https://www.seas.upenn.edu/%7Edischer/pdfs/Cell_on_Gel-CELLpaper.pdf

Matrix elasticity directs stem cell lineage specification.

Gold, enigmatically represented by the target-like design of its ancient alchemical symbol, has been considered a mystical material of great value for centuries. Nanoscale particles of gold now command a great deal of attention for biomedical applications. Depending on their size, shape, degree of aggregation, and local environment, gold nanoparticles can appear red, blue, or other colors. These visible colors reflect the underlying coherent oscillations of conduction-band electrons (“plasmons”) upon irradiation with light of appropriate wavelengths. These plasmons underlie the intense absorption and elastic scattering of light, which in turn forms the basis for many biological sensing and imaging applications of gold nanoparticles. The brilliant elastic light-scattering properties of gold nanoparticles are sufficient to detect individual nanoparticles in a visible light microscope with ∼102 nm spatial resolution. Despite the great excitement about the potential uses of gold nanoparticles for medical diag...

Gold nanoparticles in biology: beyond toxicity to cellular imaging

Mechanical properties of the adventitia are largely determined by the organization of collagen fibers. Measurements on the waviness and orientation of collagen, particularly at the zero-stress state, are necessary to relate the structural organization of collagen to the mechanical response of the adventitia. Using the fluorescence collagen marker CNA38-OG488 and confocal laser scanning microscopy, we imaged collagen fibers in the adventitia of rabbit common carotid arteries ex vivo. The arteries were cut open along their longitudinal axes to get the zero-stress state. We used semi-manual and automatic techniques to measure parameters related to the waviness and orientation of fibers. Our results showed that the straightness parameter (defined as the ratio between the distances of endpoints of a fiber to its length) was distributed with a beta distribution (mean value 0.72, variance 0.028) and did not depend on the mean angle orientation of fibers. Local angular density distributions revealed four axially symmetric families of fibers with mean directions of 0°, 90°, 43° and −43°, with respect to the axial direction of the artery, and corresponding circular standard deviations of 40°, 47°, 37° and 37°. The distribution of local orientations was shifted to the circumferential direction when measured in arteries at the zero-load state (intact), as compared to arteries at the zero-stress state (cut-open). Information on collagen fiber waviness and orientation, such as obtained in this study, could be used to develop structural models of the adventitia, providing better means for analyzing and understanding the mechanical properties of vascular wall.

/pdf/experimental-investigation-of-collagen-waviness-and-35sv8tu15v.pdf

Experimental investigation of collagen waviness and orientation in the arterial adventitia using confocal laser scanning microscopy.

Fibroblast biology in three-dimensional collagen matrices.

The use of bone grafts is the standard to treat skeletal fractures, or to replace and regenerate lost bone, as demonstrated by the large number of bone graft procedures performed worldwide. The most common of these is the autograft, however, its use can lead to complications such as pain, infection, scarring, blood loss, and donor-site morbidity. The alternative is allografts, but they lack the osteoactive capacity of autografts and carry the risk of carrying infectious agents or immune rejection. Other approaches, such as the bone graft substitutes, have focused on improving the efficacy of bone grafts or other scaffolds by incorporating bone progenitor cells and growth factors to stimulate cells. An ideal bone graft or scaffold should be made of biomaterials that imitate the structure and properties of natural bone ECM, include osteoprogenitor cells and provide all the necessary environmental cues found in natural bone. However, creating living tissue constructs that are structurally, functionally and mechanically comparable to the natural bone has been a challenge so far. This focus of this review is on the evolution of these scaffolds as bone graft substitutes in the process of recreating the bone tissue microenvironment, including biochemical and biophysical cues.

Scaffold Design for Bone Regeneration

A stent for use in a medical procedure having opposing sets of curved apices, where the curved section of one set of apices has a radius of curvature that is greater than the curved section of the other set of apices. One or more such stents may be attached to a graft material for use in endovascular treatment of, for example, aneurysm, thoracic dissection, or other body vessel condition.

Low profile non-symmetrical stent

Various stent structures are provided with improved axial and torsional flexibility. One type of stent structure includes multiple segmented stent structures connected to each other by biodegradable interconnectors. A delivery system adapted to delivery the multiple segmented stents is also described. Another type of stent structure includes biodegradable connectors that are incorporated into a framework of non-biodegradable interconnecting members that form the support structure of the stent. The biodegradable connectors in both stent structures degrade or are absorbed after the stent is deployed. Stabilizing elements may be provided to the stent structures to supplement the stiffness of the stent with stability during loading and deployment.

Stents With Biodegradable Connectors And Stabilizing Elements

The present invention provides apparatus and methods for deployment of a modular stent-graft system In one embodiment, a prosthesis comprises a first tubular graft comprising a layer of graft material, at least one lumen extending longitudinally therein, and a first fenestration extending through the layer of graft material A layer of fenestration covering material attaches to the layer of graft material The layer of fenestration covering material is disposed in the lumen of the first tubular graft and partitions the first fenestration from the lumen of the first tubular graft A first non-stented opening is disposed proximal to the first fenestration and communicates with the first fenestration between the layer of graft material and the fenestration covering material In use, a proximal end of a second tubular graft sealably engages the first non-stented opening, and the second tubular graft further extends through the first fenestration and into a branch vessel

Apparatus and methods for deployment of a modular stent-graft system

The disclosure relates to a method for coating a target. The method includes providing a target and an electrospinning apparatus. The target comprises a first surface and an opposing second surface. The electrospinning apparatus comprises a mandrel, a mask including an aperture, a reservoir loaded with a solution, and an orifice fluidly coupled to the reservoir. The mandrel is located adjacent the target second surface. The orifice is located at a distance from the target first surface. The mask is located intermediate the orifice and the target first surface. The solution is electrospun through the mask aperture onto the target first surface. In one example the target is an endoluminal prosthesis.

Manufacturing methods for covering endoluminal prostheses

A delivery system may include a stent-graft, a locking member, and one or more diameter reducing members The stent-graft may include a tubular graft comprising first and second longitudinally extending sides disposed opposite each other and connected at a tangent line When the locking member is in a locked position, the locking member restrains a surface of the graft against the cannula The first diameter reducing member may be slidably connected to a first portion of the graft that is disposed proximate the tangent line and may be slidably connected to a second portion of the graft that is spaced circumferentially away from the tangent line When the first diameter reducing member is in a restrained position, the second portion of the graft is drawn toward the first portion of the graft and the proximal portion of the stent-graft has a reduced diameter configuration with at least two lobes

Blayne A. Roeder

Papers

Low profile non-symmetrical stent

Stents With Biodegradable Connectors And Stabilizing Elements

Apparatus and methods for deployment of a modular stent-graft system

Manufacturing methods for covering endoluminal prostheses

Conformable prosthesis delivery system and method for deployment thereof