Gelatin-based hydrogel, which mimics the natural dermal extracellular matrix, is a promising tissue engineering material. However, insufficient and uncontrollable mechanical and degradation properties remain the major obstacles for its application in medical bone regeneration material. Herein, we develop a facile but efficient strategy for a novel hydrogel as guided bone regeneration (GBR) material. In this study, methacrylic anhydride (MA) has been used to modify gelatin to obtain photo-crosslinkable methacrylated gelatin (GelMA). Moreover, the GelMA/PEGDA hydrogel was prepared by photo-crosslinking GelMA and PEGDA with photoinitiator I2959 under UV treatment. Compared with the GelMA hydrogel, the GelMA/PEGDA hydrogel exhibits several times stronger mechanical properties than pure GelMA hydrogel. The GelMA/PEGDA hydrogel shows a suitable degradation rate of more than 4 weeks, which is beneficial to implant in body. In vitro cell culture showed that osteoblast can adhere and proliferate on the surface of the hydrogel, indicating that the GelMA/PEGDA hydrogel had good cell viability and biocompatibility. Furthermore, by changing the quantities of GelMA, I2959, and PEGDA, the gelation time can be controlled easily to meet the requirement of its applications. In short, this study demonstrated that PEGDA enhanced the performance and extended the applications of GelMA hydrogels, turning the GelMA/PEGDA hydrogel into an excellent GBR material.

Hydrogels with adhesion properties and a wetted structure are promising alternatives to traditional wound dressing materials. The insufficiency of gelatin hydrogels in terms of their adhesive and mechanical strength limits their application in wound dressings. This work presents the design and preparation of a gelatin-based hydrogel functionalized with dopamine (DA) and layered double hydroxide (LDH). The combination of DA and LDH improves the hydrogel’s adhesion properties in terms of interfacial adhesion and inner cohesion. Hydrogels with 8% DA and 4% LDH attained the highest adhesion strength of 266.5 kPa, which increased to 295.5 and 343.3 kPa after hydrophobically modifying the gelatin with octanoyl and decanoyl aldehydes, respectively. The gelatin-based hydrogels also demonstrated a macroporous structure, excellent biocompatibility, and a good anti-inflammatory effect. The developed hydrogels accelerated wound healing in Sprague Dawley rat skin full-thickness wound models.

In this study, taking NdCl₃ and 2-amino-1,4-benzenedicarboxylic acid (H₂ATA) as raw materials, a novel lanthanide metal–organic framework, Nd(ATA), was synthesized by the coprecipitation method. After loading antibiotic levofloxacin (LEV), Nd(ATA) was combined with GelMA hydrogel to prepare a drug-loaded composite hydrogel, LEV@Nd(ATA)-Gel, which can emit near-infrared fluorescence under excitation at 808 nm and possesses improved mechanical properties compared to pure GelMA hydrogel. LEV@Nd(ATA)-Gel exhibited high bactericidal activity and low cytotoxicity, with cell viability increased by 35% compared to the control group. The release rate of the loaded LEV was found increasing with the pH decreasing from 7 to 3, and demonstrated a potential responsiveness to wound microenvironment. Furthermore, drug delivery studies revealed a significant correlation with the fluorescence intensity of the composite hydrogel and the drug release behavior, and the extent of drug release was quantitatively captured by an in vitro imaging technology. This study successfully integrated the drug release with fluorescent signal of carrier, providing a highly sensitive and visualizable strategy for the development of internal wound adhesive.