Porphyrin-Based Nanostructures for Sensing Applications

The construction of nanosized supramolecular hosts via self-assembly of molecular components is a fascinating field of research. Such intriguing class of architectures, beside their intrinsic intellectual stimuli, is of importance in many fields of chemistry and technology, such as material chemistry, catalysis, and sensor applications. Within this wide scenario, tailored solid films of porphyrin derivatives are structures of great potential for, among others, chemical sensor applications. The formation ofsupramoleculesrelays on noncovalent interactions (electrostatic, hydrogen bond, , or coordinative interactions) driven by the chemical information stored on the assembling molecules, such as shape and functional groups. This allows, for example, the formation of large well-defined porphyrin aggregates in solution that can be spontaneously transferred onto a solid surface, so achieving a solid system with tailored features. These films have been used, covering the bridge between nanostructures and microsystems, for the construction of solid-state sensors for volatiles and metal ion recognition and detection. Moreover, the variation of peripheral substituents of porphyrins, such as, for example, chiral appended functionalities, can result in the formation of porphyrin aggregates featuring high supramolecular chirality. This would allow the achievement of porphyrin layers characterised by different chiroptical and molecular recognition properties

PARP inhibition: a promising therapeutic target in ovarian cancer

Ovarian cancer is burdened by the highest mortality rate among gynecological cancers. Gold standard is represented by the association of platinum-taxane -based chemotherapy and radical surgery. Despite several adjustments occurred in cytotoxic drug in last decades, most patients continue to relapse, and no significant enhancement has been reached in the overall survival. The development of drug resistance and the recurrence of disease have prompted the investigations of other targets that can be used in the treatment of ovarian cancers. Among such targets, polyadenosine diphosphate-ribose polymerase (PARP) represents a novel way to target specific patways involved in tumor growth. PARP accelerates the reaction of the polyADP-ribosylation of proteins implicated in DNA repair. PARP inhibitors have shown activity in cancers with BRCA mutations, with other deficient DNA repair genes or signaling pathways that modulate DNA repair, or in association with DNA damaging agents not involved in DNA repair dysfunction. A number of inhibitors for PARP has been developed, and such drugs are under investigation in clinical trials to identify their impact in the treatment of ovarian cancers. This review aims to summarize the recent researches and clinical progress on PARP inhibitors as novel target agents in ovarian cancer

Recent advances in chemical sensors using porphyrin-carbon nanostructure hybrid materials

Porphyrins and carbon nanomaterials are among the most widely investigated and applied compounds, both offering multiple options to modulate their optical, electronic and magnetic properties by easy and well-established synthetic manipulations. Individually, they play a leading role in the development of efficient and robust chemical sensors, where they detect a plethora of analytes of practical relevance. But even more interesting, the merging of the peculiar features of these single components into hybrid nanostructures results in novel materials with amplified sensing properties exploitable in different application fields, covering the areas of health, food, environment and so on. In this contribution, we focused on recent examples reported in literature illustrating the integration of different carbon materials (i.e., graphene, nanotubes and carbon dots) and (metallo)porphyrins in heterostructures exploited in chemical sensors operating in liquid as well as gaseous phase, with particular focus on research performed in the last four years

Chiral selectivity of porphyrin-ZnO nanoparticle conjugates

Recognition of enantiomers is one of the most arduous challenges in chemical sensor development. Although several chiral systems exist, their effective exploitation as the sensitive layer in chemical sensors is hampered by several practical implications that hinder stereoselective recognition in solid state. In this paper, we report a new methodology to efficiently prepare chiral solid films, by using a hybrid material approach where chiral porphyrin derivatives are grafted onto zinc oxide nanoparticles. Circular dichroism (CD) evidences that the solid-state film of the material retains supramolecular chirality due to porphyrin interactions, besides an additional CD feature in correspondence of the absorbance of ZnO (375 nm), suggesting the induction of chirality in the underlying zinc oxide nanoparticles. The capability of hybrid material to detect and recognize vapors of enantiomer pairs was evaluated by fabricating gas sensors based on quartz microbalances. Chiral films of porphyrin on its own were used for comparison. The sensor based on functionalized nanostructures presented a remarkable stereoselectivity in the recognition of limonene enantiomers, whose ability to intercalate in the porphyrin layers makes this terpene an optimal chiral probe. The chiroptical and stereoselective properties of the hybrid material confirm that the use of porphyrin-capped ZnO nanostructures is a viable route for the formation of chiral selective surfaces. © 2019 American Chemical Society

Porphyrins Through the Looking Glass: Spectroscopic and Mechanistic Insights in Supramolecular Chirogenesis of New Self-Assembled Porphyrin Derivatives

The solvent driven aggregation of porphyrin derivatives, covalently linked to a L- or D-prolinate enantiomer, results in the stereospecific formation of species featuring remarkable supramolecular chirality, as a consequence of reading and amplification of the stereochemical information stored in the proline-appended group. Spectroscopic, kinetic, and topographic SEM studies gave important information on the aggregation processes, and on the structures of the final chiral architectures. The results obtained may be the seeds for the construction of stereoselective sensors aiming at the detection, for example, of novel emergent pollutants from agrochemical, food, and pharmaceutical industry

Tunable supramolecular chirogenesis in the self-assembling of amphiphilic porphyrin triggered by chiral amines

Supramolecular chirality is one of the most important issues in different branches of science and technology, as stereoselective molecular recognition, catalysis, and sensors. In this paper, we report on the self-assembly of amphiphilic porphyrin derivatives possessing a chiral information on the periphery of the macrocycle (i.e., D- or L-proline moieties), in the presence of chiral amines as co-solute, such as chiral benzylamine derivatives. The aggregation process, steered by hydrophobic effect, has been studied in aqueous solvent mixtures by combined spectroscopic and topographic techniques. The results obtained pointed out a dramatic effect of these ligands on the morphology and on the supramolecular chirality of the final self-assembled structures. Scanning electron microscopy topography, as well as fluorescence microscopy studies revealed the formation of rod-like structures of micrometric size, different from the fractal structures formerly observed when the self-assembly process is carried out in the absence of chiral amine co-solutes. On the other hand, comparative experiments with an achiral porphyrin analogue strongly suggested that the presence of the prolinate moiety is mandatory for the achievement of the observed highly organized suprastructures. The results obtained would be of importance for unraveling the intimate mechanisms operating in the selection of the homochirality, and for the preparation of sensitive materials for the detection of chiral analytes, with tunable stereoselectivity and morphology

Seeding chiral ensembles of prolinated porphyrin derivatives on glass surface: simple and rapid access to chiral porphyrin films

An easy and fast method to achieve chiral porphyrin films on glass is herein reported. The on-surface formation of organized supramolecular architectures with distinctive and remarkable chiroptical features strictly depends on the macrocycles used, the solvent chosen for the casting deposition, and most importantly, on the roughness of the glass slide. Dynamic light scattering studies performed on 10−4–10−6 M porphyrin solutions revealed the presence of small porphyrin aggregates, whose size and number increase depending on the initial concentration. Once transferred on surface, these protoaggregates act as nucleation seeds for the following, self-assembling into larger structures upon solvent evaporation, with a process driven by a fine balance between intermolecular and molecule–substrate interactions. The described method represents a straightforward way to fabricate porphyrin-based chiral surfaces onto a transparent and economic substrate in few minutes. The results obtained can be particularly promising for the development of sensors based on stereoselective optical active films, targeting the detection of chiral analytes of practical relevance, such as the so-called emerging pollutants released in the environment from agrochemical, food, and pharmaceutical manufacturing

Chiral recognition by supramolecular porphyrin-hemicucurbit[8]uril-functionalized gravimetric sensors

Enantiorecognition of a chiral analyte usually requiresthe abilityto respond with high specificity to one of the two enantiomers ofa chiral compound. However, in most cases, chiral sensors have chemicalsensitivity toward both enantiomers, showing differences only in theintensity of responses. Furthermore, specific chiral receptors areobtained with high synthetic efforts and have limited structural versatility.These facts hinder the implementation of chiral sensors in many potentialapplications. Here, we utilize the presence of both enantiomers ofeach receptor to introduce a novel normalization that allows the enantio-recognitionof compounds even when single sensors are not specific for one enantiomerof a target analyte. For this purpose, a novel protocol that permitsthe fabrication of a large set of enantiomeric receptor pairs withlow synthetic efforts by combining metalloporphyrins with (R,R)- and (S,S)-cyclohexanohemicucurbit[8]uril is developed. The potentialitiesof this approach are investigated by an array of four pairs of enantiomericsensors fabricated using quartz microbalances since gravimetric sensorsare intrinsically non-selective toward the mechanism of interactionof analytes and receptors. Albeit the weak enantioselectivity of singlesensors toward limonene and 1-phenylethylamine, the normalizationallows the correct identification of these enantiomers in the vaporphase indifferent to their concentration. Remarkably, the achiralmetalloporphyrin choice influences the enantioselective properties,opening the way to easily obtain a large library of chiral receptorsthat can be implemented in actual sensor arrays. These enantioselectiveelectronic noses and tongues may have a potential striking impactin many medical, agrochemical, and environmental fields

The Efficacy of Fractional {CO}2 Laser in the Treatment of Genitourinary Syndrome of Menopause. A Large Prospective Observational Study

Background: Genitourinary syndrome of menopause (GSM) majorly caused by the physiological decline in estrogen, affects up to 90% of menopausal women. Hormonal therapy seems to be an effective treatment, often not executable for contraindication or patient's low compliance to local or systemic medical therapy. Fractional CO2 laser therapy is an emerging and effective choice for women affected by vulvo-vaginal atrophy (VVA), promoting collagen regeneration and improving blood flow of the vaginal mucosa and elasticity of tissues. Methods: Ninety-two menopausal Patients affected by vulvo-vaginal atrophy (VVA) were considered for the present prospective observational study. All women were treated with Fractional CO2 laser Lumenis AcuPulse in a fractionated sequential mode laser pulse. Patients were requested to complete questionnaires regarding the Female Sexual Functional Index (FSFI), Female Sexual Distress Scale (FSDS) and severity of Most Bothersome Symptoms (MBS) at baseline (T0) and at three-month following three-treatment-sessions (T1). Results: Data indicated a significant improvement of MBS (vaginal itching (p < 0.0001), post-coital vaginal bleeding (p < 0.002), vaginal dryness (p < 0.0001), dyspareunia (p < 0.0001) and dysuria (p < 0.0001), higher Vaginal Health Index Score (VHIS) (4.1 +/- 1.21; 95% CI = 3.84-4.35) and reduces pH (-0.53 +/- 0.24; 95% CI = 0.48-0.58) after CO2 laser treatment. A significantly improvement of FSFI Total score (p < 0.0001) and FSDS (p < 0.0001) have been demonstrated. Conclusions: Fractional CO2 laser improves vaginal health as well as signs and symptoms associated with GSM, while significantly elevating quality of life and sexual functionality among postmenopausal symptomatic women

Benzene and lipid asset

Background: In relation to the medico-social and medico-legal aspects of urban pollution we studied the effects of benzene present in urban pollution on outdoor workers exposed to physical, chemical, and psychosocial stressors. The purpose of this study is to evaluate the possible correlation between the levels of benzene and its urinary metabolites in the blood (Trans muconic acid and S-phenylmecapturic acid) and the parameters of the lipid structure: Total cholesterol, High Density Lipoprotein (HDL), Low Density Lipoprotein (LDL), triglycerides and blood sugar. Materials and methods: From an initial group 1,500 we selected a group of 199 subjects. A blood sample was taken for each worker to assess blood benzene levels and urinalysis to determine the levels of trans, trans-muconic acid and S-phenyl mercapturic acid. We compared the mean and standard deviation of the following lipid parameters: Total Cholesterol, HDL, LDL, Triglycerides and glycemia with benzene and urinary metabolites; we excluded the workers with confounding factors and performed the Pearson’s correlation between lipid parameters and urinary metabolites in the total sample and also among age, seniority, sex and BMI; multiple linear regression was performed for the evaluation of the main confounding factors. Results: We did not find a statistically significant alteration between the values of the lipid structure between the two groups of workers and the parameters of benzene. Triglycerides and HDL are statistically significantly influenced by sex (p=0.001) and (p=0.00) and BMI (p=0.00) and (p=0.001) as well as total cholesterol is influenced in a statistically significant way from age (p=0.003) and blood glucose from BMI (p=0.002) A statistically significant difference was found among the averages of phenylmercapturic S acid values of traffic policeman and police drivers (p<0.05), where higher values were among drivers. Conclusions: The results suggest that occupational exposure to levels of benzene, present in urban pollution, would appear not to influence the values of the lipid parameters in traffic policeman