Nanoparticles-stacked superhydrophilic coating supported synergistic antimicrobial ability for enhanced wound healing

Asymmetric Janus Nanofibrous Agar-Based Wound Dressing Infused with Enhanced Antioxidant and Antibacterial Properties

In the present study, we have developed an agar-based asymmetric Janus nanofibrous wound dressing comprising a support and an electrospun layer with antibacterial and antioxidant properties, respectively, to facilitate healing effectively. The support layer containing agar and silver nitrate was fabricated by using solvent casting for sustained release, combating the dose-dependent cytotoxicity of silver nanoparticles, where nanoparticles were synthesized using a one-pot reduction method. The electrospun layer, fabricated with a mixture of agar and polycaprolactone infused with gallic acid, was electrospun over the support layer to impart antioxidant properties. Characterizations using UV-vis spectroscopy, transmission electron microscopy, scanning electron microscopy, and Fourier transform infrared spectroscopy validated the synthesis of nanoparticles in 10-20 nm diameter and the asymmetric Janus dressing. The developed Janus nanofibrous structure exhibited 98% porosity, excellent fluid-handling properties, a moisture permeability of 1200 g/m2/day, and a water absorption of ∼250%. Moreover, the time-kill assay confirmed potent bacteriostatic effect against Gram-positive and Gram-negative bacteria, and sustained release of silver nanoparticles followed the Korsmeyer-Peppas model. With over 90% free radical scavenging efficacy, 37% degradation in 7 days, and less than 2% hemolysis, the dressings demonstrated exceptional antioxidant, biodegradable, and hemocompatible properties. The biocompatibility assessment further confirmed its cytocompatible efficacy, with more than 79% wound closure in the wound scratch assay. Most importantly, in vivo studies demonstrated the efficacy of the developed Janus dressing, promoting over 97% healing within 12 days of injury with higher epithelial formation. Overall, the in vitro and in vivo assessment of the developed Janus dressing confirmed its potential to function as a versatile and effective material for wound care applications.

N-Acetyl Cysteine-Decorated Nitric Oxide-Releasing Interface for Biomedical Applications

Biomedical devices are vulnerable to infections and biofilm formation, leading to extended hospital stays, high expenditure, and increased mortality. Infections are clinically treated via the administration of systemic antibiotics, leading to the development of antibiotic resistance. A multimechanistic strategy is needed to design an effective biomaterial with broad-spectrum antibacterial potential. Recent approaches have investigated the fabrication of innately antimicrobial biomedical device surfaces in the hope of making the antibiotic treatment obsolete. Herein, we report a novel fabrication strategy combining antibacterial nitric oxide (NO) with an antibiofilm agent N-acetyl cysteine (NAC) on a polyvinyl chloride surface using polycationic polyethylenimine (PEI) as a linker. The designed biomaterial could release NO for at least 7 days with minimal NO donor leaching under physiological conditions. The proposed surface technology significantly reduced the viability of Gram-negative Escherichia coli (>97%) and Gram-positive Staphylococcus aureus (>99%) bacteria in both adhered and planktonic forms in a 24 h antibacterial assay. The composites also exhibited a significant reduction in biomass and extra polymeric substance accumulation in a dynamic environment over 72 h. Overall, these results indicate that the proposed combination of the NO donor with mucolytic NAC on a polymer surface efficiently resists microbial adhesion and can be used to prevent device-associated biofilm formation.

Fibronectin Connecting Cell Sheet Based on Click Chemistry for Wound Repair

As a living repair material, cell sheet exhibits significant potential in wound repair. Nonetheless, wound healing is a complicated and protracted process that necessitates specific repair functions at each stage, including hemostasis and antibacterial activity. In this work, on the basis of harvesting the cell sheet via a photothermal response strategy, a fibronectin attached cell sheet (FACS) is prepared to enhance its wound repair capability. For this purpose, the azide group (N3 ) is initially tagged onto the cell surface through metabolic glycoengineering of unnatural sugars, and then the conjugate (DBCO-fibronectin) comprises of the dibenzocyclooctyne (DBCO) and fibronectin with multiple wound repair functions is linked to N3 using click chemistry. Biological evaluations following this demonstrates that the FACS preparation exhibits excellent biocompatibility, and the fibronectin modification enhances the capacity for cell proliferation and migration. Moreover, in vivo wound healing experiment confirms the reparative efficacy of FACS. It not only has a wound closure rate 1.46 times that of a conventional cell sheet but also reduces inflammatory cell infiltration, promotes hair follicle and blood vessel regeneration, and encourages collagen deposition. This strategy holds enormous clinical potential and paves the way for advanced functional modifications of cell sheets.

Facile Construction of Antimicrobial Surface via One-Step Co-Deposition of Peptide Polymer and Dopamine

The infections associated with implantable medical devices can greatly affect the therapeutic effect and impose a heavy financial burden. Therefore, it is of great significance to develop antimicrobial biomaterials for the prevention and mitigation of healthcare-associated infections. Here, a facile construction of antimicrobial surface via one-step co-deposition of peptide polymer and dopamine is reported. The co-deposition of antimicrobial peptide polymer DLL60 BLG40 with dopamine (DA) on the surface of thermoplastic polyurethane (TPU) provides peptide polymer-modified TPU surface (TPU-DLL60 BLG40 ). The antimicrobial test shows that the TPU-DLL60 BLG40 surfaces of the sheet and the catheter both exhibit potent killing of 99.9% of methicillin-resistant Staphylococcus aureus (MRSA) and Escherichia coli (E. coli). In addition, the TPU-DLL60 BLG40 surface also exhibits excellent biocompatibility. This one-step antimicrobial modification method is fast and efficient, implies promising application in surface antimicrobial modification of implantable biomaterials and medical devices.

Electrohydrodynamic Nanopatterning: A Novel Solvent-Assisted Technique for Unconventional Substrates

Electrohydrodynamic (EHD)-driven patterning is a pioneering lithographic technique capable of replicating and modifying micro/nanostructures efficiently. However, this process is currently restricted to conventional substrates, as it necessitates a uniform and robust electric field over a large area. Consequently, the use of nontraditional substrates, such as those that are flexible, nonflat, or have high insulation, has been notably limited. In our study, we extend the applicability of EHD-driven patterning by introducing a solvent-assisted capillary peel-and-transfer method that allows the successful removal of diverse EHD-induced structures from their original substrates. Compared with the traditional route, our process boasts a success rate close to 100%. The detached structures can then be efficiently transferred to nonconventional substrates, overcoming the limitations of the traditional EHD process. Our method exhibits significant versatility, as evidenced by successful transfer of structures with engineered wettability and patterned structures composed of metals and metal oxides onto nonconventional substrates.

Porous polydimethylsiloxane films with specific surface wettability but distinct regular physical structures fabricated by 3D printing

Porous polydimethylsiloxane (PDMS) films with special surface wettability have potential applications in the biomedical, environmental, and structural mechanical fields. However, preparing porous PDMS films with a regular surface pattern using conventional methods, such as chemical foaming or physical pore formation, is challenging. In this study, porous PDMS films with a regular surface pattern are designed and prepared using 3D printing to ensure the formation of controllable and regular physical structures. First, the effect of the surface wettability of glass substrates with different surface energies (commercial hydrophilic glass and hydrophobic glass (F-glass) obtained by treating regular glass with 1H,1H,2H,2H-perfluorooctyl-trichlorosilane) on the structural characteristics of the 3D printed PDMS filaments is investigated systematically. Additionally, the effect of the printing speed and the surface wettability of the glass substrate on the PDMS filament morphology is investigated synchronously. Next, using the F-glass substrate and an optimized printing speed, the effects of the number of printed layers on both the morphologies of the individual PDMS filaments and porous PDMS films, and the surface wettability of the films are studied. This study reveals that regularly patterned porous PDMS films with distinct structural designs but the same controllable surface wettability, such as anisotropic surface wettability and superhydrophobicity, can be easily fabricated through 3D printing. This study provides a new method for fabricating porous PDMS films with a specific surface wettability, which can potentially expand the application of porous PDMS films.

Nano tantalum-coated 3D printed porous polylactic acid/beta-tricalcium phosphate scaffolds with enhanced biological properties for guided bone regeneration

Bone defects caused by tumors section, traffic accidents, and surgery remain a challenge in clinical. The drawbacks of traditional autografts and allografts limit their clinical application. 3D printed porous scaffolds have monumental potential to repair bone defects but still cannot effectively promote bone formation. Nano tantalum (Ta) has been reported with effective osteogenesis capability. Herein, we fabricated 3D printed PLA/β-TCP scaffold by using the fused deposition modeling (FDM) technique. Ta was doped on the surface of scaffolds utilizing the surface adhesion ability of polydopamine to improve its properties. The constructed PLA/β-TCP/PDA/Ta had good physical properties. In vitro studies demonstrated that the PLA/β-TCP/PDA/Ta scaffolds considerably promote cell proliferation and migration, and it additionally has osteogenic properties. Therefore, Ta doped 3D printed PLA/β-TCP/PDA/Ta scaffold could incontestably improve surface bioactivity and lead to better osteogenesis, which may provide a unique strategy to develop bioactive bespoke implants in orthopedic applications.

Nanostructured Electrospun Polycaprolactone-Propolis Mats Composed of Different Morphologies for Potential Use in Wound Healing

This study aimed to investigate different types of morphologies obtained using the electrospinning process to produce a material that enables wound healing while performing a controlled release. Using benign solvents, the authors prepared and characterised electrospun polycaprolactone mats loaded with propolis, a popular extract in traditional medicine with potential for skin repair. Different morphologies were obtained from distinct storage periods of the solution before electrospinning to investigate the effect of PCL hydrolysis (average diameters of fibres and beads: 159.2-280.5 nm and 1.9-5.6 μm, respectively). Phytochemical and FTIR analyses of the extract confirmed propolis composition. GPC and viscosity analyses showed a decrease in polymer molecular weight over the storage period (about a 70% reduction over 14 days) and confirmed that it was responsible for the nanostructure diversity. Moreover, propolis acted as a lubricant agent, affecting the spun solutions' viscosity and the thermal properties and hydrophilicity of the mats. All samples were within the value range of the water vapour transpiration rate of the commercial products (1263.08 to 2179.84 g/m²·day). Even though the presence of beads did not affect the propolis release pattern, an in vitro wound-healing assay showed that propolis-loaded mats composed of beaded fibres increased the cell migration process. Thus, these films could present the potential for use in wound dressing applications.