Hyaluronan Hydrogels: Rheology and Stability in Relation to the Type/Level of Biopolymer Chemical Modification

BDDE (1,4-butanediol-diglycidylether)-crosslinked hyaluronan (HA) hydrogels are widely used for dermo-aesthetic purposes. The rheology and stability of the gels under physiological conditions greatly affect their clinical indications and outcomes. To date, no studies investigating how these features are related to the chemistry of the polymeric network have been reported. Here, four available HA-BDDE hydrogels were studied to determine how and to what extent their rheology and stability with respect to enzymatic hydrolysis relate to the type and degree of HA structural modification.1 H-/13 C-NMR analyses were associated for the quantification of the “true” HA chemical derivatization level, discriminating between HA that was effectively crosslinked by BDDE, and branched HA with BDDE that was anchored on one side. The rheology was measured conventionally and during hydration in a physiological medium. Sensitivity to bovine testicular hyaluronidase was quantified. The correlation between NMR data and gel rheology/stability was evaluated. The study indicated that (1) the gels greatly differed in the amounts of branched, crosslinked, and overall modified HA, with most of the HA being branched; (2) unexpectedly, the conventionally measured rheological properties did not correlate with the chemical data; (3) the gels’ ranking in terms of rheology was greatly affected by hydration; (4) the rheology of the hydrated gels was quantitatively correlated with the amount of crosslinked HA, whereas the correlations with the total HA modification level and with the degree of branched HA were less significant; (5) increasing HA derivatization/crosslinking over 9/3 mol% did not enhance the stability with respect to hyaluronidases. These results broaden our knowledge of these gels and provide valuable information for improving their design and characterization

Excess of power during electrochemical loading : materials, electrochemical conditions and techniques

"Notes on The ENEA-University of Missouri NRL-SRI International Research Activities." ENEA, University of Missouri, NRL and SRI are cooperating within the frame of an International Program. The research field is on Metal Hydrogen Systems for Energy Applications and is oriented to develop nanostructured materials to be used into electrochemical devices and to study the Fleischmann and Pons Effect. Progress in material science and improvement in controlling the effect is presented

L'AVVENTURA DELLA LINGUA: MARIA LUISA ALTIERI BIAGI FRA RICERCA E DIDATTICA: PRESENTAZIONE di Silvia Morgana

Gli allievi di Maria Luisa Altieri Biagi ripercorrono in tre articoli il suo lungo impegno teorico e civile per l’educazione linguistica e la formazione degli insegnanti. Angela Chiantera e Cristiana De Santis analizzano le sue molteplici esperienze per il rinnovamento della didattica linguistica nella stretta connessione tra lingua e pensiero. Francesca Gatta ne illustra gli studi sulla letteratura contemporanea e le analisi del testo letterario in prospettiva di educazione linguistica, mentre Fabio Atzori evidenzia i rapporti tra i suoi fondamentali studi sulla lingua scientifica e la sua produzione per la scuola.   The adventure of language: Maria Luisa Altieri Biagi from research to teaching The students of Maria Luisa Altieri Biagi review her long-standing theoretical and civil commitment to language education and teacher training in three articles. Angela Chiantera and Cristiana De Santis analyze her multiple efforts to renew language teaching with focus on the close connection between language and thought. Francesca Gatta illustrates her studies on contemporary literature and the analysis of the literary text in the perspective of language education, while Fabio Atzori highlights the relationship between her fundamental studies on scientific language and her production for schools

In vitro analysis of the effects on wound healing of high- and low-molecular weight chains of hyaluronan and their hybrid H-HA/L-HA complexes

Abstract Background: Recent studies have reported the roles of Hyaluronic acid (HA) chains of diverse length in wound repair, especially considering the simultaneous occurrence in vivo of both high- (H-HA) and low-molecular weight (L-HA) hyaluronan at an injury site. It has been shown that HA fragments (5 ≤ MW ≤ 20 kDa) usually trigger an inflammatory response that, on one hand, is the first signal in the activation of a repair mechanism but on the other, when it’s overexpressed, it may promote unwanted side effects. The present experimental research has aimed to investigate H-HA, L-HA and of a newly developed complex of the two (H-HA/L-HA) for stability (e.g. hyaluronidases digestion), for their ability to promote wound healing of human keratinocytes in vitro and for their effect on cellular biomarker expression trends. Results: Time-lapse video microscopy studies proved that the diverse HA was capable of restoring the monolayer integrity of HaCat. The H-HA/L-HA complex (0.1 and 1%w/v) proved faster in regeneration also in co-culture scratch test where wound closure was achieved in half the time of H-HA stimulated cells and 2.5-fold faster than the control. Gene expression was evaluated for transformation growth factor beta 1 (TGF-β1) proving that L-HA alone increased its expression at 4 h followed by restoration of similar trends for all the stimuli. Depending on the diverse stimulation (H-HA, L-HA or the complex), metalloproteinases (MMP-2, -9, -13) were also modulated differently. Furthermore, type I collagen expression and production were evaluated. Compared to the others, persistence of a significant higher expression level at 24 h for the H-HA/L-HA complex was found. Conclusions: The outcomes of this research showed that, both at high and low concentrations, hybrid complexes proved to perform better than HA alone thus suggesting their potential as medical devices in aesthetic and regenerative medicine. Keywords: Wound healing, Hyaluronan, MMPs, Hybrid complexe

Dramatic Repositioning of c-Myb to Different Promoters during the Cell Cycle Observed by Combining Cell Sorting with Chromatin Immunoprecipitation

The c-Myb transcription factor is a critical regulator of proliferation and stem cell differentiation, and mutated alleles of c-Myb are oncogenic, but little is known about changes in c-Myb activity during the cell cycle. To map the association of c-Myb with specific target genes during the cell cycle, we developed a novel Fix-Sort-ChIP approach, in which asynchronously growing cells were fixed with formaldehyde, stained with Hoechst 33342 and separated into different cell cycle fractions by flow sorting, then processed for chromatin immunoprecipitation (ChIP) assays. We found that c-Myb actively repositions, binding to some genes only in specific cell cycle phases. In addition, the specificity of c-Myb is dramatically different in small subpopulations of cells, for example cells in the G2/M phase of the cell cycle, than in the bulk population. The repositioning of c-Myb during the cell cycle is not due to changes in its expression and also occurs with ectopically expressed, epitope-tagged versions of c-Myb. The repositioning occurs in established cell lines, in primary human CD34+ hematopoietic progenitors and in primary human acute myeloid leukemia cells. The combination of fixation, sorting and ChIP analysis sheds new light on the dynamic nature of gene regulation during the cell cycle and provides a new type of tool for the analysis of gene regulation in small subsets of cells, such as cells in a specific phase of the cell cycle

Clinical intervals and diagnostic characteristics in a cohort of prostate cancer patients in Spain: a multicentre observational study

Background: Little is known about the healthcare process for patients with prostate cancer, mainly because hospital-based data are not routinely published. The main objective of this study was to determine the clinical characteristics of prostate cancer patients, the diagnostic process and the factors that might influence intervals from consultation to diagnosis and from diagnosis to treatment. Methods: We conducted a multicentre, cohort study in seven hospitals in Spain. Patients' characteristics and diagnostic and therapeutic variables were obtained from hospital records and patients' structured interviews from October 2010 to September 2011. We used a multilevel logistic regression model to examine the association between patient care intervals and various variables influencing these intervals (age, BMI, educational level, ECOG, first specialist consultation, tumour stage, PSA, Gleason score, and presence of symptoms) and calculated the odds ratio (OR) and the interquartile range (IQR). To estimate the random inter-hospital variability, we used the median odds ratio (MOR). Results: 470 patients with prostate cancer were included. Mean age was 67.8 (SD: 7.6) years and 75.4 % were physically active. Tumour size was classified as T1 in 41.0 % and as T2 in 40 % of patients, their median Gleason score was 6.0 (IQR:1.0), and 36.1 % had low risk cancer according to the D'Amico classification. The median interval between first consultation and diagnosis was 89 days (IQR:123.5) with no statistically significant variability between centres. Presence of symptoms was associated with a significantly longer interval between first consultation and diagnosis than no symptoms (OR:1.93, 95%CI 1.29-2.89). The median time between diagnosis and first treatment (therapeutic interval) was 75.0 days (IQR:78.0) and significant variability between centres was found (MOR:2.16, 95%CI 1.45-4.87). This interval was shorter in patients with a high PSA value (p = 0.012) and a high Gleason score (p = 0.026). Conclusions: Most incident prostate cancer patients in Spain are diagnosed at an early stage of an adenocarcinoma. The period to complete the diagnostic process is approximately three months whereas the therapeutic intervals vary among centres and are shorter for patients with a worse prognosis. The presence of prostatic symptoms, PSA level, and Gleason score influence all the clinical intervals differently

The Italian fund for Alzheimer's and other dementias: strategies and objectives to face the dementia challenge

The Italian Fund for Alzheimer's and other dementias was approved and signed in December 2021. The Fund is financed with 15 million euros in three years. The main goal is to provide new strategies in the field of dementia with a Public Health perspective. The Fund includes eight main activities that will be monitored and supervised by the Italian National Institute of Health: 1) development of a guideline for the assessment, management and support for people with dementia and their families/carers; 2) updating of the Dementia National Plan (DNP); 3) implementation of the documents of the DNP; 4) conducting surveys dedicated to the Italian Dementia Services; 5) promotion of dementia prevention strategies; 6) training strategies for healthcare professionals, families and caregivers; 7) creation of a National Electronic Record for Dementia; 8) evaluation and monitoring of activities promoted by Regions and Autonomous Provinces in the field of dementia, together with the dementia National Permanent Table. These activities are outlined in detail in the present paper