A natural adhesive-based nanomedicine initiates photothermal-directed in situ immunotherapy with durability and maintenance.

Tumor immunotherapies have emerged as a promising frontier in the realm of cancer treatment. However, challenges persist in achieving localized, durable immunostimulation while counteracting the tumor's immunosuppressive environment. Here, we develop a natural mussel foot protein-based nanomedicine with spatiotemporal control for tumor immunotherapy. In this nanomedicine, an immunoadjuvant prodrug and a photosensitizer are integrated, which is driven by their dynamic bonding and non-covalent assembling with the protein carrier. Harnessing the protein carrier's bioadhesion, this nanomedicine achieves a drug co-delivery with spatiotemporal precision, by which it not only promotes tumor photothermal ablation but also broadens tumor antigen repertoire, facilitating in situ immunotherapy with durability and maintenance. This nanomedicine also modulates the tumor microenvironment to overcome immunosuppression, thereby amplifying antitumor responses against tumor progression. Our strategy underscores a mussel foot protein-derived design philosophy of drug delivery aimed at refining combinatorial immunotherapy, offering insights into leveraging natural proteins for cancer treatment.

3D printed teeth with adhesive bridge preparation guide.

In this study a 3D printed tooth with adhesive bridge preparation guide was designed and tested for feasibility and evaluated by students. The tooth, printed by a stereolithographic printer, consisted of two differently colored layers with an integrated adhesive bridge preparation. This showed the extent and thickness of the preparation. 42 dental students in the fourth year of their studies were trained in a voluntary course. The printed teeth were evaluated with a questionnaire using German school grades from 1 (best) to 6 (worst). The production of the printed teeth for the adhesive bridge preparation was feasible and inexpensive. Overall, the students rated the teeth as good (Ø1.9 ± 0.2) in the questionnaire and evaluated the teaching method positively in the free text questions. This method supported the students to visualize the target preparation and develop a self-assessment through the ability to control their work directly on their own. The feasibility of this teaching concept was confirmed. It is suitable for teaching of new preparations forms such as adhesive bridges. The color-coded integrated preparation in the printed teeth and the printed tooth model enabled the students to learn the preparation of an adhesive bridge independently.

Review of Medical Adhesive Technology in the Context of Medical Adhesive-Related Skin Injury.

In clinical practice, a large variety of medical devices adhere to skin to perform their function. The repeated application and removal of these devices can lead to skin damage or medical adhesive-related skin injury. Awareness of this problem has increased in the past decade, and this adverse event can be prevented with appropriate selection of adhesive products and the appropriate techniques for application and removal. A wide variety of adhesives and backing systems have been developed to create medical devices with an array of attributes, so they can accomplish many different indications in the clinical setting and meet various needs, including doing the clinical job without damaging the skin and causing further patient complications. The selection of an adhesive product should take into consideration a patient's skin assessment and history of medical adhesive-related skin injury, and using only the minimal adhesive strength needed to perform the function while protecting the skin from damage.

Medical Adhesive-Related Skin Injury at 10 Years: An Updated Consensus.

Awareness of medical adhesive-related skin injury (MARSI) has increased in the decade since a foundational consensus report was published in 2013. Additional research has provided greater knowledge of the epidemiology of MARSI, along with its assessment, prevention, and management. To summarize knowledge generated in the past decade and review our current understanding of MARSI, a panel of nine clinical experts from four countries (United States of America, United Kingdom, Canada, and Brazil) convened to discuss the literature published since the initial 2013 document and develop updated recommendations for clinical practice. The group formulated 20 updated consensus statements covering the assessment, prevention, and management of skin injuries related to adhesive medical devices and proposed next steps to address remaining gaps in research and knowledge of this complex and clinically relevant condition.

Assessing and Managing Medical Adhesive-Related Skin Injury in Patients with a Peripherally Inserted Central Catheter: A Case Series.

BACKGROUND: Medical adhesive-related skin injuries (MARSIs) are prevalent adverse effects associated with use of medical devices and increasingly recognized as potentially avoidable. Despite advances in preventive measures, MARSI events still occur, and individualized care must be designed to meet patient needs. CASES: This article describes three cases where skin injuries occurred because of application, removal, and ongoing use of a medical adhesive device; all three cases occurred underneath dressings used to secure and protect the skin adjacent to a peripherally inserted central catheter (PICC). The first case describes evaluation and management of a skin tear in an elderly female with multiple comorbid conditions, and Case 2 describes assessment and care of contact irritant dermatitis occurring under a PICC dressing. In both cases, specialist nurses with knowledge of MARSI assessed and managed the skin underneath the medical adhesive device in a manner that allowed maintenance of the PICC and continuation of therapy. In contrast, Case 3 describes a female with irritant contact dermatitis underneath a PICC dressing that was responding to care by the nurse specialists of a vascular access team. In this case, the patient presented to their facility's emergency department with severe itching. The vascular access team initially was not consulted, and the PICC line was removed, although inspection revealed dry skin without signs of infection. CONCLUSIONS: Medical adhesive-related skin injury is a clinically relevant and useful construct that identifies a variety of prevalent conditions associated with the use of medical adhesive device such as tapes and PICC dressings. These cases, in particular Cases 1 and 2, illustrate that the MARSI construct provides a framework for assessing and managing medical skin injuries with the possibility of preserving the PICC and the ongoing therapy these patients were receiving.

Efficacy of Clonidine Adhesive Patch for Patients With Tourette Syndrome: A Randomized, Double-blind, Placebo-Controlled, Multicenter Clinical Trial.

OBJECTIVE: This study aimed to explore the efficacy of the clonidine adhesive patch for participants with Tourette syndrome (TS). METHODS: This randomized, double-blind, placebo-controlled, multicenter phase IV clinical trial included participants with TS at 20 centers between May 2012 and March 2015. Treatment efficacy at week 8 was the primary outcome. The Clinical Global Impression-Severity scale and Improvement scale were the secondary endpoints. RESULTS: This trial included 488 participants, with 121 participants in the 2.0-mg/wk group, 119 participants in the 1.5-mg/wk group, 126 participants in the 1.0-mg/wk group, and 122 participants in the placebo group. For Yale Global Tic Severity Scale score reduction rate, compared with the placebo group (39.60 ± 25.56), those of the 2.0-mg/wk group (63.21 ± 32.60) and the 1.5-mg/wk group (68.16 ± 25.88) were statistically significantly different (all P < 0.001). For total Yale Global Tic Severity Scale score, compared with the placebo group (17.0 ± 8.03), the score for the 2.0-mg/wk group was 9.9 ± 8.36 ( P < 0.001); 1.5-mg/wk group, 9.6 ± 8.03 ( P < 0.001); and 1.0-mg/wk group, 10.5 ± 9.28 ( P < 0.001). The Clinical Global Impression-Severity scale and Improvement scale scores were statistically significantly different in the 3 clonidine (or experimental) groups compared with the placebo group (all P < 0.001). CONCLUSIONS: Larger doses of the clonidine adhesive patch such as 1.5 and 2.0 mg/wk are effective in improving the symptoms and overall function of participants with TS.

Dihydromyricetin-loaded oxidized polysaccharide/L-arginine chitosan adhesive hydrogel promotes bone regeneration by regulating PI3K/AKT signaling pathway and MAPK signaling pathway.

Bone defects caused by trauma, infection and congenital diseases still face great challenges. Dihydromyricetin (DHM) is a kind of flavone extracted from Ampelopsis grossedentata, a traditional Chinese medicine. DHM can enhance the osteogenic differentiation of human bone marrow mesenchymal stem cells with the potential to promote bone regeneration. Hydrogel can be used as a carrier of DHM to promote bone regeneration due to its unique biochemical characteristics and three-dimensional structure. In this study, oxidized phellinus igniarius polysaccharides (OP) and L-arginine chitosan (CA) are used to develop hydrogel. The pore size and gel strength of the hydrogel can be changed by adjusting the oxidation degree of oxidized phellinus igniarius polysaccharides. The addition of DHM further reduce the pore size of the hydrogel (213 µm), increase the mechanical properties of the hydrogel, and increase the antioxidant and antibacterial activities of the hydrogel. The scavenging rate of DPPH are 72.30 ± 0.33 %, and the inhibition rate of E.coli and S.aureus are 93.12 ± 0.38 % and 94.49 ± 1.57 %, respectively. In addition, PCAD has good adhesion and biocompatibility, and its extract can effectively promote the osteogenic differentiation of MC3T3-E1 cells. Network pharmacology and molecular docking show that the promoting effect of DHM on osteogenesis may be achieved by activating the PI3K/AKT and MAPK signaling pathways. This is confirmed through in vitro cell experiments and in vivo animal experiments.

Wearable bio-adhesive metal detector array (BioMDA) for spinal implants.

Dynamic tracking of spinal instrumentation could facilitate real-time evaluation of hardware integrity and in so doing alert patients/clinicians of potential failure(s). Critically, no method yet exists to continually monitor the integrity of spinal hardware and by proxy the process of spinal arthrodesis; as such hardware failures are often not appreciated until clinical symptoms manifest. Accordingly, herein, we report on the development and engineering of a bio-adhesive metal detector array (BioMDA), a potential wearable solution for real-time, non-invasive positional analyses of osseous implants within the spine. The electromagnetic coupling mechanism and intimate interfacial adhesion enable the precise sensing of the metallic implants position without the use of radiation. The customized decoupling models developed facilitate the precise determination of the horizontal and vertical positions of the implants with incredible levels of accuracy (e.g., <0.5 mm). These data support the potential use of BioMDA in real-time/dynamic postoperative monitoring of spinal implants.

Fabrication of liquid-free ionic conductive elastomer (ICE) from cellulose-rosin derived poly(esterimide) towards temperature-tolerant and solvent-resistant UV shadowless adhesive and sensor.

Recently, the utilization of the cellulose to fabricate the multifunctional materials with aim to replace the petroleum-based product, is receiving significant attentions. However, the development of cellulose-based multifunctional materials with high mechanical strength and temperature resistance is still a challenge. Herein, the intrinsic feature and property of cellulose and rosin were creatively employed to fabricate a novel cellulose-rosin based poly(esterimide) (PEI) by esterification reaction and imidization reaction, and the obtained cellulose-rosin derived PEI exhibits superior thermal stability. Then the as-prepared cellulose-rosin derived PEI was dissolved in polymerizable deep eutectic solvents (PDES) and in-situ formed the ionic conductive elastomer (ICE) with via UV-induced polymerization. These cellulose-rosin based ICE exhibited excellent mechanical properties, solvent resistance, and temperature tolerance. By adjusting the mass ratio of cellulose-rosin derived PEI and PDES, the as-prepared liquid-free ICE functions as UV shadowless adhesive and wearable sensors. The bonding strength of UV shadowless adhesive could 1.52 MPa, which could be applied to fix the broken glass toy models. Furthermore, wearable sensors based those ICE could monitor the large and subtle movements even under extreme environmental condition, such as being soaked in organic solvent (such as tetrahydrofuran) or at low/high temperature (-25 °C or 80 °C). This work opens a new avenue for the next-generation of multifunctional ICE.

Mechanisms of the effect of high-performance ester composite materials on plant growth under soilless conditions.

The utilization of high-performance ester materials in addressing soil erosion and conserving water remains a crucial area of research in soil remediation. Currently, however, the mechanism underlying the role of these materials in vegetation restoration remains unclear, hampering the accurate determination of the optimal ratio of high-performance ester composite materials for soil enhancement. To address this issue, this study examines the mechanism of how high-performance ester composite materials affect the germination and growth of plant seeds through soilless cultivation experiments. The results revealed that the high-performance ester composite materials significantly enhanced seed germination ability and fostered plant seedling growth. Notably, the promotional effects of the ester adhesive and water-retaining materials within the high-performance ester composite varied. Specifically, the adhesive material significantly spurred radicle development, while the water-retaining material significantly accelerated germ growth. Varying concentrations of adhesive materials exerted distinct effects on plant growth. In particular, a small amount of adhesive materials enhanced seed germination, whereas excessive amounts exhibited inhibitory effects. Consequently, the optimal adhesive materials dosage conducive to plant growth and the optimal weight ratio of adhesive to water-retaining materials were ascertained. Additionally, the underlying mechanism of high-performance ester composite materials influence plant growth was elucidated. Overall, this research offers a theoretical foundation for the optimal ratio adjustment of high-performance ester composite materials to optimize soil improvement efforts.

Thermoresponsive On-Demand Adhesion and Detachment of a Polyurethane-Urea Bioadhesive.

The development of bioadhesives with strong adhesion and on-demand adhesion-detachment behavior is still critically important and challenging for facilitating painless and damage-free removal in clinical applications. In this work, for the first time, we report the easy fabrication of novel polyurethane-urea (PUU)-based bioadhesives with thermoresponsive on-demand adhesion and detachment behavior. The PUU copolymer was synthesized by a simple copolymerization of low-molecular-weight, hydrophilic, and biocompatible poly(ethylene glycol), glyceryl monolaurate (GML, a special chain extender with a long side hydrophobic alkyl group), and isophorone diisocyanate (IPDI). Here, GML was expected to not only adjust the temperature-dependent adhesion behavior but also act as an internal plasticizer. By simple adjustment of the water content, the adhesion strength of the 15 wt % water-containing PUU film toward porcine skin is as high as 55 kPa with an adhesion energy of 128 J/m2 at 37 °C. The adhesion strength dramatically decreases to only 3 kPa at 10 °C, exhibiting switching efficiency as high as 0.95. Furthermore, the present PUU-based adhesive also shows good on-demand underwater adhesion and detachment with a cell viability close to 100%. We propose that biomaterial research fields, especially novel PUU/polyurethane (PU)-based functional materials and bioadhesives, could benefit from such a novel thermoresponsive copolymer with outstanding mechanical and functional performances and an easy synthesis and scaled-up process as described in this article.

Ultrahigh Stretchable, Highly Transparent, Self-Adhesive, and Environment-Tolerant Chitin Nanocrystals Engineered Eutectogels toward Multisignal Sensors.

Addressing the conflict between achieving elevated mechanical stretchability and environmental adaptability is significant to a breakthrough in the practical application of flexible wearable materials. Therefore, inspired by the perceptive and protective properties of human skin, flexible wearable electronic skins (E-skins) based on deep eutectic solvent (DES) liquid and multiresponse eutectogel have been widely considered to be a promising platform for building a flexible wearable management system to achieve the purpose of "one stone, two birds". In this work, a multifunctional E-skin was designed based on an ultrastretchable, transparent, self-adhesive, and environmentally tolerant eutectogel by first incorporating cationized modified chitin nanocrystals into a covalently cross-linked polymer network comprised of the skeleton formed by a PAA polymerization network structure serving as a stretchable matrix and filled with DESs (ChCl:EG). The obtained eutectogel exhibits superhigh stretchability (up to 6707%), high toughness (17.7 MJ/m3), mechanical strength (0.48 MPa), self-adhesive, and high transparency (91.2%). Simultaneously, the multisignal sensor based on the above comprehensive properties and thermosensitive capacity exhibits a wide monitoring range, high strain/compression/temperature sensitivity, and good reproducibility. Remarkably, the sensor could be attached to rat hearts without glue or stickers for long-term monitoring of high-quality in vivo heartbeat signals. In this way, it is believed that the designed E-skin system based on eutectogel has great potential to serve as a promising platform for the next generation of flexible multisignal monitoring integrated wearable management systems.

Adhesive technology based on biomass tar documents engineering capabilities in the African Middle Stone Age.

The foragers of the southern African Middle Stone Age were among the first humans to adapt their environment and its resources to their needs. They heat-treated stone to alter its mechanical properties, transformed yellow colorants into red pigments and produced moldable adhesive substances from plants. Until now, only Podocarpus conifers have been identified as the botanical origin of Middle Stone Age adhesives. This is curious as these conifers do not produce sticky exudations that could be recognized as potential adhesives. To obtain an adhesive, tar must be made with a technical process based on fire. However, the nature of these technical processes has remained unknown, hampering our understanding of the meaning of this adhesive technology for the cultural evolution of early Homo sapiens. Here, we present the first evidence of a technique used for tar making in the Middle Stone Age. We created an experimental reference collection containing naturally available adhesives along manufactured tars from plants available in the Middle Stone Age and compared these to artifacts using gas chromatography-mass spectrometry and infrared spectroscopy. We found that, in the Howiesons Poort at Sibhudu Cave, tar was made by condensation, an efficient above-ground process. Even more surprisingly, the condensation method was not restricted to Podocarpus. The inhabitants of Sibhudu also produced tar from the leaves of other plants. These tars were then used, either without further transformation or were processed into ochre-based compound adhesives, suggesting that people needed different moldable substances with distinct mechanical properties. This has important implications for our understanding of Middle Stone Age H. sapiens, portraying them as skilled engineers who used and transformed their resources in a knowledgeable way.

Gelatin/sodium alginate-based strongly adhesive, environmentally resistant, highly stable hydrogel for 3D printing to prepare multifunctional sensors and flexible supercapacitors.

The increasing demand for environmentally friendly performance materials in the field of wearable electronics has brought renewable and low-cost hydrogels based on natural polymers into the research spotlight. As a biodegradable natural polymer, sodium alginate (SA) shows great promise for applications in wearable electronics. Here, we report a hydrogel with printability, adhesion, and is highly stable based on gelatin (Gel) and SA. SA improves the viscosity of the hydrogel, which can bond iron products weighing up to 20 kg due to metal coordination with the material, and the hydrogel binder is recyclable and reusable. The presence of glycerin allowed the hydrogel sensor device to maintain sensitivity after exposure to air at 25 °C for up to 35 days, and printed hydrogel samples retained their compressive resilience after exposure to air (25 °C, 55 % RH) for 30 days. Hydrogel-based supercapacitors show good stability after 58 h of charge/discharge cycling. This paper provides research ideas for the preparation of hydrogels with strong adhesion properties, as well as hydrogel 3D printing technology for the preparation of flexible sensor devices and flexible energy storage devices.

Allylation of cellulose microfibers for hydrosilylation with various hydrosilanes and hydrosiloxanes, and their application in corn-starch-mimosa tannin (CSMT) adhesive to improve particleboard properties.

Recently, Cellulose microfibers (CMF) have garnered significant attention due to their renewability, biodegradability, and unique properties such as high aspect ratio, low density, high strength, stiffness, and distinctive optical properties. These characteristics have been highlighted in publications worldwide. However, the structure of CMF is difficult to access with solvents, limiting its dissolution in common organic solvents. The synthesis of CMF-siloxane or CMF-silane hybrid materials from cellulose generally involves several reactions steps, and therefore catalysts. The allylation of CMF is catalyzed by the phase-transfer catalyst tetrabutylammonium bromide (TBAB), which enables the combination of CMF with allyl. This is followed by a hydrosilylation reaction catalyzed by Karstedt's catalyst, based on platinum (0), to combine the hydrophilic allylated CMF with hydride-terminated hydrophobic hydrosilane or hydrosiloxane. Environmentally friendly particleboards were developed using bio-based adhesives composed of corn-starch and Mimosa tannin (CSMT) mixtures. These mixtures included 4, 6, 8, and 10 wt% of CMF, allylated CMF and silylated CMF. The mechanical and physical properties of particleboards, such as modulus of elasticity (MOE), modulus of rupture (MOR), internal bond strength (IB), surface soundness (SS), water absorption (WA) and thickness swelling (TS) were determined.

Self-Adhesive, Stretchable, and Thermosensitive Iontronic Hydrogels for Highly Sensitive Neuromorphic Sensing-Synaptic Systems.

Artificial sensory afferent nerves that emulate receptor nanochannel perception and synaptic ionic information processing in chemical environments are highly desirable for bioelectronics. However, challenges persist in achieving life-like nanoscale conformal contact, agile multimodal sensing response, and synaptic feedback with ions. Here, a precisely tuned phase transition poly(N-isopropylacrylamide) (PNIPAM) hydrogel is introduced through the water molecule reservoir strategy. The resulting hydrogel with strongly cross-linked networks exhibits excellent mechanical performance (∼2000% elongation) and robust adhesive strength. Importantly, the hydrogel's enhanced ionic conductance and heterogeneous structure of the temperature-sensitive component enable highly sensitive strain information perception (GFmax = 7.94, response time ∼ 87 ms), temperature information perception (TCRmax = -1.974%/°C, response time ∼ 270 ms), and low energy consumption synaptic plasticity (42.2 fJ/spike). As a demonstration, a neuromorphic sensing-synaptic system is constructed integrating iontronic strain/temperature sensors with fiber synapses for real-time information sensing, discrimination, and feedback. This work holds enormous potential in bioinspired robotics and bioelectronics.

Polyphenol-Enabled 2D Nanopatch for Enhanced Nasal Mucoadhesion and Immune Activation.

The advancement of effective nasal mucoadhesive delivery faces challenges due to rapid mucociliary clearance (MCC). Conventional studies have employed mucoadhesive materials, mainly forming spherical nanoparticles, but these offer limited adhesion to the nasal mucosa. This study hypothesizes that a 2D nanoscale structure utilizing adhesive polyphenols can provide a superior strategy for countering MCC, aligning with the planar mucosal layers. We explore the use of tannic acid (TA), a polyphenolic molecule known for its adhesive properties and ability to form complexes with biomolecules. Our study introduces an unprecedented 2D nanopatch, assembled through the interaction of TA with green fluorescent protein (GFP), and cell-penetrating peptide (CPP). This 2D nanopatch demonstrates robust adhesion to nasal mucosa and significantly enhances immunoglobulin A secretions, suggesting its potential for enhancing nasal vaccine delivery. The promise of a polyphenol-enabled adhesive 2D nanopatch signifies a pivotal shift from conventional spherical nanoparticles, opening new pathways for delivery strategies through respiratory mucoadhesion.

Highly Adhesive and Stretchable Epidermal Electrode for Bimodal Recording Patch.

For numerous biological and human-machine applications, it is critical to have a stable electrophysiological interface to obtain reliable signals. To achieve this, epidermal electrodes should possess conductivity, stretchability, and adhesiveness. However, limited types of materials can simultaneously satisfy these requirements to provide satisfying recording performance. Here, we present a dry electromyography (EMG) electrode based on conductive polymers and tea polyphenol (CPT), which offers adhesiveness (0.51 N/cm), stretchability (157%), and low impedance (14 kΩ cm2 at 100 Hz). The adhesiveness of the electrode is attributed to the interaction between catechol groups and hydroxyls in the polymer blend. This adhesive electrode ensures stable EMG recording even in the presence of vibrations and provides signals with a high signal-to-noise ratio (>25 dB) for over 72 h. By integrating the CPT electrode with a liquid metal strain sensor, we have developed a bimodal rehabilitation monitoring patch (BRMP) for sports injuries. The patch utilizes Kinesio Tape as a substrate, which serves to accelerate rehabilitation. It also tackles the challenge of recording with knee braces by fitting snugly between the brace and the skin, due to its thin and stretchable design. CPT electrodes not only enable BRMP to assist clinicians in formulating effective rehabilitation plans and offer patients a more comfortable rehabilitation experience, but also hold promise for future applications in biological and human-machine interface domains.

Effective cerebral tuberculosis treatment via nose-to-brain transport of anti-TB drugs using mucoadhesive nano-aggregates.

Central nervous system tuberculosis (CNS-TB) is a severe form of extra-pulmonary tuberculosis with high mortality and morbidity rates. The standard treatment regimen for CNS-TB parallels that of pulmonary TB, despite the challenge posed by the blood-brain barrier (BBB), which limits the efficacy of first-line anti-TB drugs (ATDs). Nose-to-brain (N2B) drug delivery offers a promising solution for achieving high ATD concentrations directly at infection sites in the brain while bypassing the BBB. This study aimed to develop chitosan nanoparticles encapsulating ATDs, specifically isoniazid (INH) and rifampicin (RIF). These nanoparticles were further processed into micro-sized chitosan nano-aggregates (NA) via spray drying. Both INH-NA and RIF-NA showed strong mucoadhesion and significantly higher permeation rates across RPMI 2650 cells compared to free ATDs. Intranasal administration of these NAs to TB-infected mice for four weeks resulted in a significant reduction of mycobacterial load by approximately ∼2.86 Log 10 CFU compared to the untreated group. This preclinical data highlights the efficacy of intranasal chitosan nano-aggregates in treating CNS-TB, demonstrating high therapeutic potential, and addressing brain inflammation challenges. To our knowledge, this study is the first to show nasal delivery of ATD nano-formulations for CNS-TB management.