LBL Noninvasively Peelable Biointerfacial Adhesives for Cutaneo‐Inspired pH/Tactility Artificial Receptors

Abstract

Besides barrier functions, skin possesses multiple sentiences to external stimuli (e.g., temperature, force, and humidity) for human‐outside interaction. Thus, skincare should be taken very seriously, especially by patients with sensory disorders. However, currently available skin‐mimicking devices are always limited by so much insufficient response functions and nontunable interface behaviors so as not to realize precise health monitoring and self‐defense against injury. Herein, a bioinspired cutaneous receptor‐perceptual system (CRPS) patch is presented, integrating hybrid pH indicators and triboelectric nanogenerators into biointerface film‐adhesives that are fabricated through facile layer‐by‐layer (LBL) self‐assembly of amide and Schiff‐base linkages between alginate grafted with N‐hydroxysuccinimide ester (AN), tannic acid (TA), and polyethylenimine (PEI). This CRPS patch is adhered robustly to the soft‐curved skin surface without failure via “molecular suturing,” and amino acid enables its benign peel‐on‐demand from tissue interfaces. Postdamage self‐healing brings it without surgical reoperation, avoiding extra cost, pain, as well as infection risks. Significantly, CRPS patches as artificial chemo/mechanoreceptors can remotely visualize skin physiological status by pH‐induced chromism using smartphones and prevent skin contact injury by tactility‐driven self‐powered electrical signals. Overall, the LBL‐based strategy to create controllably biointerface‐adhesive CRPS patches will usher in a new era of the mobihealth care platform supporting smart diagnosis and self‐protection.

Layer-by-Layer Microneedle-Mediated rhEGF Transdermal Delivery for Enhanced Wound Epidermal Regeneration and Angiogenesis

“…Compared to the traditional “fast followed by slow” cargo release model, drug carriers with LBL hierarchical structures could show slow release behaviors as the delayed-release time of bovine serum albumin through dynamic hydrogen-bonded polyethylene glycol/tannic acid films reported by Zhang and co-workers . Consequently, with the help of the LBL self-assembly technology skillfully grasped by our research group, − we hypothesize that the bioactive drug molecules are LBL self-assembled into the microneedle array to further enhance its sustained-release ability and stability. However, this new strategy integrating the passive diffusion mechanism of the LBL self-assembled cargo and the active transdermal technology of the microneedle is expected to treat wounds in situ as far as we are concerned, which has not been reported.…”

“…32 Cytocompatibility In Vitro. Similar to our previous work, 30 we extracted LBL MN-rhEGF patches in DMEM without FBS for 24 h and obtained this extract after filtration and sterilization with a filter membrane. NHDF cells (1.5 × 10 5 cells/well) were seeded on a 96-well plate and cultured in DMEM with 10% FBS added in a 37 °C incubator containing 5% CO 2 for 24 h. After the cells adhered to the wall, we suck out the old DMEM medium and add the extract to the 96-well plates for incubation for 24 h. After adding MTT solution (100 μL 1.00 mg/mL) and incubating for 4 h, subsequently, isopropanol (150 μL) was employed for replacing the MTT solution in the 96-well plates and shaken for 15 min.…”

Biomimetic Materials for Skin Tissue Regeneration and Electronic Skin

“…These technologies leverage deep learning algorithms, colorimetric sensors, and advanced materials to capture sensory information, provide holistic wound assessment, and enable real-time monitoring of wound healing progress. Additionally, bioinspired cutaneous receptor-perceptual systems [216] and stimulus-responsive wound dressings [217] have been designed to visualize skin physiological status remotely and adjust antibiotic release based on wound conditions, enhancing treatment outcomes.…”