Baoqing Yu

Fabrication of curcumin-loaded mesoporous silica incorporated polyvinyl pyrrolidone nanofibers for rapid hemostasis and antibacterial treatment

Nanofiber mats have been widely applied in various biomedical fields such as drug delivery, tissue repair and wound dressing. In this study, the curcumin-loaded mesoporous silica incorporated nanofiber mats were prepared using blend electrospinning of curcumin-loaded mesoporous silica nanoparticles (CCM-MSNs) and polyvinyl pyrrolidone (PVP) for hemostasis. The prepared mats were then evaluated to determine their structure, biocompatibility and antibacterial activity, especially focusing on the hemostatic effect using an in vivo liver injury model. The results showed that CCM-MSN loading ratios less than 8 wt% could be homogeneously dispersed in the PVP electrospun nanofibers. The in vitro studies demonstrated that the hybrid nanofiber mats had no obvious toxic effect on the growth of L929 cells. The hybrid nanofiber mats also exhibited enhanced in vitro antibacterial effects against methicillin-resistant Staphylococcus aureus (MRSA). The antibacterial effect of the hybrid nanofiber mats was further confirmed by in vivo experiments. Moreover, the in vivo hemostasis studies revealed that the hybrid nanofiber mats could rapidly transform into hydrogel when they contact with blood, and then activate the clotting system to stop the wound bleeding. Therefore, the CCM-MSN incorporated PVP nanofiber mats provide a practical possibility for nanofiber-based hemostatic materials with good biocompatibility and high antibacterial activity.

3D printing of pearl/CaSO4 composite scaffolds for bone regeneration

The development of biomaterials with high osteogenic ability for fast osteointegration with a host bone is of great interest. In this study, pearl/CaSO4 composite scaffolds were fabricated using three-dimensional (3D) printing, followed by a hydration process. The pearl/CaSO4 scaffolds showed uniform interconnected macropores (∼400 μm), high porosity (∼60%), and enhanced compressive strength. With CaSO4 scaffolds as a control, the biological properties of the pearl/CaSO4 scaffolds were evaluated in vitro and in vivo. The results showed that the pearl/CaSO4 scaffolds possessed a good apatite-forming ability and stimulated the proliferation and differentiation of rat bone mesenchymal stem cells (rBMSCs), as well as giving a better expression of related osteogenic genes. Importantly, micro-computed tomography and histology of the critical-sized rabbit femoral condyle defects implanted with the scaffolds illustrated the osteogenic capacity of the pearl/CaSO4 scaffolds. New bone was observed within 8 weeks. The bone-implant contact index was significantly higher for the pearl/CaSO4 scaffolds implant than for the CaSO4 scaffolds implant, indicating that the pearl/CaSO4 scaffolds would be promising implants for bone regeneration.

Single lateral versus medial and lateral plates for treating displaced scapular body fractures: a retrospective comparative study

BACKGROUND This study compared the outcomes and complications of single lateral plating vs. dual plating for treating displaced scapular body fractures. METHODS Open reduction and internal fixation using locking plates was performed in 45 patients with displaced scapular fractures. A single lateral plate fixed in the lateral border was used in 22 patients (group A), and dual plates fixed in both the lateral and medial borders were used in 23 (group B). RESULTS The average follow-up duration in both groups was 20 months. A remarkable difference was seen between the 2 groups in mean operative time and blood loss, although the Disabilities of the Arm, Shoulder and Hand and Constant Shoulder scores at the final follow-up were similar. The prominence rate of the hardware was 27.3% (6 of 22) in group A and 65.2% (15 of 23) in group B. The plate removal rate was 31.8% (7 of 22) in group A and 78.3% (18 of 23) in group B. CONCLUSIONS Open reduction using a single plate on the lateral border for treating displaced scapular body fractures can lead to good functional outcomes, shorter operative time, less blood loss, and fewer plate-related complications compared with the dual-plating technique.

Self-Assembled Hydroxyapatite-Graphene Scaffold for Photothermal Cancer Therapy and Bone Regeneration

Repairing large tumor-related bone defects remains a difficult clinical problem because of the significant risk of locoregional relapse after surgical curettage. In this study, a composite scaffold of nano-hydroxyapatite (nHA) and reduced graphene oxide (rGO) sheets was fabricated by self-assembly, and a 20 wt% nHA-rGO sheet solution formed the most stable hydrogel. In vitro, nHA-rGO scaffolds killed all but 8% of osteosarcoma cells (MG-63) under 808 nm near-infrared laser irradiation for 20 min. SEM images and live/dead staining of MG-63 cells in nHA-rGO also confirmed the therapeutic efficacy of the scaffolds. Tumors implanted with nHA-rGO scaffolds reached 60 °C after 4 min. of irradiation; xenografted tumors stopped growth or even decreased in size after photothermal therapy. In vitro the scaffolds promoted adhesion, proliferation, and osteogenic mineralization of rat bone marrow stem cells (rBMSCs). Live cell staining and CCK-8 showed good proliferation for rBMSCs in nHA-rGO scaffolds. Alkaline phosphatase activity and qPCR demonstrated osteogenic mineralization of rBMSCs in nHA-rGO scaffolds. Micro-CT and histology verified that the scaffold promotes bone regeneration in rat cranial defects. At 8 weeks, 35% of the cranial defect area remained in the scaffold-implanted group, while 80% remained for the control. Bone mineral density of the scaffold-implanted group reached 284.58±20.78 mg/cm³, indicating new bone mineral deposition, versus only 96.04±2.67 mg/cm³ for the control. Histology showed scaffold stimulation of osteoblast mineralization and collagen deposition. Therefore, nHA-rGO scaffolds may be an effective treatment of large tumor-related bone defects due to their excellent photothermal and osteogenic effects.

Three dimensionally printed pearl powder/poly-caprolactone composite scaffolds for bone regeneration.

Abstract Pearl has great potential as a natural biomaterial for bone tissue engineering, but it suffers from low porosity, difficulty in molding, and poor anti-buckling property. In this study, we used the 3-D printing technique to fabricate original pearl powder and PCL composite scaffolds with different concentrations of pearl powder. The four groups of scaffolds were termed PCL, 30% Pearl/PCL, 50% Pearl/PCL and 80% Pearl/PCL scaffolds according to the proportion of pearl powder. The samples were systematically investigated by scanning electron microscopy (SEM), wide-angle XRD, liquid substitution, Zwick static materials testing, and energy dispersive X-ray analysis. Biological characterization included SEM, fluorescent staining using calcein-AM, cell counting kit-8 assay, alkaline phosphatase and qRT-PCR analysis. The results show that the pore size and the pore morphology of the scaffolds are closely controlled via 3-D printing. This is very beneficial for tissue growth and nutrition transmission. The regular and uniform square macropore structure ensured that the pearl powder/PCL scaffolds had favorable mechanical strength. As the concentration of pearl powder in the scaffolds increase, the compressive strength and apatite formation increase as well as cell adhesion, proliferation, and osteogenic differentiation. These results show that pearl powder/PCL scaffolds fit the requirements of bone tissue engineering. The structures as well as physicochemical and biological properties of pearl powder/PCL composite scaffolds are positively associated with pearl powder concentrations.