Monodisperse nanoparticles of biodegradable polyhydroxyalkanoates (PHAs) polymers, copolymers of 3-hydroxybutyrate (3HB) and 4-hydroxybutyrate (4HB), are synthesized using a membrane-assisted emulsion encapsulation and evaporation process for biomedical resorbable adhesives. The precise control over the diameter of these PHA particles, ranging from 100 nm to 8 μm, is achieved by adjusting the diameter of emulsion or the PHA concentration. Mechanical properties of the particles can be tailored based on the 3HB to 4HB ratio and molecular weight, primarily influenced by the level of crystallinity. These monodisperse PHA particles in solution serve as adhesives for hydrogel systems, specifically those based on poly(N, N-dimethylacrylamide) (PDMA). Semi-crystalline PHA nanoparticles exhibit stronger adhesion energy than their amorphous counterparts. Due to their self-adhesiveness, adhesion energy increases even when those PHA nanoparticles form multilayers between hydrogels. Furthermore, as they degrade and are resorbed into the body, the PHA nanoparticles demonstrate efficacy in in vivo wound closure, underscoring their considerable impact on biomedical applications.

Multifunctional bio-adhesives with tunable mechanical properties are obtained by controlling the orientation of anisotropic particles in a blend of fast-curing hydrogel with an imposed capillary flow. The suspensions\' microstructural evolution was monitored by the small-angle light scattering (SALS) method during flow up to the critical Péclet number (Pe≈1) necessary for particle orientation and hydrogel crosslinking. The multifunctional bio-adhesives were obtained by combining flow and UV light exposure for rapid photo-curing of PEGDA medium and freezing titania rods\' ordered microstructures. Blending the low- and high-molecular weight of PEGDA polymer improved the mechanical properties of the final hydrogel. All the hydrogel samples were non-cytotoxic up to 72 h after cell culturing. The system shows rapid blood hemostasis and promotes adhesive and cohesive strength matching targeted tissue properties with an applicating methodology compatible with surgical conditions. The developed SALS approach to optimize nanoparticles\' microstructures in bio-adhesive applies to virtually any optically transparent nanocomposite and any type of anisotropic nanoparticles. As such, this method enables rational design of bio-adhesives with enhanced anisotropic mechanical properties which can be tailored to potentially any type of tissue.

Marine mussels produce strong underwater adhesives called mussel adhesive proteins (MAPs) that can adhere to a variety of surfaces under physiological conditions. Thus, MAPs have been investigated as a potentially sustainable alternative to conventional petrochemical-based adhesives. Recombinant MAPs would be promising for large-scale production and commercialization; however, MAPs are intrinsically adhesive, aggregative, and insoluble in water. In this study, we have developed a solubilization method for the control of MAP adhesion by fusion protein technique. Foot protein 1 (Fp1), a kind of MAP, was fused with the highly water-soluble protein, which is the C-terminal domain of ice-nucleation protein K (InaKC), separated by a protease cleaving site. The fusion protein exhibited low adhesion but high solubility and stability. Notably, Fp1 recovered its adhesive property after removal from the InaKC moiety by protease cleaving, which was evaluated and confirmed by the agglomeration of magnetite particles in water. The ability to control adhesion and agglomeration makes MAPs favorable prospects for bio-based adhesives.

OBJECTIVE: To summarize the available evidence and to quantitatively evaluate the global results of different waterproofing layers in substantiating the UCF repair.
METHODS: After defining the study protocol, the review was conducted according to the PRISMA guidelines by a team comprising experts in hypospadiology, systematic reviews and meta-analysis, epidemiology, biostatistics and data science. Studies published from 2000 onwards, reporting on the results of UCF closure after hypospadias repair were searched for on PUBMED, Embase and Google Scholar. Study quality was assessed using Joanna Briggs Checklist (JBI) critical appraisal tool. The results with different techniques were compared with the two samples independent proportions test with the help of Microsoft Excel, MedCalc software and an online calculator.
RESULTS: Seventy-three studies were shortlisted for the synthesis; the final analysis included 2886 patients (71 studies) with UCF repair failure in 539. A summary of various dimensions involved with the UCF repair has been generated including time gap after last surgery, stent-vs-no stent, supra-pubic catheterization, suture material, suturing technique, associated anomalies, complications, etc. The success rates associated with different techniques were calculated and compared: simple catheterization (100%), simple primary closure (73.2%), dartos (78.8%), double dartos flaps (81%), scrotal flaps (94.6%), tunica vaginalis (94.3%), PATIO repair (93.5%), biomaterials or dermal substitutes (92%), biocompatible adhesives (56.5%) and skin-based flaps (54.5%). Several techniques were identified as solitary publications and discussed.
CONCLUSIONS: Tunica vaginalis and scrotal flaps offer the best results after UCF closure in the synthesis. However, it is not possible to label any technique as ideal or perfect. Almost all popular waterproofing layers have depicted absolute (100%) success sometimes. There are a vast number of other factors (patient\'s local anatomy, surgeon\'s expertise and technical perspectives) which influence the final outcome.

Glue-type bio-adhesives are in high demand for many applications, including hemostasis, wound closure, and integration of bioelectronic devices, due to their injectable ability and in situ adhesion. However, most glue-type bio-adhesives cannot be used for short-term tissue adhesion due to their weak instant cohesion. Here, we show a novel glue-type bio-adhesive based on the phase separation of proteins and polysaccharides by functionalizing polysaccharides with dopa. The bio-adhesive exhibits increased adhesion performance and enhanced phase separation behaviors. Because of the cohesion from phase separation and adhesion from dopa, the bio-adhesive shows excellent instant and long-term adhesion performance for both organic and inorganic substrates. The long-term adhesion strength of the bio-glue on wet tissues reached 1.48 MPa (shear strength), while the interfacial toughness reached ~880 J m-2. Due to the unique phase separation behaviors, the bio-glue can even work normally in aqueous environments. At last, the feasibility of this glue-type bio-adhesive in the adhesion of various visceral tissues in vitro was demonstrated to have excellent biocompatibility. Given the convenience of application, biocompatibility, and robust bio-adhesion, we anticipate the bio-glue may find broad biomedical and clinical applications.

Tissue adhesives have been widely used for preventing wound leaks, sever bleeding, as well as for enhancing drug delivery and biosensing. However, only a few among suggested platforms cover the circumstances required for high-adhesion strength and biocompatibility, without toxicity. Antibacterial properties, controllable degradation, encapsulation capacity, detectability by image-guided procedures and affordable price are also centered to on-demand tissue adhesives. Herein we overview the history of tissue adhesives, different types of polysaccharide-based tissue adhesives, their mechanism of gluing, and different applications of polysaccharide-based tissue adhesives. We also highlight the latest progresses in engineering of tissue adhesives followed by existing challenges in fabrication processes. We argue that future studies have to place focus on a holistic understanding of biomaterials and tissue surface properties, proper fabrication procedures, and development of magnetic and conductive responsive adhesives in order to bridge the huge gap between the present studies for clinical implementation.

Existing research on mycelium-based materials recognizes the binding capacity of fungal hyphae. Fungal hyphae digest and bond to the surface of the substrate, form entangled networks, and enhance the mechanical strength of mycelium-based composites. This investigation was driven by the results of an ongoing project, where we attempt to provide basic concepts for a broad application of a mycelium and chipped wood composite for building components. Simultaneously, we further explore the binding capacity of mycelium and chipped wood composites with a series of experiments involving different mechanical interlocking patterns. Although the matrix material was analyzed on a micro-scale, the samples were developed on a meso-scale to enhance the bonding surface. The meso-scale allows exploring the potential of the bio-based material for use in novel construction systems. The outcome of this study provides a better understanding of the material and geometrical features of mycelium-based building elements.

Cartilage damage is a prevalent health concern among humans. The inertness of cartilage, the absence of self-healing properties, and the lack of appropriate repair materials that integrate into the tissue pose a significant challenge for cartilage repair. Thus, it is important to develop novel soft biomaterials with strong tissue adhesion and chondrogenic capabilities for cartilage repair. Herein, a new type of protein adhesive is reported that exhibits superior cartilage repair performance. The material is fabricated by the electrostatic combination of chondroitin sulfate (CS) and positively charged elastin-like protein, which is derived from natural components of the extracellular matrix (ECM). The adhesive showed robust adhesion properties on different tissue substrates, offering a favorable environment for cartilage tissue integration. Noncovalent bonding between CS molecules in the glue allows for its controlled release, which is required for efficient chondrogenic differentiation. When implanted into a rat model of cartilage defect, this protein adhesive exhibited beneficial healing effects, as evidenced by enhanced chondrogenesis, sufficient ECM production, and lateral integration. Therefore, this engineered protein complex is a promising candidate for translational application in the field of cartilage repair.

The potential of producing eco-friendly, formaldehyde-free, high-density fiberboard (HDF) panels from hardwood fibers bonded with urea-formaldehyde (UF) resin and a novel ammonium lignosulfonate (ALS) is investigated in this paper. HDF panels were fabricated in the laboratory by applying a very low UF gluing factor (3%) and ALS content varying from 6% to 10% (based on the dry fibers). The physical and mechanical properties of the fiberboards, such as water absorption (WA), thickness swelling (TS), modulus of elasticity (MOE), bending strength (MOR), internal bond strength (IB), as well as formaldehyde content, were determined in accordance with the corresponding European standards. Overall, the HDF panels exhibited very satisfactory physical and mechanical properties, fully complying with the standard requirements of HDF for use in load-bearing applications in humid conditions. Markedly, the formaldehyde content of the laboratory fabricated panels was extremely low, ranging between 0.7-1.0 mg/100 g, which is, in fact, equivalent to the formaldehyde release of natural wood.

As an important auxiliary material, adhesive materials have many important applications in various fields including but not limited to industrial packaging, marine engineering, and biomedicine. Naturally occurring adhesives such as mussel foot proteins are usually biocompatible and biodegradable, but their limited sources and poor mechanical properties in physiological conditions have limited their widespread uses in biomedical field. Inspired by the underwater adhesion phenomenon of natural organisms, a series of biomimetic adhesive materials have been developed through chemical or bioengineering approaches. Notably, some of those synthetic adhesives have exhibited great promise for medical applications in terms of their biocompatibility, biodegradability, strong tissue adhesion and many other attractive functional properties. As natural adhesive materials possess distinctive \"living\" attributes such as environmental responsiveness, self-regeneration and autonomous repairs, the development of various biologically inspired and biomimetic adhesive materials using natural adhesives as blueprints will thus be of keen and continuous interest in the future. The emerging field of synthetic biology will likely provide new opportunities to design living glues that recapitulate the dynamic features of those naturally occurring adhesives.
粘合材料作为一种重要的辅助材料，在工业包装、海洋工程以及生物医药等多个领域都有广泛的应用需求。天然存在的粘合剂如贻贝足丝粘合蛋白等具有良好的生物相容性和生物可降解性，但因其来源受限及在生理环境下较弱的粘合性能，因此在生物医药领域的应用受到了限制。从自然生物的粘合现象中汲取灵感，各种利用化学或生物合成方法制备的仿生粘合材料应运而生，针对生物医药领域的特定需求，一些新兴粘合材料在生物相容性、生物可降解性以及组织粘附等方面都表现出在医药领域应用的潜力。展望未来，受自然粘合材料兼具环境响应、自我再生和自修复等特征的启迪，各种生物灵感和生物仿生粘合材料的开发势必是未来的发展热点，而合成生物学技术为创建具有上述特征的活体粘合材料提供了新的可能。.