Gelatin-Nanodiamond Hydrogel for Drug Delivery and Bone Tissue Engineering

Abstract

As one of the few human tissues to recover without scars, bone’s capacity to remodel itself and recover from injury is undoubtedly impressive. However, non-union fractures and critical sized defects, often the result of trauma, disease-related fractures, and tumor resection, have great difficulty healing without intervention. Common treatments for these maladies include using bone autografts and allografts to fill the defect, though each of these treatments have their own potential complications and drawbacks. Tissue engineering strategies aim to recreate bone or bone’s natural healing processes on a lab-made scaffold along with cells and therapeutics for implantation. In addition, recreation of bone-like functions by improving in vitro models is crucial for drug testing and mechanistic studies. One class of materials used for both therapeutics and in vitro modeling are hydrogels, water-swollen polymeric networks that often exhibit great biocompatibility due to their similarity to native extracellular matrix. Hydrogels’ fragile mechanical properties relative to the remarkable strength of bone limit their application in heavy load-bearing regions of bone. Including nanomaterials within the polymeric network can both increase the strength of the network and allow exploitation of their unique abilities to interact with encapsulated cells and therapeutics. Here, we hypothesize that the inclusion of nanodiamonds, octahedral carbon-based nanoparticles, can both improve the mechanical properties of a gelatin methacrylamide system and enable dexamethasone loading and delivery to encapsulated human adipose-derived mesenchymal stem cells. In the first section, we review bone tissue engineering strategies with a focus on hydrogels and carbon nanomaterials. In the second section, this project and its results are reported and analyzed, and finally, ideas for future work with nanodiamonds and hydrogels are discussed.