Atomic force microscopy investigation of vocal fold collagen.
OBJECTIVE
Collagen is an important constituent of the vocal fold extracellular matrix and is necessary for providing tensile strength and maintaining tissue geometry. Traditional investigations of vocal fold collagen using light and electron microscopy do not provide information on the organization and mechanical properties of collagen in native topographic state. The primary objective of this study was to use Atomic Force Microscopy (AFM) to examine the surface characteristics and organization of collagen in the deep layer of the lamina propria at nanoscale resolution.


METHODS
Experimental in vitro design.


METHODS
Freshly dissected porcine vocal folds were mounted on AFM discs and imaged under contact and tapping mode to obtain information on topographic distribution of collagen.


RESULTS
AFM imaging of the deep layer of the lamina propria revealed dense, abundant collagen fibers with a characteristic banding pattern. The distribution of collagen was heterogeneous, with both hydrophilic and hydrophobic regions within a sample.


CONCLUSIONS
AFM offers a useful tool to obtain topographic information about biologic samples at nanoscale resolution with minimal sample preparation. Mapping the topography and mechanical properties of vocal fold collagen is necessary for designing rheologically compatible bioimplants for the treatment of dysphonia resulting from vocal fold scarring and bowing.
Sivasankar
Mahalakshmi
M
Department of Speech, Language, and Hearing Sciences, Purdue University, West Lafayette, Indiana 47907, USA. msivasankar@purdue.edu
Ivanisevic
Albena
A
D000367:Age Factors; D000818:Animals; D003094:Collagen / Q000378:metabolism* / Q000648:ultrastructure*; D005109:Extracellular Matrix / Q000378:metabolism / Q000648:ultrastructure; D005240:Feasibility Studies; D008297:Male; D018625:Microscopy, Atomic Force / Q000379:methods*; D009092:Mucous Membrane / Q000378:metabolism / Q000648:ultrastructure; D013552:Swine; D014827:Vocal Cords / Q000378:metabolism* / Q000648:ultrastructure*
D003094:Collagen