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In this study, the effects of chitosan and surface-deacetylated chitin nanofibrils (SDACNFs) on hair growth were evaluated. In human follicle dermal papilla cells in vitro, chitosan and SDACNFs were shown to increase cell growth on day 3 after the initiation of treatment, together with an increase in the production of fibroblast growth factor-7 (FGF-7) by these cells on day 3. Furthermore, in an in vivo study in mice, chitosan and SDACNF application promoted hair growth. The number of anagen follicles significantly increased compared with that in the control group, whereas the number of telogen follicles significantly decreased in the chitosan and SDACNF groups. In the chitosan and SDACNFs groups, moreover, the expression levels of FGF-7 and Sonic hedgehog were significantly upregulated in hair follicles. Overall, our results demonstrated that chitosan and SDACNFs promoted hair growth and therefore may have applications as novel therapeutic agents for the treatment of hair loss in patients.

Two Y-shaped molecules combining two dissimilar (hydrophilic and hydrophobic) units with a reactive triethoxysilane moiety were synthesized by Michael addition reaction of (aminopropyl)triethoxysilane with 2-hydroxyethyl acrylate (HEA), followed by the addition of 2,2,2-trifluoroethyl acrylate (TFEA) or 1 H ,1 H ,5 H -octafluoropentyl acrylate (OFPA). Hydrolytic condensations of the Y-shaped triethoxysilane precursors proceeded as homogeneous systems in acetone in presence of the acidic catalyst to afford amphiphilic silsesquioxane nanoparticles (SQ-NPs) having hydroxyl and fluoroalkyl groups (HEA/TFEA-SQ and HEA/OFPA-SQ). Scanning force microscope (SFM), X-ray diffraction (XRD), and size-exclusion chromatography (SEC) measurements indicated the formation of nanoparticles (average particle diameter is about 2.0 nm) with reasonable molecular weights and low dispersities ( M n = 5100-5400, M w / M n = 1.22–1.36) without aggregation. Characteristic assembled structures and surface properties of the amphiphilic SQ-NPs in different solvents were also evaluated. Flexible self-standing films were obtained from the amphiphilic SQ-NPs without any additional compounds, which are due to intermolecular hydrogen bondings.

Amphiphilic silsesquioxanes-based hybrids were synthesized by hydrolytic co-condensation of a hydroxyl-functionalized triethoxysilane precursor derived from 2-hydroxyethyl acrylate (HEA) and fluorinated triethoxysilane precursors derived from 1H,1H,5H-octafluoropentyl acrylate (OFPA) and 2,2,2-trifluoroethyl acrylate (TFEA). Hydrolytic co-condensations of two functionalized triethoxysilane precursors proceeded as homogeneous systems in N,N-dimethylformamide (DMF) to afford amphiphilic silsesquioxanes hybrids, which were soluble in a variety of solvents, depending on the composition. The structure of the constitutional unit of the hybrids was confirmed by the results of NMR and FT-IR measurements. Scanning force microscope (SFM) measurements indicated the formation of spherical hybrids having relatively narrow size distributions (average particle diameter < 3.0 nm) without aggregation. The sizes of the hybrids were also confirmed by X-ray diffraction (XRD). Flexible semitransparent films were obtained from the amphiphilic silsesquioxane hybrids prepared by hydrolytic co-condensations at suitable feed ratios. The organic-inorganic amphiphilites exhibited a high density of chemically bonded peripheral fluoroalkyl and hydroxyalkyl groups, in which various characteristic properties involving amphiphilicity, film-forming property, refractive index, responsive surface, nanometer size, and narrow size distribution can be manipulated by varying the composition in the feed.