Biology subjects

Dabbour, A.-H.

Publications and source records attributed to Dabbour, A.-H..

3 recordsLinked to original sources

bioRxiv2026

Pulsed electrical stimulation enhances intestinal permeability

Oral ingestion of drugs remains the most convenient method for pharmacotherapy. However, oral absorption is hampered by digestive enzymes and the intestinal epithelial barrier. Here we investigate the ability of electrical stimuli to biologically modulate intestinal permeability. We demonstrate that pulsed electrical stimulation increases intestinal permeability, facilitating transport of chemical species across the epithelium. We evaluate the effects of several stimulation parameters in silico and subsequently characterize the biological effects in vitro using Caco-2 colorectal cancer cells, and an acute in vivo intestinal model. Our findings suggest that these effects may be mediated through calcium-dependent interactions with tight junction proteins which induce a reversible permeability increase differing based on the total charge delivered, amplitude and frequency of the current delivered. Pulsed electrical stimulation could be a potential strategy for transiently modulating the intestinal barrier.

bioengineering↗

bioRxiv2026

3D Printed Customizable Radiopaque Markers for Assessing Gastrointestinal Transit

Tracking gastrointestinal (GI) transit in preclinical models is essential for assessing gut motility and drug delivery. Current preclinical methods rely on end-to-end transit measurements or emptying studies that require terminal endpoints and organ explanation. Clinically, radiopaque "Sitz" markers are administered orally and their position in the GI tract is assessed through radiography. Sitz markers have been in use since 1969 and are typically mass-produced using industrial molding or extrusion, resulting in a single, fixed geometry with limited tunability. We present a stereolithography (SLA)-based method to fabricate customizable radiopaque markers using additive manufacturing with a barium sulfate (BaSO4)-doped resin. We demonstrate precise control over marker geometry, a key advantage over existing markers. Furthermore, we apply this method in vivo, tracking markers in a live rat model from ingestion to excretion using serial CT imaging. We systematically investigate how changes in marker geometry impact GI residency and transit time. Our results show that 3D printed markers provide a flexible and tunable platform for radiopaque marker fabrication and enable investigation of the fundamental relationship between a markers physical properties and its performance in a dynamic biological environment. This work establishes a novel, tunable platform for GI motility evaluation and drug delivery studies.

bioengineering↗

bioRxiv2026

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↗