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Australian Dental Journal Jun 2011Improved dental adhesive technology has extensively influenced modern concepts in restorative dentistry. In light of minimal-invasive dentistry, this new approach... (Review)
Review
Improved dental adhesive technology has extensively influenced modern concepts in restorative dentistry. In light of minimal-invasive dentistry, this new approach promotes a more conservative cavity design, which basically relies on the effectiveness of current enamel-dentine adhesives. Nowadays, the interaction of adhesives with the dental substrate is based on two different strategies, commonly described as an etch-and-rinse and a self-etch approach. In an attempt to simplify the bonding technique, manufacturers have decreased the number of steps necessary for the accomplishment of the bonding procedure. As a consequence, two-step etch-and-rinse and one-step (self-etch) adhesives were introduced and gained rapid popularity in the dental market due to their claimed user-friendliness and lower technique sensitivity. However, many concerns have been raised on the bonding effectiveness of these simplified adhesives, especially in terms of durability, although this tends to be very material dependent. In order to blend all the adhesive components into one single solution, one-step adhesives were made more acidic and hydrophilic. Unfortunately, these properties induce a wide variety of seemingly unrelated problems that may jeopardize the effectiveness and stability of adhesion to the dental substrate. Being more susceptible to water sorption and thus nanoleakage, these adhesives are more prone to bond degradation and tend to fail prematurely as compared to their multi-step counterparts. Incidentally, another factor that may interfere with the bonding effectiveness of adhesives is the technique used for caries removal and cavity preparation. Several tools are on the market today to effectively remove carious tissue, thereby respecting the current trend of minimum intervention. Despite their promising performance, such techniques modify the tooth substrate in different aspects, possibly affecting bonding effectiveness. Altogether, we may conclude that not only the adhesive formulation, but also substrate nature must be taken into account to achieve a stable bonding interface, rendering the restorative treatment more predictable in terms of clinical performance. In this review, we analyse the current theoretical and clinical aspects of adhesion to enamel and dentine, and discuss the diverse possibilities to overcome problems which nowadays still challenge clinicians in their achievement of a more stable and effective bond to tooth enamel and dentine.
Topics: Adhesiveness; Adhesives; Dental Bonding; Dental Cavity Preparation; Dental Enamel; Dental Etching; Dental Stress Analysis; Dentin; Dentin-Bonding Agents; Humans
PubMed: 21564114
DOI: 10.1111/j.1834-7819.2011.01294.x -
Journal of Materials Chemistry. B Jan 2021With the rapid development of hydrogels, hydrogel adhesion has attracted increasing attention in the last decade, but strong adhesion remains a challenge due to the... (Review)
Review
With the rapid development of hydrogels, hydrogel adhesion has attracted increasing attention in the last decade, but strong adhesion remains a challenge due to the large amount of water in hydrogels. The factors that affect hydrogel adhesion mainly include chemistries of bonds, topologies of connection, and mechanisms of energy dissipation. Strategies such as surface modification, surface initiation, bulk modification, bridging polymers, topological adhesion, and the use of nanocomposites have been developed to achieve strong hydrogel adhesion. In nanocomposite hydrogels, nanoparticles interlink with polymer chains to form strong bonds, which lower adhesion energy and offer energy dissipation, thus enhancing the adhesion. This review emphatically outlines nanocomposite adhesive hydrogels from design to application and provides useful understanding for the design and further development of nanocomposite adhesive hydrogels.
Topics: Adhesives; Nanogels; Particle Size; Surface Properties
PubMed: 33290489
DOI: 10.1039/d0tb02000a -
Biomaterials Nov 2018Designing wound dressing materials with outstanding therapeutic effects, self-healing, adhesiveness and suitable mechanical property has great practical significance in...
Designing wound dressing materials with outstanding therapeutic effects, self-healing, adhesiveness and suitable mechanical property has great practical significance in healthcare, especially for joints skin wound healing. Here, we designed a kind of self-healing injectable micelle/hydrogel composites with multi-functions as wound dressing for joint skin damage. By combining the dynamic Schiff base and copolymer micelle cross-linking in one system, a series of hydrogels were prepared by mixing quaternized chitosan (QCS) and benzaldehyde-terminated PluronicF127 (PF127-CHO) under physiological conditions. The inherent antibacterial property, pH-dependent biodegradation and release behavior were investigated to confirm multi-functions of wound dressing. The hydrogel dressings showed suitable stretchable and compressive property, comparable modulus with human skin, good adhesiveness and fast self-healing ability to bear deformation. The hydrogels exhibited efficient hemostatic performance and biocompatibility. Moreover, the curcumin loaded hydrogel showed good antioxidant ability and pH responsive release profiles. In vivo experiments indicated that curcumin loaded hydrogels significantly accelerated wound healing rate with higher granulation tissue thickness and collagen disposition and upregulated vascular endothelial growth factor (VEGF) in a full-thickness skin defect model. Taken together, the antibacterial adhesive hydrogels with self-healing and good mechanical property offer significant promise as dressing materials for joints skin wound healing.
Topics: Adhesiveness; Adhesives; Animals; Anti-Bacterial Agents; Antioxidants; Bandages, Hydrocolloid; Benzaldehydes; Biocompatible Materials; Chitosan; Cross-Linking Reagents; Curcumin; Drug Liberation; Female; Humans; Hydrogels; Injections; Joints; Mechanical Phenomena; Mice; Micelles; Poloxamer; Schiff Bases; Skin; Vascular Endothelial Growth Factor A; Wound Healing
PubMed: 30172244
DOI: 10.1016/j.biomaterials.2018.08.044 -
Colloids and Surfaces. B, Biointerfaces Oct 2022Polyethylene glycol (PEG)-based tissue glue has been widely used in surgery, but the sealants were weak in strength and could not be in place of sutures. This paper...
Polyethylene glycol (PEG)-based tissue glue has been widely used in surgery, but the sealants were weak in strength and could not be in place of sutures. This paper prepared a PEG-based tissue patch made of F127-DA hydrogel and PEG-DA as adhesive. For the patch adhesion on tissues, photoinitiator of lithium phenyl-2,4,6-trimethylbenzoylphosphinate (LAP, 0.1 % w/v) and UV flashlight at 395 nm for 30 s irradiation was used. The adhesion energy on pig skin, lung, heart, liver, kidney and stomach was 85.33, 56.40, 75.56, 70.22, 66.67 and 36.89 N/m, indicating the well stitching to different tissues. The hydrogel patch could also seal the punched tissues to prevent the leakage of liquid or air. Finally, the patch showed good tissue compatibility after 2 days adhesion on pig skin. In this regard, the hydrogel patch is expected to repair the wounded tissues without suture, being a biocompatible adhesive for wound healing of various tissues.
Topics: Adhesives; Animals; Biocompatible Materials; Hydrogels; Polyethylene Glycols; Swine; Tissue Adhesions; Tissue Adhesives
PubMed: 35961117
DOI: 10.1016/j.colsurfb.2022.112751 -
ACS Applied Bio Materials Mar 2022Adhesive and stretchable nanofibrous hydrogels have attracted extensive attraction in wound dressings, especially for joint wound treatment. However, adhesive hydrogels...
Adhesive and stretchable nanofibrous hydrogels have attracted extensive attraction in wound dressings, especially for joint wound treatment. However, adhesive hydrogels tend to display poor stretchable behavior. It is still a significant challenge to integrate excellent adhesiveness and stretchability in a nanofibrous hydrogel. Herein, a highly adhesive, stretchable, and breathable nanofibrous hydrogel was developed via an in situ hybrid cross-linking strategy of electrospun nanofibers comprising dopamine (DA) and gelatin methacryloyl (GelMA). Benefiting from the balance of cohesion and adhesion based on photocross-linking of methacryloyl (MA) groups in GelMA and the chemical/physical reaction between GelMA and DA, the nanofibrous hydrogels exhibited tunable adhesive and mechanical properties through varying MA substitution degrees of GelMA. The optimized GelMA60-DA exhibited 2.0 times larger tensile strength (2.4 MPa) with an elongation of about 200%, 2.3 times greater adhesive strength (9.1 kPa) on porcine skin, and 3.1 times higher water vapor transmission rate (10.9 kg m d) compared with gelatin nanofibrous hydrogels. In parallel, the GelMA60-DA nanofibrous hydrogels could facilitate cell growth and accelerate wound healing. This work presented a type of breathable nanofibrous hydrogels with excellent adhesive and stretchable capacities, showing great promise as wound dressings.
Topics: Adhesives; Bandages; Gelatin; Hydrogels; Methacrylates; Nanofibers
PubMed: 35200003
DOI: 10.1021/acsabm.1c01087 -
ACS Biomaterials Science & Engineering Oct 2023The strategy of robust adhesion employed by barnacles renders them fascinating biomimetic candidates for developing novel wet adhesives. Particularly, barnacle cement...
The strategy of robust adhesion employed by barnacles renders them fascinating biomimetic candidates for developing novel wet adhesives. Particularly, barnacle cement protein 19k (cp19k) has been speculated to be the key adhesive protein establishing the priming layer in the initial barnacle cement construction. In this work, we systematically studied the sequence design rationale of cp19k by designing adhesive peptides inspired by the low-complexity STGA-rich and the charged segments of cp19k. Combining structure analysis and the adhesion performance test, we found that cp19k-inspired adhesive peptides possess excellent disparate adhesion strategies for both hydrophilic mica and hydrophobic self-assembled monolayer surfaces. Specifically, the low-complexity STGA-rich segment offers great structure flexibility for surface adhesion, while the hydrophobic and charged residues can contribute to the adhesion of the peptides on hydrophobic and charged surfaces. The adaptive adhesion strategy identified in this work broadens our understanding of barnacle adhesion mechanisms and offers valuable insights for designing advanced wet adhesives with exceptional performance on various types of surfaces.
Topics: Animals; Adhesives; Thoracica; Peptides; Hydrophobic and Hydrophilic Interactions
PubMed: 37722068
DOI: 10.1021/acsbiomaterials.3c01047 -
Advanced Healthcare Materials Nov 2023The optimized physical adhesion between bees' leg hairs and pollen grains-whereby the latter's diameter aligns with the spacing between the hairs-has previously inspired...
The optimized physical adhesion between bees' leg hairs and pollen grains-whereby the latter's diameter aligns with the spacing between the hairs-has previously inspired the development of a biomimetic drug dressing. Combining this optimized process with the improved natural mussels' adhesion in wet environments in a dual biomimetic process, it is herein proposed the fabrication of a natural-derived micropatterned hydrogel patch of methacrylated laminarin (LAM-MET), with enriched drug content and improved adhesiveness, suitable for applications like wound healing. Enhanced adhesion is accomplished by modifying LAM-MET with hydroxypyridinone groups, following the patch microfabrication by soft lithography and UV/vis-irradiation, resulting in a membrane with micropillars with a high aspect ratio. Following the biomimetics rational, a drug patch is engineered by combining the microfabricated dressing with drug particles milled to fit the spaces between pillars. Controlled drug release is achieved, together with inherent antibacterial activity against Escherichia coli and Pseudomonas aeruginosa, and enhanced biocompatibility using the bare micropatterned patches. This new class of biomimetic dressings overcomes the challenges of current patches, like poor mechanical properties and biocompatibility, limited adhesiveness and drug dosage, and lack of prolonged antimicrobial activity, opening new insights for the development of high drug-loaded dressings with improved patient compliance.
Topics: Animals; Humans; Adhesives; Biomimetics; Hydrogels; Drug Liberation; Wound Healing; Anti-Bacterial Agents
PubMed: 37515450
DOI: 10.1002/adhm.202301513 -
ACS Applied Bio Materials Oct 2023Stimulus-responsive dry adhesives, inspired by the adhesive mechanisms displayed by the fibrillar structures present on the feet of geckos, have emerged as a promising... (Review)
Review
Stimulus-responsive dry adhesives, inspired by the adhesive mechanisms displayed by the fibrillar structures present on the feet of geckos, have emerged as a promising area of research for applications such as robotic grippers and climbing robots. These stimulus-responsive dry adhesives exhibit some unique capabilities, as their ability to adhere to and detach from surfaces can be controlled with the help of an external stimulus. For example, studies have developed magnetic field-responsive dry adhesives and show that the adhesion of these materials can be turned on and off by controlling the applied magnetic field. Light-responsive adhesives have also been developed and shown to reverse their adhesion using infrared light as the stimulus. Such materials show tremendous promise in pick-and-place systems for handling delicate objects and microelectronic products. The focus of this article is to review the stimulus-responsive materials that have been used to develop dry adhesives. The mechanisms adopted by these stimulus-responsive materials to switch their adhesion are discussed. Applications of stimulus-responsive dry adhesives are presented, and last, the future perspective of these materials is discussed.
Topics: Animals; Adhesives; Lizards; Magnetic Fields
PubMed: 37795994
DOI: 10.1021/acsabm.3c00504 -
Macromolecular Rapid Communications Sep 2023Flexible self-adhesive hydrogel sensors are attracting considerable concerns in recent years. However, creating a self-adhesive hydrogel sensor with excellent mechanical...
Flexible self-adhesive hydrogel sensors are attracting considerable concerns in recent years. However, creating a self-adhesive hydrogel sensor with excellent mechanical properties remains to be challenging. Herein, a double-sided self-adhesive hydrogel capable of strain sensor with high strength is demonstrated by penetration strategy. The middle poly(acrylic acid)-polyacrylamide/Fe (PAA-PAM/Fe ) tough layer endows the double-sided self-adhesive hydrogel with high mechanical properties, while the bilateral poly[2-(methacryloyloxy) ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide-polyacrylamide (PSBMA-PAM) adhesive layers are used to ensure excellent adhesiveness on diverse substrates. The tough layer of the double-sided self-adhesive hydrogel sensor shows a strong interface bonding force against the adhesive layer. The double-sided self-adhesive hydrogel sensor enables excellent adhesiveness on diverse substrates. More importantly, it can accurately detect different strains and human motions as a self-adhesive hydrogel strain sensor. This work manifests a new route of structural design to develop a self-adhesive hydrogel sensor with excellent mechanical properties that is suitable for a wide range of applications.
Topics: Humans; Adhesives; Resin Cements; Hydrogels; Motion; Wearable Electronic Devices; Electric Conductivity
PubMed: 37294660
DOI: 10.1002/marc.202300182 -
Acta Biomaterialia Jul 2022Postoperative adhesion is a serious and frequent complication, but there is currently no reliable anti-adhesive barrier available due to low tissue adhesiveness,...
Postoperative adhesion is a serious and frequent complication, but there is currently no reliable anti-adhesive barrier available due to low tissue adhesiveness, undesirable chemical reactions, and poor operability. To overcome these problems, we report a single-syringe hotmelt tissue adhesive that dissolves upon warming over 40 °C and coheres at 37 °C as a postoperative barrier. Tendon-derived gelatin was conjugated with the ureidopyrimidinone unit to supramolecularly control the sol-gel transition behavior. This functionalization improved bulk mechanical strength, tissue-adhesive properties, and stability under physiological conditions through the augmentation of intermolecular hydrogen bonding by ureidopyrimidinone unit. This biocompatible adhesive prevented postoperative adhesion between cecum and abdominal wall in adhesion models of rats. This hotmelt tissue adhesive has enormous potential to prevent postoperative complications and may contribute to minimally invasive surgery. STATEMENT OF SIGNIFICANCE: There is a strong need to develop medical tissue adhesives with high biocompatibility, tissue adhesiveness, and operatability to prevent postoperative complications. In this report, single syringe, hotmelt-type tissue adhesive was developed by controlling sol-gel transition behavior of gelatin through supramolecular approach. The functionalization of gelatin with quadruple hydrogen bonding improved key features necessary for anti-adhesive barrier including bulk mechanical strength, tissue adhesive property, stability under physiological conditions, and anti-adhesive property. The hotmelt tissue adhesive can be used for a sealant, hemostatic reagent, and wound dressing to prevent postoperative complications including delayed bleeding, perforation, and inflammation and contribute to minimally invasive surgery.
Topics: Adhesives; Animals; Gelatin; Postoperative Complications; Rats; Tissue Adhesions; Tissue Adhesives
PubMed: 35500814
DOI: 10.1016/j.actbio.2022.04.037