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

Julias M, Edgar LT, Buettner HM, Shreiber DI - Biomed Eng Online (2008)

Bottom Line: 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.For the same depth of insertion, alignment was greater in thinner gels.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Biomedical Engineering, Rutgers, The State University of New Jersey, Piscataway, NJ, USA. tikus@eden.rutgers.edu

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.

Show MeSH

Related in: MedlinePlus

Revolutions to failure (average +/- standard error) during in vitro acupuncture. The number of revolutions before gel tearing was identified from alignment area curves and verified visually from the image sets. Crosslinking the collagen significantly decreased the ability of the collagen gels to withstand needle rotation without tearing (*, 2-way ANOVA, P < 0.001), whereas changing the collagen concentration had no effect (P = 0.274)
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC2483714&req=5

Figure 4: Revolutions to failure (average +/- standard error) during in vitro acupuncture. The number of revolutions before gel tearing was identified from alignment area curves and verified visually from the image sets. Crosslinking the collagen significantly decreased the ability of the collagen gels to withstand needle rotation without tearing (*, 2-way ANOVA, P < 0.001), whereas changing the collagen concentration had no effect (P = 0.274)

Mentions: During continuous needle rotation, all gels exhibited tearing prior to 10 revolutions. Whereas collagen concentration did not affect the failure of the gels (P = 0.274), crosslinked gels failed at a significantly lower number of revolutions than untreated gels (P < 0.001) (two-way ANOVA) (Figure 4). Therefore, to compare different conditions, quantitative analyses were performed up to a standardized number of revolutions that represented the lowest integer number before failure among all samples.


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

Julias M, Edgar LT, Buettner HM, Shreiber DI - Biomed Eng Online (2008)

Revolutions to failure (average +/- standard error) during in vitro acupuncture. The number of revolutions before gel tearing was identified from alignment area curves and verified visually from the image sets. Crosslinking the collagen significantly decreased the ability of the collagen gels to withstand needle rotation without tearing (*, 2-way ANOVA, P < 0.001), whereas changing the collagen concentration had no effect (P = 0.274)
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2483714&req=5

Figure 4: Revolutions to failure (average +/- standard error) during in vitro acupuncture. The number of revolutions before gel tearing was identified from alignment area curves and verified visually from the image sets. Crosslinking the collagen significantly decreased the ability of the collagen gels to withstand needle rotation without tearing (*, 2-way ANOVA, P < 0.001), whereas changing the collagen concentration had no effect (P = 0.274)
Mentions: During continuous needle rotation, all gels exhibited tearing prior to 10 revolutions. Whereas collagen concentration did not affect the failure of the gels (P = 0.274), crosslinked gels failed at a significantly lower number of revolutions than untreated gels (P < 0.001) (two-way ANOVA) (Figure 4). Therefore, to compare different conditions, quantitative analyses were performed up to a standardized number of revolutions that represented the lowest integer number before failure among all samples.

Bottom Line: 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.For the same depth of insertion, alignment was greater in thinner gels.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Biomedical Engineering, Rutgers, The State University of New Jersey, Piscataway, NJ, USA. tikus@eden.rutgers.edu

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.

Show MeSH
Related in: MedlinePlus