An in vitro assay of collagen fiber alignment by acupuncture needle rotation

Margaret Julias, Lowell T. Edgar, Helen M. Buettner, David I. Shreiber

    Research output: Contribution to journalArticle

    Abstract

    Background: During traditional acupuncture therapy, soft tissues attach to and wind around the acupuncture needle. To study this phenomenon in a controlled and quantitative setting, we performed acupuncture needling in vitro. Methods: Acupuncture was simulated in vitro in three-dimensional, type I collagen gels prepared at 1.5 mg/ml, 2.0 mg/ml, and 2.5 mg/ml collagen, and either crosslinked with formalin or left untreated. Acupuncture needles were inserted into the gels and rotated via a computer-controlled motor at 0.3 rev/sec for up to 10 revolutions while capturing the evolution of birefringence under cross-polarization. Results: Simulated acupuncture produced circumferential alignment of collagen fibers close to the needle that evolved into radial alignment as the distance from the needle increased, which generally matched observations from published tissue explant studies. All gels failed prior to 10 revolutions, and the location of failure was near the transition between circumferential and radial alignment. Crosslinked collagen failed at a significantly lower number of revolutions than untreated collagen, whereas collagen concentration had no effect on gel failure. The strength of the alignment field increased with increasing collagen concentration and decreased with crosslinking. Separate studies were performed in which the gel thickness and depth of needle insertion were varied. As gel thickness increased, gels failed at fewer needle revolutions. For the same depth of insertion, alignment was greater in thinner gels. Alignment increased as the depth of insertion increased. Conclusion: These results indicate that the mechanostructural properties of soft connective tissues may affect their response to acupuncture therapy. The in vitro model provides a platform to study mechanotransduction during acupuncture in a highly controlled and quantitative setting.

    Original languageEnglish (US)
    Article number19
    JournalBioMedical Engineering Online
    Volume7
    DOIs
    StatePublished - Jul 7 2008

    Fingerprint

    Acupuncture
    Collagen
    Needles
    Assays
    Gels
    Fibers
    Acupuncture Therapy
    Tissue
    Birefringence
    In Vitro Techniques
    Collagen Type I
    Formaldehyde
    Crosslinking
    Connective Tissue
    Polarization

    ASJC Scopus subject areas

    • Radiological and Ultrasound Technology
    • Biomaterials
    • Biomedical Engineering
    • Radiology Nuclear Medicine and imaging

    Cite this

    An in vitro assay of collagen fiber alignment by acupuncture needle rotation. / Julias, Margaret; Edgar, Lowell T.; Buettner, Helen M.; Shreiber, David I.

    In: BioMedical Engineering Online, Vol. 7, 19, 07.07.2008.

    Research output: Contribution to journalArticle

    Julias, Margaret ; Edgar, Lowell T. ; Buettner, Helen M. ; Shreiber, David I. / An in vitro assay of collagen fiber alignment by acupuncture needle rotation. In: BioMedical Engineering Online. 2008 ; Vol. 7.
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