ABSTRACT
Mechanical forces between cells and their extracellular matrix (ECM) are mediated by dozens of different receptors. These biophysical interactions play fundamental roles in processes ranging from cellular development to tumor progression. However, mapping the spatial and temporal dynamics of tension among various receptor-ligand pairs remains a significant challenge. To address this issue, we have developed a synthetic strategy to generate modular tension probes combining the native chemical ligation (NCL) reaction with solid phase peptide synthesis (SPPS). In principle, this approach accommodates virtually any peptide or expressed protein amenable to NCL. We generated a small library of tension probes displaying different ligands, flexible linkers, and fluorescent reporters, enabling the mapping of integrin and cadherin tension, and demonstrating the first example of long-term (â¼3 days) molecular tension imaging. This approach provides a toolset to better understand mechanotransduction events fundamental to cell biology.
Subject(s)
Fluorescent Dyes/chemistry , Microscopy, Fluorescence/methods , Receptors, Cell Surface/chemistry , Animals , Dogs , Fluorescent Dyes/chemical synthesis , Integrins/chemistry , Madin Darby Canine Kidney Cells , Mechanotransduction, Cellular , Mice , NIH 3T3 Cells , Oligopeptides/chemistry , Peptides/chemistry , Polyethylene Glycols/chemistry , Receptors, Cell Surface/analysis , Rhodamines/chemistry , Small Molecule Libraries/chemical synthesis , Small Molecule Libraries/chemistry , Solid-Phase Synthesis TechniquesABSTRACT
OBJECTIVES: To evaluate the impact of cosmetics on silicone hydrogel (SiHy) contact lens shape, lens power, and optical performance. METHODS: In this in vitro experiment, 7 SiHy materials were coated with 9 marketed brands of cosmetics, including hand creams (HCs) (3), eye makeup removers (MRs) (3), and mascaras (3). Diameter, sagittal depth, and base curve were determined using the Chiltern (Optimec Limited), whereas lens power and optical performance were assessed using the Contest Plus (Rotlex). Six replicates were used for each lens and cosmetic combination. Measurements were repeated after a cleaning cycle using a one-step hydrogen peroxide solution. RESULTS: Makeup removers had the greatest impact on diameter, sagittal depth, and base curve, resulting in changes of up to 0.5, 0.15, and 0.77 mm, respectively. The HCs and mascaras had little impact on these parameters; however, differences were observed between lens types. Optical performance was reduced with all mascaras, and a decrease of greater than 2 units on a 0 to 10 scale (10=uniform power distribution) was seen for 5 lens types exposed to waterproof mascara (P<0.01). Most HCs and MRs had minimal impact on image quality. Lens power did not change with any of the cosmetics (± 0.25 diopter; P>0.05). Lens cleaning resulted in some recovery of the lens parameters, and efficiency varied between cosmetics. CONCLUSION: Some eye MRs and waterproof mascaras changed the shape and optical performance of some SiHy lenses. Further research is needed to understand the clinical implications for SiHy lens wearers using cosmetics.
Subject(s)
Contact Lenses, Hydrophilic , Cosmetics/adverse effects , Disposable Equipment , Humans , Hydrogel, Polyethylene Glycol Dimethacrylate , Silicones , Skin Cream/adverse effectsABSTRACT
PURPOSE: This study evaluated the impact of various cosmetics on the surface properties of silicone hydrogel (SiHy) contact lens materials. METHODS: In this in vitro experiment, 7 SiHy contact lens materials were coated with 1 of 9 cosmetics, including common hand creams (3), eye makeup removers (3), and mascaras (3). Dark-field microscopy images were taken to determine pixel brightness (PB) after cosmetic exposure, which describes the visible surface deposition (n=6 for each lens type), with a higher PB indicating increased deposition. The sessile drop technique was used to determine the advancing contact angle (CA). Measurements were repeated for both methods after a single peroxide-based cleaning cycle. RESULTS: Pixel brightness was significantly higher for mascara-coated lenses compared with the other cosmetic products (P<0.01). The peroxide-based lens care solution removed most deposits from the nonwaterproof mascara for 4 lens types, whereas deposits remained relatively unchanged for 1 waterproof mascara (P>0.05). Hand creams and makeup remover had minimal impact on PB. Changes in CA measurements after cosmetic application were highly lens dependent. Hand creams caused primarily a decrease in CA for 5 of the 7 lens types, whereas 1 of the waterproof mascaras caused a significant increase of 30 to 50° for 3 lens types. CONCLUSION: Some mascara-lens combinations resulted in increased CA and PB, which could have an impact on in vivo lens performance. Nonwaterproof mascara was mostly removed after a cleaning cycle. Further research is needed to understand the clinical implications for SiHy lens wearers using cosmetics.
