scholarly journals Efficacy and safety of a thermosensitive hydrogel for endoscopic submucosal dissection: An in vivo swine study

PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0260458
Author(s):  
Han Jo Jeon ◽  
Hyuk Soon Choi ◽  
Eun Ju Bang ◽  
Kang Won Lee ◽  
Sang Hyun Kim ◽  
...  
Keyword(s):  
Hyaluronic Acid ◽  
Normal Saline ◽  
Muscularis Propria ◽  
Efficacy And Safety ◽  
Clinical Implementation ◽  
En Bloc ◽  
Thermosensitive Hydrogel ◽  
Chitosan Hydrogel ◽  
Chitosan Hydrogels

Injectable thermo-sensitive chitosan hydrogels have recently been developed for the use of submucosal fluids in endoscopic submucosal dissections (ESD). This study aimed to investigate the efficacy and safety of chitosan hydrogels during ESD. Submucosal fluids were administered as follows: 0.9% normal saline (NS), 0.4% hyaluronic acid (HA) and chitosan/β-glycerophosphate (CS/GP) hydrogel. Each solution was administered twice into the stomach and colon of a pig, with a total of 72 ESD procedures performed on 12 pigs. The injected volume and procedure-related parameters were recorded and analyzed. ESDs that created ulcers after 7 days were histologically compared. All ESD specimens were resected en bloc. The total injected volumes during ESD of the stomach (NS, 16.09±3.27 vs. HA, 11.17±2.32 vs. CS/GP, 9.44±2.33; p<0.001) and colon (NS, 9.17±1.80 vs. HA, 6.67±1.50 vs. CS/GP, 6.75±1.57; p = 0.001) were significantly different. Hydrogel showed significant differences from normal saline in terms of fluid power (mm2/vol; NS, 35.70±9.00 vs. CS/GP 57.48±20.77; p = 0.001) and consumption rate (vol/min; NS, 2.59±0.86 vs. CS/GP, 1.62±0.65; p = 0.013) in the stomach. Histological examination revealed preserved muscularis propria, although the chitosan hydrogel resulted in a partial inflammatory response, with a hypertrophied submucosal layer. Chitosan hydrogel was found to be superior to normal saline, with an efficacy similar to that of hyaluronic acid. Nonetheless, long-term histological changes should be evaluated before clinical implementation.

scholarly journals Yb3+-containing chitosan hydrogels induce B-16 melanoma cell anoikis via a Fak-dependent pathway

2019 ◽  
Vol 8 (1) ◽  
pp. 645-660 ◽  
Author(s):  
Yu Miao ◽  
Jiawei Lu ◽  
Junhui Yin ◽  
Changchun Zhou ◽  
Yaping Guo ◽  
...  
Keyword(s):  
Acetic Acid Solution ◽  
Tumor Model ◽  
In Vivo Studies ◽  
High Recurrence Rate ◽  
Mixed Solution ◽  
Chitosan Hydrogel ◽  
Chitosan Hydrogels ◽  
Dermal Cells

AbstractMelanoma is the most lethal dermal tumor, and a high recurrence rate and skin defects are two main serious problems. An antimelanoma material,which effectively inhibits tumor recurrence and possesses excellent biocompatibility, is urgently needed to treat melanoma. In this study, we developed a novel antitumor Yb3+ [Yb(NO3)3]containing chitosan hydrogel (Yb-CS hydrogel) by dissolving Yb(NO3)3 and chitosan in acetic acid solution and forming composite hydrogels by a freeze-drying process after adding NaOH to the mixed solution. In vitro studies demonstrated that the Yb3+ produces effect of inducing cell death in Yb-CS hydrogel. Moreover, we found that the Yb-CS hydrogel inhibited a focal adhesion kinase (FAK)-dependent signaling pathway and induced B-16 cell anoikis. However, the Yb-CS hydrogel was less effective on L929 normal mouse dermal cells. In vivo studies showed that the Yb-CS hydrogel inhibited the recurrence of melanoma in a mouse bare xenograft tumor model. We concluded that the Yb-CS hydrogel could potentially be used in the antimelanoma field, especially in the inhibition of melanoma recurrence.

scholarly journals Efficacy and safety of a combination of hyaluronic acid, chondroitin sulfate, and poloxamer 407 as a submucosal injection solution for endoscopic resection: pilot study on a swine model

2017 ◽  
Vol 05 (06) ◽  
pp. E450-E454 ◽  
Author(s):  
G. Fernández-Esparrach ◽  
M. Cuatrecasas ◽  
C. Rodríguez de Miguel ◽  
C. Sánchez-Montes ◽  
H. Córdova
Keyword(s):  
Hyaluronic Acid ◽  
Chondroitin Sulfate ◽  
Endoscopic Resection ◽  
Muscularis Propria ◽  
Poloxamer 407 ◽  
In Vivo Model ◽  
Swine Model ◽  
Injection Solution ◽  
Submucosal Injection

Abstract Background and aims Endoscopic resection techniques require use of submucosal injection. The aim of this study was to assess a new solution that combines hyaluronic acid, chondroitin sulfate, and poloxamer 407 for submucosal injection. Methods A total of 48 gastric submucosal cushions were created in fresh porcine stomachs using gelafundin (n = 16) or the new solution diluted at 50 % (n = 16), or 80 % (n = 16). The duration of mucosal elevation was measured. In an in vivo model, 10 gastric submucosal cushions were created by injecting 2 mL of the new solution at 80 % and the animal was euthanized 30 minutes after the last injection. Results Submucosal cushions with the new solution at 80 % and 50 % concentration lasted longer than with gelafundin (23.13 ± 15.57, 13.1 ± 6.6, 3.94 ± 1.53 minutes, respectively; P = 0.000). In the in vivo study, no damage or necrosis was observed in the mucosa or muscularis propria. Conclusion The combination of hyaluronic acid, chondroitin sulfate, and poloxamer 407 produces a long-lasting submucosal cushion and does not seem to induce acute damage in the tissue making it suitable for submucosal injection.

scholarly journals Influence of Chitosan or Keratin on Titanium Implant Surface - A Systematic Review

2020 ◽  
pp. 1-12
Author(s):  
Robert Love ◽  
Eliza Ranjit ◽  
Ajay Sharma ◽  
Stephen Hamlet ◽  
Roy George ◽  
...  
Keyword(s):  
Systematic Review ◽  
Dental Implant ◽  
Science Studies ◽  
Titanium Implant ◽  
Biological Properties ◽  
Implant Surface ◽  
Chitosan Hydrogel ◽  
Chitosan Hydrogels

Purpose: This systematic review was carried out to investigate the effects of keratin and chitosan hydrogel preparations on dental implant osseointegration. Materials and Methods: The electronic search was conducted on five databases: Scopus, EBSCOhost MEDLINE, EBSCOhost Dentistry and Oral Science, PubMed, and Web of Science. Studies that determined the in vitro or in vivo efficacy of keratin and chitosan hydrogel on osseointegration were included in the review. Results: Of the 760 studies initially gathered, nine met the inclusion criteria. These studies demonstrated that dental implants coated with keratin and chitosan hydrogels resulted in improved biological properties. It was also concluded that the inclusion of chitosan in keratin hydrogels improves the mechanical strength and helps increase durability through ameliorating degradation and swelling characters. Both the polymers increased bone-implant contact and new bone formation in animal models. Conclusion: This systematic review demonstrates that keratin and chitosan hydrogel, is effective in initiating osteogenesis, reinforcing the currently available evidence that these polymers could be a substrate in dental implant treatment.

Osseointegration interface of calcified bone and endosseous implants

1992 ◽  
Vol 50 (2) ◽  
pp. 1096-1097
Author(s):  
K.E. Krizan ◽  
J.E. Laffoon ◽  
M.J. Buckley
Keyword(s):  
Structure And Function ◽  
Titanium Implants ◽  
En Bloc ◽  
Endosseous Implants ◽  
Ultrastructural Studies ◽  
The Past ◽  
Cacodylate Buffer ◽  
One Year ◽  
And Function

With increase use of tissue-integrated prostheses in recent years it is a goal to understand what is happening at the interface between haversion bone and bulk metal. This study uses electron microscopy (EM) techniques to establish parameters for osseointegration (structure and function between bone and nonload-carrying implants) in an animal model. In the past the interface has been evaluated extensively with light microscopy methods. Today researchers are using the EM for ultrastructural studies of the bone tissue and implant responses to an in vivo environment. Under general anesthesia nine adult mongrel dogs received three Brånemark (Nobelpharma) 3.75 × 7 mm titanium implants surgical placed in their left zygomatic arch. After a one year healing period the animals were injected with a routine bone marker (oxytetracycline), euthanized and perfused via aortic cannulation with 3% glutaraldehyde in 0.1M cacodylate buffer pH 7.2. Implants were retrieved en bloc, harvest radiographs made (Fig. 1), and routinely embedded in plastic. Tissue and implants were cut into 300 micron thick wafers, longitudinally to the implant with an Isomet saw and diamond wafering blade [Beuhler] until the center of the implant was reached.

Kinetics of Various 99mTc-Sn-Pyrophosphate Compounds in the Rat

1977 ◽  
Vol 16 (04) ◽  
pp. 157-162 ◽  
Author(s):  
C. Schümichen ◽  
B. Mackenbrock ◽  
G. Hoffmann
Keyword(s):  
Normal Saline ◽  
Half Life ◽  
Compound A ◽  
Short Half Life ◽  
Low Concentrations ◽  
The Stability ◽  
Kinetics Of ◽  
In Vitro Stability

SummaryThe bone-seeking 99mTc-Sn-pyrophosphate compound (compound A) was diluted both in vitro and in vivo and proved to be unstable both in vitro and in vivo. However, stability was much better in vivo than in vitro and thus the in vitro stability of compound A after dilution in various mediums could be followed up by a consecutive evaluation of the in vivo distribution in the rat. After dilution in neutral normal saline compound A is metastable and after a short half-life it is transformed into the other 99mTc-Sn-pyrophosphate compound A is metastable and after a short half-life in bone but in the kidneys. After dilution in normal saline of low pH and in buffering solutions the stability of compound A is increased. In human plasma compound A is relatively stable but not in plasma water. When compound B is formed in a buffering solution, uptake in the kidneys and excretion in urine is lowered and blood concentration increased.It is assumed that the association of protons to compound A will increase its stability at low concentrations while that to compound B will lead to a strong protein bond in plasma. It is concluded that compound A will not be stable in vivo because of a lack of stability in the extravascular space, and that the protein bond in plasma will be a measure of its in vivo stability.

Aspiration Revisited: Prospective Evaluation of a Physiologically Pressurized Model With Animal Correlation and Broader Applicability to Filler Complications

2021 ◽  
Author(s):  
Hyoung-Jin Moon ◽  
Won Lee ◽  
Ji-Soo Kim ◽  
Eun-Jung Yang ◽  
Hema Sundaram
Keyword(s):  
Normal Saline ◽  
False Negative ◽  
Vascular Complications ◽  
Filler Injection ◽  
Negative Results ◽  
Needle Position ◽  
False Negative Results ◽  
In Vivo Testing

Abstract Background Aspiration testing before filler injection is controversial. Some believe that aspiration can help prevent inadvertent intravascular injection, while others cite false-negative results and question its value given that the needle position always changes somewhat during injection procedures. Objectives To test the relation of false-negative results to the viscosity of the material within the needle lumen and determine whether a less viscous material within the needle lumen could decrease the incidence of false-negative results. Methods In vitro aspiration tests were performed using 30-G and 27-G needle gauges, two cross-linked hyaluronic acid fillers, normal saline bags pressurized at 140 and 10 mmHg to mimic human arterial and venous pressures, and three needle lumen conditions (normal saline, air, and filler). Testing was repeated three times under each study condition (72 tests in total). For in vivo correlation, aspiration tests were performed on femoral arteries and central auricular veins in three rabbits (4–5 aspirations per site, 48 tests in total). Results In vitro and in vivo testing using 30-G needles containing filler both showed false-negative results on aspiration testing. In vitro and in vivo testing using needles containing saline or air showed positive findings. Conclusions False-negative results from aspiration testing may be reduced by pre-filling the needle lumen with saline rather than a filler. The pressurized system may help overcome challenges of animal models with intravascular pressures significantly different from those of humans. The adaptability of this system to mimic various vessel pressures may facilitate physiologically relevant studies of vascular complications.

Terephthalaldehyde as better crosslinking agent in crosslinked chitosan hydrogel for selective removal of anionic dyes

2021 ◽  
Author(s):  
Madhvi Garg ◽  
Navneet Bhullar ◽  
Bharat Bajaj ◽  
Dhiraj Sud
Keyword(s):  
Crosslinking Agent ◽  
Selective Removal ◽  
Synthetic Dyes ◽  
Anionic Dyes ◽  
Chitosan Hydrogel ◽  
Ultrasound Radiation ◽  
Radiation Induced ◽  
Crosslinked Chitosan ◽  
Chitosan Hydrogels ◽  
Crosslinking Agents

The present manuscript reports the ultrasound radiation induced synthesis of grafted chitosan hydrogels (CAAT and CAAG) using terephthalaldehyde/glutaraldehyde as crosslinking agents and its application for removal of synthetic dyes from...

scholarly journals Secreted KIAA1199 promotes the progression of rheumatoid arthritis by mediating hyaluronic acid degradation in an ANXA1-dependent manner

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Wei Zhang ◽  
Guoyu Yin ◽  
Heping Zhao ◽  
Hanzhi Ling ◽  
Zhen Xie ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Hyaluronic Acid ◽  
Dependent Manner ◽  
Collagen Induced Arthritis ◽  
Intracellular Degradation ◽  
Main Pathway ◽  
First Time

AbstractIn inflamed joints, enhanced hyaluronic acid (HA) degradation is closely related to the pathogenesis of rheumatoid arthritis (RA). KIAA1199 has been identified as a hyaladherin that mediates the intracellular degradation of HA, but its extracellular function remains unclear. In this study, we found that the serum and synovial levels of secreted KIAA1199 (sKIAA1199) and low-molecular-weight HA (LMW-HA, MW < 100 kDa) in RA patients were significantly increased, and the positive correlation between them was shown for the first time. Of note, treatment with anti-KIAA1199 mAb effectively alleviated the severity of arthritis and reduced serum LMW-HA levels and cytokine secretion in collagen-induced arthritis (CIA) mice. In vitro, sKIAA1199 was shown to mediate exogenous HA degradation by attaching to the cell membrane of RA fibroblast-like synoviosytes (RA FLS). Furthermore, the HA-degrading activity of sKIAA1199 depended largely on its adhesion to the membrane, which was achieved by its G8 domain binding to ANXA1. In vivo, kiaa1199-KO mice exhibited greater resistance to collagen-induced arthritis. Interestingly, this resistance could be partially reversed by intra-articular injection of vectors encoding full-length KIAA1199 instead of G8-deleted KIAA119 mutant, which further confirmed the indispensable role of G8 domain in KIAA1199 involvement in RA pathological processes. Mechanically, the activation of NF-κB by interleukin-6 (IL-6) through PI3K/Akt signaling is suggested to be the main pathway to induce KIAA1199 expression in RA FLS. In conclusion, our study supported the contribution of sKIAA1199 to RA pathogenesis, providing a new therapeutic target for RA by blocking sKIAA1199-mediated HA degradation.

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