scholarly journals Editorial: Tailored Porous Biomaterials for Hard and Soft Tissues: Focus on Surface Functionalization

2021 ◽  
Vol 8 ◽  
Author(s):  
Yadir Torres ◽  
Ana M. Beltrán ◽  
Juan V. Cauich-Rodriguez
2015 ◽  
Vol 1719 ◽  
Author(s):  
Prakash D. Nallathamby ◽  
Tracie L. Mcginnity ◽  
Lisa E. Cole ◽  
Margaret E. Best ◽  
Tracy Vargo-Gogola ◽  
...  

ABSTRACTComputed tomography (CT) is an important tool in clinical diagnostic imaging enabling three-dimensional anatomic imaging at high spatial resolution with short scan times. However, X-ray attenuation differences in physiological fluids and soft tissues are relatively small, requiring the use of contrast agents to achieve sufficient imaging contrast. Recent advances in energy-sensitive X-ray detectors have made spectral (color) CT commercially feasible by unmixing the energy-dependent attenuation profile of different materials and will potentially enable molecular imaging in CT. In order to leverage these capabilities for diagnostic imaging, we are developing a spectral library of nanoparticle contrast agents with K-shell absorption edges spaced at least 10 keV apart. The objective of this study was to demonstrate the ability of spectral CT to simultaneously detect up to three different contrast agents and unmixed their signals to create color images. Gadolinium oxide (Gd), hafnium oxide (Hf) and gold (Au) were chosen due to exhibiting K-edges spaced 10-20 keV apart. Core-shell nanoparticles of each composition were synthesized by various methods to have a core diameter of 15-20 nm and were coated with a silica shell at least 2-4 nm in thickness to create a common platform for surface functionalization. The contrast agents were imaged in a soft tissue equivalent phantom using source-side method for spectral CT imaging. The source-side approach utilized monochromatic synchrotron radiation at the Argonne National Laboratory which, while not clinically applicable, served as a gold standard due to providing the highest spectral resolution. The nanoparticles designed for this study have broad applications in biomedical imaging due to their modular assembly, potential for enabling multi-modal detection, and surface functionalization with biomolecules (e.g., antibodies, peptides or enzymes) for active targeting.


2001 ◽  
Vol 7 (S2) ◽  
pp. 834-835 ◽  
Author(s):  
Andrew J. Marshall ◽  
Buddy D. Ratner

Introduction Applications for porous biomaterials include scaffolds for tissue engineering and spatial control of wound healing. Porous hydrogels are of particular interest due to their hydrophilic nature, elasticity, and mechanical compatibility with soft tissues. We present an optical technique for quantitatively analyzing the pore structure of porous hydrogel materials. The technique presented here is especially useful for analyzing a new class of porous hydrogels with spherical pore shape. Many important properties of the three-dimensional pore structure of these materials can be quantitatively described by analyzing a twodimensional slice (thin section) of material.Materials and MethodsPorous cross-linked hydrogels were prepared using a previously described method. Briefly, poly(hydroxyethyl methacrylate) (polyHEMA) was polymerized around a pore template of close-packed poly(methyl methacrylate) (PMMA) microspheres (Sekisui Plastics, grade MB-8C or MB-20C). The microspheres were then leached out with 90% v/v acetone.Scanning electron microscope (SEM) images were obtained using an FEI 2020 Environmental SEM with a gun voltage of 15 kV and a chamber pressure of 5 torr.


Author(s):  
C.A. Baechler ◽  
W. C. Pitchford ◽  
J. M. Riddle ◽  
C.B. Boyd ◽  
H. Kanagawa ◽  
...  

Preservation of the topographic ultrastructure of soft biological tissues for examination by scanning electron microscopy has been accomplished in the past by using lengthy epoxy infiltration techniques, or dehydration in ethanol or acetone followed by air drying. Since the former technique requires several days of preparation and the latter technique subjects the tissues to great stress during the phase change encountered during air-drying, an alternate rapid, economical, and reliable method of surface structure preservation was developed. Turnbill and Philpott had used a fluorocarbon for the critical point drying of soft tissues and indicated the advantages of working with fluids having both moderately low critical pressures as well as low critical temperatures. Freon-116 (duPont) which has a critical temperature of 19. 7 C and a critical pressure of 432 psi was used in this study.


Author(s):  
M.E. Lee ◽  
A. Moller ◽  
P.S.O. Fouche ◽  
I.G Gaigher

Scanning electron microscopy of fish scales has facilitated the application of micro-structures to systematics. Electron microscopy studies have added more information on the structure of the scale and the associated cells, many problems still remain unsolved, because of our incomplete knowledge of the process of calcification. One of the main purposes of these studies has been to study the histology, histochemistry, and ultrastructure of both calcified and decalcified scales, and associated cells, and to obtain more information on the mechanism of calcification in the scales. The study of a calcified scale with the electron microscope is complicated by the difficulty in sectioning this material because of the close association of very hard tissue with very soft tissues. Sections often shatter and blemishes are difficult to avoid. Therefore the aim of this study is firstly to develop techniques for the preparation of cross sections of fish scales for scanning electron microscopy and secondly the application of these techniques for the determination of the structures and calcification of fish scales.


Author(s):  
Yasushi P. Kato ◽  
Michael G. Dunn ◽  
Frederick H. Silver ◽  
Arthur J. Wasserman

Collagenous biomaterials have been used for growing cells in vitro as well as for augmentation and replacement of hard and soft tissues. The substratum used for culturing cells is implicated in the modulation of phenotypic cellular expression, cellular orientation and adhesion. Collagen may have a strong influence on these cellular parameters when used as a substrate in vitro. Clinically, collagen has many applications to wound healing including, skin and bone substitution, tendon, ligament, and nerve replacement. In this report we demonstrate two uses of collagen. First as a fiber to support fibroblast growth in vitro, and second as a demineralized bone/collagen sponge for radial bone defect repair in vivo.For the in vitro study, collagen fibers were prepared as described previously. Primary rat tendon fibroblasts (1° RTF) were isolated and cultured for 5 days on 1 X 15 mm sterile cover slips. Six to seven collagen fibers, were glued parallel to each other onto a circular cover slip (D=18mm) and the 1 X 15mm cover slip populated with 1° RTF was placed at the center perpendicular to the collagen fibers. Fibroblast migration from the 1 x 15mm cover slip onto and along the collagen fibers was measured daily using a phase contrast microscope (Olympus CK-2) with a calibrated eyepiece. Migratory rates for fibroblasts were determined from 36 fibers over 4 days.


1972 ◽  
Vol 11 (01) ◽  
pp. 70-78
Author(s):  
Esther Miller ◽  
Leopoldo Anghileri

SummaryThe distribution of 32P-polyphosphates (lineal and cross-linked) and 32Porthophosphate in normal and tumor bearing animals has been studied. Differences between the cross-linked and the lineal form are related to a different degree of susceptibility to the hydrolysis by the phosphatases. In contrast to orthophosphate, the polyphosphates showed a lower accumulation in soft tissues which gives an advantageous reduction of the total body radiation dose.


2020 ◽  
Vol 64 (1-4) ◽  
pp. 1253-1259
Author(s):  
Minghui Wang ◽  
Hongliu Yu

Clamping devices with constant force or pressure are desired in medical device, such as hemostatic forceps and the artificial sphincter, to prevent soft tissues from injures due to overloading. It is easily obtained by stretching an SMA wire. However, studies with SMA bending round bar have seldom been reported before. This paper studied constant force characteristic of C-shaped round bar with shape memory alloys. Optimization designs of the components were carried out with computational simulation. Numerical results show that the phenomenon of constant force strongly depends on contour curve shape and geometric dimensions of the C-shaped round bar of SMA component.


Author(s):  
V. Deepika ◽  
T. Rajasenbagam

A brain tumor is an uncontrolled growth of abnormal brain tissue that can interfere with normal brain function. Although various methods have been developed for brain tumor classification, tumor detection and multiclass classification remain challenging due to the complex characteristics of the brain tumor. Brain tumor detection and classification are one of the most challenging and time-consuming tasks in the processing of medical images. MRI (Magnetic Resonance Imaging) is a visual imaging technique, which provides a information about the soft tissues of the human body, which helps identify the brain tumor. Proper diagnosis can prevent a patient's health to some extent. This paper presents a review of various detection and classification methods for brain tumor classification using image processing techniques.


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