Search results for "healing"
showing 10 items of 642 documents
Histological and ultrastructural study of corneal tunnel incisions using diamond and steel keratomes
1998
Abstract Purpose: To study the morphology of corneal tunnel incisions using diamond and steel keratomes. Setting: Department of Ophthalmology, University of Giessen, Germany. Methods: Corneal tunnel incisions were performed in six human cadaver eyes using three types of diamond keratomes and a steel keratome. The incision profile and morphology were evaluated and compared using light and scanning electron microscopy. Results: The steel keratome caused more disruption of corneal stromal tissue, while the diamond keratomes produced a more regular, smoother incision. The dissecting incision resulted in a smoother surface of cut stromal tissue than the stab incision. Conclusions: The high quali…
Designed biodegradable hydrogel structures prepared by stereolithography using poly(ethylene glycol)/poly(D,L-lactide)-based resins
2010
Designed three-dimensional biodegradable poly(ethylene glycol)/poly(D,L-lactide) hydrogel structures were prepared for the first time by stereolithography at high resolutions. A photo-polymerisable aqueous resin comprising PDLLA-PEG-PDLLA-based macromer, visible light photo-initiator, dye and inhibitor in DMSO/water was used to build the structures. Porous and non-porous hydrogels with well-defined architectures and good mechanical properties were prepared. Porous hydrogel structures with a gyroid pore network architecture showed narrow pore size distributions, excellent pore interconnectivity and good mechanical properties. The structures showed good cell seeding characteristics, and human…
Monitoring of fracture calluses with color Doppler sonography.
1999
Purpose Fracture callus formation is closely associated with vascular invasion, and the use of color Doppler sonography has been suggested as a means to monitor, earlier than gray-scale sonography, the first stages of the healing process. We report the findings in a series of patients with tibial fractures in whom both gray-scale sonography and color Doppler imaging were employed to monitor new bone formation at the fracture site. Methods Twenty patients with tibial fractures treated with external fixator frames were examined sonographically about 10 days after surgery and then about every 25 days until radiographic demonstration of consolidation. Results Eighteen of 20 patients had a well-…
Introduction to Immediate Loading in Implantology
2019
Branemark traditional recommendation was to perform implant rehabilitation in two stages: the first entry was only for implant placement; after 3–6 months of undisturbed submerged healing for mandible and maxilla, respectively, a second surgical entry would have allowed loading of the implants. The rationale behind this approach was that implant micro-movements as consequence by an inadequate primary stability, caused by functional forces at the bone-implant interface in the early wound healing stages, could have induced fibrous tissue formation rather than new bone, eventually causing clinical failure. The main request was to reduce the overall rehabilitation time from surgery to final res…
Tissue response and biomaterial integration: the efficacy of in vitro methods
2002
Implantation involves tissue trauma, which evokes an inflammatory response, coupled to a wound healing reaction, involving angiogenesis, fibroblast activation and matrix remodelling. Until now the type and extent of such reactions to give optimal integration of various biomaterials are practically unknown. Three principal fields of research can yield useful data to understand these phenomena better: studies on explanted biomaterials, animal models and relevant in vitro techniques. This paper will present examples of the latter field and the application of endothelial cell (EC) culture systems to study the effects of important tissue (e.g. pro-inflammatory cytokines, chemokines) and material…
What is the physiological function of mast cells?
2003
Under physiological conditions, skin mast cells preferentially localize around nerves, blood vessels and hair follicles. This observation, which dates back to Paul Ehrlich, intuitively suggests that these enigmatic, multifacetted protagonists of natural immunity are functionally relevant to many more aspects of tissue physiology than just to the generation of inflammatory and vasodilatory responses to IgE-dependent environmental antigens. And yet, for decades, mainstream-mast cell research has been dominated by a focus on the -undisputedly prominent and important - mast cell functions in type I immune responses and in the pathogenesis and management of allergic diseases. Certainly, it is ha…
Encapsulation Response ofCiona intestinalis(Ascidiacea) to Intratunical Erythrocyte Injection
1996
Previous studies on the ascidian Ciona intestinalis have shown that an encapsulation response is experimentally induced by inserting vertebrate erythrocytes into the tunic, which initiates a massive inflammatory cell infiltration to isolate the injured area. Several hemocytes contribute to capsule formation, destruction of the foreign cells, tunic regeneration, and wound healing. The fine features of some inflammatory cell types are described although the complete capsular structure is not yet reported. Accordingly, the present investigation further examines various aspects of this cellular reaction against erythrocytes and, for the first time, presents the involvement of extratunical circu…
Timing effect of intramyocardial hydrogel injection for positively impacting left ventricular remodeling after myocardial infarction
2015
Intramyocardial injection of various injectable hydrogel materials has shown benefit in positively impacting the course of left ventricular (LV) remodeling after myocardial infarction (MI). However, since LV remodeling is a complex, time dependent process, the most efficacious time of hydrogel injection is not clear. In this study, we injected a relatively stiff, thermoresponsive and bioabsorbable hydrogel in rat hearts at 3 different time points - immediately after MI (IM), 3 d post-MI (3D), and 2 w post-MI (2W), corresponding to the beginnings of the necrotic, fibrotic and chronic remodeling phases. The employed left anterior descending coronary artery ligation model showed expected infar…
Ag Nanoparticles for Biomedical Applications—Synthesis and Characterization—A Review
2022
Silver nanoparticles have been intensively studied over a long period of time because they exhibit antibacterial properties in infection treatments, wound healing, or drug delivery systems. The advantages that silver nanoparticles offer regarding the functionalization confer prolonged stability and make them suitable for biomedical applications. Apart from functionalization, silver nanoparticles exhibit various shapes and sizes depending on the conditions used through their fabrications and depending on their final purpose. This paper presents a review of silver nanoparticles with respect to synthesis procedures, including the polluting green synthesis. Currently, the most commonly used cha…
Tunable and Large-Scale Model Network StarPEG-DNA Hydrogels
2021
The use of DNA as a building block in synthetic polymer hydrogels promises high levels of programmability regarding sol/gel temperatures, tunable bond lifetimes, biocompatibility, and interaction w...