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Makhambetova, Z.

Publications and source records attributed to Makhambetova, Z..

2 recordsLinked to original sources

Biodegradable Architected Stents for Endoscopic Internal Drainage

Postoperative gastric leak after bariatric surgery is a serious complication associated with prolonged treatment, repeated interventions, and substantial morbidity. Endoscopic internal drainage using double pigtail stents is widely adopted. However, current stents, originally designed for biliary use and often based on simple cylindrical geometries, are not optimized for post-bariatric gastric leak anatomy, mechanical support, or fluid drainage. Here, we present BRIDGE (Biodegradable aRchitected Internal DrainaGE), a stent concept integrating triply periodic minimal surface (TPMS) architectures to control mechanical compliance, kink resistance, and drainage performance. Using computational modeling, mechanical testing, and benchtop flow studies, we evaluate TPMS designs and identify volume fraction as a key parameter balancing flexibility, structural integrity, and hydraulic performance. TPMS-integrated designs tolerated a 7.1-fold smaller bend radius than a commercial stent without kinking and achieved up to a 2-fold increase in drainage. We also developed a stereolithography-printable biodegradable resin and fabricated a prototype lattice-integrated stent. TeaserA biodegradable, 3D-printed stent with an architected lattice design improves flexibility, kink resistance, and abscess drainage while eliminating the need for device removal.

bioengineering↗

Wirelessly-Powered Ingestible Electronic Capsule for Non-invasive Gastrointestinal Optogenetics

Optogenetics enables the activation and inhibition of neurons with cell specificity. The gut harbors intricate networks of enteric and central neurons. Uncovering these neuronal pathways in vivo is challenging with traditional neuroscience probes due to the highly motile and harsh gut environment. Here we report the development of an ingestible electronic capsule for non-invasive optical gut stimulation (ICOPS) in rodents. ICOPS is powered wirelessly via a transmitter coil, dosed via oral gavage, and safely excreted without causing obstruction. ICOPS permits modular interchangeability of onboard light-emitting diodes (LEDs) for illumination. We exemplify this with optical irradiance at 470 nm, a commonly-used wavelength in optogenetics for activating channelrhodopsin2. ICOPS features a micro-LED ({micro}LED), a 460-turn coil wound around a ferrite core, and a resonating capacitor. We optimized the transmitting and receiving circuits to achieve maximum power transfer at low operating frequencies (45-140 kHz), overcoming challenges like loose coupling and misalignment. The capsule operates effectively at a distance up to 12 cm longitudinally, 9 cm laterally, and 75{degrees} rotational angle relative to the magnetic field. Specific absorption rate (SAR) calculations indicate transmitter-induced SAR levels within safe limits for the occupational environment at 6 Arms and 45 and 63 kHz frequencies ICOPS is robust and transits through the rat gastrointestinal (GI) tract in under 20 hours intact. We demonstrate in vivo functionality and viability of ICOPS using IVIS micro-computed tomography ({micro}CT). ICOPS could pave the way for non-invasive optogenetic interfacing of enteric neural circuits towards their use to regulate motility, visceral pain, and other gastrointestinal disorders.

bioengineering↗