Intelligent Paper‐Free Sprayable Skin Mask Based on an In Situ Formed Janus Hydrogel of an Environmentally Friendly Polymer

Abstract

Traditional skin care masks usually use a piece of paper to hold the aqueous essences, which are not environmentally friendly and not easy to use. While a paper-free mask is desired, it is faced with a dilemma of moisture holding and rapid release of encapsulated bioactive substances. Herein, a paper-free sprayable skin mask is designed from an intelligent material-a thermogel which undergoes sol-gel-suspension transitions upon heating-to solve this dilemma. A synthesized block copolymer of poly(ethylene glycol) and poly(lactide-co-glycolide) with appropriate ratios can be dissolved in water, and thus easily mixed with a biological substance. The mixture is sprayable. After spraying, a Janus film is formed in situ with a physical gel on the outside and a suspension on the inside facing skin. Thus, both moisture holding and rapid release are achieved. Such a thermogel composed of biodegradable amphiphilic block copolymers loaded with nicotinamide as a skin mask is verified to reduce pigmentation on a 3D pigmented reconstructed epidermis model and further in a clinical study. This work might be stimulating for investigations and applications of biodegradable and intelligent soft matter in the fields of drug delivery and regenerative medicine.

3D-Printed Porous Scaffolds of Hydrogels Modified with TGF-β1 Binding Peptides to Promote In Vivo Cartilage Regeneration and Animal Gait Restoration

“…Hydrogels are useful in tissue regeneration owing to their biomimetic properties to the extracellular matrix (ECM). − The pores inside the bulk hydrogel are usually insufficient for cell migration, and thus, porosity and pore size are sometimes vague subjects in a bulk hydrogel . Considering cell sizes, migration, and transport requirements, the minimum pore size is about 100 μm .…”

RGD Nanoarrays with Nanospacing Gradient Selectively Induce Orientation and Directed Migration of Endothelial and Smooth Muscle Cells

“…Understanding cell–material interactions is fundamental for the research and development of new biomaterials. − Surface patterning affords a powerful way to reveal the factors to regulate cell behaviors on materials. − While most of the patterns are irregular with a random distribution or regular with an even distribution, , the present study reports a nanopattern with a gradient distribution along one dimension. Using the block copolymer micelle nanolithography with speed change during the dip-coating process, we prepared the RGD nanopatterns with a gradient of approximately 20 nm mm –1 .…”

Unified Therapeutic‐Prophylactic Vaccine Demonstrated with a Postoperative Filler Gel to Prevent Tumor Recurrence and Metastasis

“…Such a kind of intelligent materials can be mixed with therapeutic agents in a state of low‐viscous sol at room temperature, then become a reservoir of loaded drugs in the body after the injection. [ 63 ] Nevertheless, only a small fraction of PLGA‐ b ‐PEG‐ b ‐PLGA triblock copolymers with specific M n , and PEG/PLGA proportions can lead to a thermogel, [ 64 ] and the available chemical composition window is very narrow. Hence, we use the strategy of “block blends” put forward in our previous publication [ 65 ] to develop a TPV‐gel by mixing two PLGA‐ b ‐PEG‐ b ‐PLGA triblock copolymers with different PEG/PLGA ratios.…”