Biocompatibility and Antibacterial Effect of Ginger Fraction Loaded PLGA Microspheres Fabricated by Coaxial Electrospray.

Various poly(lactic-co-glycolic acid) (PLGA) microspheres loaded with the ginger fraction were fabricated by controlling the electrospray parameters and their biocompatibility and antibacterial activity were identified in this study. The morphology of the microspheres was observed using scanning electron microscopy. The core-shell structures of the microparticles and the presence of ginger fraction in the microspheres were confirmed by fluorescence analysis using a confocal laser scanning microscopy system. In addition, the biocompatibility and antibacterial activity of PLGA microspheres loaded with ginger fraction were evaluated through a cytotoxicity test using osteoblast MC3T3-E1 cells and an antibacterial test using Streptococcus mutans and Streptococcus sanguinis, respectively. The optimum PLGA microspheres loaded with ginger fraction were fabricated under electrospray operational conditions with 3% PLGA concentration in solution, an applied voltage of 15.5 kV, a flow rate of 15 µL/min in the shell nozzle, and 3 µL/min in the core nozzle. The effectual antibacterial effect and enhanced biocompatibility were identified when a 3% ginger fraction in PLGA microspheres was loaded.

Evaluation of Corrosion Behavior and In Vitro of Strontium-Doped Calcium Phosphate Coating on Magnesium.

This study investigated the biocompatibility of strontium-doped calcium phosphate (Sr-CaP) coatings on pure magnesium (Mg) surfaces for bone applications. Sr-CaP coated specimens were obtained by chemical immersion method on biodegradable magnesium. In this study, Sr-CaP coated magnesium was obtained by immersing pure magnesium in a solution containing Sr-CaP at 80 °C for 3 h. The corrosion resistance and biocompatibility of magnesium according to the content of Sr-CaP coated on the magnesium surface were evaluated. As a result, the corrosion resistance of Sr-CaP coated magnesium was improved compared to pure magnesium. In addition, it was confirmed that the biocompatibility of the group containing Sr was increased. Thus, the Ca-SrP coating with a reduced degradation and improved biocompatibility could be used in Mg-based orthopedic implant applications.

Fabrication and Characterization of Biodegradable Gelatin Methacrylate/Biphasic Calcium Phosphate Composite Hydrogel for Bone Tissue Engineering.

In the field of bone tissue, maintaining adequate mechanical strength and tissue volume is an important part. Recently, biphasic calcium phosphate (BCP) was fabricated to solve the shortcomings of hydroxyapatite (HA) and beta-tricalcium phosphate (ß-TCP), and it is widely studied in the field of bone-tissue engineering. In this study, a composite hydrogel was fabricated by applying BCP to gelatin methacrylate (GelMA). It was tested by using a mechanical tester, to characterize the mechanical properties of the prepared composite hydrogel. The fabricated BCP was analyzed through FTIR and XRD. As a result, a different characteristic pattern from hydroxyapatite (HA) and beta-tricalcium phosphate (ß-TCP) was observed, and it was confirmed that it was successfully bound to the hydrogel. Then, the proliferation and differentiation of preosteoblasts were checked to evaluate cell viability. The analysis results showed high cell viability and relatively high bone differentiation ability in the composite hydrogel to which BCP was applied. These features have been shown to be beneficial for bone regeneration by maintaining the volume and shape of the hydrogel. In addition, hydrogels can be advantageous for clinical use, as they can shape the structure of the material for custom applications.

Characteristics of Biodegradable Gelatin Methacrylate Hydrogel Designed to Improve Osteoinduction and Effect of Additional Binding of Tannic Acid on Hydrogel.

In this study, a hydrogel using single and double crosslinking was prepared using GelMA, a natural polymer, and the effect was evaluated when the double crosslinked hydrogel and tannic acid were treated. The resulting hydrogel was subjected to physicochemical property evaluation, biocompatibility evaluation, and animal testing. The free radicals generated through APS/TEMED have a scaffold form with a porous structure in the hydrogel, and have a more stable structure through photo crosslinking. The double crosslinked hydrogel had improved mechanical strength and better results in cell compatibility tests than the single crosslinked group. Moreover, in the hydrogel transplanted into the femur of a rat, the double crosslinked group showed an osteoinductive response due to the attachment of bone minerals after 4 and 8 weeks, but the single crosslinked group did not show an osteoinductive response due to rapid degradation. Treatment with a high concentration of tannic acid showed significantly improved mechanical strength through H-bonding. However, cell adhesion and proliferation were limited compared to the untreated group due to the limitation of water absorption capacity, and no osteoinduction reaction was observed. As a result, it was confirmed that the treatment of high-concentration tannic acid significantly improved mechanical strength, but it was not a suitable method for improving bone induction due to the limitation of water absorption.

Mammalian and Fish Gelatin Methacryloyl-Alginate Interpenetrating Polymer Network Hydrogels for Tissue Engineering.

Gelatin methacryloyl (GelMA) has been widely studied as a biomaterial for tissue engineering. Most studies focus on mammalian gelatin, but certain factors, such as mammalian diseases and diet restrictions, limit the use of mammalian gelatin. Thus, fish gelatin has received much attention as a substitute material in recent years. To develop a broadly applicable hydrogel with excellent properties, an interpenetrating polymer network (IPN) hydrogel was synthesized, since IPN hydrogels consist of at least two different hydrogel components to combine their advantages. In this study, we prepared GelMA using type A and fish gelatin and then synthesized IPN hydrogels using GelMA with alginate. GelMA single-network hydrogels were used as a control group. The favorable mechanical properties of type A and fish hydrogels improved after the synthesis of the IPN hydrogels. Type A and fish IPN hydrogels showed different mechanical properties (mechanical strength, swelling ratio, and degradation rate) and different cross-sectional morphologies, since the degree of mechanical enhancement in fish IPN hydrogels was less than that in type A; however, the cell biocompatibilities were not significantly different. Therefore, these findings could serve as a reference for future studies when selecting GelMA as a biological material for tissue engineering.