Gelatin Templated Polypeptide Co‐Cross‐Linked Hydrogel for Bone Regeneration

Abstract

Polypeptides with short chains of amino acid monomers have been widely applied in the clinic because of their various biological functions. However, the easily‐inactivated characteristics and burst releasing of the peptides limit their application in vivo. Here, a novel osteogenic polypeptide hydrogel (GelMA‐c‐OGP) is created by co‐cross‐linking template photo‐cross‐linked gelatin (GelMA) with photo‐cross‐linkable osteogenic growth peptides (OGP) using ultraviolet radiation. GelMA enables the formation of hydrogel with photo‐cross‐linkable OGP with good mechanical properties and also promotes bone regeneration. GelMA‐c‐OGP hydrogel accelerates the bone formation procedure of osteogenic precursor cells by significantly enhancing the expression of osteogenic‐related genes BMP‐2, OCN, and OPN, and increasing the precipitation of calcium salts in osteoblasts. Similarly, GelMA‐c‐OGP hydrogel promotes bone regeneration in vivo. Furthermore, it is observed that more collagen fibers connect cortical bones in the GelMA‐c‐OGP implanted group than the control group by hematoxylin‐eosin and immunohistochemical staining of Collagen I and TGF‐β. The co‐cross‐linked OGP polypeptide converts from liquid to solid hydrogel with transient UV light in situ, which also can strengthen the mechanical property of the defect bone and avoid burst osteogenic peptide, releasing during the bone defect healing period. Overall, this hydrogel delivering system has a significant impact on bone defect healing compared with traditional methods.

Efficacy, Drug Sensitivity, and Safety of a Chronic Ocular Hypertension Rat Model Established Using a Single Intracameral Injection of Hydrogel into the Anterior Chamber

“…Taking the aforementioned limitations into account, it was necessary to explore a stable, effective, and simple COH animal model and to conduct a comprehensive evaluation. The cross-linking hydrogel has low toxicity, high water-retention capacity, multifunctional usefulness, and excellent biocompatibility [ 35 , 36 ], and has been applied in several biomedical research fields such as drug release [ 37 , 38 ], cell culture [ 39 ], tissue regeneration [ 40 – 42 ], 3D bioprinting [ 43 ], and prevention of postoperative intra-abdominal adhesion [ 44 ]. In the field of ophthalmology, cross-linking hydrogel has been used in tissue engineering, including corneal transplant [ 45 , 46 ] and retinal progenitor cell transplantation [ 47 ], drug delivery systems for multiple eye diseases such as glaucoma [ 48 ] and uveitis treatment [ 49 ], treatment of ocular surface [ 50 ] and lacrimal diseases [ 51 ], and substitution of the vitreous body [ 52 , 53 ], showing great potential.…”

<p>Nano-Silicate-Reinforced and SDF-1α-Loaded Gelatin-Methacryloyl Hydrogel for Bone Tissue Engineering</p>

“…Gelatin methacryloyl (GelMA) hydrogels have widely been employed in tissue engineering because of their biological compatibility and tunable physical properties. 18 To introduce osteogenic properties into hydrogels, various bioactive components, such as BMP, 19 osteogenic peptides, 20 and bioactive nanoparticles, 21 have been added. In particular, bioactive silicate nanoplatelets (SN) [Laponite: Na + 0.7[(Si8Mg5.5:Li0.3)O20(OH)4 − 0.7)] has been attracting interest because of its ability to induce osteogenic differentiation in the bone marrow and human mesenchymal stem cells (hMSCs) in the absence of extra osteoinductive factors, such as BMP-2 or dexamethasone.…”

Development of Cell Spheroids by Advanced Technologies

“…Drug or biological research based on 2D cell culture may produce bias, while 3D cell culture can provide us with more realistic information, thus reducing the time and cost of drug development. [6][7][8][9][10][11][12] Among them, 3D tumor spheroids have become a useful tool for drug screening and testing because they can mimic tumor microenvironment in vitro. [139,140] Microfluidics, on the other hand, has been widely used to prepare cell spheroids due to its high-throughput characteristic.…”