Preparation of co-electrospinning membrane loaded with simvastatin and substance P to accelerate bone regeneration by promoting cell homing, angiogenesis and osteogenesis.

Bone regeneration is a complex process that requires the coordination of various biological events. Developing a tissue regeneration membrane that can regulate this cascade of events is challenging. In this study, we aimed to fabricate a membrane that can enrich the damaged area with mesenchymal stem cells, improve angiogenesis, and continuously induce osteogenesis. Our approach involved creating a hierarchical polycaprolactone/gelatin (PCL/GEL) co-electrospinning membrane that incorporated substance P (SP)-loaded GEL fibers and simvastatin (SIM)-loaded PCL fibers. The membrane could initiate a burst release of SP and a slow/sustained release of SIM for over a month. In vitro experiments, including those related to angiogenesis and osteogenesis (e.g., migration, endothelial network formation, alkaline phosphatase activity, mineralization, and gene expression), clearly demonstrated the membrane's superior ability to improve cell homing, revascularization, and osteogenic differentiation. Furthermore, a series of in vivo studies, including immunofluorescence of CD29+/CD90+ double-positive cells and immunohistochemical staining for CD34 and vWF, confirmed the co-electrospinning membrane's ability to enhance MSC migration and revascularization response after five days of implantation. After one month, the Micro-CT and histological (Masson and H&E) results showed accelerated bone regeneration. Our findings suggest that a co-electrospinning membrane with time-tunable drug delivery could advance the development of tissue engineering therapeutic strategies and potentially improve patient outcomes.

Vitamin D and curcumin-loaded PCL nanofibrous for engineering osteogenesis and immunomodulatory scaffold.

The accelerating bone healing process is still a major challenge in clinical orthopedics, especially in critical-sized bone defects. Recently, Nanofiber membranes are showing increasing attention in the biomedical field due to their good biocompatibility, mechanical stability, and the ability to work as a drug carrier to achieve localized and sustained drug delivery. Herein, a multifunction nanofiber membrane loaded with vitamin D (Vit D) and curcumin (Cur) was successfully fabricated using electrospinning technology. In addition, we innovatively modified Vit D with PEG to improve the hydrophilicity of PCL nanofibers. The vitro results of CCK-8, alkaline phosphatase (ALP) and mineralization demonstrated that the PCL/Vit D-Cur membrane had great potential for enhancing the proliferation/differentiation of osteoblasts. Moreover, the synergistic effect of Vit D-Cur loaded PCL nanofiber membrane showed a superior ability to improve the anti-inflammatory activity through M2 polarization. Furthermore, in vivo results confirmed that the defect treated with PCL/Vit D-Cur nanofiber membrane was filled with the newly formed bone after 1 month. These results indicate that the Vit D/Cur loaded membrane can be applied for potential bone regeneration therapy.

JK-2 loaded electrospun membrane for promoting bone regeneration.

Hydrogen sulfide (H2S) has been as an essential gasotransmitter and a potential therapeutic approach for several biomedical treatments such as cardiovascular disorders, hypertension, and other diseases. The endogenous and exogenous H2S also plays a crucial role in the bone anabolic process and a protective mechanism in cell signalling. In this study, we have utilized two types of polymers, polycaprolactone (PCL) and gelatin (Gel), for the fabrication of JK-2 (H2S donor) loaded nanofibrous scaffold via electrospinning process for bone healing and bone tissue engineering. Comparing the PCL/Gel and PCL/Gel-JK-2 scaffolds, the latter demonstrated enhanced cell adhesion and proliferation capabilities. Furthermore, both experimental scaffolds have been subjected to an in vivo experiment for 4 and 8 weeks in a bone-defect model of a rabbit to determine their biological responses under physiological conditions. There was an obvious increase in bone regeneration in the PCL/Gel-JK-2 group compared to the control and PCL/Gel groups. These results indicate the use of PCL/Gel scaffolds loaded with JK-2 should be considered for possible bone regeneration.

Multifunctional TaCu-nanotubes coated titanium for enhanced bacteriostatic, angiogenic and osteogenic properties.

In this study, multifunctional tantalum copper composite nanotubes (TaCu-NTs) were coated on titanium for enhanced bacteriostatic, angiogenic and osteogenic properties. Three coatings of Ta, TaCu1 (Ta: Cu = 4:1 at.%), and TaCu2 (Ta: Cu = 1:1 at.%) were deposited on titanium by magnetron sputtering. The bare titanium and the three coatings were subsequently anodized into four kinds of nanotubes (NT) of TNT, Ta-NT, TaCu1-NT, and TaCu2-NT, respectively. The released copper ions measured by inductively coupled plasma atomic emission spectroscopy (ICP/AES) presented that TaCu2-NT coating released the highest amount of copper ions, which led to the best bacteriostasis against Escherichia coli and Staphylococcus aureus. Potentiodynamic polarization tests clarified that Ta-NT showed the highest corrosion resistance, followed by TaCu1-NT and TaCu2-NT. TaCu2-NT showed not only the best angiogenic property in terms of cell migration, tube formation, and real-time quantitative polymerase chain reaction (RT-qPCR) of human umbilical vein endothelial cells (HUVECs), but also the best osteogenic property in terms of cell viability, alkaline phosphatase activity, and mineralization of MC3T3-E1 cells. Therefore, TaCu2-NT coating has a greater potential than the other coatings of TNT, Ta-NT and TaCu1-NT in promoting bacteriostasis, angiogenesis and osteointegration for titanium implants.

Preparation of Zirconium Hydrogen Phosphate Coatings on Sandblasted/Acid-Etched Titanium for Enhancing Its Osteoinductivity and Friction/Corrosion Resistance.

BACKGROUND: Sandblasted/acid-etched titanium (SLA-Ti) implants are widely used for dental implant restoration in edentulous patients. However, the poor osteoinductivity and the large amount of Ti particles/ions released due to friction or corrosion will affect its long-term success rate. PURPOSE: Various zirconium hydrogen phosphate (ZrP) coatings were prepared on SLA-Ti surface to enhance its friction/corrosion resistance and osteoinduction. METHODS: The mixture of ZrCl4 and H3PO4 was first coated on SLA-Ti and then calcined at 450°C for 5 min to form ZrP coatings. In addition to a series of physiochemical characterization such as morphology, roughness, wettability, and chemical composition, their capability of anti-friction and anti-corrosion were further evaluated by friction-wear test and by potential scanning. The viability and osteogenic differentiation of MC3T3-E1 cells on different substrates were investigated via MTT, mineralization and PCR assays. RESULTS: The characterization results showed that there were no significant changes in the morphology, roughness and wettability of ZrP-modified samples (SLA-ZrP0.5 and SLA-ZrP0.7) compared with SLA group. The results of electrochemical corrosion displayed that both SLA-ZrP0.5 and SLA-ZrP0.7 (especially the latter) had better corrosion resistance than SLA in normal saline and serum-containing medium. SLA-ZrP0.7 also exhibited the best friction resistance and great potential to enhance the spreading, proliferation and osteogenic differentiation of MC3T3-E1 cells. CONCLUSION: We determined that SLA-ZrP0.7 had excellent comprehensive properties including anti-corrosion, anti-friction and osteoinduction, which made it have a promising clinical application in dental implant restoration.