title: Nanomechanical signatures of oral submucous fibrosis in sub-epithelial connective tissue.
abstract: Oral sub-mucous fibrosis (OSF), a potentially malignant disorder, exhibits extensive remodeling of extra-cellular matrix in the form of sub-epithelial fibrosis which is a possible sequel of assaults from different oral habit related irritants. It has been assumed that micro/nanobio-mechanical imbalance experienced in the oral mucosa due to fibrosis may be deterministic for malignant potential (7-13%) of this pathosis. Present study explores changes in mechanobiological attributes of sub-epithelial connective tissue of OSF and the normal counterpart. The atomic force microscopy was employed to investigate tissue topography at micro/nano levels. It documented the presence of closely packed parallel arrangement of dense collagen fibers with wide variation in bandwidth and loss of D-space in OSF as compared to normal. The AFM based indentation revealed that sub-epithelium of OSF tissue has lost its flexibility with increased Young's modulus, stiffness, adhesiveness and reduced deformation of the juxta-epithealial connective tissue towards the deeper layer. These significant variations in nano-mechanical properties of the connective tissue indicated plausible impacts on patho-physiological microenvironment. Excessive deposition of collagen I and diminished expression of collagen III, fibronectin along with presence of α-SMA positive myofibroblast in OSF depicted its pathological basis and indicated the influence of altered ECM on this pathosis. The mechanobiological changes in OSF were corroborative with change in collagen composition recorded through immunohistochemistry and RT-PCR. The revelation of comparative nanomechanical profiles of normal oral mucosa and OSF in the backdrop of their structural and cardinal molecular attributes thus became pivotal for developing holistic pathobiological insight about possible connects for malignant transformation of this pre-cancer.
authors.affiliation: School of Medical Science and Technology, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal 721302, India. Electronic address: anji.anura7@gmail.com.
authors.forename: Anji
authors.initials: A
authors.lastname: Anura
authors.affiliation: Department of Electrical Engineering, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal 721302 India.
authors.forename: Debanjan
authors.initials: D
authors.lastname: Das
authors.affiliation: Guru Nanak Institute of Dental Science and Research, 157/F Nilgunj Road, Panihati, Kolkata, West Bengal 700114, India.
authors.forename: Mousumi
authors.initials: M
authors.lastname: Pal
authors.affiliation: Guru Nanak Institute of Dental Science and Research, 157/F Nilgunj Road, Panihati, Kolkata, West Bengal 700114, India.
authors.forename: Ranjan Rashmi
authors.initials: RR
authors.lastname: Paul
authors.affiliation: School of Medical Science and Technology, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal 721302, India.
authors.forename: Soumen
authors.initials: S
authors.lastname: Das
authors.affiliation: School of Medical Science and Technology, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal 721302, India.
authors.forename: Jyotirmoy
authors.initials: J
authors.lastname: Chatterjee
mesh_terms: D000199:Actins / Q000032:analysis; D001696:Biomechanical Phenomena; D003094:Collagen / Q000032:analysis; D003238:Connective Tissue / Q000473:pathology*; D005353:Fibronectins / Q000032:analysis; D006801:Humans; D018625:Microscopy, Atomic Force; D009061:Mouth Mucosa / Q000473:pathology*; D050997:Nanomedicine; D009914:Oral Submucous Fibrosis / Q000473:pathology*
chemical_list: D000199:Actins; D005353:Fibronectins; D003094:Collagen
keywords: Atomic force microscopy (AFM); Collagen; Extracellular matrix; Nanomechanical properties; Oral submucous fibrosis (OSF); Young's modulus