Injectable Biomimetic Hydrogel Guided Functional Bone Regeneration by Adapting Material Degradation to Tissue Healing

Abstract

The treatment of irregular bone defects remains a clinical challenge since the current biomaterials (e.g., calcium phosphate bone cement (CPC)) mainly act as inert substitutes, which are incapable of transforming into a regenerated host bone (termed functional bone regeneration). Ideally, the implant degradation rate should adapt to that of bone regeneration, therefore providing sufficient physicochemical support and giving space for bone growth. This study aims to develop an injectable biomaterial with bone regeneration‐adapted degradability, to reconstruct a biomimetic bone‐like structure that can timely transform into new bone, facilitating functional bone regeneration. To achieve this goal, a hybrid (LP‐CPC@gelatin, LC) hydrogel is synthesized via one‐step incorporation of laponite (LP) and CPC into gelatin hydrogel, and the LC gel degradation rate is controlled by adjusting the LP/CPC ratio to match the bone regeneration rate. Such an LC hydrogel shows good osteoinduction, osteoconduction, and angiogenesis effects, with complete implant‐to‐new bone transformation capacity. This 2D nanoclay‐based bionic hydrogel can induce ectopic bone regeneration and promote ligament graft osseointegration in vivo by inducing functional bone regeneration. Therefore, this study provides an advanced strategy for functional bone regeneration and an injectable biomimetic biomaterial for functional skeletal muscle repair in a minimally invasive therapy.

Gelatin/Hyaluronic Acid Photocrosslinked Double Network Hydrogel with Nano-Hydroxyapatite Composite for Potential Application in Bone Repair

“…Since the GelMA/HAMA/nHap composite hydrogels are intended for use in bone repair by injection in vivo, the rheological properties of the hydrogels should be tested to determine their injectability. The shear thinning property of the fluid, which is defined as the viscosity of the fluid decreasing with increasing shear rate, indicates the injectability of the fluid [ 27 , 28 ]. Figure 2 a shows the change in viscosity of the precursor solution for hydrogels with the increasing of shear rate at 25 °C.…”

Polyhydroxyalkanoates: the natural biopolyester for future medical innovations

“…To enhance the hardness and osteoinduction effect of the PHA scaffolds, hydroxyapatite (HA), 394 the main component of the natural bone matrix (65–70%), is often blended with PHAs to form composites of different forms, including 3D scaffolds, 132,175,180–182,227–235 films, 104,131,236–241 plates 242 and microspheres. 161 Compared to the pure PHA scaffolds, the composite scaffolds of PHB and HA improved the osteoblastic response, including cell growth, alkaline phosphatase activity, 180,227–229,235,237,238 and bone regeneration in mice, 228 rats, 237 and rabbits.…”

A Biomimetic Fibrous Composite Scaffold with Nanotopography-Regulated Mineralization for Bone Defect Repair

“…The resultant hydrogel can induce ectopic bone regeneration and promote ligament graft osseointegration in vivo. 18 To balance the immune response and bone metabolism, a hybrid scaffold with hierarchical pores was fabricated by integrating the 3D printed polylactide/ hydroxyapatite (HA) scaffold with the gelatin methacryloyl hydrogel containing deferoxamine@PCL nanoparticles and MnCO nanosheets. 19 A hybrid interleaved scaffold composed of collagen type I and nano-HA was assembled using dopamine-modified hyaluronic acid as a macromolecular cross-linking.…”