Battery-free, lightweight, injectable microsystem for in vivo wireless pharmacology and optogenetics

Abstract

Pharmacology and optogenetics are widely used in neuroscience research to study the central and peripheral nervous systems. While both approaches allow for sophisticated studies of neural circuitry, continued advances are, in part, hampered by technology limitations associated with requirements for physical tethers that connect external equipment to rigid probes inserted into delicate regions of the brain. The results can lead to tissue damage and alterations in behavioral tasks and natural movements, with additional difficulties in use for studies that involve social interactions and/or motions in complex 3-dimensional environments. These disadvantages are particularly pronounced in research that demands combined optogenetic and pharmacological functions in a single experiment. Here, we present a lightweight, wireless, battery-free injectable microsystem that combines soft microfluidic and microscale inorganic light-emitting diode probes for programmable pharmacology and optogenetics, designed to offer the features of drug refillability and adjustable flow rates, together with programmable control over the temporal profiles. The technology has potential for large-scale manufacturing and broad distribution to the neuroscience community, with capabilities in targeting specific neuronal populations in freely moving animals. In addition, the same platform can easily be adapted for a wide range of other types of passive or active electronic functions, including electrical stimulation.

Wirelessly controlled, bioresorbable drug delivery device with active valves that exploit electrochemically triggered crevice corrosion

“…These devices operate on the basis of diffusion-controlled leakage of drug molecules, with rates that depend on the state of the system as it interacts with the surrounding biology. Although technologies with electronically programmable valves built into reservoirs and fluidic channels enable much greater versatility in the controlled drug release kinetics ( 5 – 7 ), secondary surgical procedures to extract the implanted hardware after completion of the delivery function are required. To overcome these key disadvantages, drug delivery platforms should ideally incorporate (i) active systems with wireless control, (ii) mechanically stable reservoir structures with complete sealing for zero leakage of drugs in the off state and compatibility with any drug chemistry, and (iii) fully bioresorbable construction to eliminate the need for secondary surgical removal processes after treatment.…”

Toward Nontransient Silk Bioelectronics: Engineering Silk Fibroin for Bionic Links

“…Such a multimodal use for silk films is quite challenging as it involves combining wireless powering and data transmission, vertical interconnect accesses and sensing elements on annealed silk films, all the while ensuring the mechanical and functional integrity of the resulting silk bioelectronic interface. Even with conventional plastic substrate materials such as the polyimide and elastomers, few bioelectronic systems exist [ 116–121 ] that represent the integration of the aforementioned functionalities in a compliant realization.…”

“…[ 118–121,123–134 ] This, in turn, can refashion the current material‐based neurotechnology research and complement the current state of the art in soft bioelectronics. [ 68,116,117,119,120,123,124,133–138 ]…”

Hearing restoration by a low-weight power-efficient multichannel optogenetic cochlear implant system

“…The same sound processor and a similar driver circuitry can also serve for the control of laser diodes in multichannel "passive" oCIs 56 where the light is fed into the cochlea via polymer-based waveguides probes 66 . Future modifications of the described hard-and software framework will also accommodate the combination of electrical and optical stimulation (combined oCI and eCI) for hybrid electro-optical stimulation 26 or optofluidics circuitry for application of photopharmacology into the cochlea and later optical stimulation [67][68][69] . Most studies presenting optogenetic stimulators address brain stimulation [70][71][72][73] , e.g.…”