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Biomaterials Advances Aug 2023The central nervous system (CNS) has a limited ability to regenerate after a traumatic injury or a disease due to the low capacity of the neurons to re-grow and the... (Review)
Review
The central nervous system (CNS) has a limited ability to regenerate after a traumatic injury or a disease due to the low capacity of the neurons to re-grow and the inhibitory environment formed in situ. Current therapies include the use of drugs and rehabilitation, which do not fully restore the CNS functions and only delay the pathology progression. Tissue engineering offers a simple and versatile solution for this problem through the use of bioconstructs that promote nerve tissue repair by bridging cavity spaces. In this approach, the choice of biomaterial is crucial. Herein, we present recent advances in the design and development of adhesive and self-healing materials that support CNS healing. The adhesive materials have the advantage of promoting recovery without the use of needles or sewing, while the self-healing materials have the capacity to restore the tissue integrity without the need for external intervention. These materials can be used alone or in combination with cells and/or bioactive agents to control the inflammation, formation of free radicals, and proteases activity. We discuss the advantages and drawbacks of different systems. The remaining challenges that can bring these materials to clinical reality are also briefly presented.
Topics: Adhesives; Biocompatible Materials; Central Nervous System; Tissue Engineering; Neurons
PubMed: 37146528
DOI: 10.1016/j.bioadv.2023.213439 -
Macromolecular Bioscience Oct 2021Cyanoacrylate glues are a renowned synthetic tissue sealant that cures rapidly through polymerization at room temperature, felicitating medical glues to treat skin...
Cyanoacrylate glues are a renowned synthetic tissue sealant that cures rapidly through polymerization at room temperature, felicitating medical glues to treat skin wounds and surgical openings. Despite a wide range of cyanoacrylates available, only 2-octyl cyanoacrylates (OCA) provides the best biocompatibility. In this study, the polymerization and adhesive properties of 2-octyl cyanoacrylates (OCA) are explored in the presence of a highly biocompatible and biochemically inert polymer, poly(ethylene glycol) polyhedral oligomeric silsesquioxane (PEG-POSS). The effect of PEG-POSS on the polymerization of OCA is examined on a plastic surface and over pig skin. A peel-test is performed to evaluate the strength of OCA adhesive properties between two pieces of pig skin samples. Additionally, thin films of OCA are prepared using different fillers and evaluated for tear test. The results reveal that when applied on the plastic or pig skin, PEG-POSS initiated polymerization in OCA yields a high molecular weight OCA polymer with much better adhesive properties compared to commercially available cyanoacrylate adhesives. The relative change in the molecular weights of OCA compared to commercially available cyanoacrylate bioadhesives such as Dermaflex is much higher. The pig skin peeling test shows that OCA needs higher peeling force than Dermaflex.
Topics: Adhesives; Animals; Cyanoacrylates; Polymerization; Polymers; Swine; Tissue Adhesives
PubMed: 34268867
DOI: 10.1002/mabi.202100143 -
Journal of Colloid and Interface Science Sep 2023Marine organisms, such as mussels and sandcastle worms, can master rapid and robust adhesion in turbulent seawater, becoming leading archetypes for the design of... (Review)
Review
Marine organisms, such as mussels and sandcastle worms, can master rapid and robust adhesion in turbulent seawater, becoming leading archetypes for the design of underwater adhesives. The adhesive proteins secreted by the organisms are rich in catecholic amino acids along with ionic and amphiphilic moieties, which mediate the adaptive adhesion mainly through catechol chemistry and coacervation process. Catechol allows a broad range of molecular interactions both at the adhesive-substrate interface and within the adhesive matrix, while coacervation promotes the delivery and surface spreading of the adhesive proteins. These natural design principles have been translated to synthetic systems toward the development of biomimetic adhesives with water-resist adhesion and cohesion. This review provides an overview of the recent progress in bio-inspired wet adhesives, focusing on two aspects: (1) the elucidation of the versatile molecular interactions (e.g., electrostatic interactions, metal coordination, hydrogen bonding, and cation-π/anion-π interactions) used by natural adhesives, mainly through nanomechanical characterizations; and (2) the rational designs of wet adhesives based on these biomimetic strategies, which involve catechol-functionalized, coacervation-induced, and hydrogen bond-based approaches. The emerging applications (e.g., tissue glues, surgical implants, electrode binders) of the developed biomimetic adhesives in biomedical, energy, and environmental fields are also discussed, with future research directions proposed.
Topics: Animals; Adhesives; Bivalvia; Proteins; Cations; Catechols
PubMed: 37167909
DOI: 10.1016/j.jcis.2023.04.150 -
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 Applied Materials & Interfaces May 2022The adhesion between flexible epidermal sensors and human skin is essential for maintaining the stable functionality of the sensors. However, it is still challenging for...
The adhesion between flexible epidermal sensors and human skin is essential for maintaining the stable functionality of the sensors. However, it is still challenging for epidermal electronic devices to achieve durable adhesion to the surface of the skin, especially under sweaty or humid conditions. Here, we report a silk fibroin-polyacrylamide (SF-PAAm) double network (DN) hydrogel adhesive with excellent biocompatibility, strong and durable adhesion on wet surfaces, and tunable adhesive properties. The hydrophilic PAAm network greatly improves the water retention capability of the DN hydrogel and reduces the β-sheet crystalline content of SF, leading to excellent adhesive properties of the hydrogel across a wide range of humidity. The SF-PAAm DN hydrogel adhesive can be readily integrated with different epidermal sensor arrays and performs very well in real-time on-body sweat sensing. The SF-PAAm DN hydrogels have great potential for application in various epidermal healthcare sensors as well as medical adhesives for other medical applications.
Topics: Adhesives; Fibroins; Humans; Hydrogels; Silk; Sweat; Wearable Electronic Devices
PubMed: 35507426
DOI: 10.1021/acsami.2c02534 -
ACS Applied Materials & Interfaces Feb 2022Translating fundamental studies of marine mussel adhesion into practical mussel-inspired wet adhesives remains an important technological challenge. To adhere, mussels...
Translating fundamental studies of marine mussel adhesion into practical mussel-inspired wet adhesives remains an important technological challenge. To adhere, mussels secrete adhesive proteins rich in the catecholic amino acid 3,4-dihydroxyphenylalanine (Dopa) and positively charged lysine. Consequently, numerous synthetic adhesives incorporating catecholic and cationic functionalities have been designed. However, despite widespread research, uncertainties remain about the optimal design of synthetic mussel-inspired adhesives. Here, we present a study of the adhesion of mussel-inspired pressure-sensitive adhesives. We explore the effects of catechol content, molecular architecture, and solvent quality on pressure-sensitive adhesive (PSA) adhesion and cohesion measured in a surface forces apparatus. Our findings demonstrate that the influence of catechol content depends on the choice of solvent and that adhesive performance is dictated by film composition rather than molecular architecture. Our results also highlight the importance of electrostatic and hydrophobic interactions for adhesion and cohesion in aqueous environments. Together, our findings contribute to an improved understanding of the interplay between materials chemistry, environmental conditions, and adhesive performance to facilitate the design of bioinspired wet adhesives.
Topics: Acrylic Resins; Adhesiveness; Adhesives; Catechols; Ethanol; Pressure; Solvents; Water
PubMed: 35050591
DOI: 10.1021/acsami.1c22295 -
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 -
British Journal of Nursing (Mark Allen... Mar 2020The skin's main function is to act as a physical barrier against harmful substances. Medical adhesive-related skin injury (MARSI) is a prevalent and under-reported...
The skin's main function is to act as a physical barrier against harmful substances. Medical adhesive-related skin injury (MARSI) is a prevalent and under-reported condition that compromises the skin's integrity. Repeated applications and removal of appliances can increase the likelihood of MARSI occurring. Prevention and treatment are key to ensure appropriate skin preparation, product appliance and removal. The use of structured approaches is imperative and there is a need to increase the awareness of MARSI among patients and health professionals to ensure that informed decisions are made.
Topics: Adhesives; Humans; Skin; Skin Physiological Phenomena
PubMed: 32207648
DOI: 10.12968/bjon.2020.29.6.S20 -
International Journal of Biological... Dec 2023The inadequacy of conventional surgical techniques for wound closure and repair in soft and resilient tissues may lead to poor healing outcomes such as local tissue...
The inadequacy of conventional surgical techniques for wound closure and repair in soft and resilient tissues may lead to poor healing outcomes such as local tissue fibrosis and contracture. Therefore, the development of adhesive and resilient hydrogels that can adhere firmly to irregular and dynamic wound interfaces and provide a "tension-free proximity" environment for tissue regeneration has become extremely important. Herein, we describe an integrated modeling-experiment-application strategy for engineering a promising hydrogel-based bioadhesive based on recombinant human collagen (RHC) and catechol-modified hyaluronic acid (HA-Cat). Molecular modeling and simulations were used to verify and explore the hypothesis that RHC and HA-Cat can form an assembly complex through physical interactions. The complex was synergistically crosslinked via a catechol/o-quinone coupling reaction and a carbodiimide coupling reactions, resulting in superior hydrogels with strong adhesion and resilience properties. The application of this bioadhesive to tissue adhesion and wound sealing in vivo was successfully demonstrated, with an optimum collagen index, epidermal thickness, and lowest scar width. Furthermore, subcutaneous implantation demonstrated that the bioadhesive exhibited good biocompatibility and degradability. This newly developed hydrogel may be a highly promising surgical adhesive for medical applications, including wound closure and repair.
Topics: Humans; Hydrogels; Adhesives; Wound Healing; Collagen; Hyaluronic Acid; Tissue Adhesions; Catechols
PubMed: 37793510
DOI: 10.1016/j.ijbiomac.2023.127192 -
Nature Materials Feb 2021Reliable functions of bioelectronic devices require conformal, stable and conductive interfaces with biological tissues. Integrating bioelectronic devices with tissues...
Reliable functions of bioelectronic devices require conformal, stable and conductive interfaces with biological tissues. Integrating bioelectronic devices with tissues usually relies on physical attachment or surgical suturing; however, these methods face challenges such as non-conformal contact, unstable fixation, tissue damage, and/or scar formation. Here, we report an electrical bioadhesive (e-bioadhesive) interface, based on a thin layer of a graphene nanocomposite, that can provide rapid (adhesion formation within 5 s), robust (interfacial toughness >400 J m) and on-demand detachable integration of bioelectronic devices on diverse wet dynamic tissues. The electrical conductivity (>2.6 S m) of the e-bioadhesive interface further allows bidirectional bioelectronic communications. We demonstrate biocompatibility, applicability, mechanical and electrical stability, and recording and stimulation functionalities of the e-bioadhesive interface based on ex vivo porcine and in vivo rat models. These findings offer a promising strategy to improve tissue-device integration and enhance the performance of biointegrated electronic devices.
Topics: Adhesives; Animals; Biosensing Techniques; Electric Conductivity; Hydrogels; Rats; Swine
PubMed: 32989277
DOI: 10.1038/s41563-020-00814-2