scholarly journals Ferromagnetic soft catheter robots for minimally invasive bioprinting

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Cheng Zhou ◽  
Youzhou Yang ◽  
Jiaxin Wang ◽  
Qingyang Wu ◽  
Zhuozhi Gu ◽  
...  
Keyword(s):  
Minimally Invasive ◽  
The Body ◽  
Magnetic Actuation ◽  
Internal Organs ◽  
Planar Surfaces ◽  
Reinforced Polymer ◽  
Direct Fabrication ◽  
Digitally Controlled

AbstractIn vivo bioprinting has recently emerged as a direct fabrication technique to create artificial tissues and medical devices on target sites within the body, enabling advanced clinical strategies. However, existing in vivo bioprinting methods are often limited to applications near the skin or require open surgery for printing on internal organs. Here, we report a ferromagnetic soft catheter robot (FSCR) system capable of in situ computer-controlled bioprinting in a minimally invasive manner based on magnetic actuation. The FSCR is designed by dispersing ferromagnetic particles in a fiber-reinforced polymer matrix. This design results in stable ink extrusion and allows for printing various materials with different rheological properties and functionalities. A superimposed magnetic field drives the FSCR to achieve digitally controlled printing with high accuracy. We demonstrate printing multiple patterns on planar surfaces, and considering the non-planar surface of natural organs, we then develop an in situ printing strategy for curved surfaces and demonstrate minimally invasive in vivo bioprinting of hydrogels in a rat model. Our catheter robot will permit intelligent and minimally invasive bio-fabrication.

scholarly journals A New Participant in the Pathogenesis of Alcoholic Gastritis: Pyroptosis

2018 ◽  
Vol 49 (1) ◽  
pp. 406-418 ◽  
Author(s):  
Gang Li ◽  
Lei Zhu ◽  
Zhigang Cao ◽  
Jing Wang ◽  
Fuxin Zhou ◽  
...  
Keyword(s):  
Immunofluorescence Assay ◽  
The Body ◽  
Common Disease ◽  
Internal Organs ◽  
Gastric Mucosal Cells ◽  
Caspase 1 ◽  
Promising Agent ◽  
Mucosal Cells

Background/Aims: Alcohol abuse exerts deleterious effects on the internal organs of the body, and alcohol-related gastritis is a common disease for which prompt treatment is essential to prevent the condition from growing worse. However, the therapeutic methods have some adverse effects. Determining the pathogenic mechanisms of alcoholic gastritis is therefore essential. Methods: The MTT assay was developed in order to determine the optimal concentration of alcohol needed to treat gastric mucosal cells. The effects of alcohol on the gastric mucosal cells were determined by qRT-PCR and western blot. The release of IL-1β and IL-18 were determined by ELISA assay. The immunofluorescence assay was used to detect caspase-1 activation levels, while immunohistochemical assay and HE staining were performed to identify the effectiveness of the caspase-1 inhibitor on alcoholic gastritis. The TUNEL assay was used to determine DNA fragmentation. Results: Here, we clarified that ethanol treatment could cause cell DNA damage, activate caspase-1, and promote the generation and release of IL-1β and IL-18. In other words, ethanol could induce pyroptosis. Interestingly, a caspase-1 inhibitor could significantly suppress pyroptosis, decrease the release of inflammatory cytokines induced by ethanol, and cause no side effects in vivo and in vitro. Conclusion: Collectively, our results showed that pyroptosis is involved in the pathogenesis of alcohol-induced gastritis and that caspase-1 inhibitor Ac-yvad-cmk could effectively decrease the damage caused by alcohol, making it a potentially promising agent for the treatment of alcoholic gastritis.

Imaging Sarcomeres of Extensor Carpi Radialis Brevis in Humans Using Minimally Invasive Microendoscopy

2009 ◽  
Author(s):  
Melinda J. Cromie ◽  
Gabriel N. Sanchez ◽  
Mark J. Schnitzer ◽  
Scott L. Delp
Keyword(s):  
Minimally Invasive ◽  
Fluorescent Dyes ◽  
Second Harmonic ◽  
Human Subjects ◽  
The Body ◽  
Biomechanical Analysis ◽  
Capacity Measurement ◽  
Generating Capacity ◽  
Extensor Carpi Radialis

Sarcomeres are the smallest contractile elements of muscle. Muscle generates force when overlapping myosin and actin filaments within the sarcomere interact to generate force. The amount of force these interactions generate depends on sarcomere length. The range of sarcomere lengths over which a muscle normally operates in the body is an important factor in analyzing a muscle’s force generating capacity. Measurement of sarcomere lengths in vivo is limited by their small size (2–4 μm) and the inability to use fluorescent dyes in humans. We recently developed a microendoscopy system to image sarcomeres in humans via Second Harmonic Generation (SHG) [1]. Here we demonstrate the use of this microendoscopy system as a robust, minimally-invasive tool for biomechanical analysis by measuring sarcomere lengths of the forearm muscle extensor carpi radialis brevis (ECRB) in 5 human subjects.

scholarly journals Fiber-integrated Brillouin microspectroscopy: Towards Brillouin endoscopy

2017 ◽  
Vol 10 (06) ◽  
pp. 1742002 ◽  
Author(s):  
Irina V. Kabakova ◽  
YuChen Xiang ◽  
Carl Paterson ◽  
Peter Török
Keyword(s):  
Optical Fiber ◽  
Brillouin Scattering ◽  
Region Of Interest ◽  
The Body ◽  
Propagation Model ◽  
Micromechanical Characterization ◽  
First Time

Brillouin imaging (BI) for micromechanical characterization of tissues and biomaterials is a fast-developing field of research with a strong potential for medical diagnosis of disease-modified tissues and cells. Although the principles of BI imply its compatibility with in vivo and in situ measurements, the integration of BI with a flexible catheter, capable of reaching the region of interest within the body, is yet to be reported. Here, for the first time, we experimentally investigate integration of the Brillouin spectroscope with standard optical fiber components to achieve a Brillouin endoscope. The performance of single-fiber and dual-fiber endoscopes are demonstrated and analyzed. We show that a major challenge in construction of Brillouin endoscopes is the strong backward Brillouin scattering in the optical fiber and we present a dual-fiber geometry as a possible solution. Measurements of Brillouin spectra in test liquids (water, ethanol and glycerol) are demonstrated using the dual-fiber endoscope and its performance is analyzed numerically with the help of a beam propagation model.

scholarly journals Multimode fibres for micro-endoscopy

2015 ◽  
Vol 2 (1) ◽  
Author(s):  
Sergey Turtaev ◽  
Ivo T. Leite ◽  
Tomáš Čižmár
Keyword(s):  
Minimally Invasive ◽  
In Vivo Imaging ◽  
Beam Shaping ◽  
Optical Fibres ◽  
Fibre Optic ◽  
Methods And Techniques ◽  
On Chip ◽  
Multimode Waveguides

AbstractThere has been a tremendous effort in modern microscopy towards miniaturisation and fibre-based technology, driven by the need to access hostile or difficult environments in situ and in vivo. Most of these rely on reducing the size of endoscopes based on fibre-optic bundles, and systems incorporating microfabricated lenses. Recently, the use of standard multimode optical fibres for lensless microscopy has become possible mainly due to advances in holographic beam shaping. This article reviews the methods and techniques behind this progress paving theway towards minimally invasive in vivo imaging as well as other applications of multimode waveguides including on-chip integration of optical micro-manipulation and numerous other biophotonics techniques.

scholarly journals ABSOLUTE AND RELATIVE BIOAVAILABILITY STUDY FOR THE NEWLY DEVELOPED NASAL NANOEMULSION IN SITU GEL OF ONDANSETRON HCl IN COMPARISON TO CONVENTIONALLY PREPARED IN SITU GEL AND INTRAVENOUS DOSAGES FORMS

2018 ◽  
Vol 10 (5) ◽  
pp. 105
Author(s):  
Nidhal K. Maraie ◽  
Yasser Q. Almajidi ◽  
Ahmed Alshadher
Keyword(s):  
Relative Bioavailability ◽  
The Body ◽  
Absolute Bioavailability ◽  
Pharmacokinetic Studies ◽  
Bioavailability Enhancement ◽  
In Situ Gel ◽  
Bioavailability Study ◽  
The Absolute

Objective: The aim of the work was to study the absolute and relative bioavailability (using rabbits) of ondansetron HCl (ONH)from our newly prepared intranasal mucoadhesive nanoemulsion in situ gel (NIG) in comparison to intranasal mucoadhesive in situ gel (IG) prepared by the conventional method and intravenous injection.Methods: Six male rabbits weighing 2.5-3 kg were used in this study, where the dose of ondansetron HCl (ONH) was calculated based on the body surface area (BSA) which is equivalent to 140μl (containing 10 mg/ml) of NIG and IG and 700μl of intravenous Zofran® injection (containing 2 mg/ml) were given to the rabbits, separated with one week washout period. Serial blood samples were withdrawn and analyzed for simultaneous determination of the drug using HPLC (Knaure; 150 ×4.6 mm; 5 μm particle size; 25 cm length) supported by guard column C18-4 mm diameter.Results: The pharmacokinetics parameters for NIG; Cmax, Tmax, AUC0-t, AUC0-∞were found to be greater than conventional in situ gel (IG). In vivo pharmacokinetic studies in rabbits showed a significant increase in Cmax and AUC 0-α(P<0.001) with shorter Tmaxusing NIG compared to IG containing the same NIG excipients, while the absolute bioavailability for NIG and IG (was 80.541 and 51.068 respectively).Conclusion: The present studies ratify the bioavailability enhancement potential of NE used to prepare NIG for the drug and significantly high absolute bioavailability to be used as a successful alternative route to the IV injection and improve patient compliance.

834 CRISPR-mediated in situ editing of liver resident macrophages for treating liver cancers

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A886-A886
Author(s):  
Zhutian Zeng ◽  
Wei Liu
Keyword(s):  
Immune Responses ◽  
Genome Editing ◽  
Kupffer Cells ◽  
Coli Strain ◽  
The Body ◽  
E Coli ◽  
Liver Macrophage ◽  
Liver Cancers

BackgroundLiver cancer is one of the leading cause of cancer death worldwide with limited treatment options. The liver accommodates the largest population of tissue resident macrophages in the body, namely Kupffer cells. Immune deviation of hepatic immune responses from anti-tumor towards pro-tumor is crucial for cancer progression. This process is closely correlated with the functional polarization of these macrophages. In situ genome editing of liver resident macrophage with intention to shift macrophage function to stimulate anti-tumor immune responses is promising in treating liver cancers.MethodsWe have previously shown that Kupffer cells quickly capture and phagocytose circulating bacteria, making bacteria as a potential liver macrophage-specific deliver vector. Taking advantages of the clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9 technology, we have established a bacteria mediated genome editing methods for liver resident macrophages in vivo.ResultsWe used a non-pathogenic Escherichia coli (E. coli) strain as a deliver vector for the CRISPR-Cas9 plasmids, essentially all liver resident macrophages but neither liver sinusoids endothelial cells nor hepatocytes were shown to taken up the bacteria, indicating the robustness and specificity of E. coli-mediated plasmid delivery. To test the genome editing efficiency, we chose VSIG4, Tim-4 and F4/80 that were highly expressed by Kupffer cells and validated the gene knockout/knockdown effects using intravital imaging. Expression of these receptors by Kupffer cells diminished by more than 90%. Simultaneously editing of multiple genes was also achieved with a slightly decreased efficiency when compared to single gene editing. The acute inflammatory responses and the hepatotoxity caused by bacteria were ameliorated by pre-immunization with the same E. coli strain, and can be further minimized by using a mutant E. coli strain that processed a modified LPS structure, which dramatically decreased the TLR-4 mediated inflammatory signaling and improved the safety of this method. Moreover, we have shown that not only embryonically-derived Kupffer cell but also monocyte-derived liver macrophages could be edited. The applications of this approach in treating primary liver cancers and liver metastasis are under investigation.ConclusionsTaken together, we have established a rapid, efficient and convenient method to achieve in situ genome editing of liver resident macrophages in vivo. By targeting essential genes that instruct macrophage polarization, this method could be used as immunotherapy for liver diseases, including cancers.

scholarly journals Zymography-types, advantages, uses and troubleshooting - A detailed review

2021 ◽  
Vol 12 (3) ◽  
pp. 2190-2199
Author(s):  
Madhu Narayan
Keyword(s):  
Cost Reduction ◽  
Hydrolytic Enzymes ◽  
The Body ◽  
Detailed Review ◽  
Substrate Conversion ◽  
Staining Protocol ◽  
Ponceau S ◽  
In Situ Zymography

There are many methods for the study and quantification of enzymes in the body systems. Off-late, the method of zymography has assumed immense importance in diagnostic medicine. It is a method where enzymes are visualized using the substrate conversion technique. The product of reaction appears, or the substrate disappears and the mechanisms specific for the recognition of this measure the biochemical reaction. This procedure has many advantages, the most important ones being providing both qualitative and measurable data, such as molecular zymography methods for visualising hydrolytic enzymes and differentiating among whole molecules, degradation and complexes. There are three main types of zymography, namely- In-Gel zymography (IGZ), In-Situ zymography (ISZ) and In-vivo zymography (IVZ). There are many variations of this technique like transfer 2D and reverse zymography. This method is mainly used to study the expression of matrix metalloproteinases. Alternate to the conventional zymography techniques have been suggested, like usage of the new Ponceau S staining protocol that provides significant benefits in terms of assay usability and cost reduction and is comparatively faster and easier. Mild alterations in the actual procedure of zymography can take care of minor issues arising during the procedure.

scholarly journals STUDIES ON THE MECHANISM OF IMMUNITY IN TUBERCULOSIS

1939 ◽  
Vol 69 (4) ◽  
pp. 555-578 ◽  
Author(s):  
Max B. Lurie
Keyword(s):  
Guinea Pig ◽  
Guinea Pigs ◽  
Body Fluids ◽  
The Body ◽  
Host Responses ◽  
Tubercle Bacillus ◽  
Internal Organs ◽  
Free Body ◽  
Portal Of Entry

1. The fate of bacilli of reinfection at the portal of entry and in metastatic foci, and also the associated host responses, are essentially similar in rabbits and guinea pigs. 2. However, in the guinea pig tubercle bacilli of reinfection are more effectively fixed at the portal of entry than in the rabbit. 3. The guinea pig fixes at the site of reinfection unrelated substances, such as trypan blue and agar particles, more effectively than the rabbit. 4. At the site of a local non-specific inflammation precipitins from the circulating blood accumulate in higher concentration in tuberculous guinea pigs than in tuberculous rabbits. 5. These differing fixing capacities of the two species are associated with differences of extracellular character in the inflammation resulting from reinfection. (a) In the guinea pig, whose tissues are highly sensitized and greatly injured by the tubercle bacillus, the lymphatics adjoining the site of reinfection become thrombosed. In the rabbit whose tissues are moderately sensitized and less injured by the tubercle bacillus the corresponding lymphatics remain open. (b) In the guinea pig the fibrinous network at the site of inflammation forms a fine sieve-like structure. In the rabbit this network forms a coarse sieve-like barrier. 6. In rabbits and guinea pigs primarily infected, the destruction of tubercle bacilli takes place first and most extensively at the portal of entry. At this time they are less effectively destroyed in the nearest metastatic foci. Simultaneously they are still growing without hinderance in such foci in remote internal organs. 7. The cell-free body fluids of normal animals support the growth of tubercle bacilli in vivo. The body fluids of tuberculous animals under the same conditions are bacteriostatic for this microorganism. 8. Tubercle bacilli often multiply by preliminary subdivision into non-acid-fast granules, from which the acid-fast rods sprout. This confirms the work of Kahn.

In Situ Material Transformations in Tissue Engineering

MRS Bulletin ◽  
1996 ◽  
Vol 21 (11) ◽  
pp. 33-35 ◽  
Author(s):  
Jeffrey A. Hubbell
Keyword(s):  
Tissue Engineering ◽  
Minimally Invasive ◽  
Artery Bypass ◽  
The Body ◽  
Surgical Instruments ◽  
Small Hole ◽  
Thermal Transitions ◽  
Surgical Access ◽  
Minimally Invasive Surgical

Novel applications exist for biomedical materials that can undergo transitions in material properties in situ—that is, at the site of implantation in the body. Such transitions in polymeric biomaterials can be accomplished by crosslinking a material in situ, by heating or cooling to induce thermal transitions, and by precipitating polymer from solution in situ. This article will point out the need for materials that can be induced to undergo such transitions in situ and will describe selected tissue-engineering approaches that have been employed for this purpose.Delivering materials to the body in one form and utilizing them in another form after a transition at the site of implantation has, generally speaking, two potential advantages: (1) the ability to match the morphology of a material implant to a complex tissue shape and (2) the ability to deliver a large device through a small hole in the body. With respect to the former motivation, tissue shapes in the body have an enormous range of complexity: a region of a blood vessel—for example with a curved central axis, a diameter that varies along the length, an eccentric diseased plaque, and numerous side branches. One could develop a variety of implant shapes—arterial stents in this example (for use in structurally supporting arteries after balloon angioplasty, thereby creating a larger cross section for blood flow above the diseased plaque)—and then select the most appropriate implant shape after detailed imaging of the tissue site. One can alternatively attempt to employ some material transformation to deliver a precursor to the final shape of the implant, utilizing the tissue shape to obtain the proper final implant morphology. With regard to the second motivation, it may be desirable to deliver a large object through a small hole, utilizing material transformations. Advances in surgery have focused on manipulating (cutting, coagulating, suturing, stapling) large tissue sites through small holes in the body via minimally invasive surgery. Using such approaches, it has become possible to perform many complex surgical procedures in the joints, abdominopelvic cavity, thoracic cavity, and nasal sinuses, for example, using surgical instruments that are manipulated through surgical access holes less than 1 cm in diameter. Even procedures as complex as coronary-artery bypass surgery have been performed in this way. It still remains generally impossible however to implant devices in the body through such holes unless these implants are very small. If such devices were for example able to be delivered as liquids and then shaped into devices at the implant site, such minimally invasive surgical-device placement could be envisioned.

scholarly journals Potentially toxic metallic wear nanoparticles and trace metal ions release from metal-on-metal orthopedic implants in the human biological specimens: An Overview of in vivo and ex vivo clinical studies

2020 ◽  
Vol 8 (3) ◽  
pp. 242-292
Author(s):  
Henryk Matusiewicz ◽  
Magdalena Richter
Keyword(s):  
Trace Metal ◽  
Metal Ions ◽  
Ex Vivo ◽  
Orthopedic Implants ◽  
The Body ◽  
Trace Metal Ions ◽  
Bodily Fluids ◽  
Metal On Metal

The use of metallic biomaterials in the medical implant devices has become increasingly prevalent over the past few decades. Patients find themselves being exposed to metals in a variety of ways, ranging from external exposure to instruments such as medical devices to internal exposure via surgical devices being implanted in their bodies. In situ generation of metallic wear nanoparticles, corrosion products and in vivo trace metal ions release from metal and metallic alloys implanted into the body in orthopedic surgery is becoming a major cause for concern regarding the health and safety of patients. The chemical form, particulate vs. ionic, of the metal species in the bodily fluids and tissues is a key to the local nanotoxicity effects arising in the body. Potential health risks are associated with metallic wear debris in the form of nanoparticles in situ generation and the release of in vivo trace metal ions into human biological specimen's circulation. This overview explores how migration of metallic wear nanoparticles and ultratrace metal ions in the area of metal-on-metal orthopedic implants influences the surrounding tissues and bodily fluids, and what the toxicological consequences of this process may be. Specifically, the present article is more informative of indicative multilevel in situ/in vivo/ex vivo analytical/clinical methodologies which will be helpful in a way to plan, understand and lead the analytical innovations in the area of nano-analysis to improve patient outcomes.

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