Honey was used in traditional medicine to treat wounds until the advent of modern medicine. The rising global antibiotic resistance has forced the development of novel therapies as alternatives to combat infections. Consequently, honey is experiencing a resurgence in evaluation for antimicrobial and wound healing applications. A range of both Gram-positive and Gram-negative bacteria, including antibiotic-resistant strains and biofilms, are inhibited by honey. Furthermore, susceptibility to antibiotics can be restored when used synergistically with honey. Honey’s antimicrobial activity also includes antifungal and antiviral properties, and in most varieties of honey, its activity is attributed to the enzymatic generation of hydrogen peroxide, a reactive oxygen species. Non-peroxide factors include low water activity, acidity, phenolic content, defensin-1, and methylglyoxal (Leptospermum honeys). Honey has also been widely explored as a tissue-regenerative agent. It can contribute to all stages of wound healing, and thus has been used in direct application and in dressings. The difficulty of the sustained delivery of honey’s active ingredients to the wound site has driven the development of tissue engineering approaches (e.g., electrospinning and hydrogels). This review presents the most in-depth and up-to-date comprehensive overview of honey’s antimicrobial and wound healing properties, commercial and medical uses, and its growing experimental use in tissue-engineered scaffolds.

Complex and hierarchically functionalized scaffolds composed of micro- and nanoscale structures are a key goal in tissue engineering. The combination of three-dimensional (3D) printing and electrospinning enables the fabrication of these multiscale structures. This study presents a polycaprolactone 3D-printed and electrospun scaffold with multiple mesh layers and fiber densities. The results show successful fabrication of a dual-scale scaffold with the 3D-printed scaffold acting as a gap collector with the printed microfibers as the electrodes and the pores a series of insulating gaps resulting in aligned nanofibers. The electrospun fibers are highly aligned perpendicular to the direction of the printed fiber and form aligned meshes within the pores of the scaffold. Mechanical testing showed no significant difference between the number of mesh layers whereas the hydrophobicity of the scaffold increased with increasing fiber density. Biological results indicate that increasing the number of mesh layers improves cell proliferation, migration, and adhesion. The aligned nanofibers within the microscale pores allowed enhanced cell bridging and cell alignment that was not observed in the 3D-printed only scaffold. These results demonstrate a facile method of incorporating low-density and aligned fibers within a 3D-printed scaffold that is a promising development in multiscale hierarchical scaffolds where alignment of cells can be desirable.

Acrylonitrile butadiene styrene (ABS), a petroleum-based thermoplastic, is widely used in various industry. It is important to make product costs without reducing the wear characteristics of products. For this reason, over the past 20 years, researchers have focused on improving product performance by reducing material weight. The literature has limited information about the tribological properties of the ABS polymer samples produced with fused deposition modelling. In this study, gyroid-patterned ABS samples with different infill densities (25%, 50%, and 75%) were produced and the effect on the wear properties of the samples was investigated. The main aim of the study is to show the infill density effect on wear and friction performance of the samples and find the coefficient of friction values. So, this study is one of the first studies which investigated wear and friction properties of ABS polymer produced as gyroid pattern with different infill densities. The study might also be used to have an initial information whether ABS polymer can be used in additive manufacturing systems for the joint components. As the performance indicator, diameter deviation, hardness, surface roughness, test temperature, friction coefficient, weight loss, and wearing surface results of the samples were evaluated. The results show that infill density is an important property that effect the tribological and heating characteristic of ABS samples. The friction and heat of the samples increase by increasing infill density. According to the tribological test results, the highest coefficient of friction and friction temperature were reached in the samples with 75% infill density.

Investigating the mechanical and wear properties of widely used PETG (polyethylene terephthalate glycol) filaments is important to understanding the material's performance, reliability, and suitability in different application areas. This study performed tensile and wear tests on PETG samples produced with a 3D printer using four infill patterns (honeycomb, grid, triangular, and gyroid). The study aimed to investigate the effect of infill patterns on the tensile and wear properties of the samples. In the evaluations, friction coefficient, wear rate, SEM microscope images, hardness test, temperature measurement during tensile, diameter accuracy value, Young's modulus, and yield values were analyzed. The mechanical results present that the triangular pattern showed 133% higher mechanical strength compared to other patterns with the highest Young's modulus. As a result of the wear tests, horizontal patterns showed more homogeneous wear, while vertical patterns caused irregular wear by creating more brittle structures. It was found that dense patterns, such as honeycomb and grid, were more resistant to wear. The triangular pattern samples can be preferred for high strength and thermal stability, while gyroid and grid pattern samples can be used in the flexibility field. The results revealed that different infill patterns significantly affect the mechanical and tribological performances of the materials and that appropriate pattern selection can optimize performance in engineering applications.

Skin is a hierarchical and multi-cellular organ exposed to the external environment with a key protective and regulatory role. Wounds caused by disease and trauma can lead to a loss of function, which can be debilitating and even cause death. Accelerating the natural skin healing process and minimizing the risk of infection is a clinical challenge. Electrospinning is a key technology in the development of wound dressings and skin substitutes as it enables extracellular matrix-mimicking fibrous structures and delivery of bioactive materials. Honey is a promising biomaterial for use in skin tissue engineering applications and has antimicrobial properties and potential tissue regenerative properties. This preliminary study investigates a solution electrospun composite nanofibrous mesh based on polycaprolactone and a medical grade honey, SurgihoneyRO. The processing conditions were optimized and assessed by scanning electron microscopy to fabricate meshes with uniform fiber diameters and minimal presence of beads. The chemistry of the composite meshes was examined using Fourier transform infrared spectroscopy and X-ray photon spectroscopy showing incorporation of honey into the polymer matrix. Meshes incorporating honey had lower mechanical properties due to lower polymer content but were more hydrophilic, resulting in an increase in swelling and an accelerated degradation profile. The biocompatibility of the meshes was assessed using human dermal fibroblasts and adipose-derived stem cells, which showed comparable or higher cell metabolic activity and viability for SurgihoneyRO-containing meshes compared to polycaprolactone only meshes. The meshes showed no antibacterial properties in a disk diffusion test due to a lack of hydrogen peroxide production and release. The developed polycaprolactone-honey nanofibrous meshes have potential for use in skin applications.