Electro-thermally induced structural failure actuator (ETISFA) for implantable controlled drug delivery devices based on Micro-Electro-Mechanical-Systems

Elman, Noel M.; Masi, Byron C.; Cima, Michael J.; Langer, Robert

doi:10.1039/c005135g

Cited by 17 publications

(9 citation statements)

References 40 publications

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“…It is a multidisciplinary field intersecting engineering, physics, chemistry, microtechnology, and biotechnology, with practical applications to the design of systems in which such small volumes of fluids will be used. Microfluidics has emerged at the beginning of the 1980s and is used in the development of DNA chips, labon-chip technology, micropropulsion, and microthermal technologies [69][70][71].…”

Section: Paa Hydrogels For Microfluidics and Lab-on-chip Applicationsmentioning

confidence: 99%

Poly(amidoamine) Hydrogels as Scaffolds for Cell Culturing and Conduits for Peripheral Nerve Regeneration

Fenili

Manfredi

Ranucci

et al. 2011

International Journal of Polymer Science

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Biodegradable and biocompatible poly(amidoamine)-(PAA-) based hydrogels have been considered for different tissue engineering applications. First-generation AGMA1 hydrogels, amphoteric but prevailing cationic hydrogels containing carboxylic and guanidine groups as side substituents, show satisfactory results in terms of adhesion and proliferation properties towards different cell lines. Unfortunately, these hydrogels are very swellable materials, breakable on handling, and have been found inadequate for other applications. To overcome this problem, second-generation AGMA1 hydrogels have been prepared adopting a new synthetic method. These new hydrogels exhibit good biological propertiesin vitrowith satisfactory mechanical characteristics. They are obtained in different forms and shapes and successfully testedin vivofor the regeneration of peripheral nerves. This paper reports on our recent efforts in the use of first-and second-generation PAA hydrogels as substrates for cell culturing and tubular scaffold for peripheral nerve regeneration.

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Section: Paa Hydrogels For Microfluidics and Lab-on-chip Applicationsmentioning

confidence: 99%

Poly(amidoamine) Hydrogels as Scaffolds for Cell Culturing and Conduits for Peripheral Nerve Regeneration

Fenili

Manfredi

Ranucci

et al. 2011

International Journal of Polymer Science

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“…This electrical pulse causes resistive heating, which causes expansion of the gold fuse and rupture, ‘activation’, of the underlying nitride membrane (34). The patency of each membrane can be assessed by monitoring the electrical resistance across the respective leads.…”

Section: 0 Resultsmentioning

confidence: 99%

“…The fabrication process for the microchip portion of the active device has been described previously (34). Briefly, one side of the wafer was patterned via standard photolithography and etched via reactive ion etching (RIE) to define ~720 μm by 720 μm regions of bare silicon.…”

Section: Methodsmentioning

confidence: 99%

Intracranial MEMS based temozolomide delivery in a 9L rat gliosarcoma model

Masi¹,

Tyler²,

Ho³

et al. 2012

Biomaterials

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Primary malignant brain tumors (BT) are the most common and aggressive malignant brain tumor. Treatment of BTs is a daunting task with median survival just at 21 months. Methods of localized delivery have achieved success in treating BT by circumventing the blood brain barrier and achieving high concentrations of therapeutic within the tumor. The capabilities of localized delivery can be enhanced by utilizing mircoelectromechanical systems (MEMS) technology to deliver drugs with precise temporal control over release kinetics. An intracranial MEMS based device was developed to deliver the clinically utilized chemotherapeutic temozolomide (TMZ) in a rodent glioma model. The device is a liquid crystalline polymer reservoir, capped by a MEMS microchip. The microchip contains three nitride membranes that can be independently ruptured at any point during or after implantation. The kinetics of TMZ release were validated and quantified in vitro. The safety of implanting the device intracranially was confirmed with preliminary in vivo studies. The impact of TMZ release kinetics was investigated by conducting in vivo studies that compared the effects of drug release rates and timing on animal survival. TMZ delivered from the device was effective at prolonging animal survival in a 9L rodent glioma model. Immunohistological analysis confirmed that TMZ was released in a viable, cytotoxic form. The results from the in vivo efficacy studies indicate that early, rapid delivery of TMZ from the device results in the most prolonged animal survival. The ability to actively control the rate and timing of drug(s) release holds tremendous potential for the treatment of BTs and related diseases.

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“…Apart from the major actuation techniques discussed above, other concepts such as electro-thermal, dielectrophoretic and electrostatic actuations have also shown potential Electrothermal actuation incorporates a V-shaped beam which is subjected to thermal expansion stretching along the apex. [62][63][64] Although this technique has been extensively used for micromanipulation in MEMS technology, it has not yet been exploited due to the thermosensitivity of cells. However, a number of researchers have employed the thermal expansion properties of shape memory alloy (SMA) for cell stretching.…”

Section: Other Actuatorsmentioning

confidence: 99%

Cell stretching devices as research tools: engineering and biological considerations

et al. 2016

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Cells within the human body are subjected to continuous, cyclic mechanical strain caused by various organ functions, movement, and growth. Cells are well known to have the ability to sense and respond to mechanical stimuli. This process is referred to as mechanotransduction. A better understanding of mechanotransduction is of great interest to clinicians and scientists alike to improve clinical diagnosis and understanding of medical pathology. However, the complexity involved in in vivo biological systems creates a need for better in vitro technologies, which can closely mimic the cells' microenvironment using induced mechanical strain. This technology gap motivates the development of cell stretching devices for better understanding of the cell response to mechanical stimuli. This review focuses on the engineering and biological considerations for the development of such cell stretching devices. The paper discusses different types of stretching concepts, major design consideration and biological aspects of cell stretching and provides a perspective for future development in this research area.

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Electro-thermally induced structural failure actuator (ETISFA) for implantable controlled drug delivery devices based on Micro-Electro-Mechanical-Systems

Cited by 17 publications

References 40 publications

Poly(amidoamine) Hydrogels as Scaffolds for Cell Culturing and Conduits for Peripheral Nerve Regeneration

Poly(amidoamine) Hydrogels as Scaffolds for Cell Culturing and Conduits for Peripheral Nerve Regeneration

Intracranial MEMS based temozolomide delivery in a 9L rat gliosarcoma model

Cell stretching devices as research tools: engineering and biological considerations

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