The Experts below are selected from a list of 6045 Experts worldwide ranked by ideXlab platform
Michael J. Cima - One of the best experts on this subject based on the ideXlab platform.
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continuous intravesical lidocaine treatment for interstitial cystitis bladder pain syndrome safety and efficacy of a new Drug Delivery Device
Science Translational Medicine, 2012Co-Authors: Curtis J Nickel, Pankaj Jain, Neal Shore, Jessica K Anderson, Dennis Giesing, Karen Daniel, Suellen White, Cheryl Larriveeelkins, Julie Lekstromhimes, Michael J. CimaAbstract:Limited treatment options exist for patients who suffer from a painful bladder condition known as interstitial cystitis/bladder pain syndrome (IC/BPS). Whether given systemically (orally) or by short-duration (1 to 2 hours) exposure via intravesical instillation, therapeutic agents have exhibited poor efficacy because their concentrations in the bladder are low. A previous attempt to develop a Drug Delivery Device for use in the bladder was unsuccessful, likely as a result of poor tolerability. A continuous lidocaine-releasing intravesical system (LiRIS) was designed to be retained in the bladder and release therapeutic amounts of the Drug into urine over a period of 2 weeks. The Device was tested in healthy volunteers and IC/BPS patients and was found to be well tolerated in both subject groups because of its small size and freedom of movement within the bladder. The 16 women with IC/BPS who were enrolled in the study met the National Institute of Diabetes and Digestive and Kidney Diseases criteria for bladder hemorrhages or Hunner’s lesions. Subjects received either LiRIS 200 mg or LiRIS 650 mg for 2 weeks. Safety, efficacy, cystoscopic appearance of the bladder, and limited pharmacokinetic data were collected. Both doses were well tolerated, and clinically meaningful reductions were seen in pain, urgency, voiding frequency, and disease questionnaires. Cystoscopic examinations showed improvement on day 14 (day of removal) compared with day 1, including resolution of Hunner’s lesions in five of six subjects with baseline lesions. Global response assessment showed an overall responder rate of 64% at day 14 and a sustained overall responder rate of 64% 2 weeks later. Extended follow-up suggests that the reduction in pain was maintained for several months after the Device was removed.
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intracranial microcapsule Drug Delivery Device for the treatment of an experimental gliosarcoma model
Biomaterials, 2011Co-Authors: Alexander W Scott, R. Langer, Betty Tyler, Byron Masi, Urvashi Upadhyay, Yoda R Patta, Rachel Grossman, Luca Basaldella, Henry Brem, Michael J. CimaAbstract:Abstract Controlled-release Drug Delivery systems are capable of treating debilitating diseases, including cancer. Brain cancer, in particular glioblastoma multiforme (GBM), is an extremely invasive cancer with a dismal prognosis. The use of Drugs capable of crossing the blood–brain barrier has shown modest prolongation in patient survival, but not without unsatisfactory systemic, dose-limiting toxicity. Among the reasons for this improvement include a better understanding of the challenges of Delivery of effective agents directly to the brain tumor site. The combination of carmustine delivered by biodegradable polyanhydride wafers (Gliadel ® ), with the systemic alkylating agent, temozolomide, allows much higher effective doses of the Drug while minimizing the systemic toxicity. We have previously shown that locally delivering these two Drugs leads to further improvement in survival in experimental models. We postulated that microcapsule Devices capable of releasing temozolomide would increase the therapeutic capability of this approach. A biocompatible Drug Delivery microcapsule Device for the intracranial Delivery of temozolomide is described. Drug release profiles from these microcapsules can be modulated based on the physical chemistry of the Drug and the dimensions of the release orifices in these Devices. The Drug released from the microcapsules in these experiments was the clinically utilized chemotherapeutic agent, temozolomide. In vitro studies were performed in order to test the function, reliability, and Drug release kinetics of the Devices. The efficacy of the temozolomide-filled microcapsules was tested in an intracranial experimental rodent gliosarcoma model. Immunohistochemical analysis of tissue for evidence of DNA strand breaks via terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay was performed. The experimental release curves showed mass flow rates of 36 μg/h for single-orifice Devices and an 88 μg/h mass flow rate for multiple-orifice Devices loaded with temozolomide. In vivo efficacy results showed that localized intracranial Delivery of temozolomide from microcapsule Devices was capable of prolonging animal survival and may offer a novel form of treatment for brain tumors.
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An implantable MEMS Drug Delivery Device for rapid Delivery in ambulatory emergency care
Biomedical Microdevices, 2009Co-Authors: Noel M. Elman, H. L. Ho Duc, Michael J. CimaAbstract:We introduce the first implantable Drug Delivery system based on MEMS (Micro-Electro-Mechanical-Systems) technology specifically designed as a platform for treatment in ambulatory emergency care. The Device is named IRD(3) (implantable rapid Drug Delivery Device) and allows rapid Delivery of Drugs. Vasopressin was used as a model Drug for in vitro tests as it is a commonly used Drug for cardiac resuscitation. Experimental results reveal that the IRD(3) provides an effective method for rapid Delivery without significant Drug degradation. Several medical uses and Delivery modalities for IRD(3) are proposed.
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Repeated in vivo electrochemical activation and the biological effects of microelectromechanical systems Drug Delivery Device.
Journal of Biomedical Materials Research Part A, 2004Co-Authors: Rebecca S. Shawgo, R. Langer, Gabriela Voskerician, J M Anderson, Yawen Li, Aaron Lynn, Matthew R. Macewan, Michael J. CimaAbstract:The repeated activation of a microelectromechanical systems (MEMS) Drug Delivery Device was studied in vivo in rats to examine the effect of implantation on the Device operation and the effect of electrochemical activation on the inflammatory and wound-healing response. The MEMS Devices were fabricated from a silicon wafer into which reservoirs were etched and covered with gold membranes. The membranes were electrochemically removed when an anodic voltage was applied. Devices were implanted subcutaneously both with and without stainless steel mesh cages for 4, 7, 14, 21, or 28 days before activation. Devices were activated every other day for five activations. Leukocyte concentrations indicated that both the application of voltage and the gold corrosion products elevated the inflammatory response which was resolved within 48 h after each activation. The efficiency of gold membrane removal was not impaired throughout the implantation, although a bimodal distribution of background current densities was observed after long implantation times. The thickness of the fibrous capsule surrounding the MEMS Devices was similar between activated and control Devices explanted at each time point. It was concluded that the repeated activation of MEMS Drug Delivery Devices was successful and the activation produced an acceptable biological response that resolved promptly. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 71A: 559–568, 2004
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in vivo release from a Drug Delivery mems Device
Journal of Controlled Release, 2004Co-Authors: Yawen Li, Rebecca S. Shawgo, R. Langer, Betty Tyler, Henry Brem, Paul T Henderson, John S Vogel, Aron Rosenberg, Phillip B Storm, Michael J. CimaAbstract:A Drug Delivery microelectromechanical systems (MEMS) Device was designed to release complex profiles of multiple substances in order to maximize the effectiveness of Drug therapies. The Device is based on micro-reservoirs etched into a silicon substrate that contain individual doses of Drug. Each dose is released by the electrochemical dissolution of the gold membrane that covers the reservoir. The first in vivo operation of this Device was reported in this study. Subcutaneous release was demonstrated in rats using two tracer molecules, fluorescein dye and radiolabeled mannitol, and one radiolabeled chemotherapeutic agent, carmustine (BCNU). BCNU was chosen because of the need to improve the direct Delivery of chemotherapy to malignant tumors. The spatial profile of fluorescein dye release from the Drug Delivery Device was evaluated by fluorimetry, the temporal profile of 14C labeled mannitol release was evaluated by liquid scintillation counting, and the temporal profile of 14C labeled BCNU release was evaluated by accelerator mass spectrometry (AMS). Release profiles obtained from injected controls were compared with those from activated Devices. The in vivo dye release results showed high concentration of fluorescein in the flank tissue surrounding the Devices 1 h after activation. The 14C labeled mannitol released from the Drug Delivery Devices was rapidly cleared (1 day) from the rat urine. In vivo release of 14C labeled BCNU from activated Devices showed slightly slower kinetics than the injected and in vitro controls, and the time to reach the steady-state plasma 14C concentration was on the order of 1 h. All these results demonstrated the capability of this Drug Delivery Device to achieve localized Delivery of various compounds with well-defined temporal profiles.
Nathan K Cobb - One of the best experts on this subject based on the ideXlab platform.
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e cigarette or Drug Delivery Device regulating novel nicotine products
The New England Journal of Medicine, 2011Co-Authors: Nathan K Cobb, David B AbramsAbstract:The FDA intends to regulate e-cigarettes as tobacco products, since the courts blocked it from treating them as Drug-Delivery Devices. Until the FDA asserts its new authority over tobacco, concentrated nicotine products may be sold to consumers, raising safety concerns.
Mu Chiao - One of the best experts on this subject based on the ideXlab platform.
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magnetically actuated Drug Delivery Device maddd for minimally invasive treatment of prostate cancer an in vivo animal pilot study
The Prostate, 2017Co-Authors: Werner J Struss, John K. Jackson, Payam Zachkani, Igor Moskalev, Ali Shademani, Ninadh M Dcosta, Peter A Raven, Sebastian Frees, Claudia Chavezmunoz, Mu ChiaoAbstract:Background The vast majority of prostate cancer presents clinically localized to the prostate without evidence of metastasis. Currently, there are several modalities available to treat this particular disease. Despite radical prostatectomy demonstrating a modest prostate cancer specific mortality benefit in the PIVOT trial, several novel modalities have emerged to treat localized prostate cancer in patients that are either not eligible for surgery or that prefer an alternative approach. Methods Athymic nude mice were subcutaneously inoculated with prostate cancer cells. The mice were divided into four cohorts, one cohort untreated, two cohorts received docetaxel (10 mg/kg) either subcutaneously (SC) or intravenously (IV) and the fourth cohort was treated using the magnetically-actuated docetaxel Delivery Device (MADDD), dispensing 1.5 μg of docetaxel per 30 min treatment session. Treatment in all three therapeutic arms (SC, IV, and MADDD) was administered once weekly for 6 weeks. Treatment efficacy was measured once a week according to tumor volume using ultrasound. In addition, calipers were used to assess tumor volume. Results Animals implanted with the Device demonstrated no signs of distress or discomfort, neither local nor systemic symptoms of inflammation and infection. Using an independent sample t-test, the tumor growth rate of the treated tumors was significant when compared to the control. Post hoc Tukey HSD test results showed that the mean tumor growth rate of our Device cohort was significantly lower than SC and control cohorts. Moreover, IV cohort showed slight reduction in mean tumor growth rates than the ones from the Device cohort, however, there was no statistical significance in tumor growth rate between these two cohorts. Furthermore, immunohistochemistry demonstrated an increased cellular apoptosis in the MADDD treated tumors and a decreased proliferation when compared to the other cohorts. In addition, IV cohort showed increased treatment side effects (weight loss) when compared to the Device cohort. Finally, MADDD showed minimal expression of CD45 comparable to the control cohort, suggesting no signs of chronic inflammation. Conclusions In conclusion, this study showed for the first time that MADDD, clearly suppressed tumor growth in local prostate cancer tumors. This could potentially be a novel clinical treatment approach for localized prostate cancer.
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A cylindrical magnetically-actuated Drug Delivery Device proposed for minimally invasive treatment of prostate cancer
RSC Advances, 2015Co-Authors: Payam Zachkani, Fatemeh Nazly Pirmoradi, John K. Jackson, Mu ChiaoAbstract:A cylindrically shaped magnetically-actuated MEMS (microelectromechanical systems) Drug Delivery Device for localized prostate cancer treatment is proposed in this work. The Device is designed for implantation through a gauge 12 needle for minimally invasive procedures. The Drug Delivery Device consists of a Drug reservoir, a PDMS (polydimethylsiloxane) membrane, a magnetic block and a housing. Under external magnetic fields, the movement of the magnetic block deflects the membrane and discharges the Drug through an aperture and into the housing. The housing has a large opening which allows the released Drug to diffuse to the surrounding tissues while it prevents the tissues from touching the membrane. On-demand Drug release with consistent release rates and Device implantation using a needle into ex vivo porcine bladder tissue are demonstrated.
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Delivery of an anti-cancer Drug from a magnetically controlled MEMS Device show cytotoxicity in PC3 and HUVEC cells
2011 16th International Solid-State Sensors Actuators and Microsystems Conference, 2011Co-Authors: Fatemeh Nazly Pirmoradi, John K. Jackson, Helen M. Burt, Mu ChiaoAbstract:We have developed a magnetically controlled MEMS Drug Delivery Device for on-demand release of defined quantities of an anti-cancer Drug, docetaxel (DTX). A Drug-loaded micro reservoir (O6mm×550µm) is sealed by a 40µm-thick elastic magnetic PDMS (polydimethylsiloxane) membrane with a laser-drilled aperture (∼100×100µm2). Discharge of the Drug solution and the release rates are controlled by an external magnetic field. Controlled and reproducible release rates of DTX have been achieved for 35 days. We report on the cytotoxicity of the released Drug from the Device (monitored as cell viability) and show that DTX maintains cytotoxic effects for two months.
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On-demand controlled release of docetaxel from a battery-less MEMS Drug Delivery Device
Lab on a Chip, 2011Co-Authors: Fatemeh Nazly Pirmoradi, John K. Jackson, Helen M. Burt, Mu ChiaoAbstract:We report the development of a magnetically controlled MEMS Device capable of on-demand release of defined quantities of an antiproliferative Drug, docetaxel (DTX). Controlled release of DTX with a dosage suitable for the treatment of diabetic retinopathy has been achieved for 35 days. The Device consists of a Drug-loaded microreservoir (Ø6 mm ×∼550 μm), sealed by an elastic magnetic PDMS (polydimethylsiloxane) membrane (Ø6 mm × 40 μm) with a laser-drilled aperture (∼100 × 100 μm(2)). By applying a magnetic field, the magnetic PDMS membrane deforms, causing the discharge of the Drug solution from the Device. Controlled DTX release at a rate of 171 ± 16.7 ng per actuation interval has been achieved for 35 days using a 255 mT magnetic field. The background leakage of Drug solution through the aperture was negligible at 0.053 ± 0.014 ng min(-1). The biological activity of the released Drug was investigated using a cytotoxicity assay (cell apoptosis) for two cell lines, HUVEC (human umbilical vein endothelial cells) and PC3 (prostate cancer) cells. Reproducible release rates have been achieved and DTX within the PDMS MEMS reservoir maintains full pharmacological efficacy for more than two months. This Device is a proof-of-concept development for targeted Delivery of hydrophobic Drugs such as DTX and other taxane-based agents that require accurate Delivery in nanomolar concentrations.
R. Langer - One of the best experts on this subject based on the ideXlab platform.
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intracranial microcapsule Drug Delivery Device for the treatment of an experimental gliosarcoma model
Biomaterials, 2011Co-Authors: Alexander W Scott, R. Langer, Betty Tyler, Byron Masi, Urvashi Upadhyay, Yoda R Patta, Rachel Grossman, Luca Basaldella, Henry Brem, Michael J. CimaAbstract:Abstract Controlled-release Drug Delivery systems are capable of treating debilitating diseases, including cancer. Brain cancer, in particular glioblastoma multiforme (GBM), is an extremely invasive cancer with a dismal prognosis. The use of Drugs capable of crossing the blood–brain barrier has shown modest prolongation in patient survival, but not without unsatisfactory systemic, dose-limiting toxicity. Among the reasons for this improvement include a better understanding of the challenges of Delivery of effective agents directly to the brain tumor site. The combination of carmustine delivered by biodegradable polyanhydride wafers (Gliadel ® ), with the systemic alkylating agent, temozolomide, allows much higher effective doses of the Drug while minimizing the systemic toxicity. We have previously shown that locally delivering these two Drugs leads to further improvement in survival in experimental models. We postulated that microcapsule Devices capable of releasing temozolomide would increase the therapeutic capability of this approach. A biocompatible Drug Delivery microcapsule Device for the intracranial Delivery of temozolomide is described. Drug release profiles from these microcapsules can be modulated based on the physical chemistry of the Drug and the dimensions of the release orifices in these Devices. The Drug released from the microcapsules in these experiments was the clinically utilized chemotherapeutic agent, temozolomide. In vitro studies were performed in order to test the function, reliability, and Drug release kinetics of the Devices. The efficacy of the temozolomide-filled microcapsules was tested in an intracranial experimental rodent gliosarcoma model. Immunohistochemical analysis of tissue for evidence of DNA strand breaks via terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay was performed. The experimental release curves showed mass flow rates of 36 μg/h for single-orifice Devices and an 88 μg/h mass flow rate for multiple-orifice Devices loaded with temozolomide. In vivo efficacy results showed that localized intracranial Delivery of temozolomide from microcapsule Devices was capable of prolonging animal survival and may offer a novel form of treatment for brain tumors.
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Repeated in vivo electrochemical activation and the biological effects of microelectromechanical systems Drug Delivery Device.
Journal of Biomedical Materials Research Part A, 2004Co-Authors: Rebecca S. Shawgo, R. Langer, Gabriela Voskerician, J M Anderson, Yawen Li, Aaron Lynn, Matthew R. Macewan, Michael J. CimaAbstract:The repeated activation of a microelectromechanical systems (MEMS) Drug Delivery Device was studied in vivo in rats to examine the effect of implantation on the Device operation and the effect of electrochemical activation on the inflammatory and wound-healing response. The MEMS Devices were fabricated from a silicon wafer into which reservoirs were etched and covered with gold membranes. The membranes were electrochemically removed when an anodic voltage was applied. Devices were implanted subcutaneously both with and without stainless steel mesh cages for 4, 7, 14, 21, or 28 days before activation. Devices were activated every other day for five activations. Leukocyte concentrations indicated that both the application of voltage and the gold corrosion products elevated the inflammatory response which was resolved within 48 h after each activation. The efficiency of gold membrane removal was not impaired throughout the implantation, although a bimodal distribution of background current densities was observed after long implantation times. The thickness of the fibrous capsule surrounding the MEMS Devices was similar between activated and control Devices explanted at each time point. It was concluded that the repeated activation of MEMS Drug Delivery Devices was successful and the activation produced an acceptable biological response that resolved promptly. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 71A: 559–568, 2004
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in vivo release from a Drug Delivery mems Device
Journal of Controlled Release, 2004Co-Authors: Yawen Li, Rebecca S. Shawgo, R. Langer, Betty Tyler, Henry Brem, Paul T Henderson, John S Vogel, Aron Rosenberg, Phillip B Storm, Michael J. CimaAbstract:A Drug Delivery microelectromechanical systems (MEMS) Device was designed to release complex profiles of multiple substances in order to maximize the effectiveness of Drug therapies. The Device is based on micro-reservoirs etched into a silicon substrate that contain individual doses of Drug. Each dose is released by the electrochemical dissolution of the gold membrane that covers the reservoir. The first in vivo operation of this Device was reported in this study. Subcutaneous release was demonstrated in rats using two tracer molecules, fluorescein dye and radiolabeled mannitol, and one radiolabeled chemotherapeutic agent, carmustine (BCNU). BCNU was chosen because of the need to improve the direct Delivery of chemotherapy to malignant tumors. The spatial profile of fluorescein dye release from the Drug Delivery Device was evaluated by fluorimetry, the temporal profile of 14C labeled mannitol release was evaluated by liquid scintillation counting, and the temporal profile of 14C labeled BCNU release was evaluated by accelerator mass spectrometry (AMS). Release profiles obtained from injected controls were compared with those from activated Devices. The in vivo dye release results showed high concentration of fluorescein in the flank tissue surrounding the Devices 1 h after activation. The 14C labeled mannitol released from the Drug Delivery Devices was rapidly cleared (1 day) from the rat urine. In vivo release of 14C labeled BCNU from activated Devices showed slightly slower kinetics than the injected and in vitro controls, and the time to reach the steady-state plasma 14C concentration was on the order of 1 h. All these results demonstrated the capability of this Drug Delivery Device to achieve localized Delivery of various compounds with well-defined temporal profiles.
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In vivo inflammatory and wound healing effects of gold electrode voltammetry for MEMS micro-reservoir Drug Delivery Device
IEEE Transactions on Biomedical Engineering, 2004Co-Authors: Gabriela Voskerician, Rebecca S. Shawgo, P.a. Hiltner, Michael J. Cima, J M Anderson, R. LangerAbstract:The in vivo biocompatibility and biofouling of gold electrodes for a microelectromechanical systems Drug Delivery Device were investigated in a rodent model. The role of the applied voltage and gold electrolysis products in modulating the inflammatory response (biocompatibility), and the temporal adhesion of cellular populations onto macroscopic gold film electrodes (biofouling) were analyzed in reference to two controls, Devices to which voltage was not applied (uncorroded) or voltage was applied to inert platinum electrodes (electrical controls). Voltammetry was applied to the gold surfaces once (day 4, 7, 14, 21, 28, 35, 42, or 49), while voltage of identical magnitude was applied to the electrical controls. An inflammatory response characterized by a rapid decrease of leukocyte concentration to control levels was observed 48 h following voltage application with no significant cell concentration difference (p>0.05) between the corroded Devices and electrical controls. The histological evaluation of the direct implant fibrous capsule showed comparable thickness of voltage applied and control specimens. The gold corrosion peak current showed no significant difference (p>0.05) among peak values at all time points. It was concluded that gold electrode corrosion was biocompatible and its electrochemical performance was not hindered by fibrous capsule formation.
Ellis Meng - One of the best experts on this subject based on the ideXlab platform.
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Implantable MEMS Drug Delivery Device for cancer radiation reduction
2010 IEEE 23rd International Conference on Micro Electro Mechanical Systems (MEMS), 2010Co-Authors: Heidi Gensler, Po Ying Li, Ronalee Lo, Roya Sheybani, Ken-tye Yong, Paras N. Prasad, Rizwan Masood, Uttam K. Sinha, Ellis MengAbstract:We present the first implantable MEMS Drug Delivery Device that includes an electrochemical bellows pump, refillable Drug reservoir, and dual regulation valve. Multiple Drug pump configurations were fabricated, assembled, and tested. Delivery of agents for cancer radiation reduction was demonstrated. In vivo chronic Delivery of radiation sensitizing agents in the form of small interfering (siRNA)-gold nanorod complexes (nanoplexes) directly to tumors induced in mice was achieved. Radiation therapy in conjunction with active Drug pumping by electrolysis actuation resulted in significant reduction of colon cancer tumor (HT29) size (~50%) over diffusion-based Delivery and intravenous injections. To our knowledge, this is the first MEMS Drug Delivery pump suitable for safe, efficacious, and local Delivery of short half-life siRNA in vivo.
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A refillable microfabricated Drug Delivery Device for treatment of ocular diseases
Lab on a Chip, 2008Co-Authors: Ronalee Lo, Sınav Saati, Po Ying Li, Rajat Agrawal, Mark S. Humayun, Ellis MengAbstract:An implantable manually-actuated microfabricated Drug Delivery Device was demonstrated as a new approach for delivering therapeutic compounds to ocular tissue in acute in vitro, ex vivo, and in vivo studies.
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an electrochemical intraocular Drug Delivery Device
Sensors and Actuators A-physical, 2008Co-Authors: Po Ying Li, Sınav Saati, Rajat Agrawal, Ronalee Lo, Mark S. Humayun, Jason Shih, Ellis MengAbstract:A microelectromechanical systems (MEMS) Drug Delivery Device is investigated for the treatment of incurable ocular diseases. Unlike conventional ocular Drug Delivery Devices, this MEMS Device is capable of being refilled, features electronic control of the Drug regimen, and enables targeted intraocular Drug Delivery. The refillable design permits long-term Drug therapy and avoids repetitive surgeries. Electronic control of dosing is achieved by using electrolysis-actuated pumping to deliver pharmaceuticals directly to the intraocular space. A flexible Parylene transscleral cannula allows targeted Delivery to tissues in both the anterior and posterior segments of the eye. This electrochemically driven Drug Delivery Device was demonstrated to provide flow rates suitable for ocular Drug therapy (pL/min to μL/min). Both continuous and bolus Drug Delivery modes were performed to achieve accurate Delivery of a target volume of 250 nL. An encapsulation packaging technique was developed for acute surgical studies and preliminary ex vivo Drug Delivery experiments in porcine eyes were performed.
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An electrochemical intraocular Drug Delivery Device
Sensors and Actuators A: Physical, 2008Co-Authors: Po Ying Li, Sınav Saati, Rajat Agrawal, Ronalee Lo, Mark S. Humayun, Jason Shih, Ellis MengAbstract:A microelectromechanical systems (MEMS) Drug Delivery Device is investigated for the treatment of incurable ocular diseases. Unlike conventional ocular Drug Delivery Devices, this MEMS Device is capable of being refilled, features electronic control of the Drug regimen, and enables targeted intraocular Drug Delivery. The refillable design permits long-term Drug therapy and avoids repetitive surgeries. Electronic control of dosing is achieved by using electrolysis-actuated pumping to deliver pharmaceuticals directly to the intraocular space. A flexible Parylene transscleral cannula allows targeted Delivery to tissues in both the anterior and posterior segments of the eye. This electrochemically driven Drug Delivery Device was demonstrated to provide flow rates suitable for ocular Drug therapy (pL/min to μL/min). Both continuous and bolus Drug Delivery modes were performed to achieve accurate Delivery of a target volume of 250 nL. An encapsulation packaging technique was developed for acute surgical studies and preliminary ex vivo Drug Delivery experiments in porcine eyes were performed. © 2007 Elsevier B.V. All rights reserved.
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An electrochemical intraocular Drug Delivery Device
2007 IEEE 20th International Conference on Micro Electro Mechanical Systems (MEMS), 2007Co-Authors: Po Ying Li, Sınav Saati, Ronalee Lo, Mark S. Humayun, Jason Shih, Bonnie Adams, Rajat Agrawa, Ellis MengAbstract:This paper presents the first implantable intraocular MEMS Drug Delivery Device capable of being refilled. To avoid repetitive surgeries, a refillable reservoir constructed of silicone rubber is implanted and capable of withstanding multiple needle punctures necessary for Drug refill. The Device uses electrolysis-actuated pumping to provide long- term Drug treatment at therapeutic levels, and a flexible parylene transscleral cannula for precise targeting of difficult-to-reach areas in the eye. This electrochemically driven micropump provides flow rates suitable for ocular Drug Delivery (pL/min to muL/min). An encapsulation packaging technique was developed for demonstrating Device operation in acute surgical studies. Preliminary surgical results in ex vivo porcine eyes are presented.
