Synthetic biology-based bacterial extracellular vesicles displaying BMP-2 and CXCR4 to ameliorate osteoporosis.

Osteoporosis (OP) is a systematic bone disease characterized by low bone mass and fragile bone microarchitecture. Conventional treatment for OP has limited efficacy and long-term toxicity. Synthetic biology makes bacterial extracellular vesicle (BEVs)-based therapeutic strategies a promising alternative for the treatment of OP.

Advancing homogeneous networking principles for the development of fatigue-resistant, low-swelling and sprayable hydrogels for sealing wet, dynamic and concealed wounds in vivo.

Effective sealing of wet, dynamic and concealed wounds remains a formidable challenge in clinical practice. Sprayable hydrogel sealants are promising due to their ability to cover a wide area rapidly, but they face limitations in dynamic and moist environments. To address this issue, we have employed the principle of a homogeneous network to design a sprayable hydrogel sealant with enhanced fatigue resistance and reduced swelling.

A paintable ophthalmic adhesive with customizable properties based on symmetrical/asymmetrical cross-linking.

and efficient incision sealing for ophthalmic surgery remains unresolved. Current commercially available gel adhesives often suffer from unsuitable gelation time, difficulty in micro-delivery, and mismatched degradation period, leading to difficulties for application in ocular tissue areas. Herein, a novel hydrogel adhesive was developed based on the simultaneous crosslinking of poly(lysine) (PLL) and lysine (Lys) with an end-modified active ester multi-arm polyethylene glycol (PEG) the amidation reaction, where the residual terminal active ester of PEG can also bond to amino groups on tissue to provide strong adhesion.

Tag-Free Site-Specific BMP-2 Immobilization with Long-Acting Bioactivities via a Simple Sugar-Lectin Interaction.

The construction of a biomaterial matrix with biological properties is of great importance to developing functional materials for clinical use. However, the site-specific immobilization of growth factors to endow materials with bioactivities has been a challenge to date. Considering the wide existence of glycosylation in mammalian proteins or recombinant proteins, we establish a bioaffinity-based protein immobilization strategy (bioanchoring method) utilizing the native sugar-lectin interaction between concanavalin A (Con A) and the oligosaccharide chain on glycosylated bone morphogenetic protein-2 (GBMP-2).

Enlisting a Traditional Chinese Medicine to tune the gelation kinetics of a bioactive tissue adhesive for fast hemostasis or minimally invasive therapy.

Gelation kinetics is important in tailoring chemically crosslinked hydrogel-based injectable adhesives for different applications. However, the regulation of gelation rate is usually limited to varying the gel precursor and/or crosslinker concentration, which cannot reach a fine level and inevitably alters the physical properties of hydrogels. Amidation reactions are widely used to synthesize hydrogel adhesives.

A reduced polydopamine nanoparticle-coupled sprayable PEG hydrogel adhesive with anti-infection activity for rapid wound sealing.

There is a growing demand to develop sprayable hydrogel adhesives with rapid-forming and antibacterial abilities to instantly seal open wounds and combat pathogen infection. Herein, we propose to design a polydopamine nanoparticle (PDA NP) coupled PEG hydrogel that can quickly solidify via an amidation reaction after spraying as well as tightly binding PDA NPs to deliver reactive oxygen species (ROS) and induce a photothermal effect for bactericidal activity, and provide a hydrophilic surface for antifouling activity. The molecular structure of the 4-arm-PEG-NHS precursor was regulated to increase its reactivity with 4-arm-PEG-NH2, which thus shortened the gelation time of the PEG adhesive to 1 s to allow a fast solidification after being sprayed.

Coupling PEG-LZM polymer networks with polyphenols yields suturable biohydrogels for tissue patching.

Poor mechanical performances severely limit the application of hydrogels in vivo; for example, it is difficult to perform a very common suturing operation on hydrogels during surgery. There is a growing demand to improve the mechanical properties of hydrogels for broadening their clinical applications. Natural polyphenols can match the potential toughening sites in our previously reported PEG-lysozyme (LZM) hydrogel because polyphenols have unique structural units including a hydroxyl group and an aromatic ring that can interact with PEG via hydrogen bonding and form hydrophobic interactions with LZM.

Redox-Channeling Polydopamine-Ferrocene (PDA-Fc) Coating To Confer Context-Dependent and Photothermal Antimicrobial Activities.

Microbial disinfection associated with medical device surfaces has been an increasing need, and surface modification strategies such as antibacterial coatings have gained great interest. Here, we report the development of polydopamine-ferrocene (PDA-Fc)-functionalized TiO nanorods (Ti-Nd-PDA-Fc) as a context-dependent antibacterial system on implant to combat bacterial infection and hinder biofilm formation. In this work, two synergistic antimicrobial mechanisms of the PDA-Fc coating are proposed.

Role of polydopamine's redox-activity on its pro-oxidant, radical-scavenging, and antimicrobial activities.

Polydopamine (PDA) is a bioinspired material and coating that offers diverse functional activities (e.g., photothermal, antioxidant, and antimicrobial) for a broad range of applications.

A PEG-Lysozyme hydrogel harvests multiple functions as a fit-to-shape tissue sealant for internal-use of body.

In situ formation of surgical sealants to stop internal fluids leakage is more attractive compared to the traditional suture or staple. However, commercial sealants have weak points in tissue adhesive, cell affinity, antibacterial etc., which make them remain suboptimal for internal use of body.

A turn-on near-infrared fluorescence probe with aggregation-induced emission based on dibenzo[a,c]phenazine for detection of superoxide anions and its application in cell imaging.

A new turn-on near-infrared fluorescence probe (BDP) based on dibenzo[a,c]phenazine for superoxide anion detection with aggregation-induced emission properties as well as a desirable large Stokes shift was designed and synthesized. After BDP reacted with superoxide, the initial diphenyl-phosphinyl groups of BDP were cleaved, resulting in the production of the pyridinium modified fluorophore (BD) with near-infrared emission. The fluorescent sensor BDP has a high selectivity for superoxide anions over some other intracellular ROSs, reductants, metal ions and amino acids.

Targetable N-annulated perylene-based colorimetric and ratiometric near-infrared fluorescent probes for the selective detection of hydrogen sulfide in mitochondria, lysosomes, and serum.

Hydrogen sulfide (HS) serves an effective role in biological systems as the acknowledged third endogenous gasotransmitter, so it makes great sense to detect and analyze HS sensitively and quantitatively in subcellular environments, such as in mitochondria and lysosomes where HS is widespread and functions as the mediator. Considering the excellent photophysical properties and multiple modification sites, N-annulated perylene (NP) was firstly chosen as the fluorophore to design a series of colorimetric and ratiometric near-infrared (NIR) fluorescent probes for the sensitive and selective detection of HS. The probes showed near-infrared fluorescence at 681 nm in the absence of HS.

Self-assembly of dual drug-delivery coating for synergistic bone regeneration.

Bone regeneration for the treatment of bone diseases represents a major clinical need. Introducing recombinant human bone morphogenetic protein-2 (rhBMP-2) into biomaterials is an extensively used approach to induce osteogenic differentiation and accelerate bone regeneration. However, serious adverse events can occur in the event of an overdose of rhBMP-2.