250 research outputs found

    Photocrosslinkable polyaspartamide/polylactide copolymer and its porous scaffolds for chondrocytes

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    With the aim to produce, by a simple and reproducible technique, porous scaffolds potentially employable for tissue engineering purposes, in this work, we have synthesized a methacrylate (MA) copolymer of \u3b1,\u3b2-poly(N-2-hydroxyethyl)-DL-aspartamide (PHEA) and polylactic acid (PLA). PHEA-PLA-MA has been dissolved in organic solvent at different concentrations in the presence of NaCl particles with different granulometry, and through UV irradiation and further salt leaching technique, various porous scaffolds have been prepared. Obtained samples have been characterized by scanning electron microscopy and their porosity has been evaluated as well as their degradation profile in aqueous medium in the absence or in the presence of esterase from porcine liver. PHEA-PLA-MA scaffold that has shown homogeneous porosity and the best degradation profile has been further characterized to study its mechanical properties along with its capacity to incorporate and to control the release of dexamethasone. Finally, the ability to allow a three-dimensional culture of bovine articular chondrocytes have been also investigate

    Antibacterial Broad-Spectrum Dendritic/Gellan Gum Hybrid Hydrogels with Rapid Shape-Forming and Self-Healing for Wound Healing Application

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    Treating wound infections is a difficult task ever since pathogenic bacteria started to develop resistance to common antibiotics. The present study develops hybrid hydrogels based on the formation of a polyelectrolyte complex between the anionic charges of dopamine-functionalized Gellan Gum (GG-DA) and the cationic moieties of the TMP-G2-alanine dendrimer. The hydrogels thus obtained can be doubly crosslinked with CaCl2, obtaining solid hydrogels. Or, by oxidizing dopamine to GG-DA, possibly causing further interactions such as Schiff Base and Michael addition to take place, hydrogels called injectables can be obtained. The latter have shear-thinning and self-healing properties (efficiency up to 100%). Human dermal fibroblasts (HDF), human epidermal keratinocytes (HaCaT), and mouse monocyte cells (RAW 264.7), after incubation with hydrogels, in most cases show cell viability up to 100%. Hydrogels exhibit adhesive behavior on various substrates, including porcine skin. At the same time, the dendrimer serves to crosslink the hydrogels and endows them with excellent broad-spectrum microbial eradication activity within four hours, evaluated using Staphylococcus aureus 2569 and Escherichia coli 178. Using the same GG-DA/TMP-G2-alanine ratios hybrid hydrogels with tunable properties and potential for wound dressing applications can be produced

    Role of perfusion CT in the evaluation of metastatic nodal tumor response after radiochemotherapy in head and neck cancer: preliminary findings

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    OBJECTIVE: To assess changes of CT perfusion parameters (ΔPCTp) of cervical lymph node metastases from head and neck cancer (HNC) before and after radiochemotherapy (RT-CT) and their association with nodal tumor persistence. PATIENTS AND METHODS: Eligibility criteria included HNC (Stage III-IV) candidates for RT-CT. Patients underwent perfusion CT (PCT) at baseline 3 weeks and 3 months after RT-CT. Blood volume (BV), blood flow (BF), mean transit time (MTT) and permeability surface (PS) were calculated. PET/CT examination was also performed at baseline and 3 months after treatment for metabolic assessment. RESULTS: Between July 2012 and May 2016, 27 patients were evaluated. Overall, only 3 patients (11%) experienced tumor persistence in the largest metastatic lymph node. A significant reduction of all PCTp values (p<0.0001), except MTT (from 6.3 to 5.7 s; p=0.089), was observed at 3 weeks post-RT-CT compared to baseline. All PCTp values including MTT were significantly lower at 3-month follow-up compared to baseline (p<0.05). Moreover, a statistical significant association was observed between nodal tumor persistence and high BF values (p=0.045) at 3 months after treatment that did not occur for the other parameters. CONCLUSIONS: Our preliminary findings show that all PCTp except MTT are significantly reduced after RT-CT. High BF values at 3 months post-RTCT are predictive of nodal tumor persistence

    Multimodal approach of advanced gastric cancer: Based therapeutic algorithm

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    Gastric cancer (GC) is the third leading cause of cancer death in both sexes worldwide, with the highest estimated mortality rates in Eastern Asia and the lowest in Northern America. However, the availability of modern treatment has improved the survival and the prognosis is often poor due to biological characteristics of the disease. In oncology, we are living in the "Era" of target treatment and, to know biological aspects, prognostic factors and predictive response informations to therapy in GC is mandatory to apply the best strategy of treatment. The purpose of this review, according to the recently published English literature, is to summarize existing data on prognostic aspects and predictive factors to response to therapy in GC and to analyze also others therapeutic approaches (surgery and radiotherapy) in locally, locally advanced and advanced GC. Moreover, the multidisciplinary approach (chemotherapy, surgery and radiotherapy) can improve the prognosis of GC

    Use of complementary and alternative medicine (CAM) in cancer patients. An italian multicenter survey

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    INTRODUCTION: Complementary and Alternative Medicine (CAM) include a wide range of products (herbs, vitamins, minerals, and probiotics) and medical practices, developed outside of the mainstream Western medicine. Patients with cancer are more likely to resort to CAM first or then in their disease history; the potential side effects as well as the costs of such practices are largely underestimated. PATIENTS AND METHOD: We conducted a descriptive survey in five Italian hospitals involving 468 patients with different malignancies. The survey consisted of a forty-two question questionnaire, patients were eligible if they were Italian-speaking and receiving an anticancer treatment at the time of the survey or had received an anticancer treatment no more than three years before participating in the survey. RESULTS: Of our patients, 48.9% said they use or have recently used CAM. The univariate analysis showed that female gender, high education, receiving treatment in a highly specialized institute and receiving chemotherapy are associated with CAM use; at the multivariate analysis high education (Odds Ratio, (OR): 1.96 95% Confidence Interval, CI, 1.27-3.05) and receiving treatment in a specialized cancer center (OR: 2.75 95% CI, 1.53-4.94) were confirmed as risk factors for CAM use. CONCLUSION: Roughly half of our patients receiving treatment for cancer use CAM. It is necessary that health professional explore the use of CAM with their cancer patients, educate them about potentially beneficial therapies in light of the limited available evidence of effectiveness, and work towards an integrated model of health-care provision

    A Fibrillar Biodegradable Scaffold for Blood Vessels Tissue Engineering

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    In recent years there has been a growing interest for the development of tubular scaffolds employed to assist the replacement of small blood vessels. Materials designed for this purpose need to be biodegradable, have good mechanical properties and improve cell adhesion, proliferation and differentiation. To obtain biomaterials with these properties, electrospinning seems to be one of the most useful technique. Several biodegradable synthetic polymers or constituents of the extracellular matrix (ECM) have been electrospun showing optimal mechanical properties and biodegradability. However, such polymers are lacking in versatile chemical structure affordable to immobilize growth factors or chemokines. The glycosaminoglycan heparin is able to bind several growth factors like vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) and, when grafted onto the scaffold surface it is able to attract cells thus improving their proliferation and differentiation. Aim of this research was the production and the preliminary in vitro biological characterization of a new biodegradable material, obtained by electrospun a polyaminoacid-graft-polyester copolymer. The electrospun biomaterial has been successfully grafted with heparin exploiting the better chemical reactivity of the polyaminoacid portions of the graft copolymer. Then its morphology has been investigated by scanning electron microscopy (SEM) and the potential biodegradability of the material has been studied until 60 days. Preliminary biological data in vitro, on human endothelial cells, show a good compatibility of the scaffold obtained by electrospinning, with regard to cell adhesion and proliferation. Experiments are in progress to evaluate the effects of heparin on cell differentiation

    Pericardiectomy for constrictive pericarditis: a risk factor analysis for early and late failure

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    Predictors of early and late failure of pericardiectomy for constrictive pericarditis (CP) have not been established. Early and late outcomes of a cumulative series of 81 (mean age 60\ua0years; mean EuroSCORE II, 3.3%) consecutive patients from three European cardiac surgery centers were reviewed. Predictors of a combined endpoint comprising in-hospital death or major complications (including multiple transfusion) were identified with binary logistic regression. Non-parametric estimates of survival were obtained with the Kaplan\u2013Meier method. Predictors of poor late outcomes were established using Cox proportional hazard regression. There were 4 (4.9%) in-hospital deaths. Preoperative central venous pressure > 15\ua0mmHg (p = 0.005) and the use of cardiopulmonary bypass (p = 0.016) were independent predictors of complicated in-hospital course, which occurred in 29 (35.8%) patients. During follow-up (median, 5.4\ua0years), preoperative renal impairment was a predictor of all-cause death (p = 0.0041), cardiac death (p = 0.0008), as well as hospital readmission due to congestive heart failure (p = 0.0037); while partial pericardiectomy predicted all-cause death (p = 0.028) and concomitant cardiac operation predicted cardiac death (p = 0.026), postoperative central venous pressure < 10\ua0mmHg was associated with a low risk both of all-cause and cardiac death (p < 0.0001 for both). Ten-year adjusted survival free of all-cause death, cardiac death, and hospital readmission were 76.9%, 94.7%, and 90.6%, respectively. In high-risk patients with CP, performing pericardiectomy before severe constriction develops and avoiding cardiopulmonary bypass (when possible) could contribute to improving immediate outcomes post-surgery. Complete removal of cardiac constriction could enhance long-term outcomes

    Electrospun PHEA-PLA/PCL Scaffold for Vascular Regeneration: A Preliminary in\ua0Vivo Evaluation

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    Background. There is increasing interest in the development of vessel substitutes, and many studies are currently focusing on the development of biodegradable scaffolds capable of fostering vascular regeneration. We tested a new biocompatible and biodegradable material with mechanical properties similar to those of blood vessels. Methods. The material used comprises a mixture of a,b-poly(N-2-hydroxyethyl)-D,L-aspartamide (PHEA) and polylactic acid (PLA), combined with polycaprolactone (PCL) by means of electrospinning technique. Low-molecular-weight heparin was also linked to the copolymer. A tubular PHEA-PLA/PCL sample was used to create an arteriovenous fistula in a pig model with the use of the external iliac vessels. The flow was assessed by means of Doppler ultrasound examination weekly, and 1 month after the implantation we removed the scaffold for histopathologic evaluation. Results. The implants showed a perfect leak-proof seal and adequate elastic tension to blood pressure. About w3 weeks after the implantation, Doppler examination revealed thrombosis of the graft, so we proceeded to its removal. Histologic examination showed chronic inflammation, with the presence of foreign body cells and marked neovascularization. The material had been largely absorbed, leaving some isolated spot residues. Conclusions. The biocompatibility of PHEA-PLA/PCL and its physical properties make it suitable for the replacement of vessels. In the future, the possibility of functionalizing the material with a variety of molecules, to modulate the inflammatory and coagulative responses, will allow obtaining devices suitable for the replacement of native vessels

    Electrospun Polyhydroxyethyl-Aspartamide-Polylactic Acid Scaffold for Biliary Duct Repair: A Preliminary In\ua0Vivo Evaluation

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    Tissue engineering has emerged as a new approach with the potential to overcome the limitations of traditional therapies. The objective of this study was to test whether our polymeric scaffold is able to resist the corrosive action of bile and to support a cell's infiltration and neoangiogenesis with the aim of using it as a biodegradable tissue substitute for serious bile duct injuries. In particular, a resorbable electrospun polyhydroxyethyl-aspartamide-polylactic acid (90 mol% PHEA, 10 mol% PLA)/polycaprolactone (50:50 w/w) plate scaffold was implanted into rabbit gallbladder to assess the in\ua0vivo effects of the lytic action of the bile on the scaffold structure and then as a tubular scaffold to create a biliary-digestive anastomosis as well. For the above evaluation, 5 animals were used and killed after 15 days and 5 animals after 3 months. At 15-day and 3-month follow-ups, the fibrillar structure was not digested by lytic action bile. The fibers of the scaffold were organized despite being in contact with bile action. A new epithelial tissue appeared on the scaffold surface suggesting the suitability of this scaffold for future studies of the repair of biliary tract injuries with the use of resorbable copolymer on biliary injuries
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