Mucoadhesive films inside the colonic tube: performance in a three-dimensional world

A self-propelling colonoscopic device moving inside the colonic tube should be able to periodically grip safely to the colonic wall as well as to manipulate the generated friction. The feasibility of achieving high grip and friction manipulation by covering the device with mucoadhesive films is experimentally tested. More precisely, the frictional behaviour of mucoadhesive films inside the colonic tube is tested in vitro in porcine colon. It appears that mucoadhesive films generate significantly higher friction than conventional materials (ANOVA p =0, 95% CIs=−3.04, −2.14). The geometry of the film plays a role as well. When holes are, for instance, present in the film geometry and are large enough so that the colonic tissue can wrap their borders, friction can be significantly increased (ANOVA p =0, 95% CIs=−2.53, −1.26). By altering the contact area or the film geometry, friction manipulation can be achieved. Moreover, a simple theoretical model is developed and experimentally verified ( R =0.92). The model can be used to estimate the level of the friction generated by three-dimensional configurations of mucoadhesive films as a function of their geometric characteristics and the material properties of the colon.

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The Effect of Dorsal Angulation on Distal Radioulnar Joint Arthrokinematics Measured Using Intercartilage Distance

Journal of Wrist Surgery ◽

10.1055/s-0038-1667303 ◽

2018 ◽

Vol 08 (01) ◽

pp. 010-017

Author(s):

Emily Lalone ◽

Masao Nishiwaki ◽

Ryan Willing ◽

James Johnson ◽

Graham King ◽

...

Keyword(s):

Distal Radius ◽

Contact Area ◽

Three Dimensional ◽

Distal Radioulnar Joint ◽

Radioulnar Joint ◽

Motion Data ◽

Contact Patterns ◽

Dorsal Angulation ◽

Triangular Fibrocartilage

Background The effects of dorsal angulation deformity on in vitro distal radioulnar joint (DRUJ) contact patterns are not well understood. Purpose The purpose of this study was to utilize intercartilage distance to examine the effects of forearm rotation angle, distal radius deformity, and triangular fibrocartilage complex (TFCC) sectioning on DRUJ contact area and centroid position. Methods An adjustable implant permitted the creation of simulated intact state and dorsal angulation deformities of 10, 20, and 30 degrees. Three-dimensional cartilage models of the distal radius and ulna were created using computed tomography data. Using optically tracked motion data, the relative position of the cartilage models was rendered and used to measure DRUJ cartilage contact mechanics. Results DRUJ contact area was highest between 10 and 30 degrees of supination. TFCC sectioning caused a significant decrease in contact area with a mean reduction of 11 ± 7 mm2 between the TFCC intact and sectioned conditions across all variables. The position of the contact centroid moved volarly and proximally with supination for all variables. Deformity had a significant effect on the location of the contact centroid along the volar–dorsal plane. Conclusion Contact area in the DRUJ was maximal between 10 and 30 degrees of supination during the conditions tested. There was a significant effect of simulated TFCC rupture on contact area in the DRUJ, with a mean contact reduction of 11 ± 7 mm2 after sectioning. Increasing dorsal angulation caused the contact centroid to move progressively more volar in the sigmoid notch.

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Compressive Mechanical Properties of Carbon Nanotube Sponges: Experiments and Modeling

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.528.14 ◽

2012 ◽

Vol 528 ◽

pp. 14-17

Author(s):

Peng Zhan Sun ◽

Hong Wei Zhu

Keyword(s):

Mechanical Properties ◽

Chemical Vapor Deposition ◽

Carbon Nanotube ◽

Theoretical Model ◽

Vapor Deposition ◽

Three Dimensional ◽

Chemical Vapor ◽

Environmental Applications ◽

Deep Insight ◽

Simple Theoretical Model

Carbon nanotube (CNT) sponges are three-dimensional frameworks of interconnected CNTs with great potentials in composite and environmental applications. CNT sponges with lateral sizes of centimeters have been prepared through chemical vapor deposition (CVD), and their compressive mechanical properties are studied. To gain deep insight on the microstructure and how CNTs are connected within the sponges, we propose a simple theoretical model to understand the arrangement as well as the interconnection of CNTs. The mechanical properties of CNT sponges can be well explained and predicted using this model.

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Adding exogenous biglycan or decorin improves tendon formation for equine peritenon and tendon proper cells in vitro

BMC Musculoskeletal Disorders ◽

10.1186/s12891-020-03650-2 ◽

2020 ◽

Vol 21 (1) ◽

Author(s):

Monica Y. Pechanec ◽

Tannah N. Boyd ◽

Keith Baar ◽

Michael J. Mienaltowski

Keyword(s):

Material Properties ◽

Quantitative Polymerase Chain Reaction ◽

Tendon Repair ◽

Three Dimensional ◽

Collagen Content ◽

Matrix Assembly ◽

Post Injury ◽

Transmission Electron

Abstract Background Tendon injuries amount to one of the leading causes of career-ending injuries in horses due to the inability for tendon to completely repair and the high reinjury potential. As a result, novel therapeutics are necessary to improve repair with the goal of decreasing leg lameness and potential reinjury. Small leucine-rich repeat proteoglycans (SLRPs), a class of regulatory molecules responsible for collagen organization and maturation, may be one such therapeutic to improve tendon repair. Before SLRP supplementation can occur in vivo, proper evaluation of the effect of these molecules in vitro needs to be assessed. The objective of this study was to evaluate the effectiveness of purified bovine biglycan or decorin on tendon proper and peritenon cell populations in three-dimensional tendon constructs. Methods Equine tendon proper or peritenon cell seeded fibrin three-dimensional constructs were supplemented with biglycan or decorin at two concentrations (5 nM or 25 nM). The functionality and ultrastructural morphology of the constructs were assessed using biomechanics, collagen content analysis, transmission electron microscopy (TEM), and gene expression by real time – quantitative polymerase chain reaction (RT-qPCR). Results SLRP supplementation affected both tendon proper and peritenon cells-seeded constructs. With additional SLRPs, material and tensile properties of constructs strengthened, though ultrastructural analyses indicated production of similar-sized or smaller fibrils. Overall expression of tendon markers was bolstered more in peritenon cells supplemented with either SLRP, while supplementation of SLRPs to TP cell-derived constructs demonstrated fewer changes in tendon and extracellular matrix markers. Moreover, relative to non-supplemented tendon proper cell-seeded constructs, SLRP supplementation of the peritenon cells showed increases in mechanical strength, material properties, and collagen content. Conclusions The SLRP-supplemented peritenon cells produced constructs with greater mechanical and material properties than tendon proper seeded constructs, as well as increased expression of matrix assembly molecules. These findings provide evidence that SLRPs should be further investigated for their potential to improve tendon formation in engineered grafts or post-injury.

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Analysis of the material properties of early chondrogenic differentiated adipose-derived stromal cells (ASC) using an in vitro three-dimensional micromass culture system

Biochemical and Biophysical Research Communications ◽

10.1016/j.bbrc.2007.05.098 ◽

2007 ◽

Vol 359 (2) ◽

pp. 311-316 ◽

Cited By ~ 38

Author(s):

Yue Xu ◽

Guive Balooch ◽

Michael Chiou ◽

Elena Bekerman ◽

Robert O. Ritchie ◽

...

Keyword(s):

Stromal Cells ◽

Material Properties ◽

Culture System ◽

Three Dimensional ◽

Micromass Culture ◽

Adipose Derived Stromal Cells

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A review of biomaterials scaffold fabrication in additive manufacturing for tissue engineering

Journal of Bioactive and Compatible Polymers ◽

10.1177/0883911519877426 ◽

2019 ◽

Vol 34 (6) ◽

pp. 415-435 ◽

Cited By ~ 6

Author(s):

Tang Mei Shick ◽

Aini Zuhra Abdul Kadir ◽

Nor Hasrul Akhmal Ngadiman ◽

Azanizawati Ma’aram

Keyword(s):

Tissue Engineering ◽

Additive Manufacturing ◽

Material Properties ◽

Computer Aided Design ◽

Three Dimensional ◽

Scaffold Fabrication ◽

Manufacturing Techniques ◽

Manufacturing Technologies

The current developments in three-dimensional printing also referred as “additive manufacturing” have transformed the scenarios for modern manufacturing and engineering design processes which show greatest advantages for the fabrication of complex structures such as scaffold for tissue engineering. This review aims to introduce additive manufacturing techniques in tissue engineering, types of biomaterials used in scaffold fabrication, as well as in vitro and in vivo evaluations. Biomaterials and fabrication methods could critically affect the outcomes of scaffold mechanical properties, design architectures, and cell proliferations. In addition, an ideal scaffold aids the efficiency of cell proliferation and allows the movements of cell nutrient inside the human body with their specific material properties. This article provides comprehensive review that covers broad range of all the biomaterial types using various additive manufacturing technologies. The data were extracted from 2008 to 2018 mostly from Google Scholar, ScienceDirect, and Scopus using keywords such as “Additive Manufacturing,” “3D Printing,” “Tissue Engineering,” “Biomaterial” and “Scaffold.” A 10 years research in this area was found to be mostly focused toward obtaining an ideal scaffold by investigating the fabrication strategies, biomaterials compatibility, scaffold design effectiveness through computer-aided design modeling, and optimum printing machine parameters identification. As a conclusion, this ideal scaffold fabrication can be obtained with the combination of different materials that could enhance the material properties which performed well in optimum additive manufacturing condition. Yet, there are still many challenges from the printing methods, bioprinting and cell culturing that needs to be discovered and investigated in the future.

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The Research on Multi-Material 3D Vascularized Network Integrated Printing Technology

Micromachines ◽

10.3390/mi11030237 ◽

2020 ◽

Vol 11 (3) ◽

pp. 237 ◽

Cited By ~ 1

Author(s):

Shuai Yang ◽

Hao Tang ◽

Chunmei Feng ◽

Jianping Shi ◽

Jiquan Yang

Keyword(s):

Theoretical Model ◽

Influencing Factors ◽

Three Dimensional ◽

Entire Structure ◽

Sacrificial Material ◽

Manufacture Process ◽

Novel Approach ◽

Printing Speed ◽

Cacl2 Solution

Three-dimensional bioprinting has emerged as one of the manufacturing approaches that could potentially fabricate vascularized channels, which is helpful to culture tissues in vitro. In this paper, we report a novel approach to fabricate 3D perfusable channels by using the combination of extrusion and inkjet techniques in an integrated manufacture process. To achieve this, firstly we investigate the theoretical model to analyze influencing factors of structural dimensions of the printed parts like the printing speed, pressure, dispensing time, and voltage. In the experiment, photocurable hydrogel was printed to form a self-supporting structure with internal channel grooves. When the desired height of hydrogel was reached, the dual print-head was switched to the piezoelectric nozzle immediately, and the sacrificial material was printed by the changed nozzle on the printed hydrogel layer. Then, the extrusion nozzle was switched to print the next hydrogel layer. Once the printing of the internal construct was finished, hydrogel was extruded to wrap the entire structure, and the construct was immersed in a CaCl2 solution to crosslink. After that, the channel was formed by removing the sacrificial material. This approach can potentially provide a strategy for fabricating 3D vascularized channels and advance the development of culturing thick tissues in vitro.

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Ultrastructural Investigations of the Contractile Filaments of Amoebae

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100050950 ◽

1974 ◽

Vol 32 ◽

pp. 188-189

Author(s):

P.L. Moore

Keyword(s):

Cytoplasmic Streaming ◽

Three Dimensional ◽

Freeze Fracture ◽

Amoeboid Movement ◽

Different Types ◽

Chemical Conditions ◽

Complete Interpretation

Previous freeze fracture results on the intact giant, amoeba Chaos carolinensis indicated the presence of a fibrillar arrangement of filaments within the cytoplasm. A complete interpretation of the three dimensional ultrastructure of these structures, and their possible role in amoeboid movement was not possible, since comparable results could not be obtained with conventional fixation of intact amoebae. Progress in interpreting the freeze fracture images of amoebae required a more thorough understanding of the different types of filaments present in amoebae, and of the ways in which they could be organized while remaining functional.The recent development of a calcium sensitive, demembranated, amoeboid model of Chaos carolinensis has made it possible to achieve a better understanding of such functional arrangements of amoeboid filaments. In these models the motility of demembranated cytoplasm can be controlled in vitro, and the chemical conditions necessary for contractility, and cytoplasmic streaming can be investigated. It is clear from these studies that “fibrils” exist in amoeboid models, and that they are capable of contracting along their length under conditions similar to those which cause contraction in vertebrate muscles.

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Correlated Studies of Cellular Interactions Using TEM, Freeze Etching, and SEM

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010005161x ◽

1974 ◽

Vol 32 ◽

pp. 320-321

Author(s):

J. P. Revel

Keyword(s):

Developmental Stages ◽

Three Dimensional ◽

Cell Movement ◽

Cellular Interactions ◽

Serial Sections ◽

Cell Sheets ◽

Freeze Etching ◽

Early Developmental

Movement of individual cells or of cell sheets and complex patterns of folding play a prominent role in the early developmental stages of the embryo. Our understanding of these processes is based on three- dimensional reconstructions laboriously prepared from serial sections, and from autoradiographic and other studies. Many concepts have also evolved from extrapolation of investigations of cell movement carried out in vitro. The scanning electron microscope now allows us to examine some of these events in situ. It is possible to prepare dissections of embryos and even of tissues of adult animals which reveal existing relationships between various structures more readily than used to be possible vithout an SEM.

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In vitro and in vivo polysaccharides assembly: ultrastructural and cytochemical study of growing plant cell wall components.

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100083035 ◽

1978 ◽

Vol 36 (2) ◽

pp. 434-435

Author(s):

D. Reis ◽

B. Vian ◽

J. C. Roland

Keyword(s):

Cell Wall ◽

Self Assembly ◽

Plant Cell Wall ◽

Higher Plants ◽

Three Dimensional ◽

Cytochemical Study ◽

Wall Components

Wall morphogenesis in higher plants is a problem still open to controversy. Until now the possibility of a transmembrane control and the involvement of microtubules were mostly envisaged. Self-assembly processes have been observed in the case of walls of Chlamydomonas and bacteria. Spontaneous gelling interactions between xanthan and galactomannan from Ceratonia have been analyzed very recently. The present work provides indications that some processes of spontaneous aggregation could occur in higher plants during the formation and expansion of cell wall.Observations were performed on hypocotyl of mung bean (Phaseolus aureus) for which growth characteristics and wall composition have been previously defined.In situ, the walls of actively growing cells (primary walls) show an ordered three-dimensional organization (fig. 1). The wall is typically polylamellate with multifibrillar layers alternately transverse and longitudinal. Between these layers intermediate strata exist in which the orientation of microfibrils progressively rotates. Thus a progressive change in the morphogenetic activity occurs.

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