Search results for "Prosthesis"
showing 10 items of 719 documents
Electrospun PHEA-PLA/PCL Scaffold for Vascular Regeneration: A Preliminary in Vivo Evaluation
2017
Abstract 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 α,β-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 wit…
The pre-vascularisation of a collagen-chondroitin sulphate scaffold using human amniotic fluid-derived stem cells to enhance and stabilise endothelia…
2015
Abstract A major problem in tissue engineering (TE) is graft failure in vivo due to core degradation in in vitro engineered constructs designed to regenerate thick tissues such as bone. The integration of constructs post-implantation relies on the rapid formation of functional vasculature. A recent approach to overcome core degradation focuses on the creation of cell-based, pre-engineered vasculature formed within the TE construct in vitro , prior to implantation in vivo . The primary objective of this study was to investigate whether an amniotic fluid-derived stem cell (AFSC)–human umbilical vein endothelial cell (HUVEC) co-culture could be used to engineer in vitro vasculature in a collag…
Microstructural manipulation of electrospun scaffolds for specific bending stiffness for heart valve tissue engineering
2012
Biodegradable thermoplastic elastomers are attractive for application in cardiovascular tissue construct development due to their amenability to a wide range of physical property tuning. For heart valve leaflets, while low flexural stiffness is a key design feature, control of this parameter has been largely neglected in the scaffold literature where electrospinning is being utilized. This study evaluated the effect of processing variables and secondary fiber populations on the microstructure, tensile and bending mechanics of electrospun biodegradable polyurethane scaffolds for heart valve tissue engineering. Scaffolds were fabricated from poly(ester urethane) urea (PEUU) and the deposition…
Predictors of scaffold failure and impact of optimized scaffold implantation technique on outcome: Results from the German-Austrian ABSORB RegIstRy.
2021
Aims We aimed to investigate predictors of scaffold failure and the potential impact of an optimized scaffold implantation technique by means of a learning curve on long-term clinical outcome after bioresorbable scaffold (BRS) implantation and to evaluate predictors of scaffold failure. Methods and results A total of 3326 patients were included in this prospective, observational, multi-center study (ClinicalTrials.gov NCT02066623) of consecutive patients undergoing BRS implantation between November 2013 and January 2016. The 3144 patients completed follow-up after 24 months, 3265 patients were eligible for time-to-event-analysis. Clinical endpoints were major adverse cardiac events-a compos…
Numerical study of the components positioning influence on the stability of a reverse shoulder prosthesis
2014
Aim of this paper is to setup a novel procedure able to analyze performances of a reverse shoulder prosthesis when different geometrical configurations are assumed. Nowadays, such a prosthesis is widely used but, because of its novelty, data in literature give poor information about performances and limits to its applicability. The activity has been divided into the following steps. At the beginning the shape of the prosthesis has been digitally acquired via a 3D scanner. Then, CAD models of all prosthetic components have been geometrically optimized in a way to obtain final entities suitable for numerical simulations. After that, CAD assemblies have been created between prosthetic componen…
Dynamic inguinal hernia repair with a 3d fixation-free and motion-compliant implant: a clinical study.
2014
Static solutions for highly motile structures such as the groin seem to represent a procedural incongruence. Another important issue in prosthetic hernia repair is related to the poor quality of tissue ingrowth within conventional flat meshes and plugs. These are all static, passive devices, and thus do not move in synchrony with the natural movements of the groin. In the literature there is a clear understanding of how conventional prostheses used for inguinal hernia repair are incorporated by rigid fibrotic tissue. The term "scar plate" well emphasizes this occurrence. The ingrowth of this kind of stiff fibrotic scar leads to mesh shrinkage and to the reduction of the mesh surface area. T…
Polyester vascular prostheses coated with a cyclodextrin polymer and activated with antibiotics: Cytotoxicity and microbiological evaluation
2008
Abstract Polyester (PET) vascular grafts are used to replace or bypass damaged arteries. To minimize the risk of infection during and after surgical interventions, a PET vascular prosthesis (Polythese®) was functionalized with cyclodextrin polymers (PolyCDs) in order to obtain the controlled release of antibiotics (ABs: ciprofloxacin, vancomcyin and rifampicin). An epithelial cell line (L132) was used to determine the viability of the antibiotics, and human pulmonary microvascular endothelial cells (HPMEC) were used for cell proliferation by cell counting and cell vitality with Alamar Blue fluorescent dye. Staphylococcus aureus, Escherichia coli and Enteroccocus sp. were used to determine t…
Biomechanics and Occlusion in Immediate Loading
2019
In this chapter, biomechanical concepts as tension, types of forces, and static and dynamic loads in oral implantology are explained. Also, biomechanical factors as type of bone, implant design, switching platform, connection type, crown-implant ratio, and passive fit are exposed. So, it is important to know keys for biomechanical control and occlusal pattern. The lowering of tensions is one of our aims when planning cases for immediate loading, since we know the complications they can cause. It is therefore necessary to reduce the incident forces or increase the surface upon which they fall. Increasing the number of implants is the most effective method for improving surface area and reduc…
A New Prosthetic Implant for Inguinal Hernia Repair: Its Features in a Porcine Experimental Model
2011
Even after more than 100 years of inguinal hernia repair, the rate of complications and recurrence remains unacceptably high. In the last decades, few effective advances in surgical technique and materials have been made. The authors see them as minor adjustments in the shape and materials of the prosthetic implants. Still, the underlying genesis of inguinal hernia remains undefined. Based upon this, it seems the surgical repair of inguinal protrusions cannot be based upon the pathogenesis because the etiology to date has not been addressed. Most hernia repairs are performed with some degree of point fixation (sutures/tacks) to stop the mesh from migrating and creating high recurrence rates…
Short implants (8mm) versus longer implants (≥8mm) with lateral sinus floor augmentation in posterior atrophic maxilla: A meta-analysis of RCT`s in h…
2019
Background One of the greatest challenges that dentists face today is to rehabilitate severe atrophied alveolar ridges in partially and completely edentulous patients with implants. Despite the high survival rate of implants placed next to sinus elevation, this technique presents complications that can be avoided by placing short implants, an option that also presents high survival rates. For this reason, the aim of this study is to compare the survival rate, marginal bone loss and complications associated with short implants (<8 mm) versus longer implants (≥8mm) placed with lateral sinus floor elevation in posterior atrophic maxillae. Material and Methods A literature search was conducted …