ABSTRACT
Bone tissue engineering offers a promising alternative to stimulate the regeneration of damaged tissue, overcoming the limitations of conventional autografts and allografts. Recently, titanium alloy (Ti) implants have garnered significant attention for treating critical-sized bone defects, especially with the advancement of 3D printing technology. Although Ti alloys have impressive versatility, their lack of cellular adhesion, osteogenic and antibacterial properties are significant factors that contribute to their failure. Hence, to overcome these obstacles, this study aimed to incorporate osteoinductive and antibacterial cue-loaded hydrogels into 3D-printed Ti (3D-Ti) scaffolds. 3D-Ti scaffolds were synthesized using the direct metal laser sintering method and loaded with a gelatin (Gel) hydrogel containing strontium-doped silver nanoparticles (Sr-Ag NPs). Compared with Ag NPs, Sr-doped Ag NPs increased the expression of Runx2 mRNA, which is a key bone transcription factor. We subjected the bioactive 3D-hybrid scaffolds (3D-Ti/Gel/Sr-Ag NPs) to physicochemical and material characterization, followed by cytocompatibility and osteogenic evaluation. The microporous and macroporous topographies of the scaffolds with Sr-Ag NPs showed increased Runx2 expression and matrix mineralization, with potent antibacterial properties. Therefore, the 3D-Ti scaffolds incorporated with Sr-Ag NP-loaded Gel hydrogels favored osteoblast differentiation and antibacterial activity, indicating their potential for orthopedic applications.
Subject(s)
Anti-Bacterial Agents , Cell Differentiation , Gelatin , Hydrogels , Metal Nanoparticles , Osteoblasts , Osteogenesis , Printing, Three-Dimensional , Silver , Strontium , Tissue Engineering , Tissue Scaffolds , Titanium , Silver/chemistry , Silver/pharmacology , Gelatin/chemistry , Strontium/chemistry , Strontium/pharmacology , Titanium/chemistry , Titanium/pharmacology , Tissue Engineering/methods , Osteoblasts/drug effects , Osteoblasts/cytology , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Tissue Scaffolds/chemistry , Hydrogels/chemistry , Hydrogels/pharmacology , Metal Nanoparticles/chemistry , Cell Differentiation/drug effects , Osteogenesis/drug effects , Animals , Mice , Bone and Bones/drug effectsABSTRACT
Treatment of large segmental bone loss caused by fractures, osteomyelitis, and non-union results in expenses of around USD 300,000 per case. Moreover, the worst-case scenario results in amputation in 10% to 14.5% of cases. Biomaterials, cells, and regulatory elements are employed in bone tissue engineering (BTE) to create biosynthetic bone grafts with effective functionalization that can aid in the restoration of such fractured bones, preventing amputation and alleviating expenses. Chitin (CT) and chitosan (CS) are two of the most prevalent natural biopolymers utilized in the fields of biomaterials and BTE. To offer the structural and biochemical cues for augmenting bone formation, CT and CS can be employed alone or in combination with other biomaterials in the form of nanofibers (NFs). When compared with several fabrication methods available to produce scaffolds, electrospinning is regarded as superior since it enables the development of nanostructured scaffolds utilizing biopolymers. Electrospun nanofibers (ENFs) offer unique characteristics, including morphological resemblance to the extracellular matrix, high surface-area-to-volume ratio, permeability, porosity, and stability. This review elaborates on the recent strategies employed utilizing CT and CS ENFs and their biocomposites in BTE. We also summarize their implementation in supporting and delivering an osteogenic response to treat critical bone defects and their perspectives on rejuvenation. The CT- and CS-based ENF composite biomaterials show promise as potential constructions for bone tissue creation.
ABSTRACT
BACKGROUND: Treatment of critical-sized bone defects has progressively evolved over the years from metallic implants to more ingenious three-dimensional-based scaffolds. The use of three-dimensional scaffolds for bone regeneration from biodegradable polymers like poly(lactic acid) (PLA) is gaining popularity. Scaffolds with surface functionalization using gelatin (Gel) have the advantages of biocompatibility and cell adhesion. Nano-hydroxyapatite (nHAp) is one of the most promising implant materials utilized in orthopaedics. The osteogenic potential of the nHAp can be improved by the substitution of magnesium (Mg) ions onto the crystal lattice of nHAp. Thus, the goal of this work was to make three-dimensional-PLA scaffolds covered with Gel/Mg-nHAp for osteogenic effect. METHODS AND RESULTS: The designed three-dimensional-PLA/Gel/Mg-nHAp scaffolds were attributed to various characterizations for the examination of their physicochemical, mechanical properties, cyto-compatibility, and biodegradability as well as their ability to promote osteogenesis in vitro. Mouse mesenchymal stem cells (mMSCs) were cytocompatible with these scaffolds. The osteogenic potential of three-dimensional-PLA/Gel/Mg-nHAp scaffolds employing mMSCs was validated at the cellular and molecular levels. The three-dimensional-PLA/Gel/Mg-nHAp scaffolds stimulated the differentiation of mMSCs towards osteoblastic lineage. CONCLUSION: Based on these findings, we suggest that the three-dimensional-PLA/Gel/Mg-nHAp scaffolds' osteogenic capability may be advantageous in the mending of bone defects in orthopedic applications.