Abstract
Introduction: Fibroblasts are central to a variety of homeostatic events such as wound healing and tissue regeneration. However, their pathologic activation is thought to play roles in a variety of diseases not only limited to fibrosis, foreign body reaction, scleroderma but also cancer metastasis. Biophysical properties of the extracellular matrix (ECM) deposited by an activated fibroblast determine whether there is a pro-regenerative or scarring response. Compared to aged fibroblasts, embryonic fibroblasts were shown to deposit a pro-regenerative ECM characterized by early hyaluronic acid (HA) deposition and increased levels of pro-regenerative collagens such as type III collagen. Since HA is also a regulator of collagen organization, we propose that early accumulation of HA by fibroblasts can facilitate pro-regenerative matrix formation. Given that the molecular weights of HA present in pro-regenerative matrix are higher than synthetic HA, we strategize attracting HA synthesized by fibroblasts. In this study, we used a synthetic peptide sequence known to have affinity to HA as a strategy to instruct fibroblasts to retain HA on the surface. We hypothesized that hyaluronic acid binding peptide (HABP) may instruct fibroblast endogenous HA deposition onto functionalized surfaces. Methods: We functionalized silica glass surfaces with HABP using aminoorganosilane mediated chemisorption and screened primary human dermal fibroblasts (HDFs) for cell morphology, cytoskeletal arrangement, and alpha-smooth muscle actin (α-SMA) expression. Results: Our results show HABP treated surfaces retain higher levels of HA on silica glass compared to control surfaces on fibroblast-derived matrices. Analysis of α-SMA shows increased α-SMA expression on hDFs and increased stress fiber formation. HABP treated surfaces were found to have reduced α-SMA expression. The physical features of collagen fibers deposited by fibroblasts were also organized differently in the presence of HABP. Conclusion: Due to their ability to diminish fibroblast contractility and promote regenerative ECM production, HABPs are a potentially viable strategy to instruct pro-regenerative fibroblasts and can be used therapeutically to treat fibrotic diseases.
