Lymphangiogenesis and Lymphatic Zippering in Skin Associated with the Progression of Lymphedema.

Secondary lymphedema often develops after lymph node dissection or radiation therapy for cancer treatment, resulting in marked skin fibrosis and increased stiffness owing to insufficiency of the lymphatic system caused by abnormal structure and compromised function. However, little is known about the associated changes of the dermal lymphatic vessels. In this study, using the lower limb skin samples of patients with secondary lymphedema, classified as types 1-4 by lymphoscintigraphy, we first confirmed the presence of epidermal thickening and collagen accumulation in the dermis, closely associated with the progression of lymphedema.

Extrusion-Based Bioprinting through Glucose-Mediated Enzymatic Hydrogelation.

We report an extrusion-based bioprinting approach, in which stabilization of extruded bioink is achieved through horseradish peroxidase (HRP)-catalyzed cross-linking consuming hydrogen peroxide (HO) supplied from HRP and glucose. The bioinks containing living cells, HRP, glucose, alginate possessing phenolic hydroxyl (Ph) groups, and cellulose nanofiber were extruded to fabricate 3D hydrogel constructs. Lattice- and human nose-shaped 3D constructs were successfully printed and showed good stability in cell culture medium for over a week.

Inkjet micropatterning through horseradish peroxidase-mediated hydrogelation for controlled cell immobilization and microtissue fabrication.

A simple fabrication method for cell micropatterns on hydrogel substrates was developed using an inkjet printing system that induced hydrogel micropatterns. The hydrogel micropatterns were created from inks resulting in cell-adhesive and non-cell-adhesive printed regions by horseradish peroxidase-catalyzed reaction onto non-cell-adhesive and cell-adhesive hydrogel substrates, respectively, to obtain the cell micropatterns. Cell-adhesive and non-cell-adhesive regions were obtained from gelatin and alginate derivatives, respectively.

Horseradish peroxidase-catalyzed hydrogelation consuming enzyme-produced hydrogen peroxide in the presence of reducing sugars.

In the present work, three kinds of reducing sugars: glucose, galactose, and mannose, are applied to horseradish peroxidase (HRP)-catalyzed hydrogelation of an aqueous solution containing natural polymers modified with phenolic hydroxyl moieties. In this system, HRP consumes hydrogen peroxide that was generated from the oxidation of thiol groups in HRP in the presence of reducing sugars. Herein, we highlight the versatility of applicable sugar types and the controllable hydrogel properties.

Drop-On-Drop Multimaterial 3D Bioprinting Realized by Peroxidase-Mediated Cross-Linking.

A cytocompatible inkjet bioprinting approach that enables the use of a variety of bioinks to produce hydrogels with a wide range of characteristics is developed. Stabilization of bioinks is caused by horseradish peroxidase (HRP)-catalyzed cross-linking consuming hydrogen peroxide (H O ). 3D cell-laden hydrogels are fabricated by the sequential dropping of a bioink containing polymer(s) cross-linkable through the enzymatic reaction and H O onto droplets of another bioink containing the polymer, HRP, and cells.

Cytocompatible Enzymatic Hydrogelation Mediated by Glucose and Cysteine Residues.

Hydrogels were obtained from aqueous solution containing polymer(s) possessing phenolic hydroxyl moieties through horseradish peroxidase (HRP)-catalyzed reaction without direct addition of HO. In this hydrogelation process, HO was generated from HRP and glucose contained in the aqueous solution, that is, HRP functioned not only as a catalyst, but also as a source of HO. The gelation time and mechanical properties of the resultant hydrogel could be altered by changing the concentrations of HRP and glucose.

Inkjetting Plus Peroxidase-Mediated Hydrogelation Produces Cell-Laden, Cell-Sized Particles with Suitable Characters for Individual Applications.

The authors report a method to prepare cell-laden, cell-sized microparticles from various materials suitable for individual applications. The method includes a piezoelectric inkjetting technology and a horseradish peroxidase (HRP)-catalyzed crosslinking reaction. The piezoelectric inkjetting technology enables production of cell-laden, cell-sized (20-60 μm) droplets from a polymer aqueous solution.