian centers for cognitive disorders and dementia (CCDDs) with the aim of collecting information on the number of migrants attending these services, the adopted diagnostic, and the possible barriers and resources in the provision of care.

Results

Nearly 700,000 cases of dementia and 680,000 cases of MCI can be estimated in the migrant population living in Europe in 2018. Nevertheless, the number of migrants referred to the surveyed CCDDs was very low and was considered as stable over the last 5 years. Most of CCDDs reported the possibility of contacting cultural mediators and/or interpreters, while only a few reported the availability and regular use of translated and/or cross-cultural cognitive assessment tools.

Conclusions

The data produced by the ImmiDem project allow a preliminary characterization of the emerging phenomenon of cognitive disturbances in the migrant population. The survey will be extended to all Italian dementia services (CDCD, day centers, residential structures). Activities aimed at identifying and promoting dedicated care pathways or good practices will also be conducted.

Key messages

The clinical and epidemiological characterization of cognitive disorders occurring in migrants represent an emerging public health matter for Western countries. The onset of dementia in migrants can result in important clinical-diagnostic and healthcare complexities.

Larval ascaridoid nematodes in horned and musky octopus (Eledone cirrhosa and E. moschata) and longfin inshore squid (Doryteuthis pealeii): Safety and quality implications for cephalopod products sold as fresh on the Italian market

The aim of this study was to evaluate the occurrence, infection level and distribution of ascaridoid larvae in cephalopod products sold in Italy. Data on the species most commonly commercialized as whole and fresh on the Italian market were collected. After comparing commercial and literature data, Eledone spp., comprising E. cirrhosa and E. moschata (horned octopus and musky octopus, respectively) and Doryteuthis pealeii (longfin inshore squid) were selected, as they had been rarely investigated. Overall, 75 Eledone spp. caught in the Mediterranean Sea (FAO area 37) and 70 D. pealeii from the Northwest Atlantic Ocean (FAO area 21) were examined by visual inspection and artificial digestion (viscera and mantle separately). Parasites were submitted to morphological and molecular analysis. Prevalence (P), mean intensity (MI) and mean abundance (MA) were calculated. In D. pealeii, 2 nematode larvae molecularly identified as Anisakis simplex s.s. were found in the viscera and in the mantle of two specimens (P: 2.9% 95% CI: 0-6.8%; MI: 1; MA: 0.028). In Eledone spp. 9 nematode larvae molecularly attributed to Hysterothylacium spp. were found in the mantle of 5 specimens (P: 6.7% 95% CI: 1-12.3%; MI: 1.8; MA: 0.12). This is the first report of A. simplex s.s. in D. pealeii. Considering the zoonotic and allergenic potential of these larvae and their localization also in the edible part (mantle), a potential public health issue exists.

AB0283 REDUCED HOSPITAL ADMISSION IN RA PATIENTS TAPERING BIOLOGIC DMARDS: PRELIMINARY ANALYSIS OF A RETROSPECTIVE STUDY

Background:

bDMARDs are among the most effective therapies in the management of inflammatory arthritides, but they are associated with potentially severe adverse events (AEs), particularly infection. Tapering strategies of bDMARDs for patients in remission/low disease activity (R/LDA) have demonstrated comparable efficacy to standard-dose treatments, but their safety profile has not been studied yet.

Objectives:

To compare the number and the causes of hospital admissions in RA patients in R/LDA continuing or tapering bDMARDs.

Methods:

Consecutive patients with rheumatoid arthritis (RA) evaluated between 2011 and 2017, were assigned, based on treating physician’s discretion, to continue the standard dose (STD) of bDMARDs or to undergo a predetermined tapering strategy (TAP), after being in R/LDA for two consecutive visits at least 3 months apart. Down-titration of bDMARDs was obtained by a stepwise increase of the dosing interval to achieve a reduction of about 30% (e.g. administration of etanercept every 10 days instead of weekly). Demographic, clinical data and concomitant treatments were retrospectively retrieved from the electronic charts of the outpatient clinics. Information about hospital admissions, including main diagnosis, period and duration of hospitalization, and death were retrieved from the Regional Healthcare System Database.

For the STD group, the observation period started with the occurrence of remission and finished with one of these events: loss of remission, switch to another bDMARD, withdrawal of the bDMARD, severe AE, death, end of the study period in (December 2017). For the TAP group, the observation period started with tapering onset and finished with one of these events: reduction of the dosing interval due to either a relapse (according to a DAS28 increase) or to a subjective, symptomatic relapse (according to the patient’s definition), switch to another bDMARD, withdrawal of the bDMARD, severe AE, death, end of the study period in (December 2017).

Results:

81 patients were included, of whom 40 underwent TAP. Demographic, clinical and treatment data are shown in table 1. Baseline characteristics were comparable between the two groups, except for the number of previous bDMARDs before observational period entry that was slightly higher in the STD group (STD 1.0±0.9 versus TAP 0.5±0.8, P=0.11).

Table 1.

Baseline demographic and clinical characteristics of the patients in remission or low disease activity.

NO TAPERING(n=41)TAPERING(n=40)p valueMean age (yrs)57±1158±130.563Mean disease duration (yrs)12±912±70.897Starting bDMARD to tapering/monitoring (months)52±4567±410.128Mean monitoring period (months)22±2419±230.632Taking sDMARD at any time ((n (%))40 (98%)37 (92%)0.359Taking glucocorticoids29 (71%)28 (70%)0.999Mean prednisone dose (mg/day)2.5±2.92.1±2.70.527DAS28 at the time of tapering or first LDA/REM2.3±0.82.3±0.90.863Previous bDMARDs >1 (n (%))10 (24.4%)4 (10%)0.140

In the STD group, 14 hospital admissions occurred, while in the TAP group there were 7 admissions (p=0.128). The corresponding figures for hospital admission due to infectious diseases were 6 in the STD group and 0 in the TAP group (p=0.026).

Conclusion:

Tapering bDMARDs in RA patients in R/LDA is associated with fewer hospital admissions, with a possible protective effect especially toward infections.

Acknowledgments:

The authors are indebted with Mrs Rosella Gramuglia and Mrs Cristina Olivieri for the management and analysis of the data on the flow of the drugs, and with Mrs Anna Consigliere, Mrs Anna Cosso, Mrs Romina Petralito and Mrs Laura Ravaschio for helping in retrieving clinical data.

Disclosure of Interests:

Dario Camellino Consultant of: I have received consultancy fees from Celgene, Sanofi, Novartis, Janssen-Cilag, Accord, Paid instructor for: I have served as a paid instructor for Mylan, Andrea Giusti Consultant of: UCB, Amgen, Janssen, Eli Lilly, Abiogen, EffRx, Speakers bureau: UCB, Amgen, Janssen, Eli Lilly, Abiogen, EffRx, Alfa-Sigma, Chiesi, Giuseppe Girasole: None declared, Chiara Craviotto: None declared, Paola Diana: None declared, Antonia Locaputo: None declared, Tiziana Caviglia: None declared, Lacramioara Luca: None declared, Gerolamo Bianchi Consultant of: Amgen, Janssen, Merck Sharp & Dohme, Novartis, UCB, Speakers bureau: Abbvie, Abiogen, Alfa-Sigma, Amgen, BMS, Celgene, Chiesi, Eli Lilly, GSK, Janssen, Medac, Merck Sharp & Dohme, Novartis, Pfizer, Roche, Sanofi Genzyme, Servier, UCB

Effortless creation of safe robots from modules through self-programming and self-verification

Industrial robots cannot be reconfigured to optimally fulfill a given task and often have to be caged to guarantee human safety. Consequently, production processes are meticulously planned so that they last for long periods to make automation affordable. However, the ongoing trend toward mass customization and small-scale manufacturing requires purchasing new robots on a regular basis to cope with frequently changing production. Modular robots are a natural answer: Robots composed of standardized modules can be easily reassembled for new tasks, can be quickly repaired by exchanging broken modules, and are cost-effective by mass-producing standard modules usable for a large variety of robot types. Despite these advantages, modular robots have not yet left research laboratories because an expert must reprogram each new robot after assembly, rendering reassembly impractical. This work presents our set of interconnectable modules (IMPROV), which programs and verifies the safety of assembled robots themselves. Experiments show that IMPROV robots retained the same control performance as nonmodular robots, despite their reconfigurability. With respect to human-robot coexistence, our user study shows a reduction of robot idle time by 36% without compromising on safety using our self-verification concept compared with current safety standards. We believe that by using self-programming and self-verification, modular robots can transform current automation practices.

Radiofrequency echographic multispectrometry compared with dual X-ray absorptiometry for osteoporosis diagnosis on lumbar spine and femoral neck

An innovative, non-ionizing technique to diagnose osteoporosis on lumbar spine and femoral neck was evaluated through a multicenter study involving 1914 women. The proposed method showed significant agreement with reference gold standard method and, therefore, a potential for early osteoporosis diagnoses and possibly improved patient management.

INTRODUCTION

To assess precision (i.e., short term intra-operator precision) and diagnostic accuracy of an innovative non-ionizing technique, REMS (Radiofrequency Echographic Multi Spectrometry), in comparison with the clinical gold standard reference DXA (dual X-ray absorptiometry), through an observational multicenter clinical study.

METHODS

In a multicenter cross-sectional observational study, a total of 1914 postmenopausal women (51-70 years) underwent spinal (n = 1553) and/or femoral (n = 1637) DXA, according to their medical prescription, and echographic scan of the same anatomical sites performed with the REMS approach. All the medical reports (DXA and REMS) were carefully checked to identify possible errors that could have caused inaccurate measurements: erroneous REMS reports were excluded, whereas erroneous DXA reports were re-analyzed where possible and otherwise excluded before assessing REMS accuracy. REMS precision was independently assessed.

RESULTS

In the spinal group, quality assessment on medical reports produced the exclusion of 280 patients because of REMS errors and 78 patients because of DXA errors, whereas 296 DXA reports were re-analyzed and corrected. Analogously, in the femoral group there were 205 exclusions for REMS errors, 59 exclusions for DXA errors, and 217 re-analyzed DXA reports. In the resulting dataset (n = 1195 for spine, n = 1373 for femur) REMS outcome showed a good agreement with DXA: the average difference in bone mineral density (BMD, bias ± 2SD) was -0.004 ± 0.088 g/cm² for spine and - 0.006 ± 0.076 g/cm² for femur. Linear regression showed also that the two methods were well correlated: standard error of the estimate (SEE) was 5.3% for spine and 5.8% for femur. REMS precision, expressed as RMS-CV, was 0.38% for spine and 0.32% for femur.

CONCLUSIONS

The REMS approach can be used for non-ionizing osteoporosis diagnosis directly on lumbar spine and femoral neck with a good level of accuracy and precision. However, a more rigorous operator training is needed to limit the erroneous acquisitions and to ensure the full clinical practicability.

Are Dietary Supplements and Nutraceuticals Effective for Musculoskeletal Health and Cognitive Function? A Scoping Review

OBJECTIVE

The aim of our scoping review was to summarize the state of the art regarding micronutrients in order to identify which of them might effectively improve health status in the areas typically impaired in older people: bone, skeletal muscle, and cognitive function.

DESIGN

Scoping review.

METHODS

The Italian Study Group on Healthy Aging by Nutraceuticals and Dietary Supplements (HANDS) performed this scoping review, based on the following steps: doing a list of micronutrients related with musculoskeletal or cognitive functions, included in dietary supplements and nutraceuticals commercialized in Italy; planning a research on PubMed, according to an evidence-based approach, in order to the most relevant positive study for each micronutrient into each of the three areas involved (bone, skeletal muscle and cognitive function); identifying the micronutrients effective in maintaining or achieving an adequate health status in older people, specifying the effective and safe daily doses, according to the selected studies.

RESULTS

In literature we found 12 relevant positive studies (1 international society guidelines/recommendations, 1 systematic review, 7 randomized controlled trials, and 3 prospective cohort studies). We showed that only 16 micronutrients resulted to have appropriate scientific evidences in terms of improving musculoskeletal health and/or cognitive function in older people: beta-alanine, calcium, creatine, fluorides, leucine, magnesium, omega-3 fatty acids, potassium, vitamin B6, vitamin B9, vitamin B12, vitamin C, vitamin D, vitamin E, vitamin K2, and zinc.

CONCLUSION

This scoping review showed that selected micronutrients in adequate doses might have an ancillary role in musculoskeletal health and cognitive functions in older people.

Guidelines for the diagnosis, prevention and management of osteoporosis

Osteoporosis poses a significant public health issue. National Societies have developed Guidelines for the diagnosis and treatment of this disorder with an effort of adapting specific tools for risk assessment on the peculiar characteristics of a given population. The Italian Society for Osteoporosis, Mineral Metabolism and Bone Diseases (SIOMMMS) has recently revised the previously published Guidelines on the diagnosis, riskassessment, prevention and management of primary and secondary osteoporosis. The guidelines were first drafted by a working group and then approved by the board of SIOMMMS. Subsequently they received also the endorsement of other major Scientific Societies that deal with bone metabolic disease. These recommendations are based on systematic reviews of the best available evidence and explicit consideration of cost effectiveness. When minimal evidence is available, recommendations are based on leading experts' experience and opinion, and on good clinical practice. The osteoporosis prevention should be based on the elimination of specific risk factors. The use of drugs registered for the treatment of osteoporosis are recommended when the benefits overcome the risk, and this is the case only when the risk of fracture is rather high as measured with variables susceptible to pharmacological effect. DeFRA (FRAX® derived fracture risk assessment) is recognized as a useful tool for easily estimate the long-term fracture risk. Several secondary forms of osteoporosis require a specific diagnostic and therapeutic management.

Male osteoporosis

As a result of population ageing worldwide, osteoporotic fractures are becoming a serious problem in the western world. Osteoporotic fractures are associated with a significant burden in terms of morbidity, mortality, and economic costs. Although less frequent than in women, male osteoporosis is also a relatively common problem. Since bone loss and fragility fractures in men have been recognized as a serious medical condition, over the last two decades several studies have investigated a number of aspects related to the pathogenesis, diagnosis and assessment, prevention and treatment of male osteoporosis. A better understanding of factors underlying increased bone fragility in men has led to the definition of appropriate screening and diagnostic strategies, and the development of treatments that have shown to improve bone mineral density and, in some cases, reduce fracture risk in men as well as in women. This review will summarize recent findings on male osteoporosis with a particular focus on risk factors and causes of bone loss, and available therapeutic options.

Identifying a standard set of outcome parameters for the evaluation of orthogeriatric co-management for hip fractures

BACKGROUND AND PURPOSE

Osteoporotic fractures are an increasing problem in the world due to the ageing of the population. Different models of orthogeriatric co-management are currently in use worldwide. These models differ for instance by the health-care professional who has the responsibility for care in the acute and early rehabilitation phases. There is no international consensus regarding the best model of care and which outcome parameters should be used to evaluate these models. The goal of this project was to identify which outcome parameters and assessment tools should be used to measure and compare outcome changes that can be made by the implementation of orthogeriatric co-management models and to develop recommendations about how and when these outcome parameters should be measured. It was not the purpose of this study to describe items that might have an impact on the outcome but cannot be influenced such as age, co-morbidities and cognitive impairment at admission.

METHODS

Based on a review of the literature on existing orthogeriatric co-management evaluation studies, 14 outcome parameters were evaluated and discussed in a 2-day meeting with panellists. These panellists were selected based on research and/or clinical expertise in hip fracture management and a common interest in measuring outcome in hip fracture care.

RESULTS

We defined 12 objective and subjective outcome parameters and how they should be measured: mortality, length of stay, time to surgery, complications, re-admission rate, mobility, quality of life, pain, activities of daily living, medication use, place of residence and costs. We could not recommend an appropriate tool to measure patients' satisfaction and falls. We defined the time points at which these outcome parameters should be collected to be at admission and discharge, 30 days, 90 days and 1 year after admission.

CONCLUSION

Twelve objective and patient-reported outcome parameters were selected to form a standard set for the measurement of influenceable outcome of patients treated in different models of orthogeriatric co-managed care.

A Bayesian network model for predicting pregnancy after in vitro fertilization

We present a Bayesian network model for predicting the outcome of in vitro fertilization (IVF). The problem is characterized by a particular missingness process; we propose a simple but effective averaging approach which improves parameter estimates compared to the traditional MAP estimation. We present results with generated data and the analysis of a real data set. Moreover, we assess by means of a simulation study the effectiveness of the model in supporting the selection of the embryos to be transferred.

Assessment of the 10-year risk of fracture in Italian postmenopausal women using FRAX®: a north Italian multicenter study

The aim of the study was to estimate the absolute risk of fracture in a sample of postmenopausal women with the Italian version of FRAX®, using femoral neck bone mineral density (BMD) and 3 internationally validated clinical risk factors (CRFs) (history of fragility fracture, family history of hip fracture, current smoking). We retrospectively studied 9586 women (mean age 64.1 yr) examined in three osteoporosis centers from Northern Italy over two years (2001-2002). The risk of major osteoporotic (clinical spine, hip, forearm and humerus) and hip fractures was estimated using the online version of the FRAX algorithm adapted for Italy. The median 10-year risk was 7.5% for osteoporotic fracture and 1.7% for hip fracture. 25% of subjects had a 10-year risk ≥ 12.1% for osteoporotic fracture and ≥ 4.1% for hip fracture. The median 10-year risk of fracture increased with the number of prevalent CRFs. For major osteoporotic fractures risk rose from 6.3% to 10.9%, 21.4% and 40.9% with 1, 2 and 3 prevalent CRFs, respectively. For hip fractures the corresponding figures were: 1.3%, 2.7%, 7.0% and 21.9%, respectively. However, it must be emphasized that in 2 out of 3 women, none of the CRFs examined was present and the assessment of risk was limited to age and BMD. Our data provide the first description of the effect of the combination of BMD, age and CRFs on fracture risk stratification in a large sample of Italian postmenopausal women using FRAX®. The results are a useful starting point to define criteria for the application of FRAX® in clinical practice in Italy.

[Guidelines on prevention and treatment of vitamin D deficiency. Italian Society for Osteoporosis, Mineral Metabolism and Bone Diseases (SIOMMMS)]

The Italian Society for Osteoporosis, Mineral Metabolism and Bone Diseases (SIOMMMS) has elaborated the following guidelines about the definition, prevention and treatment of inadequate vitamin D status. The highlights are presented here. Daily vitamin D allowance ranges from 1,500 IU (healthy adults) to 2,300 IU (elderly with low calcium intake). Since the average Italian diet includes around 300 IU/day, subjects with no effective sun exposure should be supplemented with 1,200-2,000 IU vitamin D per day. The serum 25-hydroxy-vitamin D [25(OH)D] levels represents the most accurate way to assess vitamin D repletion, even though there are still no standardized assay methods. Conditions of “deficiency” and “insufficiency” are defined by the following ranges of 25(OH)D levels: less than 20 ng/ml and 20-30 ng/ml, respectively. In Italy, approximately 50% of young healthy subjects have vitamin D insufficiency during the winter months. The prevalence of deficiency increases with ageing, affecting almost all elderly subjects not on vitamin D supplements. When a condition of deficiency has been identified, a cumulative dose of 300,000-1,000,000 IU, over 1-4 weeks is recommended. In subjects recently treated for deficiency-insufficiency, a maintenance dose of 800-2,000 IU/day (or weekly equivalent) is recommended. In patients on daily doses over 1,000 IU, 25(OH)D levels should be checked regularly (e.g. once every two years). The highest tolerated daily dose has been identified as 4,000 IU/day. Vitamin D supplementation should be carefully monitored in patients at higher risk of vitamin D intoxication (granulomatosis) or with primary hyperparathyroidism. In pregnant women, vitamin D supplements should be given as in non-pregnant women, but bolus administration (i.e.: single dose >25,000 IU) should be avoided.

Uses and misuses of statistics: the case of strontium ranelate and the number needed to treat

In the last 15 years, several pharmacological agents for the prevention of fractures have been developed and commercialized. Most of them showed to be effective in reducing fracture risk. The enhanced availability of drugs to prevent fractures has generated a fierce competition among pharmaceutical companies to conquer a share of the potential market, often with claims of superiority of a drug over another without direct comparisons. The definitive way to compare different treatments would require randomized head to head trials. These trials are expensive, need large samples and are unlikely to be ever performed. Therefore, it has become a common practice to compare pharmacological agents through observational studies on administrative databases or by the indirect comparison of the results of individual randomised-controlled trials (RCT) and their meta-analyses. These studies may produce evidence of clinical value, complementary to that given by RCT. However, without a proper and complete analysis, they may result in a biased picture of effectiveness and be completely misleading. In this article, we critically disclose how such competition may produce biased and misleading picture of evidence, by reviewing the significance of the number needed to treat, absolute risk reduction and relative risk reduction in relation to vertebral fractures prevention with available drugs.

Optimal setting and care organization in the management of older adults with hip fracture

Hip fracture (HF) is a common event in the geriatric population and is often associated with significant morbidity, mortality and costs for the Healthcare Systems. The growing awareness of HF consequences and the expected rise in the total number of HF worldwide have led to the development and implementation of models of care alternative to the traditional ones for the acute and post-acute management of HF older adults. These services were set to minimize in-hospital complications, streamline hospital care and provide early discharge with the main objectives of improving functional and clinical outcomes, and reducing healthcare costs associated with hip and other fractures. Basically, the main feature that distinguishes these models is the different healthcare professional that retains the responsibility of the care during the acute and postacute phases. This review has been conceived to provide a brief description of the models implemented in the last twenty years, to describe their potential benefits on short- and long-term outcomes, to define the strengths and limitations of these models and the areas of uncertain, and to make some consideration about the future. Actually, on the basis of available studies, it is not possible to define the best model of care for HF older adults. However, the more complex and sophisticated services, characterized by a multidisciplinary approach demonstrated, in randomized-controlled and before-after observational studies, to produce better outcomes compared to the traditional or simplest models. Further research is warranted to confirm long-term functional and clinical benefits of these models and to evaluate their cost-effectiveness.

Assembly of a magnetic polyoxometalate on SWNTs

Recently, the organisation of magnetic molecules on carbon nanotubes has raised much interest due to their possible interesting contribution to molecular spintronics. In this paper, we describe the assembly on SWNTs of a magnetic polyoxometalate encompassing a single cobalt ion (CoPOM) and its isostructural diamagnetic zinc analogue (ZnPOM). The simple magnetic behaviour of CoPOM and the availability of its diamagnetic counterpart render these POM@NTs systems interesting model compounds for the study of molecular electronics devices based on carbon nanotubes and magnetic molecules. The success and rate of the grafting have been investigated by electron microscopy, electron energy loss spectroscopy, X-ray photoelectron spectroscopy, cyclic voltammetry, Raman scattering and magnetisation measurements. These characterisations altogether demonstrate the preservation of the structural and magnetic properties of the molecules upon functionalisation and the existence of an electronic communication between the molecules and the nanotubes.

Dendrimer-capped nanoparticles prepared by picosecond laser ablation in liquid environment

Fifth generation ethylendiamine-core poly(amidoamine) (PAMAM G5) is presented as an efficient capping agent for the preparation of metal and semiconductor nanoparticles by ps laser ablation in water. In particular, we describe results obtained with the fundamental, second and third harmonic of a ps Nd:YAG laser and the influence of laser wavelength and pulse energy on gold particle production and subsequent photofragmentation. In this framework, the role of the dendrimer and, in particular, its interactions with gold clusters and cations are accounted.