Breakthrough injectable hydrogel drug delivery system for advanced medical treatment applications

Researchers from the Department of Mechanical Engineering at the University of Hong Kong (HKU) have recently achieved a remarkable breakthrough in the injectable hydrogel with the development of Fibro-Gel. This groundbreaking ...

The research team was led by Professor Anderson Ho Cheung Shum of the Department of Mechanical Engineering at The University of Hong Kong (HKU) and their collaborators, Professor Michael To's team from The University of Hong Kong-Shenzhen Hospital, and the group of Professor Howard Stone and Dr. Janine Nunes from the Department of Mechanical and Aerospace Engineering at Princeton University. The latest discovery has been published in Advanced Materials . Injectable hydrogels are valuable in wound healing due to their injectability, minimal invasiveness, and adaptability to irregular sites. However, challenges include scalable manufacturing, matching properties, and on-demand drug release, limiting control over biophysical cues for endogenous cell direction.

The research team designed and fabricated an oil-free, reaction-free, biomimetic, injectable, and fully scalable Fibro-Gel for wound healing applications. For the first time, Ph.D. student Yanting Shen and postdoctoral fellow DrYuan Liu of the Department of Mechanical Engineering, HKU discovered that Fibro-Gel with controllable physicochemical properties and drug release profiles can be precisely tailored by simply adjusting the microfiber lengths. They found that the mechanical properties of Fibro-Gel vary depending on the length of the microfibers. Fibro-Gel with shorter microfibers exhibits lower stiffness and a more fluid-like behavior, resulting in faster rates of drug release. Conversely, Fibro-Gel with longer microfibers demonstrates higher stiffness and a more solid-like behavior, leading to slower drug release rates.

Schematic illustrations of the injectable Fibro-gel fabrication (upper pane) and the SEM image of a dried fibro-gel showing the micromorphology of the fibro-gel (bottom pane). Credit: The University of Hong Kong Read more

Controllable mechanical properties and tunable drug release rates. Strain-sweep rheology study of fibro-gels for different fiber lengths. The arrow highlights the increase for G′ and G″ with increasing Lfiber (left pane). The TC release profile of fibro-gels for different fiber lengths. The fibro-gel with longer fibers exhibits a more sustained drug release profile. Hydrolysis and/or the drug tightly entrapped in the gel also result in the incomplete release of the drug (right pane). Credit: The University of Hong Kong Read more

Schematic illustration of a wound healing application of a two-layer fibro-gel encapsulating different drugs (upper pane). The TC was loaded into the bottom-layer with shorter fibers (Lfiber=8.8 mm), while the EGF was loaded in the upper-layer with longer fiber (Lfiber =220 mm). Two layers of the fibro-gel were extruded sequentially.In vivo proof-of-concept of the efficacy of the fibro-gel (bottom pane). Photographs of mice skin wound tissues for different groups on days 0, 4, 8, and 12 and Hematoxylin and eosin (H&E) staining of skin tissue for the fibro-gel with TC and EGF group (B) on day 8. Credit: The University of Hong Kong Read more