Transient Anomalous Diffusion MRI Measurement Discriminates Porous Polymeric Matrices Characterized by Different Sub-Microstructures and Fractal Dimension

Considering the current development of new nanostructured and complex materials and gels, it is critical to develop a sub-micro-scale sensitivity tool to quantify experimentally new parameters describing sub-microstructured porous systems. Diffusion NMR, based on the measurement of endogenous water's diffusion displacement, offers unique information on the structural features of materials and tissues. In this paper, we applied anomalous diffusion NMR protocols to quantify the subdiffusion of water and to measure, in an alternative, non-destructive and non-invasive modality, the fractal dimension d_w of systems characterized by micro and sub-micro geometrical structures. To this end, three highly heterogeneous porous-polymeric matrices were studied. All the three matrices composed of glycidylmethacrylate-divynilbenzene porous monoliths obtained through the High Internal Phase Emulsion technique were characterized by pores of approximately spherical symmetry, with diameters in the range of 2-10 μm. Pores were interconnected by a plurality of window holes present on pore walls, which were characterized by size coverings in the range of 0.5-2 μm. The walls were characterized by a different degree of surface roughness. Moreover, complementary techniques, namely Field Emission Scanning Electron Microscopy (FE-SEM) and dielectric spectroscopy, were used to corroborate the NMR results. The experimental results showed that the anomalous diffusion α parameter that quantifies subdiffusion and d_w = 2/α changed in parallel to the specific surface area S (or the surface roughness) of the porous matrices, showing a submicroscopic sensitivity. The results reported here suggest that the anomalous diffusion NMR method tested may be a valid experimental tool to corroborate theoretical and simulation results developed and performed for describing highly heterogeneous and complex systems. On the other hand, non-invasive and non-destructive anomalous subdiffusion NMR may be a useful tool to study the characteristic features of new highly heterogeneous nanostructured and complex functional materials and gels useful in cultural heritage applications, as well as scaffolds useful in tissue engineering.

Prognosis after neoadjuvant chemoradiation or chemotherapy for locally advanced gastro-oesophageal junctional adenocarcinoma

BACKGROUND

Trials typically group cancers of the gastro-oesophageal junction (GOJ) with oesophageal or gastric cancer when studying neoadjuvant chemoradiation and perioperative chemotherapy, so the results may not be fully applicable to GOJ cancer. Because optimal neoadjuvant treatment for GOJ cancer remains controversial, outcomes with neoadjuvant chemoradiation versus chemotherapy for locally advanced GOJ adenocarcinoma were compared retrospectively.

METHODS

Data were collected from all patients who underwent neoadjuvant treatment followed by surgery for adenocarcinoma located at the GOJ at a single high-volume institution between 2002 and 2017. Postoperative major complications and mortality were compared between groups using Fisher's exact test. Overall survival (OS) and disease-free survival (DFS) were assessed by log rank test and multivariable Cox regression analyses. Cumulative incidence functions were used to estimate recurrence, and groups were compared using Gray's test.

RESULTS

Of 775 patients, 650 had neoadjuvant chemoradiation and 125 had chemotherapy. These groups were comparable in terms of clinical tumour and lymph node categories, although the chemoradiation group had greater proportions of white men, complete pathological response to chemotherapy, and smaller proportions of diffuse cancer, poor differentiation, and neurovascular invasion. Postoperative major complications (20.0 versus 17.6 per cent) and 30-day mortality (1.7 versus 1.6 per cent) were not significantly different between the chemoradiation and chemotherapy groups. After adjustment, type of therapy (chemoradiation versus chemotherapy) was not significantly associated with OS (hazard ratio (HR) 1.26, 95 per cent c.i. 0.96 to 1.67) or DFS (HR 1.27, 0.98 to 1.64). Type of recurrence (local, regional, or distant) did not differ after neoadjuvant chemoradiation versus chemotherapy.

CONCLUSION

In patients undergoing surgical resection for locally advanced adenocarcinoma of the GOJ, OS and DFS did not differ significantly between patients who had neoadjuvant chemoradiation compared with chemotherapy.

4D printing in biomedical applications: emerging trends and technologies

Nature's material systems during evolution have developed the ability to respond and adapt to environmental stimuli through the generation of complex structures capable of varying their functions across direction, distances and time. 3D printing technologies can recapitulate structural motifs present in natural materials, and efforts are currently being made on the technological side to improve printing resolution, shape fidelity, and printing speed. However, an intrinsic limitation of this technology is that printed objects are static and thus inadequate to dynamically reshape when subjected to external stimuli. In recent years, this issue has been addressed with the design and precise deployment of smart materials that can undergo a programmed morphing in response to a stimulus. The term 4D printing was coined to indicate the combined use of additive manufacturing, smart materials, and careful design of appropriate geometries. In this review, we report the recent progress in the design and development of smart materials that are actuated by different stimuli and their exploitation within additive manufacturing to produce biomimetic structures with important repercussions in different but interrelated biomedical areas.

Tackling Current Biomedical Challenges With Frontier Biofabrication and Organ-On-A-Chip Technologies

In the last decades, biomedical research has significantly boomed in the academia and industrial sectors, and it is expected to continue to grow at a rapid pace in the future. An in-depth analysis of such growth is not trivial, given the intrinsic multidisciplinary nature of biomedical research. Nevertheless, technological advances are among the main factors which have enabled such progress. In this review, we discuss the contribution of two state-of-the-art technologies-namely biofabrication and organ-on-a-chip-in a selection of biomedical research areas. We start by providing an overview of these technologies and their capacities in fabricating advanced in vitro tissue/organ models. We then analyze their impact on addressing a range of current biomedical challenges. Ultimately, we speculate about their future developments by integrating these technologies with other cutting-edge research fields such as artificial intelligence and big data analysis.

The Role of Biofilm in Central Venous Catheter Related Bloodstream Infections: Evidence-based Nursing and Review of the Literature

BACKGROUND

Biofilm is a fundamental component in the pathogenesis of infections related to the use of the central venous catheter (CVC,) which can represent an important health issue in everyday practice of nursing and medical staff.

OBJECTIVE

The objective of the following review is to analyze the components of biofilm and their role in catheter-related infection determinism in an evidencebased nursing perspective in such a way as to give health professionals useful suggestions in the prevention and management of these complications.

METHODS

The following databases were consulted for the bibliographic search: Medline, Scopus, Science Direct. Biofilm can be the cause of CVC extraction and can lead to serious haematogenic infectious complications that can increase the morbidity and mortality of affected patients.

RESULTS

Updated pathophysiologic knowledge of biofilm formation and appropriate diagnostic methodology are pivotal in understanding and detecting CVC-related infections. Lock therapy appears to be a useful, preventive, and therapeutic aid in the management of CVCrelated infections. New therapies attempting to stop bacterial adhesion on the materials used could represent new frontiers for the prevention of CVC-related infections.

CONCLUSION

The correct evidence-based nursing methods, based on the use of guidelines, provides the opportunity to minimize the risks of infection through the implementation of a series of preventive measures both during the CVC positioning phase and in the subsequent phase, for example, during device management which is performed by medical and nursing staff.

PredyCLU: A prediction system for chronic leg ulcers based on fuzzy logic; part II-Exploring the arterial side

Peripheral arterial disease (PAD) and its most severe form, critical limb ischaemia (CLI), are very common clinical conditions related to atherosclerosis and represent the major causes of morbidity, mortality, disability, and reduced quality of life (QoL), especially for the onset of ischaemic chronic leg ulcers (ICLUs) and the subsequent need of amputation in affected patients. Early identification of patients at risk of developing ICLUs may represent the best form of prevention and appropriate management. In this study, we used a Prediction System for Chronic Leg Ulcers (PredyCLU) based on fuzzy logic applied to patients with PAD. The patient population consisted of 80 patients with PAD, of which 40 patients (30 males [75%] and 10 females [25%]; mean age 66.18 years; median age 67.50 years) had ICLUs and represented the case group. Forty patients (100%) (27 males [67.50%] and 13 females [32.50%]; mean age 66.43 years; median age 66.50 years) did not have ICLUs and represented the control group. In patients of the case group, the higher was the risk calculated with the PredyCLU the more severe were the clinical manifestations recorded. In this study, the PredyCLU algorithm was retrospectively applied on a multicentre population of 80 patients with PAD. The PredyCLU algorithm provided a reliable risk score for the risk of ICLUs in patients with PAD.

P6547The energy cost of His bundle pacing can be curtailed

Introduction

His bundle pacing (HBP) allows physiological ventricular activation and prevents the electrical and mechanical desynchronization generally induced by myocardial stimulation, which can increase the risk of atrial fibrillation and heart failure. On the other hand, reliable HBP capture often requires higher energy than conventional myocardial pacing. This reduces the expected life of the stimulator and might limit the diffusion of HBP in the clinical practice.

Purpose

Decreasing HBP current drain by careful management of stimulation safety margin and pulse duration.

Methods

In 28 patients undergoing DDD pacing with HBP, a third lead was implanted in RV apex to provide back-up pacing on demand. HBP and apical leads were connected, respectively, to the V1 and V2 channels of a 3-chamber stimulator. When HBP was effective, apical sensing occurred within the VV delay and prevented V2 stimulation. In contrast, in case of HBP failure, V2 sensing was missing and apical back-up pacing was promptly delivered at the end of the VV delay. The availability of a back-up pulse on demand allowed reducing the HBP safety margin with no risk. Furthermore, the individual HBP strength-duration curve was derived in the aim of optimizing the Hisian pulse parameters, which are the major determinants of the device current drain.

Results

Correct back-up inhibition by successful HBP and stimulation in the event of capture loss was achieved in all the patients. The latency from Hisian pacing to apical sensing averaged 96±14 ms. According to the pacemaker counters, no back-up pulse was delivered in daily life in 59% of patients. In the remaining, the prevalence of back-up stimulation never exceeded 15% of paced ventricular cycles. The high HBP threshold was essentially due to an increased rheobase (1.2±0.6 V), while the chronaxie ranged from 0.30 to 0.53 ms in 71% of patients (median 0.44 ms), exceeding 0.6 ms only in 29% of the cases. An average current saving of 5.4±3.0 μA was obtained at the expense of a mild reduction in HBP safety margin (from 1.6±0.2 to 1.4±0.1 times).

HBP and apical back-up

Conclusions

Back-up stimulation on demand is a reliable option to decrease HBP current drain and prolong the stimulator service life with full safety. In most of the cases, significant saving can be achieved by pulse shortening, as the chronaxie time is in the same range as with myocardial stimulation and longer pulses are not required. A pulse duration exceeding 0.6 ms is indicated in less than 1/3 of the implants.

3D bioprinted hydrogel model incorporating β-tricalcium phosphate for calcified cartilage tissue engineering

One promising strategy to reconstruct osteochondral defects relies on 3D bioprinted three-zonal structures comprised of hyaline cartilage, calcified cartilage, and subchondral bone. So far, several studies have pursued the regeneration of either hyaline cartilage or bone in vitro while-despite its key role in the osteochondral region-only few of them have targeted the calcified layer. In this work, we present a 3D biomimetic hydrogel scaffold containing β-tricalcium phosphate (TCP) for engineering calcified cartilage through a co-axial needle system implemented in extrusion-based bioprinting process. After a thorough bioink optimization, we showed that 0.5% w/v TCP is the optimal concentration forming stable scaffolds with high shape fidelity and endowed with biological properties relevant for the development of calcified cartilage. In particular, we investigate the effect induced by ceramic nano-particles over the differentiation capacity of bioprinted bone marrow-derived human mesenchymal stem cells in hydrogel scaffolds cultured up to 21 d in chondrogenic media. To confirm the potential of the presented approach to generate a functional in vitro model of calcified cartilage tissue, we evaluated quantitatively gene expression of relevant chondrogenic (COL1, COL2, COL10A1, ACAN) and osteogenic (ALPL, BGLAP) gene markers by means of RT-qPCR and qualitatively by means of fluorescence immunocytochemistry.

National guidelines may reduce socioeconomic disparities in treatment selection for esophageal cancer

The 2011 National Comprehensive Cancer Network guidelines first incorporated the results of the landmark CROSS trial, establishing induction therapy (chemotherapy ± radiation) and surgery as the treatment standard for locoregional esophageal cancer in the United States. The effect of guideline publication on socioeconomic status (SES) inequalities in cancer treatment selection remains unknown. Patients diagnosed with Stage II/III esophageal cancer between 2004 and 2013 who underwent curative treatment with definitive chemoradiation or multimodality treatment (induction and surgery) were identified from the Surveillance, Epidemiology and End Results (SEER)-Medicare registry. Clinicopathologic characteristics were compared between the two therapies. Multivariable regression analysis was used to adjust for known factors associated with treatment selection. An interaction term with respect to guideline publication and SES was included Of the 2,148 patients included, 1,478 (68.8%) received definitive chemoradiation and 670 (31.2%) induction and surgery. Guideline publication was associated with a 16.1% increase in patients receiving induction and surgery in the low SES group (21.4% preguideline publication vs. 37.5% after). In comparison, a 4.5% increase occurred during the same period in the high SES status group (31.8% vs. 36.3%). After adjusting for factors associated with treatment selection, guideline publication was associated with a 78% increase in likelihood of receiving induction and surgery among lower SES patients (odds ratio 1.78; 95% confidence interval (CI): 1.05,3.03). Following the new guideline publication, patients living in low SES areas were more likely to receive optimal treatment. Increased dissemination of guidelines may lead to increased adherence to evidence-based treatment standards.

Novel biomarkers for cardiovascular risk

Cardiovascular disease refers to different diseases involving the heart and/or the arteries and/or the veins. Cardiovascular disease, overall considered, is a notable source of morbidity and mortality worldwide. Therefore, several research studies are dedicated to explore, by means of biomarkers, the possiblity to calculate the cardiovascular risk both for the onset and for the complications of the related clinical manifestations such as coronary artery disease, carotid artery stenosis, peripheral artery disease, arterial aneurysm, chronic venous disease and venous thromboembolism. This review discusses the most updated information in the area of the novel biomarkers related to omics, imaging techniques and clinical data, that may help physicians in order to improve the knowledge and the management of the cardiovascular risk.

Emergent treatment of carotid stenosis: an evidence-based systematic review

INTRODUCTION

Stroke is one of the major causes of death in the world, but above all is the condition most associated with severe long-term disabilities. It is clear that this condition therefore requires the best therapeutic approach possible to minimize the consequences that this can lead to. The major issues concern the type of treatment to be used for revascularization (carotid endarterectomy [CEA] or stenting of the carotid artery [CAS]) and the timing of the treatment itself. Many studies have been conducted on this issue, but a definitive and unanimous verdict has not yet been reached on account of the great variety of results obtained from the various study group. The aim of this review is to analyze the latest scientific findings focused on revascularization following a symptomatic carotid stenosis (SCS).

EVIDENCE ACQUISITION

We searched all publications addressing treatments and timing of approach to SCS. Randomized trials, cohort studies and reviews were contemplated in order to give a breadth of clinical data. Medline and Science Direct were searched from January 2013 to April 2017.

EVIDENCE SYNTHESIS

Of the 819 records found, 76 matched our inclusion criteria. After reading the full-text articles, we decided to exclude 54 manuscripts because of the following reasons: 1) no innovative or important content; 2) insufficient data; 3) no clear potential biases or strategies to solve them; 4) no clear endpoints; and 5) inconsistent or arbitrary conclusions. The final set included 22 articles.

CONCLUSIONS

CEA is considered a less problematic method than CAS, especially for patients over the age of 75; CAS remains recommended in patients with a favorable anatomy or high surgical risks. Studies that showed more solid results seem to lead to the conclusion that optimal timing may be between 2 days and the end of the first week from the onset of symptoms in patients who are appropriate candidates for surgery.

Endovascular repair versus open repair in the treatment of ruptured aortic aneurysms: a systematic review

INTRODUCTION

Rupture of abdominal aortic aneurysm remains a fatal event in up to 65% of cases and emergency open surgery (ruptured open aneurysm repair or rOAR) has a great intraoperative mortality of about 30-50%. The introduction of endovascular repair of abdominal aortic aneurysm (ruptured endovascular aneurysm repair or rEVAR) has rapidly challenged the conventional approach to this catastrophic event. The purpose of this systematic review is to compare the outcomes of open surgical repair and endovascular interventions.

EVIDENCE ACQUISITION

A literature search was performed using Medline, Scopus, and Science Direct from August 2010 to March 2017 using keywords identified and agreed by the authors. Randomized trials, cohort studies, and case-report series were contemplated to give a breadth of clinical data.

EVIDENCE SYNTHESIS

Ninety-three studies were included in the final analysis. Thirty-five (50.7%) of the listed studies evaluating the within 30 days mortality rates deposed in favor of rEVAR, while the others (comprising all four included RCTs) failed detecting any difference. Late mortality rates were found to be lower in rEVAR group in seven on twenty-seven studies (25.9%), while one (3.7%) reported higher mortality rates following rEVAR performed before 2005, one found lower incidence of mortality at 6 months in the endovascular group but higher rates in the same population at 8 years of follow-up, and the remaining (66.7%) (including all three RCTs) failed finding any benefit of rEVAR on rOAR. A lower incidence of complications was reported by thirteen groups (46.4%), while other thirteen studies did not find any difference between rEVAR and rOAR. Each of these two conclusions was corroborated by one RCTs. Other two studies (7.2%) found higher rates of tracheostomies, myocardial infarction, and acute tubular necrosis or respiratory, urinary complications, and acute renal failure respectively in rOAR group. The majority of studies (59.0%, 72.7%, and 89.3%, respectively) and all RCTs found significantly lower rates of length of hospitalization, intensive care unit transfer, and blood loss with or without transfusion need in rEVAR group. The large majority of the studies did not specified neither the type nor the brands of employed stent grafts.

CONCLUSIONS

The bulk of evidence regarding the comparison between endovascular and open surgery approach to RAAA points to: 1) non-inferiority of rEVAR in terms of early (within 30 days) and late mortality as well as rate of complications and length of hospitalization, with trends of better outcomes associated to the endovascular approach; 2) significantly better outcomes in terms of intensive care unit transfer and blood loss with or without transfusion need in the rEVAR group. These conclusions reflect the results of the available RCTs included in the present review. Thus rEVAR can be considered a safe method in treating RAAA and we suggest that it should be preferred when technically feasible. However, more RCTs are needed in order to give strength of these evidences, bring to definite clinical recommendations regarding this subject, and assess the superiority (if present) of one or more brands of stent grafts over the others.

Skin tears and risk factors assessment: a systematic review on evidence-based medicine

Skin tears represent a common condition of traumatic wounds, which may be encountered in some categories of individuals at the extremes of age, such as infants and the elderly. Despite the high prevalence and cost of these lesions, there has been little investigation into the risk factors that lead to this condition. The aim of this review was to systematically evaluate the main risk factors involved in development of skin tears. We planned to include all the studies dealing with risk factors related to skin tears. Only publications in English were considered. We excluded all the studies that did not properly fit our research question and those with insufficient data. Of the 166 records found, 24 matched our inclusion criteria. After reading the full-text articles, we decided to exclude seven articles because of the following reasons: (1) not responding properly to our research questions and (2) insufficient data; the final set included 17 articles. From a literature search, we found the following main issues related to risk factors, which have been described in detail in this section: age-related skin changes, dehydration, malnutrition, sensory changes, mobility impairment, pharmacological therapies and mechanical factors related to skin care practices. Our findings clearly show that in frail populations (especially infant and elderly), the stratification risk, as a primary prevention strategy, is an effective tool in avoiding the development of chronic wounds. The development and the implementation of prevention strategies based on appropriate knowledge of the risk factors involved and the adoption of correct techniques during skin care practices could reduce or even avoid the onset of skin tears.

Engineering Muscle Networks in 3D Gelatin Methacryloyl Hydrogels: Influence of Mechanical Stiffness and Geometrical Confinement

In this work, the influence of mechanical stiffness and geometrical confinement on the 3D culture of myoblast-laden gelatin methacryloyl (GelMA) photo-crosslinkable hydrogels was evaluated in terms of in vitro myogenesis. We formulated a set of cell-laden GelMA hydrogels with a compressive modulus in the range 1 ÷ 17 kPa, obtained by varying GelMA concentration and degree of cross-linking. C2C12 myoblasts were chosen as the cell model to investigate the supportiveness of different GelMA hydrogels toward myotube formation up to 2 weeks. Results showed that the hydrogels with a stiffness in the range 1 ÷ 3 kPa provided enhanced support to C2C12 differentiation in terms of myotube number, rate of formation, and space distribution. Finally, we studied the influence of geometrical confinement on myotube orientation by confining cells within thin hydrogel slabs having different cross sections: (i) 2,000 μm × 2,000 μm, (ii) 1,000 μm × 1,000 μm, and (iii) 500 μm × 500 μm. The obtained results showed that by reducing the cross section, i.e., by increasing the level of confinement—myotubes were more closely packed and formed aligned myostructures that better mimicked the native morphology of skeletal muscle.

Skin grafting for the treatment of chronic leg ulcers - a systematic review in evidence-based medicine

Skin grafting is one of the most common surgical procedures in the area of non-healing wounds by which skin or a skin substitute is placed over a wound to replace and regenerate the damaged skin. Chronic leg ulcers are an important problem and a major source of expense for Western countries and for which many different forms of treatment have been used. Skin grafting is a method of treatment that decreases the area of chronic leg ulcers or heals them completely, thus improving a patient's quality of life. Skin grafting is an old technique, rediscovered during the first and second world wars as the main treatment for wound closure. Nowadays, skin grafting has a pivotal role in the context of modern wound healing and tissue regeneration. The aim of this review was to track and to analyse the specific outcomes this technique achieved, especially in the last decade, in relation to venous, arterial, diabetic, rheumatoid and traumatic leg ulcers. Our main findings indicate that autologous split-thickness skin grafting still remains the gold standard in terms of safety and efficacy for chronic leg ulcers; skin grafting procedures have greater success rates in chronic venous leg ulcers compared to other types of chronic leg ulcers; skin tissue engineering, also supported by genetic manipulation, is quickly expanding and, in the near future, may provide even better outcomes in the area of treatments for long-lasting chronic wounds.

Microfluidic Bioprinting of Heterogeneous 3D Tissue Constructs

3D bioprinting is an emerging field that can be described as a robotic additive biofabrication technology that has the potential to build tissues or organs. In general, bioprinting uses a computer-controlled printing device to accurately deposit cells and biomaterials into precise architectures with the goal of creating on demand organized multicellular tissue structures and eventually intra-organ vascular networks. The latter, in turn, will promote the host integration of the engineered tissue/organ in situ once implanted. Existing biofabrication techniques still lay behind this goal. Here, we describe a novel microfluidic printing head-integrated within a custom 3D bioprinter-that allows for the deposition of multimaterial and/or multicellular within a single scaffold by extruding simultaneously different bioinks or by rapidly switching between one bioink and another. The designed bioprinting method effectively moves toward the direction of creating viable tissues and organs for implantation in clinic and research in lab environments.

3D bioprinting of BM-MSCs-loaded ECM biomimetic hydrogels for in vitro neocartilage formation

In this work we demonstrate how to print 3D biomimetic hydrogel scaffolds for cartilage tissue engineering with high cell density (>10(7) cells ml(-1)), high cell viability (85 ÷ 90%) and high printing resolution (≈100 μm) through a two coaxial-needles system. The scaffolds were composed of modified biopolymers present in the extracellular matrix (ECM) of cartilage, namely gelatin methacrylamide (GelMA), chondroitin sulfate amino ethyl methacrylate (CS-AEMA) and hyaluronic acid methacrylate (HAMA). The polymers were used to prepare three photocurable bioinks with increasing degree of biomimicry: (i) GelMA, (ii) GelMA + CS-AEMA and (iii) GelMA + CS-AEMA + HAMA. Alginate was added to the bioinks as templating agent to form stable fibers during 3D printing. In all cases, bioink solutions were loaded with bone marrow-derived human mesenchymal stem cells (BM-MSCs). After printing, the samples were cultured in expansion (negative control) and chondrogenic media to evaluate the possible differentiating effect exerted by the biomimetic matrix or the synergistic effect of the matrix and chondrogenic supplements. After 7, 14, and 21 days, gene expression of the chondrogenic markers (COL2A1 and aggrecan), marker of osteogenesis (COL1A1) and marker of hypertrophy (COL10A1) were evaluated qualitatively by means of fluorescence immunocytochemistry and quantitatively by means of RT-qPCR. The observed enhanced viability and chondrogenic differentiation of BM-MSCs, as well as high robustness and accuracy of the employed deposition method, make the presented approach a valid candidate for advanced engineering of cartilage tissue.

Study on the efficacy of surgery of the superficial venous system and of compression therapy at early stages of chronic venous disease for the prevention of chronic venous ulceration

The mainstay of treatment of chronic venous ulceration (CVU), as also suggested by current treatment guidelines for chronic venous disease (CVD), is represented by surgery and compression therapy for which there is strong evidence of their role in clinically relevant improvement in wound healing and also in the reduction of CVU recurrence, but no information is available as to whether or not these treatments provide effective protection from the onset of CVU. In our study, we have followed, for a median time of 13 years, a total of 3947 patients with CVD at classes C2-C3 of CEAP classification, treated with our treatment protocol (surgery and compression therapy) in order to track the natural history of these patients with regards to CVU development. We identified four groups of patients: 2354 patients (59·64%) (Group A) fully adherent to protocols; 848 patients (21·48%) (Group B) fully adherent to surgery and non-compliant to compression therapy; 432 patients (10·95%) (Group C) fully adherent to compression therapy and non-compliant to surgery; and 313 patients (7·93%) (Group D) non-compliant to either treatments. Regardless of compliance to treatments, the ulcer development rates were very similar between groups (range: 3·23-4.79%), with no statistical significance (P = 0·1522). Currents treatments used in the early stages of CVD appear to have no effects to progression to CVU. Additional longitudinal studies are required to confirm these findings.

From varices to venous ulceration: the story of chronic venous disease described by metalloproteinases

Chronic venous disease (CVD) and its most frightening complication, chronic venous ulceration (CVU), represent an important socioeconomic burden in the western world. Metalloproteinases have been identified in the pathogenesis of several vascular diseases such as venous problems. The aim of this study was to evaluate a broad range of metalloproteinases, such as matrix metalloproteinases (MMPs), ADAMs (a disintegrin and metalloproteinases) and ADAMTSs (a disintegrin and metalloproteinases with thrombospondin motifs) and their inhibitors, tissue inhibitor of metalloproteinases (TIMPs) and a related protein, neutrophil gelatinase-associated lipocalin (NGAL), in patients with CVD in order to correlate their serum levels with each stage of the disease. We performed a multicenter open-label study that comprised the enrolment of 541 patients with CVD of clinical stages C1-C6, (178 males, 363 females; mean age 57·29, median age 53·72, age range 29-81); 29 subjects without CVD were included in this study (9 males and 20 females; mean age 54·44, median age 50, age range 28-84) as the control group. Enzyme-linked immunosorbent assay (ELISA) was performed for measuring serum levels of proteases and related proteins. The study found that the serum elevation of MMP-2, ADAMTS-1 and ADAMTS-7 appeared to be correlated with the initial stages of CVD, whereas the serum elevation of MMP-1, MMP-8, MMP-9, NGAL, ADAM-10, ADAM-17 and ADAMTS-4 was particularly involved in skin change complications. This study showed that each stage of CVD may be described by particular patterns of metalloproteinases, and this may have therapeutic implications in discovering new targets and new drugs for the treatment of CVD.

Microfluidic Bioprinting of Heterogeneous 3D Tissue Constructs Using Low-Viscosity Bioink

A novel bioink and a dispensing technique for 3D tissue-engineering applications are presented. The technique incorporates a coaxial extrusion needle using a low-viscosity cell-laden bioink to produce highly defined 3D biostructures. The extrusion system is then coupled to a microfluidic device to control the bioink arrangement deposition, demonstrating the versatility of the bioprinting technique. This low-viscosity cell-responsive bioink promotes cell migration and alignment within each fiber organizing the encapsulated cells.

PredyCLU: a prediction system for chronic leg ulcers based on fuzzy logic; part I - exploring the venous side

Chronic leg ulcers (CLUs) are a common occurrence in the western population and are associated with a negative impact on the quality of life of patients. They also cause a substantial burden on the health budget. The pathogenesis of leg ulceration is quite heterogeneous, and chronic venous ulceration (CVU) is the most common manifestation representing the main complication of chronic venous disease (CVD). Prevention strategies and early identification of the risk represent the best form of management. Fuzzy logic is a flexible mathematical system that has proved to be a powerful tool for decision-making systems and pattern classification systems in medicine. In this study, we have elaborated a computerised prediction system for chronic leg ulcers (PredyCLU) based on fuzzy logic, which was retrospectively applied on a multicentre population of 77 patients with CVD. This evaluation system produced reliable risk score patterns and served effectively as a stratification risk tool in patients with CVD who were at the risk of developing CVUs.

Microfluidic Foaming: A Powerful Tool for Tailoring the Morphological and Permeability Properties of Sponge-like Biopolymeric Scaffolds

Ordered porous polymeric materials can be engineered to present highly ordered pore arrays and uniform and tunable pore size. These features prompted a number of applications in tissue engineering, generation of meta materials, and separation and purification of biomolecules and cells. Designing new and efficient vistas for the generation of ordered porous materials is an active area of research. Here we investigate the potential of microfluidic foaming within a flow-focusing (FF) geometry in producing 3D regular sponge-like polymeric matrices with tailored morphological and permeability properties. The challenge in using microfluidic systems for the generation of polymeric foams is in the high viscosity of the continuous phase. We demonstrate that as the viscosity of the aqueous solution increases, the accessible range of foam bubble fraction (Φb) and bubble diameter (Db) inside the microfluidic chip tend to narrow progressively. This effect limits the accessible range of geometric properties of the resulting materials. We further show that this problem can be rationally tackled by appropriate choice of the concentration of the polymer. We demonstrate that via such optimization, the microfluidic assisted synthesis of porous materials becomes a facile and versatile tool for generation of porous materials with a wide range of pore size and pore volume. Moreover, we demonstrate that the size of interconnects among pores-for a given value of the gas fraction-can be tailored through the variation of surfactant concentration. This, in turn, affects the permeability of the materials, a factor of key importance in flow-through applications and in tissue engineering.

The role of adult tissue-derived stem cells in chronic leg ulcers: a systematic review focused on tissue regeneration medicine

Wound healing is an articulated process that can be impaired in different steps in chronic wounds. Chronic leg ulcers are a special type of non-healing wounds that represent an important cause of morbidity and public cost in western countries. Because of their common recurrence after conventional managements and increasing prevalence due to an ageing population, newer approaches are needed. Over the last decade, the research has been focused on innovative treatment strategies, including stem-cell-based therapies. After the initial interest in embryonic pluripotent cells, several different types of adult stem cells have been studied because of ethical issues. Specific types of adult stem cells have shown a high potentiality in tissue healing, in both in vitro and in vivo studies. Aim of this review is to clearly report the newest insights on tissue regeneration medicine, with particular regard for chronic leg ulcers.

Incidental ganglioneuromas: a presentation of 14 surgical cases and literature review

BACKGROUND AND AIMS

Ganglioneuromas are benign tumors which originate from the neural crest. This tumor affects mainly young patients rather than adult ones, and its most frequent localizations are mediastinum, retroperitoneum, adrenal glands and cervical region. Usually, ganglioneuromas are discovered as incidentalomas since they are often asymptomatic, even if they could present sympathetic or mass-related symptoms. To obtain a definitive diagnosis, histological exam is necessary since CT scan and MRI are not capable of distinguishing ganglioneuromas from other tumors, such as neuroblastomas or pheocromocytomas. The surgical excision is the chosen treatment and it offers an excellent prognosis.

METHODS

We conducted a retrospective analysis of our cases of ganglioneuroma from 2004 to 2014; this study aims to compare our experience with literature review (2000-2014). Data about patients' features, tumor localization, symptoms, treatment and follow-up were analyzed and reported in detailed tables.

RESULTS

Between 2004 and 2014 we treated 14 patients affected by ganglioneuroma. For all of them the diagnosis was incidental; 9 out of 12 (64.3 %) patients presented an adrenal mass; in 2 patients (14.3 %) the tumor was localized in cervical region; in other 2 patients (14.3 %) the tumor was in the retroperitoneum and one patient (7.1 %) presented a ganglioneuroma in the costo-vertebral space. All our patients underwent surgical removal and none of them present surgery-related complications or recurrences to date.

CONCLUSIONS

Our data widen the knowledge about ganglioneuroma and confirm that the surgical approach has an excellent prognosis with very low incidence of surgery-related complications and recurrences.

Designing unconventional Fmoc-peptide-based biomaterials: structure and related properties

We have recently employed L-amino acids in the lipase-catalyzed biofabrication of a class of self-assembling Fmoc-peptides that form 3-dimensional nanofiber scaffolds. Here we report that using d-amino acids, the homochiral self-assembling peptide Fmoc-D-Phe3 (Fmoc-F*F*F*) also forms a 3-dimensional nanofiber scaffold that is substantially distinguishable from its L-peptide and heterochiral peptide (F*FF and FF*F*) counterparts on the basis of their physico-chemical properties. Such chiral peptides self-assemble into ordered nanofibers with well defined fibrillar motifs. Circular dichroism and atomic force microscopy have been employed to study in depth such fibrillar peptide structures. Dexamethasone release kinetics from PLGA and CS-PLGA nanoparticles entrapped within the peptidic hydrogel matrix encourage its use for applications in drug controlled release.

Rapid prototyping of chitosan-coated alginate scaffolds through the use of a 3D fiber deposition technique

A novel dispensing system based on two coaxial needles is used to fabricate three dimensional, periodic scaffolds by rapid prototyping.

Morphological comparison of PVA scaffolds obtained by gas foaming and microfluidic foaming techniques

In this article, we have exploited a microfluidic foaming technique for the generation of highly monodisperse gas-in-liquid bubbles as a templating system for scaffolds characterized by an ordered and homogeneous porous texture. An aqueous poly(vinyl alcohol) (PVA) solution (containing a surfactant) and a gas (argon) are injected simultaneously at constant flow rates in a flow-focusing device (FFD), in which the gas thread breaks up to form monodisperse bubbles. Immediately after its formation, the foam is collected and frozen in liquid nitrogen, freeze-dried, and cross-linked with glutaraldehyde. In order to highlight the superior morphological quality of the obtained porous material, a comparison between this scaffold and another one, also constituted of PVA but obtained with a traditional gas foaming technique, was carried out. Such a comparison has been conducted by analyzing electron microscopy and X-ray microtomographic images of the two samples. It turned out that the microfluidic produced scaffold was characterized by much more uniform porous texture than the gas-foaming one as witnessed by narrower pore size, interconnection, and wall thickness distributions. On the other side, scarce pore interconnectivity, relatively low pore volume, and limited production rate represent, by now, the principal disadvantages of microfluidic foaming as scaffold fabrication method, emphasizing the kind of improvement that this technique needs to undergo.

In situ precipitation of amorphous calcium phosphate and ciprofloxacin crystals during the formation of chitosan hydrogels and its application for drug delivery purposes

The immobilization of more than one single substance within the structure of a biocompatible polymer provides multifunctional biomaterials with attractive and enhanced properties. In the context of bone tissue engineering, it could be of great interest to synthesize a biomaterial that simultaneously contains amorphous calcium phosphate (ACP), to favor calcium and phosphate precipitation and promote osteogenesis, and an antibiotic such as ciprofloxacin (CFX) that can, eventually, avoid infections resulting after surgical scaffold implantation. However, the co-immobilization of multiple substances is by no means a trivial issue because of the enhanced number of interactions that can take place. One of the main issues is controlling not only the diverse solid forms that individual substances can eventually adopt, but also the forces responsible for the self-organization of the individual components. The latter determines whether phase-separated structures or conjugated architectures are obtained and, consequently, may dramatically affect their functionality. Herein, we have observed-by SEM, TEM, and solid-state NMR-that enzymatically-assisted coprecipitation of ACP and CFX resulted in phase-separated structures. Thus, CFX crystals showed identical morphology to that obtained in the absence of ACP, but the size was smaller. Neither the size nor the morphology of ACP exhibited significant differences whether precipitated with or without CFX, but, in the former case, ACP was stabilized over a wider range of pH and temperature. Finally, by using this methodology and the ice segregation induced self-assembly process (ISISA), we have successfully co-immobilized ACP and CFX in chitosan-based scaffolds. Interestingly, the presence of ACP exerted significant control on the CFX release from these materials.

Dielectric characterization of hepatocytes in suspension and embedded into two different polymeric scaffolds

The dielectric and conductometric properties of hepatocytes in two different environments (in aqueous suspension and embedded into polymeric scaffolds) have been investigated in the frequency range from 1 kHz to 2 GHz, where the interfacial electrical polarization gives rise to marked dielectric relaxation effects. We analyzed the dielectric behavior of hepatocytes in complete medium aqueous suspensions in the light of effective medium approximation for heterogeneous systems and hepatocytes cultured into two different highly porous and interconnected polymeric structures. In the former case, we have evaluated the passive electrical parameters associated with both the plasmatic and nuclear membrane, finding a general agreement with the values reported elsewhere, based on a partially different analysis of the experimental spectra. In the latter case, we have evaluated the cell growth into two different polymeric scaffolds made of alginate and gelatin with a similar pore distribution and similar inter-connectivity. Based on a qualitative analysis of the dielectric spectra, we were able to provide evidence that alginate scaffolds allow an overall survival of cells better than gelatin scaffold can do. These indications, confirmed by biological tests on cell viability, suggest that hepatocytes embedded in alginate scaffolds are able to perform liver specific functions even over on extended period of time.

Role of X-ray microtomography in tissue engineering

The structure and architecture of scaffolds are crucial factors in scaffolds-based tissue engineering since they affect the functionality of the tissue engineering construct and the eventual application in health care. Therefore, effective scaffold assessment techniques are required right at the initial stages of research and development so as to select or design scaffolds with suitable properties. Furthermore, since the biological performances of a scaffold is evaluated with respect to its capacity of favouring cell adhesion, proliferation as well as production of extracellular matrix, it is important to have an analytical technique able to monitor the various stages of cell culture both in vitro and especially in vivo. Finally, the development of a vascular network inside the cell scaffold construct is a fundamental requisite for achieving a full integration of the developing tissue with the host tissue. Also in this respect it is mandatory to assess the propensity of the scaffold to be permeated by blood vessels. In the review, it will be shown how X-ray microtomography (micro-CT) can give fundamental information regarding all the three aspects outlined above.

A biomimetic porous hydrogel of gelatin and glycosaminoglycans cross-linked with transglutaminase and its application in the culture of hepatocytes

The development of blended gelatin and glycosaminoglycan (GAG) scaffolds can potentially be used in many soft tissue engineering applications since these scaffolds mimic the structure and biological function of native extracellular matrix (ECM). In this study, we were able to obtain a gelatin-GAG scaffold by using a concentrated emulsion templating technique known as high internal phase emulsion (HIPE), in which a prevailing in volume organic phase is dispersed in the form of discrete droplets inside an aqueous solution of three biopolymers represented by gelatin, hyaluronic acid (HA) and chondroitin sulfate (CS) in the presence of a suitable surfactant. In order to preserve the bioactive potential of the biopolymers employed, the cross-linking procedure involved the use of transglutaminase (MTGase) that catalyzes the formation of covalent N-ε-(γ-glutamyl) lysine amide bonds. Since neither HA nor CS possess the necessary primary amino groups toward which MTGase is active, they were functionalized with the dipeptide glycine-lysine (GK). In this way the introduction of foreign cross-linking bridging units with an unpredictable biocompatibility was avoided. These enzymatic cross-linked gelatin-GAG scaffolds were tested in the culture of primary rat and C3A hepatocytes. Results underlined the good performance of this novel support in maintaining and promoting hepatocyte functions in vitro.