Research ArticleMEDICAL ROBOTS

In vivo tissue regeneration with robotic implants

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Science Robotics  10 Jan 2018:
Vol. 3, Issue 14, eaaq0018
DOI: 10.1126/scirobotics.aaq0018
  • Fig. 1 Robotic implant for tubular tissue growth.

    (A) For the treatment of long-gap esophageal atresia, the implant applies forces (F) to disconnected esophageal segments. After inducing sufficient growth, the segments are surgically connected to form a complete esophagus. (B) As a potential treatment for short bowel syndrome, the implant applies forces (F) to connected segment of bowel. By inducing sufficient lengthening to support the absorption of necessary calories and fluids, a dependence on intravenous feeding could be reduced or eliminated. (C) The robot is covered by biocompatible waterproof skin and is attached to tubular organ by two rings (esophageal segment shown). The upper ring is fixed to the robot body, whereas lower ring translates along the body. (D) Robot with skin removed to show motor drive system and sensors. Rotation of worm gear causes the lower ring to translate along the body. (E) Rings detach from robot body to facilitate attachment to tubular organ. (F) Tissue is attached to the ring using sutures. (G) In the Foker technique for treating long-gap esophageal atresia (21), sutures externalized on the patient’s back are used to apply forces (F) to esophageal segments.

  • Fig. 2 Esophageal lengthening experiments.

    (A) An implant controller located in a vest pocket communicates wirelessly with a laptop computer. (B) Force and position data recorded over a 24-hour period. (C) Fluoroscopic image showing the flow of contrast agent through esophagus during traction. (D) Esophageal segment length versus time. Surgery occurs on day 0. Segment length corresponds to the distance between implant attachment rings for lengthened segment (blue) and that between clips for control segments (green). Average values at sacrifice are given (in red and purple, respectively). Two animals were survived to day 10, and three were survived to day 11. ***P < 0.0001. (E) Resected esophagus cut along its length and unrolled along its circumference to show epithelium. Rings are placed adjacent to attachment locations for reference. Note the normal appearance of tissue and the uniform diameter of the lengthened section.

  • Fig. 3 Implant surgery.

    (A) Suturing of rings to the esophagus. (B) A silicone sheet is inserted behind the esophagus, and the implant is connected to attachment rings. (C) Implant and esophagus, wrapped in silicone sheet, positioned between the rib cage and right lung before surgical closure. (D) Control electronics are housed in a vest pocket. (E) Necropsy view of a fibrotic capsule surrounding the implant. Bulges due to proximal ring and distal end cap can be seen in capsule.

  • Fig. 4 Esophageal tissue histology.

    (A) Longitudinal sections of Desmin-stained tissue (×1 magnification) showing tissue layers: muscularis externa (ME), which is composed of longitudinal muscle (LM) and circular muscle (CM); submucosa (SM); muscularis mucosa (MM); lamina propria (LP); and epithelium (EP). (B) Longitudinal sections of Desmin-stained tissue (×20 magnification) illustrating diameter measurement of skeletal muscle fiber cross sections. (C) Longitudinal sections of DAPI-stained tissue (×10 magnification) used to assess nuclear density. (D) Longitudinal sections of Masson’s trichrome–stained tissue (×20 magnification) for measuring relative fractions of muscle (pink) and collagen (blue).

  • Fig. 5 Histology results comparing surgical and naïve groups.

    Asterisks indicate P < 0.05 with specific values given in subcaptions. Error bars indicate 1 SD, unless otherwise noted. (A) Thickness of muscularis externa. (B) Skeletal muscle fiber diameter in longitudinal and circular layers of muscularis externa comparing lengthened surgical and naïve segments. (C) Nuclear density of muscularis externa. (D) Nuclear density in epithelium. (E) Median percentage proliferating muscle cells in muscularis externa of lengthened surgical segment versus naïve tissue. Error bars represent first and third quartiles (P = 0.025). (F) Percentage of collagen in lengthened surgical segment versus naïve tissue (P = 0.002).

Supplementary Materials

  • Supplementary Materials

    Supplementary Material for:

    In vivo tissue regeneration with robotic implants

    Dana D. Damian, Karl Price, Slava Arabagi, Ignacio Berra, Zurab Machaidze, Sunil Manjila, Shogo Shimada, Assunta Fabozzo, Gustavo Arnal, David Van Story, Jeffrey D. Goldsmith, Agoston T. Agoston, Chunwoo Kim, Russell W. Jennings, Peter D. Ngo, Michael Manfredi, Pierre E. Dupont*

    *Corresponding author. Email: pierre.dupont{at}childrens.harvard.edu

    Published 10 January 2018, Sci. Robot. 3, eaaq0018 (2018)
    DOI: 10.1126/scirobotics.aaq0018

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    Other Supplementary Material for this manuscript includes the following:

    • Movie S1 (.mp4 format). Fluoroscopic video shows in vivo adjustment of implant consisting of an increase in segment length of 2 mm.

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