We investigated the effect of ultra-high molecular weight poly-γ-glutamic acid (UHMW γ-PGA) on hair loss in vitro and in vivo. 5-Alpha reductase is an enzyme that metabolizes the male hormone testosterone into dihydrotestosterone. By performing an in vitro experiment to analyze the inhibitory effects of UHMW γ-PGA on 5-alpha reductase activity, we determined that UHMW γ-PGA did in fact inhibit 5-alpha reductase activity, indicating the use of UHMW γ-PGA as a potential 5-alpha reductase inhibitor in the treatment of men with androgenetic alopecia. To evaluate the promotion of hair growth in vivo, we topically applied UHMW γ-PGA and minoxidil on the shaved dorsal skin of telogenic C57BL/6 mice for 4 weeks. At 4 weeks, the groups treated with UHMW γ-PGA showed hair growth on more than 50% of the shaved skin, whereas the control group showed less hair growth. To investigate the progression of hair follicles in the hair cycle, hematoxylin and eosin staining was performed. Histological observations revealed that the appearance of hair follicles was earlier in the UHMW γ-PGA-treated group than in the control group. The number of hair follicles on the relative area of shaved skin in the UHMW γ-PGA-treated group was higher than that observed on the shaved skin in the control group. These results indicate that UHMW γ-PGA can promote hair growth by effectively inducing the anagen phase in telogenic C57BL/6 mice.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.4014/jmb.1411.11076 | DOI Listing |
ACS Omega
November 2024
TUBITAK-BILGEM, Electro-Optics and Laser Systems Group, 41470 Gebze, Turkey.
The laser-induced damage threshold properties of material structures play a key role in identifying and selecting optimum materials with the respective geometric configurations for laser shielding applications. The laser-induced damage mechanism is predominantly influenced by the absorption, thermal conductivity, and transition temperature characteristics of the materials. Ultrahigh-molecular weight polyethylene (UHMW-PE) ballistic composite sheet structures, traditionally employed for conventional ballistic purposes, merit examination for their laser shielding capabilities, leveraging their established use in conventional shielding applications.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
October 2024
George & Josephine Butler Polymer Research Laboratory, Center for Macromolecular Science and Engineering, Department of Chemistry, University of Florida, 32611, Gainesville, FL, United States.
We describe a methodology of post-polymerization functionalization to enable subsequent bulk depolymerization to monomer by utilizing mechanochemical macro-radical generation. By harnessing ultrasonic chain-scission in the presence of N-hydroxyphthalimide methacrylate (PhthMA), we successfully chain-end functionalize polymers to promote subsequent depolymerization in bulk, achieving up to 82 % depolymerization of poly(methyl methacrylate) (PMMA) and poly(α-methylstyrene) (PAMS) within 30 min. This method of depolymerization yields a high-purity monomer that can be repolymerized.
View Article and Find Full Text PDFUltra-high molecular weight polyethylene/graphene oxide (PE-UHMW/GO) composites have demonstrated potential in artificial joint applications. The tribological behavior of irradiated PE-UHMW/GO composites under water lubrication remained unclear, which limited their application range. In this study, the PE-UHMW/GO composites were gamma irradiated at 100 KGy in a vacuum and subsequently aged at 80 °C for 21 days in air.
View Article and Find Full Text PDFCommun Chem
May 2024
Polymer Science Group, Department of Chemical Engineering, The University of Melbourne, Parkville, 3010, Victoria, Australia.
In the forefront of advanced materials, ultra-high molecular weight (UHMW) polymers, renowned for their outstanding mechanical properties, have found extensive applications across various domains. However, their production has encountered a significant challenge: the attainment of UHMW polymers with a low dispersity (Ɖ). Herein, we introduce the pioneering technique of ultrasound (US) initiated polymerization, which has garnered attention for its capability to successfully polymerize a multitude of monomers.
View Article and Find Full Text PDFPolymers (Basel)
March 2024
Poly2 Group, Department of Materials Science and Engineering, Escola Superior d'Enginyeries Industrial, Aeroespacial i Audiovisual de Terrassa (ESEIAAT), Universitat Politècnica de Catalunya (UPC BarcelonaTech), C/ de Colom, 11, 08222 Terrassa, Spain.
The present work proposes to investigate the effect of an ultrahigh molecular weight silicone rubber (UHMW-SR) and two ethylene methyl acrylate copolymers (EMA) with different methyl acrylate (MA) content on the mechanical and fire performance of a fireproof acrylonitrile butadiene styrene copolymer (ABS) composite, with an optimum amount of ammonium polyphosphate (APP) and aluminum diethyl phosphinate (AlPi). ABS formulations with a global flame retardant weight content of 20 wt.% (ABS P) were melt-compounded, with and without EMA and UHMW-SR, in a Brabender mixer.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!