Nerve collagens from diabetic and nondiabetic Sprague–Dawley and biobreeding rats: an atomic force microscopy study

Wang, H.; Layton, Bradley E.; Sastry, Ann Marie

doi:10.1002/dmrr.372

Cited by 27 publications

(24 citation statements)

References 46 publications

(64 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Increases in collagen in the endoneurium and perineurium have been identified in human lower extremity nerves in people with Type 1 and Type 2 diabetes (Bradley et al, 2000, Hill, 2009). Increased collagen quantity and fibril diameter have also been identified in the epineurium of the sciatic nerve in rat models of experimentally induced diabetes (Wang et al, 2003, Layton et al, 2004). Greater cross sectional area of the TibN has been demonstrated in people with Type 1 and Type 2 diabetes (Watanabe et al, 2010).…”

Section: Discussionmentioning

confidence: 99%

The pattern of tibial nerve excursion with active ankle dorsiflexion is different in older people with diabetes mellitus

Boyd

Gray

Dilley

et al. 2012

Clinical Biomechanics

View full text Add to dashboard Cite

Background The peripheral nervous system has an inherent capability to tolerate the gliding (excursion), stretching (increased strain), and compression associated with limb motions necessary for functional activities. The biomechanical properties during joint movements are well studied but the influence of other factors such as limb pre-positioning, age and the effects of diabetes mellitus are not well established for the lower extremity. The purposes of this pilot study were to compare the impact of two different hip positions on lower extremity nerve biomechanics during an active ankle dorsiflexion motion in healthy individuals and to determine whether nerve biomechanics are altered in older individuals with diabetes mellitus. Methods Ultrasound imaging was used to quantify longitudinal motion of the tibial nerve and transverse plane motion of the tibial and common fibular nerves in the popliteal fossa during active ankle movements. Findings In healthy individuals, ankle dorsiflexion created mean tibial nerve movement of 2.18 millimeters distally, 1.36 millimeters medially and 3.98 millimeters superficially. When the hip was in a flexed position there was a mean three-fold reduction in distal movement. In people with diabetes mellitus there was significantly less distal movement of the tibial nerve in the neutral hip position and less superficial movement of the nerve in both hip positions compared to healthy individuals. Interpretation We have documented reductions in tibial nerve excursion due to limb pre-positioning thought to pre-load the nervous system using a non-invasive methodology. Thus, lower limb pre-positioning impacts nerve biomechanics during ankle motions common in functional activities. Additionally, our findings indicate that nerve biomechanics have the potential to be altered in older individuals with diabetes mellitus compared to younger healthy individuals.

show abstract

Section: Discussionmentioning

confidence: 99%

The pattern of tibial nerve excursion with active ankle dorsiflexion is different in older people with diabetes mellitus

Boyd

Gray

Dilley

et al. 2012

Clinical Biomechanics

View full text Add to dashboard Cite

show abstract

“…Because PGA fibers are only 13 μm in diameter, whereas the long axis of an SMC can be >50 μm, it is likely that adherent SMC extended along the long axis of the PGA fibers. Several investigators have shown that collagen-producing cells secrete collagen along their long axes (29,30); hence cellular alignment along PGA fibers may have "forced" the direction of collagen fiber deposition, at least at early times during culture before the PGA fibers degraded. Only after the scaffold fibers degraded did SMC presumably reorient consistent with macroscopic stress or strain fields and then deposit collagen fibers along directions dictated by applied loads.…”

Section: Discussionmentioning

confidence: 99%

Enabling tools for engineering collagenous tissues integrating bioreactors, intravital imaging, and biomechanical modeling

Niklason

Yeh

Calle

et al. 2009

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

Many investigators have engineered diverse connective tissues having good mechanical properties, yet few tools enable a global understanding of the associated formation of collagen fibers, the primary determinant of connective tissue stiffness. Toward this end, we developed a biomechanical model for collagenous tissues grown on polymer scaffolds that accounts for the kinetics of polymer degradation as well as the synthesis and degradation of multiple families of collagen fibers in response to cyclic strains imparted in a bioreactor. The model predicted well both overall thickness and stress-stretch relationships for tubular engineered vessels cultured for 8 weeks, and suggested that a steady state had not yet been reached. To facilitate future refinements of the model, we also developed bioreactors that enable intravital nonlinear optical microscopic imaging. Using these tools, we found that collagen fiber alignment was driven strongly by nondegraded polymer fibers at early times during culture, with subsequent mechano-stimulated dispersal of fiber orientations as polymer fibers degraded. In summary, mathematical models of growth and remodeling of engineered tissues cultured on polymeric scaffolds can predict evolving tissue morphology and mechanics after long periods of culture, and related empirical observations promise to further our understanding of collagen matrix development in vitro.collagen | connective tissue | optical microscopy | tissue engineering

show abstract

“…In an in vivo rat model, larger-than-normal, nonspecific (Type I/Type III) collagen fibril diameters were measured in diabetic rat endoneurium via transmission electron microscopy (TEM) [35]. This was also found in vivo in diabetic humans with TEM [36], and both in vivo and in vitro with rat tail tendon with atomic force microscopy (AFM) [3] and finally, in vitro in endoneurium and epineurium in two diabetic rat models with AFM [17].…”

Section: Measurements In Diabetic Tissues: Prior Artmentioning

confidence: 98%

“…This tissue undergoes glycation [17,18], and exhibits altered mechanical properties, which can be modeled using micromechanics [18,19]. The gross mechanical properties of peripheral nerve [20,21] and collagen fibrils [22,23] have been quantified, but until our own work, there was apparently no model correlating glycation with mechanical properties at the tissue scale.…”

Section: Introductionmentioning

confidence: 99%

Equal and local-load-sharing micromechanical models for collagens: Quantitative comparisons in response of non-diabetic and diabetic rat tissue

Layton

Sastry

2006

Acta Biomaterialia

View full text Add to dashboard Cite

Nerve collagens from diabetic and nondiabetic Sprague–Dawley and biobreeding rats: an atomic force microscopy study

Abstract: The best means we have found to reduce raw AFM data is to measure several diameters with a single scan, using valley-to-valley measurements. Structural, fibrillar collagens of the nerve and tendon become larger in rats exposed to prolonged diabetes.

Cited by 27 publications

References 46 publications

The pattern of tibial nerve excursion with active ankle dorsiflexion is different in older people with diabetes mellitus

The pattern of tibial nerve excursion with active ankle dorsiflexion is different in older people with diabetes mellitus

Enabling tools for engineering collagenous tissues integrating bioreactors, intravital imaging, and biomechanical modeling

Equal and local-load-sharing micromechanical models for collagens: Quantitative comparisons in response of non-diabetic and diabetic rat tissue

Contact Info

Product

Resources

About