Considerable efforts have been devoted to developing wound dressings with various functions, including rapid cell proliferation, protection against infection, and wound state monitoring to minimize severe pain and the risks of wound‐caused secondary infections. However, it remains challenging to diagnose wound conditions and achieve integration of the above functions without specialized equipment and expertise in wound care. This study describes an electrospun composite micro/nanofiber‐based bilayer‐dressing patch comprising a healing‐support layer (hyaluronic acid, gelatin, and dexpanthenol) and a protective/monitoring layer (curcumin and polycaprolactone). The improved cell regeneration function and biocompatibility of the healing‐support layer enable rapid healing, as evidenced by the expedited growth of fibroblasts. The superior antimicrobial properties (against Escherichia coli and Staphylococcus aureus) and visible color changes within the pH range of wound lesions (pH 6–9) of the protective/monitoring layer make the dressing suitable for advanced wound care. The wounds inflicted on BALB/c mice heal rapidly (12 days) without scars while the wound state can be diagnosed by the change in color of the dressing patch. The multifunctional wound dressing patch developed in this study is expected to promote wound healing and monitor wound state; thus, facilitating convenient wound management.

No abstract

Sweat pH is an important indicator for diagnosing disease state such as cystic fibrosis. However, conventional pH sensors are composed of large brittle mechanical parts and need additional instruments to...

Background Patients face a serious threat if a solid tumor leaves behind partial residuals or cannot be completely removed after surgical resection. Immunotherapy has attracted attention as a method to prevent this condition. However, the conventional immunotherapy method targeting solid tumors, that is, intravenous injection, has limitations in homing in on the tumor and in vivo expansion and has not shown effective clinical results. Method To overcome these limitations, NK cells (Natural killer cells) were encapsulated in micro/macropore-forming hydrogels using 3D bioprinting to target solid tumors. Sodium alginate and gelatin were used to prepare micro-macroporous hydrogels. The gelatin contained in the alginate hydrogel was removed because of the thermal sensitivity of the gelatin, which can generate interconnected micropores where the gelatin was released. Therefore, macropores can be formed through bioprinting and micropores can be formed using thermally sensitive gelatin to make macroporous hydrogels. Results It was confirmed that intentionally formed micropores could help NK cells to aggregate easily, which enhances cell viability, lysis activity, and cytokine release. Macropores can be formed using 3D bioprinting, which enables NK cells to receive the essential elements. We also characterized the functionality of NK 92 and zEGFR-CAR-NK cells in the pore-forming hydrogel. The antitumor effects on leukemia and solid tumors were investigated using an in vitro model. Conclusion We demonstrated that the hydrogel encapsulating NK cells created an appropriate micro–macro environment for clinical applications of NK cell therapy for both leukemia and solid tumors via 3D bioprinting. 3D bioprinting makes macro-scale clinical applications possible, and the automatic process shows potential for development as an off-the-shelf immunotherapy product. This immunotherapy system could provide a clinical option for preventing tumor relapse and metastasis after tumor resection. Graphical Abstract Micro/macropore-forming hydrogel with NK cells fabricated by 3D bioprinting and implanted into the tumor site.

In order to develop conductive-biocompatible 3D parts, poly(lactic acid) (PLA) is mixed with a hybrid of carbon black (CB, 4%) and graphene (GP, 0.1-0.5%) and the change of the particle dispersion under a flow is investigated based on rheological and electrical characterizations. In CB/PLA composite, CB aggregates are rearranged and percolation structure is disrupted under the given flow, resulting in a decrease in the modulus of the composite and lower electrical conductivity. During the 3D printing process, assemblies of CB aggregates do not remain close enough to maintain the percolation structure. When CB/PLA composite is mixed with GP, CB aggregates come into contact with GP aggregates to form percolation, maintaining a durable particle percolation against a flow and realizing electrical conductivity in 3D part. Despite the orientation effect of GP, the presence of GP enhances connectivity between the aggregates under a flow and maintains electrical percolation. A cell viability test of a 3D composite part shows good adsorption and growth of the cell due to the rough surface and biocompatibility of PLA. The addition of CB and GP to PLA improves not only the electrical properties of the 3D printing part but also enhances the cell viability.