Photoageing, also called actinic ageing, is the main cause of prematurely aged skin. Our expertise in elastic fibers has led us to discover a process triggered in response to ultraviolet (UV) light and which upsets the balance of elastin fibers: there is too much elastin and insufficient lysyl oxidase (LOXL1) enzyme to form functional elastic fibers. This imbalance then leads to an accumulation of nonfunctional elastin, which forms aggregates. In addition to this imbalance, UV rays also induce elafin synthesis by fibroblasts. Known to be a marker of elastotic aggregates, elafin crystallizes the elastin fibers and stimulates the formation of aggregates that cannot be naturally eliminated by the skin. We developed a leaf extract that was able to restore both the balance between elastin and LOXL1 and to decrease the elafin synthesis to fight and correct the damage. This specific extract increased LOXL1 expression by twofold and decreased elafin synthesis. As a consequence, elastic fibers became functional and aggregates of unfunctional fibers decreased. The specific Hamamelis extract activity was confirmed with decreasing wrinkles and improving skin firmness.
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Transl Vis Sci Technol
January 2025
College of Optometry, University of Houston, Houston, TX, USA.
Purpose: To characterize frequency-dependent wave speed dispersion in the human cornea using microliter air-pulse optical coherence elastography (OCE), and to evaluate the applicability of Lamb wave theory for determining corneal elastic modulus using high-frequency symmetric (S0) and anti-symmetric (A0) guided waves in cornea.
Methods: Wave speed dispersion analysis for transient (0.5 ms) microliter air-pulse stimulation was performed in four rabbit eyes ex vivo and compared to air-coupled ultrasound excitation.
Gels
January 2025
Department of Mechanical and Aerospace Engineering, University of Houston, Houston, TX 77204, USA.
Stimuli-responsive hydrogels hold immense promise for biomedical applications, but conventional gelation processes often struggle to achieve the precision and complexity required for advanced functionalities such as soft robotics, targeted drug delivery, and tissue engineering. This study introduces a class of 3D-printable magnetic hydrogels with tunable stiffness, adhesion, and magnetic responsiveness, prepared through a simple and efficient "one-pot" method. This approach enables precise control over the hydrogel's mechanical properties, with an elastic modulus ranging from 43 kPa to 277 kPa, tensile strength from 93 kPa to 421 kPa, and toughness from 243 kJ/m to 1400 kJ/m, achieved by modulating the concentrations of acrylamide (AM) and FeO nanoparticles.
View Article and Find Full Text PDFGels
January 2025
Research Institute of Cell Culture, Yeungnam University, Gyeongsan 38541, Republic of Korea.
Exploiting novel crosslinking chemistry, this study pioneers the use of waterborne polyurethane (WPU) to chemically crosslink porcine-derived gelatin, producing enhanced gelatin hydrogel films through a solvent-casting method. Our innovative approach harnesses the reactive isocyanate groups of WPU, coupling them effectively with gelatin's hydroxyl and primary amino groups to form robust urea and urethane linkages within the hydrogel matrix. This method not only preserves the intrinsic elasticity of polyurethane but also significantly augments the films' tensile strength and strain.
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January 2025
Department of Mechatronics Engineering, Engineering Faculty, Istanbul Ticaret University, 34854 Istanbul, Türkiye.
The aim of this project is to fabricate fiber mats and hydrogel materials that constitute the two main components of a wound dressing material. The contributions of boric acid (BA) and zinc oxide (ZnO) to the physical and mechanical properties of polycaprolactone (PCL) is investigated. These materials are chosen for their antimicrobial and antifungal effects.
View Article and Find Full Text PDFGels
January 2025
Department of Mechanical Engineering, Najafabad Branch, Islamic Azad University, Najafabad 8543131, Iran.
Using metallic/polymeric orthopedic screws causes cavities in bone trauma after the attachment of broken bones, which prolongs the healing. Yet, it remains unknown how to overcome such a challenge. The main aim of this research was to use both polymers and gels to fabricate and study a new PCL/chitosan/hydroxyapatite scaffold-like orthopedic screw for cancellous bone trauma.
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