Bioinspired self-degradable hydrogels towards wound sealing.

Inspired by the autolysis of shaggy mane, we developed a self-degradable hydrogel as a medical adhesive for skin wounds. The rapid gelation and self-degradation of the hydrogel were achieved via the Michael addition and subsequent hydrolysis of the addition product. In vivo experiments further showed that the hydrogel adhesive was efficiently applied for skin wound repair.

Osteogenesis effects of magnetic nanoparticles modified-porous scaffolds for the reconstruction of bone defect after bone tumor resection.

The treatment of bone defect after bone tumor resection is a great challenge for orthopedic surgeons. It should consider that not only to inhibit tumor growth and recurrence, but also to repair the defect and preserve the limb function. Hence, it is necessary to find an ideal functional biomaterial that can repair bone defects and inactivate tumor. Magnetic nanoparticles (MNPs) have its unique advantages to achieve targeted hyperthermia to avoid damage to surrounding normal tissues and promote osteoblastic activity and bone formation. Based on the previous stage, we successfully prepared hydroxyapatite (HAP) composite poly(lactic-co-glycolic acid) (PLGA) scaffolds and verified its good osteogenic properties, in this study, we produced an HAP composite PLGA scaffolds modified with MNPs. The composite scaffold showed appropriate porosity and mechanical characteristics, while MNPs possessed excellent magnetic and thermal properties. The cytological assay indicated that the MNPs have antitumor ability and the composite scaffold possessed good biocompatibility. In vivo bone defect repair experiment revealed that the composite scaffold had good osteogenic capacity. Hence, we could demonstrate that the composite scaffolds have a good effect in bone repair, which could provide a potential approach for repairing bone defect after bone tumor excision.

The synergetic effect of pelvic rotation and X-ray offset on radiographic angles of the acetabular cup.

The objective of this study is to investigate the synergetic effect of the pelvic rotation and X-ray offset on the radiographic anteversion/inclination (RA/RI) angles of the acetabular cup using a mathematical model. A cone model for establishing the spatial relationship between a three-dimensional (3D) circle and its two-dimensional (2D) elliptical projection is utilized to quantify the relationship between the 3D RA/RI angles of the cup and their 2D counterparts with different types of pelvic rotations in pelvic/hip anteroposterior radiographs. The results reveal that the effect of inlet/outlet views on the 2D RA angle is similar to that of iliac/obturator views. The permissible ranges of pelvic rotation for the 2D RA angle with an acceptable bias are the 3D space formed by the limits of triple axial rotations. For a specified acceptable bias of the 2D RA angle, these ranges are almost equal between pelvic and hip radiographs. The combined inlet/obturator or outlet/iliac views can maintain the 2D RA angle of a pelvic radiograph within the same range of acceptable bias as that of a hip radiograph. For a 2D RA angle with an acceptable bias, the permissible range of pelvic rotation needs to be evaluated with equal attention in both radiographs. Graphical abstract The traditional methods for calculating the radiographic angles of the acetabular cup are based on the ellipse projection of the opening circle of the cup on radiographs. However, with varying locations of the X-ray source and pelvis rotations about different axes, the outline of this ellipse projection will change, and accordingly, the traditional method and calculating results will be inaccurate. In this study, a cone model for three-dimensional circle-to-two-dimensional ellipse projection is utilized to incorporate the effect of X-ray offset and quantify the relationships of the radiographic angles of the cup with the true orientation of the cup and pelvic rotations in either pelvic or hip anteroposterior radiographic situation.

Tetra-PEG Based Hydrogel Sealants for In Vivo Visceral Hemostasis.

Medical sealant devices for in vivo hemostasis are far from satisfactory in the aged society. A major challenge is effective integration of quick hemorrhage control of the increased anticoagulated patients, high safety, and facile accessibility. Here, a well-defined ammonolysis-based Tetra-PEG hydrogel sealant is developed with rapid gelation speed, strong tissue adhesion, and high mechanical strength. Introduction of cyclized succinyl ester groups into a hydrogel matrix endows the sealant with fast degradable and controllably dissolvable properties. The hydrogel possesses outstanding hemostatic capabilities even under the anticoagulated conditions while displaying excellent biocompatibility and feasibility. These results reveal that the optimized hydrogel may be a facile, effective, and safe sealant for hemorrhage control in vivo.

Differences in Bone Mineral Density and Hip Geometry in Trochanteric and Cervical Hip Fractures in Elderly Chinese Patients.

OBJECTIVE: To assess the differences in bone mineral density (BMD) and hip geometry in trochanteric and cervical hip fractures in elderly Chinese patients. METHODS: A consecutive series of 196 hip fracture patients aged over 50 years was recruited from November 2013 to October 2015, including 109 cases of cervical fractures (36 males and 73 females) and 87 cases of trochanteric fractures (34 males and 53 females). All patients were evaluated through dual-energy X-ray absorptiometry, and baseline characteristics, BMD and structural parameters were collected and reviewed. RESULTS: There were statistically significant differences in age, height, and body mass index between patients with each type of fracture, and patients with trochanteric fractures were older than those with cervical fractures, especially in women. The BMD in trochanteric fractures was markedly lower than in cervical fractures in all five sites of the hip by an approximate reduction of 10%, in both men and women. The cross-sectional area, cross-sectional moment of inertia, and the cortical thickness in the cervical fracture group were significantly higher than in the trochanteric fracture group. However, the buckling ratio of both the femoral neck and trochanteric region were significantly lower in the cervical fracture group. Age (/10 years), cross-sectional moment of inertia in femoral neck and buckling ratio in trochanteric region were significant risk factors for trochanteric fractures compared with cervical fractures. CONCLUSIONS: Compared with cervical hip fractures, patients with trochanteric fractures were older, had a lower BMD, and had less bone mechanical strength, especially in female patients. Age, femoral neck cross-sectional moment of inertia (FNCSMI), and trochanteric region buckling ratio (ITBR) were stronger risk factors for trochanteric hip fractures than for cervical fractures.

Early Experience with Reduction of Unstable Pelvic Fracture Using a Computer-Aided Reduction Frame.

PURPOSE: The optimal closed reduction technique for unstable pelvic fractures remains controversial. The purpose of this study is to verify the effectiveness and report early experiences with the reduction of unstable pelvic fractures using a computer-aided pelvic reduction frame. METHODS: From January 2015 to August 2016, a total of 10 patients with unilateral unstable pelvic fractures were included in this study. The surgical reduction procedure was based on the protocol of the computer-aided pelvic reduction frame that we proposed in a previous work. The quality of the reductions achieved using this system was evaluated with residual translational and rotational differences between the actual and virtual reduction positions of pelvis. The duration of the operation was recorded for quality control. RESULTS: The mean times required to set up the frame, to complete the virtual surgery simulation, and to reduce the unstable pelvic fractures were 10.3, 20.9, and 7.5 min, respectively. The maximum residual translational and rotational displacements were less than 6.5 mm and 3.71 degrees, respectively. CONCLUSIONS: This computer-aided reduction frame can be a useful tool for the speedy and accurate reduction of unstable pelvic fractures. Further clinical studies should be conducted with larger patient samples to verify its safety and efficacy.

Stabilization and immobilization of aquaporin reconstituted lipid vesicles for water purification.

Aquaporins are water channel proteins in biological membranes that have extraordinary water permeability and selectivity. In this work, we have demonstrated that one of their family members, AquaporinZ (AqpZ), can be possibly applied in a pressure-driven water purification process. A nanofiltration membrane was designed and fabricated by immobilization of AqpZ-reconstituted liposomes on a polydopamine (PDA) coated microporous membrane. Amine-functionalized proteoliposomes were first deposited via gentle vacuum suction and subsequently conjugated on the PDA layer via an amine-catechol adduct formation. Due to the existence of a polymer network within the lipid bilayers, the membrane could sustain hydraulic pressure of 5 bar as well as the strong surface agitation in nanofiltration tests, indicating a relatively stable membrane structure. In comparison with membrane without AqpZ incorporation, the membrane with AqpZ-to-lipid weight ratio of 1:100 increased the water flux by 65% with enhanced NaCl and MgCl(2) rejections of 66.2% and 88.1%, respectively. With AqpZ incorporation, the vesicle immobilized membrane exhibits a promising strategy for high productivity water purification.

A novel method of AquaporinZ incorporation via binary-lipid Langmuir monolayers.

In this work, a new approach of incorporating transmembrane protein AquaporinZ (AqpZ) into a lipid bilayer has been developed with the aid of the Langmuir-Blodgett technique. The binary-lipid monolayer for AqpZ incorporation is composed of (1) gel-phase lipids resistant to detergent dissolution and (2) nickel-chelating lipids that can attach the histidine-tagged AqpZ from the subphase. Upon removal of subphase detergent with BioBeads, the incorporation is achieved by transferring the AqpZ-associated binary-lipid monolayer onto a preformed pure binary-lipid monolayer using the Langmuir-Schaefer deposition method. AFM images show an indication of AqpZ incorporation in the bilayer. Furthermore, it is also shown that BioBeads can remove a significant amount of detergent in the subphase and lipid film integrity is restored after detergent removal. The detergent removal rate is correlated to BioBeads amount and subphase circulation. The new approach of AqpZ reconstitution revealed in this work could potentially be applied in biomimetic membrane formation for water purification applications.