In cancer research, accurate characterization of the tumor microenvironment (TME) components is pivotal for diagnosis and treatment. In cancer progression, desmoplasia (a cancer-specific type of fibrosis mainly due to collagen overproduction) plays a crucial role and a specific barrier to treatment efficacy. Collagen, a key extracellular matrix component, plays a significant role in cancer progression, making its identification vital for understanding tumor behavior. This study presents a fiber optic approach utilizing adaptive focus light and fluorescence sensing techniques to detect collagen within fresh cancer specimens. Conventional methods often face challenges in precisely distinguishing collagen amidst complex TME. We demonstrate the efficacy of our approach through comprehensive experiments involving diverse cancer tissue samples. We accurately detect and characterize collagen by employing fluorescence sensing, providing invaluable insights into the TME. The adaptive focus light system optimizes imaging conditions and ensures high-resolution collagen identification. Subsequently, the proposed method simplifies the further analysis of the samples when subjected to Atomic Force Microscopy (AFM) to characterize their mechanical characteristics. The proposed techniques can offer a multimodal approach to characterizing fresh tissue biopsies, including quantitated collagen characterization through fluorescence measurements and AFM nanomechanical characterization. Our research signifies a paradigm shift in cancer tissue analysis, offering a potent toolset for researchers and clinicians alike. By enhancing our understanding of the intricate interplay between collagen and cancer cells, this innovative approach paves the way for targeted therapies and personalized interventions, ultimately advancing the forefront of cancer diagnostics and treatment.
Cancer progression is known to be accompanied by changes in mechano-cellular phenotype that reflected by changes in both the structure and mechanical properties of the tumor microenvironment (TME). Solid tumors, such as breast tumors and sarcomas, stiffen as they grow in a host healthy tissue. Stiffening is caused by an increase in the structural components of the tumor, mainly collagen fibers, and in cancer and stromal cells content. Tumor stiffening can cause blood vessel inefficiency and hypo-perfusion, and as a result, it poses major physiological barriers to the systemic delivery of drugs. Consequently, there is an urgent need for the development of novel biomarkers, that characterize the mechanical state of a particular tumor so as to support the development of novel therapeutic strategies that target the TME. In this work, polarized microscopy on picrosirius red stained tumor sections and immunofluorescence was used in order to assess collagen-based optical signatures in correlation to tumor progression, while Atomic Force Microscopy (AFM) was applied for the nano-mechanical characterization of the samples. Also, approved anti-fibrotic and chemotherapy drugs, were re-purposed so as to target the tumor matrix and alleviate stiffness The results demonstrated that solid tumors presents unique collagen-based signatures that can be combined with nanomechanical fingerprints so as to develop novel biomarkers for cancer prognosis and treatment monitoring.
Cancer progression is closely related to changes in the structure and mechanical properties of the tumor microenvironment in a complex and not well-understood manner. In many solid tumors, including pancreatic cancer, the complex interplay among the different components of tumor microenvironment leads to a desmoplastic reaction associated with fibroblasts activation and collagen overproduction. Desmoplasia is responsible for tumor stiffening, and poses a major barrier to the effective delivery of drugs and has been associated with poor prognosis. Thus, the understanding of the involved mechanisms and the identification of collagen-based signatures that characterize the state of a particular tumor can lead to the development of novel diagnostic and prognostic biomarkers. In this study, pancreatic tumor models were developed employing the human pancreatic cancer cell lines BxPc-3 and MIAPaCa-2 and tissue biopsies were obtained at different stages of cancer progression. Polarized microscopy on picrosirius red stained tumor sections was used in order to assess collagen-based optical signatures in correlation with tumor progression, while Atomic Force Microscopy (AFM) was applied for the nano-mechanical characterization of the samples. The results demonstrated that pancreatic cancer presents unique collagen-based characteristics that can be used as a novel biomarker for cancer diagnosis and prognosis.
Collagen thin films consisting of randomly oriented and oriented collagen fibrils/fibers are fabricated by hydrodynamic flow and spin coating, and then they are characterized by atomic force microscopy (AFM). Fibroblasts are cultured on these films in order to correlate their morphology and alignment, which are assessed with fluorescence and AFM imaging with different film characteristics. The results showed that the formed films could be used as substrates for culturing cells. Furthermore, cells reacted to film nanocharacteristics and especially to the orientation of fibrils/fibers. The investigation of the influence that the substrate nanotopography has on cells will help to elucidate the mechanisms of cell–biomaterial interactions, and will enable the design of intelligent coatings for implants and tissue engineering purposes.
Collagen is the major fibrous protein in the extracellular matrix and consists a significant component of skin, bone,
cartilage and tendon. Due to its unique properties, it has been widely used as scaffold or culture substrate for tissue
regeneration or/and cell-substrate interaction studies. The ultraviolet light-collagen interaction investigations are crucial
for the improvement of many applications such as that of the UV irradiation in the field of biomaterials, as sterilizing and
photo-cross-linking method. The aim of this paper was to investigate the mechanisms of UV-collagen interactions by
developing a collagen-based, well characterized, surface with controlled topography of collagen thin films in the
nanoscale range. The methodology was to quantify the collagen surface modification induced on ultraviolet radiation and
correlate it with changes induced in cells. Surface nanoscale characterization was performed by Atomic Force
Microscopy (AFM) which is a powerful tool and offers quantitative and qualitative information with a non-destructive
manner. In order to investigate cells behavior, the irradiated films were used for in vitro cultivation of human skin
fibroblasts and the cells morphology, migration and alignment were assessed with fluorescence microscopy imaging and
image processing methods. The clarification of the effects of UV light on collagen thin films and the way of cells
behavior to the different modifications that UV induced to the collagen-based surfaces will contribute to the better
understanding of cell-matrix interactions in the nanoscale and will assist the appropriate use of UV light for developing
biomaterials.
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