Learning from Nature: Bioinspired Strategies Towards Antimicrobial Nanostructured Systems

Microbial contamination still remains a major issue of the modern era, due to the widespread of drug-resistant pathogens. This has prompted researchers to come up with novel antimicrobial systems that could overcome antibiotic-resistance. In this context, nature can provide inestimable source of inspiration to design high-performance multifunctional materials with potent activity against drug-resistant pathogens. Actually, integrating the bio-inspired-approach with nanotechnology can provide cutting-edge solutions for drug-resistant infections. In this context, this review will examine recent advances in the development of bio-inspired antimicrobial nanostructures. Advantages of bioinspired approach to nanomaterials over conventional routes have been highlighted. Generally, bionspired synthesis can be carried out either by mimicking the functions of natural materials/ structures or by mimicking the biological processes employed to produce substances or materials. The review provides an overview of both strategies as applied to the synthesis of inorganic, organic as well as hybrid nanostructures. Antimicrobial efficacy and biological properties of these systems have been highlighted. Antimicrobial and antibiofouling nanostructured surfaces are also discussed

The frameshift Leu220Phefs*2 variant in KRIT1 accounts for early acute bleeding in patients affected by cerebral cavernous malformation

Abstract Background and Objectives Cerebral cavernous malformation (CCM) is a neurovascular disease characterized by abnormally expanded and tortuous microvessels with increased predisposition to thrombosis and focal hemorrhage. Its incidence is estimated to range between 0.4% and 0.8%. Sporadic and familial forms of CCM are described. The first one is characterized by single lesion, while the familial form is defined by multiple malformations. In this scenario, more than 300 mutations affecting the CCM genes have been described to date, but the exact pathogenic mechanism is yet unknown. Most of the causative variants of KRIT1 gene are frameshift but there are many missense and nonsense variants and they have been found some splicing mutations. The diagnosis is based on magnetic resonance images (MRI) and genetic testing. Case report A 15-year-old male presented with a two weeks duration worsening headache accompanied by vomiting and three months behavioral changes. Computer tomography revealed a large right temporal lesion with other smaller in left parietal and left cerebellar region. At the time of diagnosis, the two siblings of the proband were asymptomatic. Nevertheless, four months later, the 7-years-old brother was admitted to the emergency room for balance deficit, diplopia, right-hitting nystagmus and stiff neck with deviation of the head. A cerebral CT revealed polylobate hyperdense mass of the middle cerebral pedicle associated to acute bleeding. A genetic testing for hereditary cavernous brain malformation was carried out. Results The molecular analysis identified a 2-bp duplication (NM_194456.1:c.658_659dupTT) as heterozygous within the exon 8 of CCM1/KRIT1 gene (Fig. 1C). This duplication leads to a frameshift variant, resulting in a premature stop codon (p.Leu220Phefs*2). Discussion The clinical data collected confirm the variable phenotypic expression of CCM and suggest a greater severity of symptoms in the youngest patients

Detailed thermal, fire, and mechanical study of silicon-modified epoxy resin containing humic acid and other additives

Following a waste-to-wealth approach, humic acid (HA) was exploited as a flame retardant additive. The effect of its addition alone and in combination with urea (UR) and ammonium polyphosphate (APP) on the thermal, fire, and mechanical performances of a bisphenol A diglycidyl ether (DGEBA)-based epoxy resin modified with (3-aminopropyl)-triethoxysilane (AP) and cured with aliphatic isophoronediamine (IDA) has been investigated. Unlike in previous studies, a UL 94-V-0 classification was achieved for epoxy resin containing HA at 6 wt % and APP at only 1 wt % phosphorus (P) loading. The presence of silicon-modified epoxy chains ameliorated the distribution of the biowaste within the resin, and the addition of HA alone avoided melt dripping. Besides, APP and UR promoted a remarkable reduction (up to 52%) of the peak heat release rate (pHRR) values and a significant delay (up to 21%) of the time to ignition in cone calorimetry tests, and hence an increase (up to 1.8 min) of the time to flashover, without any detrimental effect on the overall mechanical behavior. The evolved gas, thermal, and fire analysis was used to propose the combined mode of action of HA, UR, APP, and silicon in the fire performance improvement of the hybrid epoxy system

Delineation and Diagnostic Criteria of Oral-Facial-Digital Syndrome Type VI

Oral-Facial-Digital Syndrome type VI (OFD VI) represents a rare phenotypic subtype of Joubert syndrome and related disorders (JSRD). In the original report polydactyly, oral findings, intellectual disability, and absence of the cerebellar vermis at post-mortem characterized the syndrome. Subsequently, the molar tooth sign (MTS) has been found in patients with OFD VI, prompting the inclusion of OFD VI in JSRD. We studied the clinical, neurodevelopmental, neuroimaging, and genetic findings in a cohort of 16 patients with OFD VI. We derived the following inclusion criteria from the literature: 1) MTS and one oral finding and polydactyly, or 2) MTS and more than one typical oral finding. The OFD VI neuroimaging pattern was found to be more severe than in other JSRD subgroups and includes severe hypoplasia of the cerebellar vermis, hypoplastic and dysplastic cerebellar hemispheres, marked enlargement of the posterior fossa, increased retrocerebellar collection of cerebrospinal fluid, abnormal brainstem, and frequently supratentorial abnormalities that occasionally include characteristic hypothalamic hamartomas. Additionally, two new JSRD neuroimaging findings (ascending superior cerebellar peduncles and fused thalami) have been identified. Tongue hamartomas, additional frenula, upper lip notch, and mesoaxial polydactyly are specific findings in OFD VI, while cleft lip/palate and other types of polydactyly of hands and feet are not specific. Involvement of other organs may include ocular findings, particularly colobomas. The majority of the patients have absent motor development and profound cognitive impairment. In OFD VI, normal cognitive functions are possible, but exceptional. Sequencing of known JSRD genes in most patients failed to detect pathogenetic mutations, therefore the genetic basis of OFD VI remains unknown. Compared with other JSRD subgroups, the neurological findings and impairment of motor development and cognitive functions in OFD VI are significantly worse, suggesting a correlation with the more severe neuroimaging findings. Based on the literature and this study we suggest as diagnostic criteria for OFD VI: MTS and one or more of the following: 1) tongue hamartoma(s) and/or additional frenula and/or upper lip notch; 2) mesoaxial polydactyly of one or more hands or feet; 3) hypothalamic hamartoma

Clinical and molecular characterization of corpus callosal abnormalities: toward a better understanding of their genetic basis

Introduction: Corpus callosum abnormalities (CCA) have an estimated prevalence ranging from 0.3% up to 0.7% in patients undergoing brain imaging. CCA can be identified incidentally, or can be part of a developmental disease. Materials and Methods: We performed a retrospective study of 556 patients, identified non-syndromic (NS) CCA and syndromic (S) CCA, reviewing clinical features, neuroradiological aspects, genetic etiology, and chromosomal microarray (CMA) results. Results: Syndromic CCA subjects were prevalent (60%) and they showed the most severe clinical features. Cortical malformations and cerebellar anomalies were 20% of cerebral malformation associated to CCA (plus), A clinical and/or genetic diagnosis was obtained in 37% of syndromic CCA including chromosomal rearrangements on high-resolution karyotype (18%), microdeletion/microduplication syndromes (31%) and monogenic diseases (51 %). Non-syndromic CCA anomalies had mildest clinical features, although intellectual disability was present in 55% of cases and epilepsy in 13%. CMA diagnostic rate in our cohort of patients ranged from 2% to 23% (NS to S). WES analysis was performed in very few selected cases of syndromic CCA allowing the identification of new causative genes. Conclusion: A high percentage of patients remain without a diagnosis. Combined high resolution CMA studies and next-generation sequencing (NGS) strategies will increase the probability to identify new causative genes of CCA and to redefine genotype-phenotype correlation

Nuove frontiere nella progettazione di dispositivi opto-elettronici: sistemi semiconduttori ibridi bio organo-inorganici

Nella realizzazione di sistemi ibridi organo-inorganico per applicazioni optoelettroniche riscuotono grande attenzione le perovskiti, anche grazie alla versatilità dei meccanismi di conduzione in esse operanti e che possono coinvolgere il trasporto di elettroni, lacune o specie ioniche [1]. Il crescente interesse per i materiali bioispirati e biocompatibili ha stimolato, inoltre, lo studio e l’ingegnerizzazione di dispositivi opto-elettronici basati su prodotti naturali. Tra questi, grandi potenzialità hanno evidenziato le eumelanine, pigmenti animali multifunzionali, con peculiare comportamento elettrico e proprietà red-ox modulabili [2]. Il loro processo di formazione in-vivo, basato sulla polimerizzazione ossidativa di composti fenolici o indolici tra cui il 5,6-diidrossiindolo (DHI), può essere riprodotto in vitro seguendo un approccio biomimetico. In particolare, l’utilizzo di una fase ceramica come templante per la polimerizzazione del precursore melanogenico determina un marcato miglioramento delle proprietà biologiche di tali pigmenti [3, 4]. Un trattamento termico degli ibridi ceramico-melanina, inoltre, modificando le proprietà dell’interfaccia può comportare una profonda modifica delle caratteristiche chimico-fisiche di tali sistemi moltiplicando le potenzialità applicative in campi ancora inesplorati. Sulla base di tali presupposti una fase ceramica a struttura perovskitica, di composizione LaFeO3 è stata utilizzata come templante per la polimerizzazione dei DHI, ottenendo ibridi ferrite-eumelanina. I risultati più promettenti delle proprietà elettriche sono stati ottenuti dai sistemi ibridi sottoposti a trattamento termico