Fast-Crosslinking Enabled Self-Roughed Polydimethylsiloxane Transparent Superhydrophobic Coating and Its Application in Anti-Liquid-Interference Electrothermal Device.

Polydimethylsiloxane (PDMS)-based transparent and superhydrophobic coatings have important applications, such as anti-icing, corrosion resistance, self-cleaning, etc. However, their applications are limited by the inevitable introduction of nanoparticles/high-temperature/segmented PDMS to facilitate a raspy surface. In this study, a self-roughed, neat PDMS superhydrophobic coating with high transparency is developed via a one-step spray-coating technique. PDMS suspensions with various droplet sizes are synthesized and used as building blocks for raspy surface formation by controlled curing on the warm substrate. The optimal coating exhibits a large water contact angle of 155.4° and transparency (T550 = 82.3%). Meanwhile, the employed spray-coating technique is applicable to modify a plethora of substrates. For proof-of-concept demonstrations, the use of the PDMS hydrophobic coating for anti-liquid-interference electrothermal devices and further transparent observation window for long-term operation in a sub-zero environment is shown successful. The proposed facile synthesis method of hydrophobic PDMS coating is expected to have great potential for a broad range of applications in the large-scale fabrication of fluorine-free, eco-friendly superhydrophobic surfaces.

Compaction of very thin corneas from ultraviolet A riboflavin-vitamin E transepithelial cross-linking.

The purpose of the study was to determine the decrease in pachymetry of very thin corneas with advanced keratoconus due to corneal compaction from the ultraviolet-A (UV-A) irradiation phase of transepithelial (epi-on) cross-linking. Twenty removed corneal buttons were obtained from patients who underwent penetrating keratoplasty for advanced keratoconus. Removed corneal buttons selected from among the post-surgical specimens for this study had intact epithelium, no scarring or surgical cautery, endothelial cell density >2500 cells/mm2, and average pachymetry over the measured points of below 400 µm. Corneas were mounted in a Franz chamber. Each epithelial surface was soaked in isotonic riboflavin and D-alpha-tocopheryl polyethylene glycol 1000 succinate (Ribocross® IROMED Group, Italy) for 15 min. Pachymetry was measured at three points over both the shielded and unshielded corneal halves for each corneal button. Surfaces were then washed in saline to remove the Ribocross®. Shields from UV-A irradiation over half of each cornea were then fixed to stand 5 mm above the test corneas. UV-A irradiation using the custom fast cross-linking (CF-CXL) protocol was then performed for the typical 10 ± 1.5 min, for a total energy of 1.08 ± 0.6 J/cm2 after which pachymetry was re-measured. The average percent change in pachymetry was -0.43% ± 0.38% (maximum -1.06%) in the shielded half. Pachymetry change was -6.2% ± 2.2% (maximum 12%) in the cross-linked halves. In conclusion, we estimate that the change in corneal thickness from corneal compaction due to the cross-linking reaction itself was -5.8% ± 2.2%. Scanning electron microscopy of cross-linked corneal segments showed stromal fiber contraction.

Development of liquid bandage used for emergency care of war wound / 医疗卫生装备

Objective To develop a liquid bandage for self aid of war wound.Methods Solution A and B were prepared containing functional polymers derived from the biocompatible poly (ethylene glycol) and hyaluronic acid,which had ability of fast crosslinking reaction when they were mixed.Among them,A solution mainly comprised of mercapto group-containing hyaluronic acid derivative (HA-SH),water-solubility starch,propylene glycol,benzoic acid and etc.B solution contained pentaerythritol tetraacrylate derivative (4arm-PEG-Acrylate) and benzoic acid.The structure of mercapto group-containing hyaluronic acid derivative was confirmed by IR,1H-NMR and etc.HA-SH and 4arm-PEG-Acrylate were formulated to different concentrations (W/V) in different buffers.The two kinds of solution were mixed in different ratios,and in situ crosslinking hyaluronic acid hydrogel was obtained;the crosslinking time was recorded.The adhesive force and waterholding capacity of the hydrogel after crosslinking were measured by adding excipients such as water-solubility starch.Results In case the concentration of HA-SH and 4arm-PEG-Acrylate was 2％ and pH value was 11,the hydrogel film on wound skin would be quickly formed in 20 seconds for wound dressing after spraying A and B solution onto the wound skin.Conclusion The liquid bandage has strong adhesive force,high water-holding capacity and controllable crosslinking time,so it could be used as a novel wound dressing for war wound.