Biodeterioration Patterns and Their Interpretation for Potential Applications to Stone Conservation: A Hypothesis from Allelopathic Inhibitory Effects of Lichens on the Caestia Pyramid (Rome)

The colonisation of stone by different organisms often leaves biodeterioration patterns (BPs) on the surfaces even if their presence is no longer detectable. Peculiar weathering patterns on monuments and rocks, such as pitting phenomena, were recognised as a source of information on past colonisers and environmental conditions. The evident inhibition areas for new bio-patinas observed on the marble blocks of the Caestia Pyramid in Rome, recognisable as tracks of previous colonisations, seem a source for developing new natural products suitable for restoration activities. To hypothesise past occurring communities and species, which gave rise to such BPs, we carried out both in situ observations and analyses of the rich historical available iconography (mainly photographs). Moreover, we analysed literature on the lichen species colonising carbonate stones used in Roman sites. Considering morphology, biochemical properties and historical data on 90 lichen species already reported in Latium archaeological sites, we suppose lichen species belonging to the genus Circinaria (Aspicilia s.l.) to be the main aetiological agent of such peculiar BPs. These results seem relevant to highlight the long-lasting allelopathic properties of some lichen substances potentially applicable as a natural product to control colonisation, improving the environmental and economical sustainability of stone restoration

Synthesis and characterization of TEOS coating added with innovative antifouling silica nanocontainers and TiO2 nanoparticles

We study the synthesis and characterisation of an innovative TEOS-based composite coating, which could improve previous formulations used in the field of monument conservation. The proposed coating is composed by a tetraethoxyorthosilicate matrix (TEOS), containing an elasticiser (hydroxyl-terminated polydimethylsiloxane (PDMS-OH)) and a non-ionic surfactant (n-octylamine). The specific self-cleaning and antifouling properties are obtained by the addition of different kinds of nanofillers: the commercial TiO2 nanoparticles, plus two different silica nanocontainers, loaded with the commercial biocide 2-mercaptobenzothiazole. Through a multi-analytical approach, we evaluate the effect of the nanoparticles concentration on the coatings drying rate, on the variation of their visual aspect and textural properties. Our results show that the addition of the silica nanocontainers at 0.05% (w/v) in sol does not change the colour of the coating and reduces the formation of cracks after drying. Moreover, the coating charged with nanocontainers undergoes slower drying, thus improving its penetration into the pores of the treated surface. Further tests of photocatalytic and biocidal properties of this new product on different lithotypes and their potential interactions are in progress

Natural biocides for the conservation of stone cultural heritage: A review

The use of traditional biocides to reduce bio-deterioration phenomena of stone monuments is increasingly deterred, due to risks for human health and the environment, as well as for potential interference with materials. Extensive research is now ongoing, aiming to find alternative and eco-friendly substances or methods to halt or reduce bio-deterioration. Here we aim to provide an assessment of the results of scientific tests, in order to evaluate the most promising substances, likewise possible deficiencies and future directions in research. We performed an extensive literature review on natural biocides for controlling bio-deterioration of stone using peer-reviewed articles between 1986 and 2018. The dataset created displays information about the experimentation of a total of 61 natural substances, mostly essential oils (23), or substances of plant origin and other compounds. The methods of application of such biocides were diverse, but the in vitro tests were the prevailing ones. The most tested organisms were fungi, followed by cyanobacteria and algae. The efficacy of the substances resulted highly variable, as did protocols and experimental doses, resulting in a lack of a robust and coherent assessment of best practices. Also, we found a few papers discussing the interference of these substances with the substrate. We believe that this area of research is very promising and necessary, although additional tests with a standardised methodology are still needed

A real-world economic analysis of biologic therapies for moderate-to-severe plaque psoriasis in Italy: results of the CANOVA observational longitudinal study

Background: Psoriasis is a chronic immune-mediated inflammatory skin disease which can also involve joints. It is often associated with burdensome comorbidities which negatively impact prognosis and quality of life (QoL). Biologic agents have been shown to be effective in controlling disease progression, but their use is associated with higher costs compared with traditional systemic treatments. The economic analysis of the CANOVA (EffeCtiveness of biologic treAtmeNts for plaque psOriasis in Italy: an obserVAtional longitudinal study of real-life clinical practice) study aims to assess the costs and cost-effectiveness of biologics in a real-world context in Italy. Methods: The annualised overall direct costs of moderate-to-severe plaque psoriasis management, the annualised cost of biologic drugs and the cost per responder in the Italian National Health System perspective were assessed. More specifically, the cost per response and cost per sustained response of the most prescribed biologic therapies for the treatment of moderate-to-severe plaque psoriasis within the CANOVA study were assessed using the Psoriasis Area Severity Index (PASI) at several score levels (75, 90 and 100%). Results: The most frequently used biologic therapies for plaque psoriasis were secukinumab, ustekinumab, adalimumab originator, and ixekizumab. Cost of biologics was the driver of expenditure, accounting for about 98% of total costs. Adalimumab originator was the biologic with the lowest cost per responder ratio (range: €7848 - €31,378), followed by secukinumab (range: €9015 - €33,419). Ustekinumab (range: €11,689 - €39,280) and ixekizumab (range: €11,092 - €34,289) ranked respectively third and fourth, in terms of cost-effectiveness ratio. As concerns the cost per sustained response analysis, secukinumab showed the lowest value observed (€21,375) over the other options, because of its high response rate (86% vs. 60-80%), which was achieved early in time. Conclusion: Biologic therapy is a valuable asset for the treatment of moderate-to-severe plaque psoriasis. Concomitant assessment of treatment costs against the expected therapeutic response over time can provide physicians and payers additional insights which can complement the traditional risk-benefit profile assessment and drive treatment decisions

Real-world evidence of biologic treatments in moderate-severe psoriasis in Italy: Results of the CANOVA (EffeCtiveness of biologic treAtmeNts for plaque psOriasis in Italy: An obserVAtional longitudinal study of real-life clinical practice) study

EffeCtiveness of biologic treAtmeNts for plaque psOriasis in Italy: An obserVAtional (CANOVA) study was aimed at providing real-world evidence of the effectiveness of biologics in Italian patients with moderate-severe psoriasis. It was an observational, retro-prospective cohort study conducted in 17 Italian dermatology clinics. Adult patients with moderate-severe plaque psoriasis, who started a biologic treatment between 24 weeks and 24 months before enrolment, were included. With a follow-up visit at 6 months after enrolment, each patient had at least 12 months of observation. The primary objective was to describe the clinical response rates (PASI 75) after 16/24/52 weeks from biologic treatment start. Secondary outcomes were sustained response, quality of life, and treatment satisfaction. Of the 669 eligible patients (64% males), 52% were naive to biologics, though a mean duration of psoriasis since first diagnosis of 18.6 years (SD 13.2). The most frequently prescribed biologics were secukinumab (41%), ustekinumab (25%), TNF-inhibitors (22%) and ixekizumab (12%). PASI 75 was achieved by 86% of patients (95% CI: 82%-89%) at 16 weeks, 90% (87%-93%) at 24 weeks, and 91% (89%-94%) at 52 weeks. Patients achieving PASI 90 and PASI 100 at 52 weeks were 75% (71%-79%) and 53% (49%-57%), respectively. Sustained PASI 75 response after 1 year from treatment start was achieved by 78% (74%-82%) of patients. Mean DLQI total score was 2.3 (SD 3.9) at enrollment and decreased at the final visit to 1.8 (3.6). A high level of treatment satisfaction was expressed by patients over the study period. This large real-world study confirms in the clinical practice the good effectiveness and acceptability of biologics in psoriasis patients