scholarly journals A Wireless Implantable System for Facilitating Gastrointestinal Motility

Micromachines ◽  
2019 ◽  
Vol 10 (8) ◽  
pp. 525
Author(s):  
Po-Min Wang ◽  
Genia Dubrovsky ◽  
James C.Y. Dunn ◽  
Yi-Kai Lo ◽  
Wentai Liu

Gastrointestinal (GI) electrical stimulation has been shown in several studies to be a potential treatment option for GI motility disorders. Despite the promising preliminary research progress, however, its clinical applicability and usability are still unknown and limited due to the lack of a miniaturized versatile implantable stimulator supporting the investigation of effective stimulation patterns for facilitating GI dysmotility. In this paper, we present a wireless implantable GI modulation system to fill this technology gap. The system consists of a wireless extraluminal gastrointestinal modulation device (EGMD) performing GI electrical stimulation, and a rendezvous device (RD) and a custom-made graphical user interface (GUI) outside the body to wirelessly power and configure the EGMD to provide the desired stimuli for modulating GI smooth muscle activities. The system prototype was validated in bench-top and in vivo tests. The GI modulation system demonstrated its potential for facilitating intestinal transit in the preliminary in vivo chronic study using porcine models.

2008 ◽  
Vol 2008 ◽  
pp. 1-10 ◽  
Author(s):  
J. A. Zhou ◽  
S. J. Woo ◽  
S. I. Park ◽  
E. T. Kim ◽  
J. M. Seo ◽  
...  

This article reports on a retinal stimulation system for long-term use in animal electrical stimulation experiments. The presented system consisted of an implantable stimulator which provided continuous electrical stimulation, and an external component which provided preset stimulation patterns and power to the implanted stimulator via a paired radio frequency (RF) coil. A rechargeable internal battery and a parameter memory component were introduced to the implanted retinal stimulator. As a result, the external component was not necessary during the stimulation mode. The inductive coil pair was used to pass the parameter data and to recharge the battery. A switch circuit was used to separate the stimulation mode from the battery recharging mode. The implantable stimulator was implemented with IC chips and the electronics, except for the stimulation electrodes, were hermetically packaged in a biocompatible metal case. A polyimide-based gold electrode array was used. Surgical implantation into rabbits was performed to verify the functionality and safety of this newly designed system. The electrodes were implanted in the suprachoroidal space. Evoked cortical potentials were recorded during electrical stimulation of the retina. Long-term follow-up using OCT showed no chorioretinal abnormality after implantation of the electrodes.


2012 ◽  
Vol 82 (3) ◽  
pp. 228-232 ◽  
Author(s):  
Mauro Serafini ◽  
Giuseppa Morabito

Dietary polyphenols have been shown to scavenge free radicals, modulating cellular redox transcription factors in different in vitro and ex vivo models. Dietary intervention studies have shown that consumption of plant foods modulates plasma Non-Enzymatic Antioxidant Capacity (NEAC), a biomarker of the endogenous antioxidant network, in human subjects. However, the identification of the molecules responsible for this effect are yet to be obtained and evidences of an antioxidant in vivo action of polyphenols are conflicting. There is a clear discrepancy between polyphenols (PP) concentration in body fluids and the extent of increase of plasma NEAC. The low degree of absorption and the extensive metabolism of PP within the body have raised questions about their contribution to the endogenous antioxidant network. This work will discuss the role of polyphenols from galenic preparation, food extracts, and selected dietary sources as modulators of plasma NEAC in humans.


Author(s):  
А.А. Раецкая ◽  
С.В. Калиш ◽  
С.В. Лямина ◽  
Е.В. Малышева ◽  
О.П. Буданова ◽  
...  

Цель исследования. Доказательство гипотезы, что репрограммированные in vitro на М3 фенотип макрофаги при введении в организм будут существенно ограничивать развитие солидной карциномы in vivo . Методика. Рост солидной опухоли инициировали у мышей in vivo путем подкожной инъекции клеток карциномы Эрлиха (КЭ). Инъекцию макрофагов с нативным М0 фенотипом и с репрограммированным M3 фенотипом проводили в область формирования солидной КЭ. Репрограммирование проводили с помощью низких доз сыворотки, блокаторов факторов транскрипции STAT3/6 и SMAD3 и липополисахарида. Использовали две схемы введения макрофагов: раннее и позднее. При раннем введении макрофаги вводили на 1-е, 5-е, 10-е и 15-е сут. после инъекции клеток КЭ путем обкалывания макрофагами с четырех сторон область развития опухоли. При позднем введении, макрофаги вводили на 10-е, 15-е, 20-е и 25-е сут. Через 15 и 30 сут. после введения клеток КЭ солидную опухоль иссекали и измеряли ее объем. Эффект введения макрофагов оценивали качественно по визуальной и пальпаторной характеристикам солидной опухоли и количественно по изменению ее объема по сравнению с группой без введения макрофагов (контроль). Результаты. Установлено, что M3 макрофаги при раннем введении от начала развития опухоли оказывают выраженный антиопухолевый эффект in vivo , который был существенно более выражен, чем при позднем введении макрофагов. Заключение. Установлено, что введение репрограммированных макрофагов M3 ограничивает развитие солидной карциномы в экспериментах in vivo . Противоопухолевый эффект более выражен при раннем введении М3 макрофагов. Обнаруженные в работе факты делают перспективным разработку клинической версии биотехнологии ограничения роста опухоли, путем предварительного программирования антиопухолевого врожденного иммунного ответа «в пробирке». Aim. To verify a hypothesis that macrophages reprogrammed in vitro to the M3 phenotype and injected into the body substantially restrict the development of solid carcinoma in vivo . Methods. Growth of a solid tumor was initiated in mice in vivo with a subcutaneous injection of Ehrlich carcinoma (EC) cells. Macrophages with a native M0 phenotype or reprogrammed towards the M3 phenotype were injected into the region of developing solid EC. Reprogramming was performed using low doses of serum, STAT3/6 and SMAD3 transcription factor blockers, and lipopolysaccharide. Two schemes of macrophage administration were used: early and late. With the early administration, macrophages were injected on days 1, 5, 10, and 15 following the injection of EC cells at four sides of the tumor development area. With the late administration, macrophages were injected on days 10, 15, 20, and 25. At 15 and 30 days after the EC cell injection, the solid tumor was excised and its volume was measured. The effect of macrophage administration was assessed both qualitatively by visual and palpation characteristics of solid tumor and quantitatively by changes in the tumor volume compared with the group without the macrophage treatment. Results. M3 macrophages administered early after the onset of tumor development exerted a pronounced antitumor effect in vivo , which was significantly greater than the antitumor effect of the late administration of M3 macrophages. Conclusion. The observed significant inhibition of in vivo growth of solid carcinoma by M3 macrophages makes promising the development of a clinical version of the biotechnology for restriction of tumor growth by in vitro pre-programming of the antitumor, innate immune response.


2020 ◽  
Author(s):  
Johannes Karges ◽  
Shi Kuang ◽  
Federica Maschietto ◽  
Olivier Blacque ◽  
Ilaria Ciofini ◽  
...  

<div>The use of photodynamic therapy (PDT) against cancer has received increasing attention overthe recent years. However, the application of the currently approved photosensitizers (PSs) is somehow limited by their poor aqueous solubility, aggregation, photobleaching and slow clearance from the body. To overcome these limitations, there is a need for the development of new classes of PSs with ruthenium(II) polypyridine complexes currently gaining momentum. However, these compounds generally lack significant absorption in the biological spectral window, limiting their application to treat deep-seated or large tumors. To overcome this drawback, ruthenium(II) polypyridine complexes designed in silico with (E,E’)-4,4´-bisstyryl 2,2´-bipyridine ligands showed impressive 1- and 2-Photon absorption up to a magnitude higher than the ones published so far. While non-toxic in the dark, these compounds were found phototoxic in various 2D monolayer cells, 3D multicellular tumor spheroids and be able to eradicate a multiresistant tumor inside a mouse model upon clinically relevant 1-Photon and 2 Photon excitation.</div>


Author(s):  
Pavani C H

Hyperlipidemia is the immediate results of the excessive fat intake in food. This results in the elevated levels of cholesterol and triglycerides in the blood. This leads to heart conditions like CAD, hypertension, congestive heart failure as risk factors which can be lethal. There are many drugs to treat and control the lipids levels in the body. These drugs are either designed to prevent LDL accumulation and VLDL synthesis. Some drugs also lower the elevated levels of saturated lipids in the body. But many drugs are known to cause side effects and adverse effects; therefore, alternatives to the drugs are the subjects for current investigations. Herbs and medicinal plants are used as treatment sources for many years. They have been used in the Indian medical systems like Ayurveda, Siddha etc. As the application of herbs in the treatment is growing, there is an urgent need for the establishment of Pharmacological reasoning and standardization of the activity of the medicinal plants. Chloris paraguaiensis Steud. is Poyaceae member that is called locally as Uppugaddi. Traditionally it is used to treat Rheumatism, Diabetes, fever and diarrhoea. The chemical constituents are known to have anti-oxidant properties and most of the anti-oxidants have anti-hyperlipidemic activity too. Since the plant has abundant flavonoid and phenol content, the current research focusses on the investigation of the anti-hyperlipidemic activity of the plant Chloris extracts. Extracts of Chloris at 200mg/kg showed a comparably similar anti hyperlipidemia activity to that of the standard drug. The extracts showed a dose based increase in the activity at 100 and 200mg/kg body weight.


Author(s):  
Bhavani J ◽  
Sunil Kumar Prajapati ◽  
Ravichandran S

Cancer is assemblage diseases involving abnormal cell growth amid the potential of spread to other parts of the body due to tobacco use are the cause of about of cancer deaths. Another 10% is due to obesity, poor diet & drinking alcohol. In 2012 about 14.1 million new cases of cancer occurred globally. In females, the most common type is breast cancer. Cisplatin also known as cytophosphane is a nitrogen mustard alkylating agent from the oxazophosphinans groups were used to treat cancers & autoimmune disorders. Based on the above reasons I will fix the aim Preparation characterization of Cisplatin- nano particles  &  its anticancer activity. Solid tumor volume examination report showed that the assessment of different day indication 15,20,25 & 30th variations of different groups of tumor volumes were decreased CPG Nanoparticles (100 mg/kg)+ DAL(15th day 4.97±0.24↓), (20th day 0.6±0.13↓), (25th day 1.35±0.30↓) & (30th day 1.89±0.13↓).


Author(s):  
Tamilarasi G P ◽  
Sabarees G

Oxidation is an essential reaction in the human body, which determines the expression of proteins in the body. This results in the altered expression like rapid growth resulting in cancers and other disorders. Many synthetic drugs are available in the market that is effective in limiting the free radical generation and the reaction of radicals with cells. Unfortunately, all those synthetic drugs were found to cause side effects and adverse effects in the body. But given the accuracy of the predictability of the results and administration, this research focuses on testing the anti-oxidant efficiency in rat models testing the biochemical parameters. Investigations have also been done on the anti-oxidant activity of Tectona, but every research was concentrated to prove the anti-oxidant activity only. extract had been tested for anti-oxidant activity by estimating various tissue parameters and it showed better activity. As predicted, there is a significant difference in the and results which can be explained are due to the physiological conditions that exist inside the body.


2020 ◽  
Vol 26 (45) ◽  
pp. 5783-5792
Author(s):  
Kholood Abid Janjua ◽  
Adeeb Shehzad ◽  
Raheem Shahzad ◽  
Salman Ul Islam ◽  
Mazhar Ul Islam

There is compelling evidence that drug molecules isolated from natural sources are hindered by low systemic bioavailability, poor absorption, and rapid elimination from the human body. Novel approaches are urgently needed that could enhance the retention time as well as the efficacy of natural products in the body. Among the various adopted approaches to meet this ever-increasing demand, nanoformulations show the most fascinating way of improving the bioavailability of dietary phytochemicals through modifying their pharmacokinetics and pharmacodynamics. Curcumin, a yellowish pigment isolated from dried ground rhizomes of turmeric, exhibits tremendous pharmacological effects, including anticancer activities. Several in vitro and in vivo studies have shown that curcumin mediates anticancer effects through the modulation (upregulation and/or downregulations) of several intracellular signaling pathways both at protein and mRNA levels. Scientists have introduced multiple modern techniques and novel dosage forms for enhancing the delivery, bioavailability, and efficacy of curcumin in the treatment of various malignancies. These novel dosage forms include nanoparticles, liposomes, micelles, phospholipids, and curcumin-encapsulated polymer nanoparticles. Nanocurcumin has shown improved anticancer effects compared to conventional curcumin formulations. This review discusses the underlying molecular mechanism of various nanoformulations of curcumin for the treatment of different cancers. We hope that this study will make a road map for preclinical and clinical investigations of cancer and recommend nano curcumin as a drug of choice for cancer therapy.


2020 ◽  
Vol 21 (13) ◽  
pp. 996-1008
Author(s):  
Mengli Wang ◽  
Qiuzheng Du ◽  
Lihua Zuo ◽  
Peng Xue ◽  
Chao Lan ◽  
...  

Background: As a new tumor therapy, targeted therapy is becoming a hot topic due to its high efficiency and low toxicity. Drug effects of targeted tumor drugs are closely related to pharmacokinetics, so it is important to understand their distribution and metabolism in vivo. Methods: A systematic review of the literature on the metabolism and distribution of targeted drugs over the past 20 years was conducted, and the pharmacokinetic parameters of approved targeted drugs were summarized in combination with the FDA's drug instructions. Targeting drugs are divided into two categories: small molecule inhibitors and monoclonal antibodies. Novel targeting drugs and their mechanisms of action, which have been developed in recent years, are summarized. The distribution and metabolic processes of each drug in the human body are reviewed. Results: In this review, we found that the distribution and metabolism of small molecule kinase inhibitors (TKI) and monoclonal antibodies (mAb) showed different characteristics based on the differences of action mechanism and molecular characteristics. TKI absorbed rapidly (Tmax ≈ 1-4 h) and distributed in large amounts (Vd > 100 L). It was mainly oxidized and reduced by cytochrome P450 CYP3A4. However, due to the large molecular diameter, mAb was distributed to tissues slowly, and the volume of distribution was usually very low (Vd < 10 L). It was mainly hydrolyzed and metabolized into peptides and amino acids by protease hydrolysis. In addition, some of the latest drugs are still in clinical trials, and the in vivo process still needs further study. Conclusion: According to the summary of the research progress of the existing targeting drugs, it is found that they have high specificity, but there are still deficiencies in drug resistance and safety. Therefore, the development of safer and more effective targeted drugs is the future research direction. Meanwhile, this study also provides a theoretical basis for clinical accurate drug delivery.


2020 ◽  
Vol 17 (1) ◽  
pp. 33-39
Author(s):  
Karen C. Vargas-Castro ◽  
Ana M. Puebla Pérez ◽  
Irma I. Rangel-Salas ◽  
Jorge I. Delgado-Saucedo ◽  
José B. Pelayo-Vázquez ◽  
...  

Background: In the therapy of cancer, several treatments have been designed using nanomaterials, among which gold nanoparticles (AuNPs) have been featured as a promising antitumoral agent. Our research group has developed the synthesis of gold nanoparticles L-AuNPs and D-AuNPs stabilized with zwitterions of imidazolium (L-1 and D-1) derived from L-methionine and D-methionine. Because the stabilizer agent is chiral, we observed through circular dichroism that AuNPs also present chirality; such chirality as well as the fact that the stabilizing agent contains fragments of methionine and imidazolium that are commonly involved in biological processes, opens up the possibility that this system may have biological compatibility. Additionally, the presence of methionine in the stabilizing agent opens the application of this system as a possible antitumor agent because methionine is involved in methylation processes of molecules such as DNA. Objective: The aim of this research is the evaluation of the antitumor activity of gold nanoparticles stabilized with zwitterions of imidazolium (L-AuNPs) derived from L-methionine in the model of BALB/c mice with lymphoma L5178Y. Methods: Taking as a parameter cell density, the evaluation of the inhibitory effect of L-AuNPs was carried out with a series of in vivo tests in BALB/c type mice; three groups of five mice each were formed (Groups 1, 2 and 3); all mice were i.p. inoculated with the lymphoblast murine L5178Y. Group 1 consisted of mice without treatment. In the Groups 2 and 3 the mice were treated with L-AuNPs at 0.3 mg/Kg on days 1, 7 and 14 by orally and intraperitonally respectively. Results: These results show low antitumor activity of these gold nanoparticles (L-NPsAu) but interestingly, the imidazolium stabilizing agent of gold nanoparticle (L-1) displayed promising antitumor activity. On the other hand, the enantiomer of L-1, (D-1) as well as asymmetric imidazole derivate from L-methionine (L-2), do not exhibit the same activity as L-1. Conclusion: The imidazolium stabilizing agent (L-1) displayed promising antitumor activity. Modifications in the structure of L-1 showed that, the stereochemistry (like D-1) and the presence of methionine fragments (like L-2) are determinants in the antitumor activity of this compound.


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