3D-printed piezocatalytic hydrogels for effective antibacterial treatment of infected wounds.

Bacterial-infected wound repair has become a significant public health concern. This study developed a novel 3D-printed piezocatalytic SF-MA/PEGDA/Ag@BT (SPAB) hydrogels were fabricated by using digital light processing. These hydrogels exhibited high consistency, mechanical properties and good biocompatibility. Besides, the SPAB hydrogels exhibited excellent piezocatalytic performance and thus could induce piezoelectric polarization under ultrasound to generate reactive oxygen species (ROS). The SPAB hydrogels possessed an antibacterial rate of 99.23% and 99.96% for Escherichia coli and Staphylococcus aureus, respectively, under 5 min of ultrasonic stimulation (US) in vitro. The US-triggered piezocatalytic performance could increase antibacterial activity and improve the healing process of the infected wound. Therefore, the 3D printed piezocatalytic SPAB hydrogels could be unutilized as wound dressing in the field of bacterial-infected wound repair.

A pH responsive tannic acid/quaternized carboxymethyl chitosan/oxidized sodium alginate hydrogels for accelerated diabetic wound healing and real-time monitoring.

Treatment of diabetic wounds is a major clinical issue. Diabetic wound dressings have higher requirements for anti-oxidant, antibacterial and wound monitoring properties compared to conventional wound dressings. In this study, a novel tannic acid (TA)/quaternized carboxymethyl chitosan (QCMCS)/oxidized sodium alginate (OSA)@carbon quantum dots (CQD) (TA/QCMCS/OSA@CQD) hydrogels for promoting diabetic wound healing and real-time monitoring have been developed. The TA/QCMCS/OSA@CQD hydrogels exhibited excellent self-healing, antibacterial and antioxidant properties. Besides, these hydrogels possessed good biocompatibility and effective hemostasis in a mouse liver injury model and significantly facilitated the healing process in a diabetic wound model. In addition, these hydrogels can reliable and timely measure the diabetic wound pH information by collecting image signals of hydrogels to monitor the healing status. Therefore, the pH responsive TA/QCMCS/OSA@CQD hydrogels could be utilized as wound dressing for promoting diabetic wound healing and real-time monitoring.

Direct distortion prediction method for AR-HUD dynamic distortion correction.

Dynamic distortion is one of the most critical factors affecting the experience of automotive augmented reality head-up displays (AR-HUDs). A wide range of views and the extensive display area result in extraordinarily complex distortions. Existing methods based on the neural network first obtain distorted images and then get the predistorted data for training mostly. This paper proposes a distortion prediction framework based on the neural network. It directly trains the network with the distorted data, realizing dynamic adaptation for AR-HUD distortion correction and avoiding errors in coordinate interpolation. Additionally, we predict the distortion offsets instead of the distortion coordinates and present a field of view (FOV)-weighted loss function based on the spatial-variance characteristic to further improve the prediction accuracy of distortion. Experiments show that our methods improve the prediction accuracy of AR-HUD dynamic distortion without increasing the network complexity or data processing overhead.

Inhibitory effect of ficin on Candida albicans biofilm formation and pre-formed biofilms.

BACKGROUND: To investigate the effect of ficin, a type of proteases, on Candida albicans (C. albicans) biofilm, including forming and pre-formed biofilms. METHODS: Crystal violet tests together with colony forming unit (CFU) counts were used to detect fungal biofilm biomass. Live/dead staining of biofilms observed by confocal laser scanning microscopy was used to monitor fungal activity. Finally, gene expression of C. albicans within biofilms was assessed by qRT-PCR. RESULTS: According to our results, biofilm biomass was dramatically reduced by ficin in both biofilm formation and pre-formed biofilms, as revealed by the crystal violet assay and CFU count (p < 0.05). Fungal activity in biofilm formation and pre-formed biofilms was not significantly influenced by ficin according to live/dead staining. Fungal polymorphism and biofilm associated gene expression were influenced by ficin, especially in groups with prominent antibiofilm effects. CONCLUSIONS: In summary, ficin effectively inhibited C. albicans biofilm formation and detached its preformed biofilm, and it might be used to treat C. albicans biofilm associated problems.

Predicting the Risk of Postoperative Complications of Schwannoma Surgery: Development and Assessment of a New Predictive Nomogram.

BACKGROUND: The aim of this study was to develop and internally validate a risk nomogram for postoperative complications of schwannoma surgery. METHODS: From 2016 to 2020, we reviewed 83 patients who underwent schwannoma resection with a total number of 85 schwannomas. A predictive model was developed based on the dataset of this group. During model construction, univariate and multivariate logistic regression analysis were used to determine the independent predictors of postoperative complications. Assessment of the discriminative function, calibrating proficiency, and clinical usefulness of the predicting model was performed using C-index, calibration plot, receiver operating characteristic (ROC) curve, and decision curve analysis. Internal validation was assessed using bootstrapping validation. RESULTS: Predictors contained in the prediction nomogram included age, tumor location, symptoms, and surgical approach. The model displayed satisfying abilities of discrimination and calibration, with a C-index of 0.901 (95% confidence [CI]: 0.837-0.965). A high C-index value of 0.853 was achieved in the interval verification. Decision curve analysis showed that the nomogram was clinically useful when intervention was decided at the complication possibility threshold of 2%. CONCLUSION: This new risk nomogram for postoperative complications of schwannoma surgery has taken age, tumor location, symptoms, and surgical approach into account. It has reasonable predictive accuracy and can be conveniently used. It shall help patients understand the risk of postoperative complications before surgery, and offer guidance to surgeons in deciding on the surgical approach.

The suppression effect of SCH-79797 on Streptococcus mutans biofilm formation.

Background: SCH-79797 was recently shown to be a broad-spectrum antibacterial agent with a dual-bactericidal mechanism. However, its anti-biofilm effect remains unknown. Purpose: To investigate the effect of SCH-79797 on the biofilm formation of the cariogenic Streptococcus mutans. Methods and Results: Crystal violet staining, colony forming units count and MTT assays (for cell metabolic activity) revealed that S. mutans biofilm formation was significantly suppressed. In addition, virulence factors, including extracellular polysaccharides (investigated by bacterial/exopolysaccharide staining and the anthrone method) and acid production (investigated by lactic acid and supernatant pH detection) were also inhibited significantly. Moreover, the biofilm inhibitory effect of SCH-79797 was mediated through its repression of bacterial growth and not by a bactericidal effect, which was verified by growth curve and bacterial live/ dead staining, respectively. Quantitative real-time PCR results disclosed that SCH-79797 affected bacterial acid production and tolerance, polysaccharide synthesis and remodeling, biofilm formation and quorum sensing-related gene expression. In addition, SCH-79797 showed good biocompatibility as determined by cytotoxicity assays. Conclusion: SCH-79797 had an anti-biofilm effect and showed application prospects in the control of dental caries.

Foot and ankle reconstruction using the lateral supramalleolar flap versus the anterolateral thigh flap in the elderly: A comparative study.

The purpose of this study was to compare the reconstructive outcomes of soft-tissue defects around the foot and ankle with anterolateral thigh (ALT) flap or lateral supramalleolar (LSM) flap and attempt to provide an optimal strategy for elderly patients. A retrospective review of all continuous patients with foot and ankle reconstruction using different flaps from October of 2010 and October of 2020 was performed. Based on the flap types, the patients were divided into two groups: ALT flap group (n = 50) and LSM flap group (n = 46). Outcomes were assessed according to the flap survival rate, early complications, general complications, late complications, cosmetic appearance, functional outcomes and Vancouver Scar Scale (VSS). We found that there was no difference in average age, gender, aetiology, size of the defect, debridement times between the two groups; however, a significant difference in operation time, hospitalisation time and cost were noted between them. What's more, the early flap complications between them were not significantly different. The LSM flap group showed less general complications, less flap bulky and lower cosmetic appearance. Moreover, the functional evaluation and VSS seem similar (P > .05). Thus, The ALT flap and LSM flap are both flaps available for foot and ankle reconstruction in elderly patients. However, the LSM flap offers short operation time, short hospitalisation time, and less cost with a lower frequency of postoperative complications. Thus, we advocate the LSM flap for the reconstruction of moderate-size defects of the foot and ankle region in elderly patients.

Ecological influence by colonization of fluoride-resistant Streptococcus mutans in oral biofilm.

Background: Dental caries is one of the oldest and most common infections in humans. Improved oral hygiene practices and the presence of fluoride in dentifrices and mouth rinses have greatly reduced the prevalence of dental caries. However, increased fluoride resistance in microbial communities is concerning. Here, we studied the effect of fluoride-resistant Streptococcus mutans (S. mutans) on oral microbial ecology and compare it with wild-type S. mutans in vitro. Methods: Biofilm was evaluated for its polysaccharide content, scanning electron microscopy (SEM) imaging, acid-producing ability, and related lactic dehydrogenase (LDH), arginine deiminase (ADS), and urease enzymatic activity determination. Fluorescence in situ hybridization (FISH) and quantitative real-time polymerase chain reaction (qRT-PCR) were used to evaluate the S. mutans ratio within the biofilm. It was followed by 16S rRNA sequencing to define the oral microbial community. Results: Fluoride-resistant S. mutans produced increased polysaccharides in presence of NaF (P < 0.05). The enzymatic activities related to both acid and base generation were less affected by the fluoride. In presence of 275 ppm NaF, the pH in the fluoride-resistant strain sample was lower than the wild type. We observed that with the biofilm development and accumulative fluoride concentration, the fluoride-resistant strain had positive relationships with other bacteria within the oral microbial community, which enhanced its colonization and survival. Compared to the wild type, fluoride-resistant strain significantly increased the diversity and difference of oral microbial community at the initial stage of biofilm formation (4 and 24 h) and at a low fluoride environment (0 and 275 ppm NaF) (P < 0.05). Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that fluoride-resistant strain enhanced the metabolic pathways and glucose transfer. Conclusions: Fluoride-resistant S. mutans affected the microecological balance of oral biofilm and its cariogenic properties in vitro, indicating its negative impact on fluoride's caries prevention effect.

Olfactory ensheathing cells seeded decellularized scaffold promotes axonal regeneration in spinal cord injury rats.

Spinal cord decellularized (DC) scaffolds can promote axonal regeneration and restore hindlimb motor function of spinal cord defect rats. However, scarring caused by damage to the astrocytes at the margin of injury can hinder axon regeneration. Olfactory ensheathing cells (OECs) integrate and migrate with astrocytes at the site of spinal cord injury, providing a bridge for axons to penetrate the scars and grow into lesion cores. The purpose of this study was to evaluate whether DC scaffolds carrying OECs could better promote axon growth. For these studies, DC scaffolds were cocultured with primary extracted and purified OECs. Immunofluorescence and electron microscopy were used for verification of cells adhere and growth on the scaffold. Scaffolds with OECs were transplanted into rat spinal cord defects to evaluate axon regeneration and functional recovery of hind limbs. Basso, Beattie, and Bresnahan (BBB) scoring was used to assess motor function recovery, and glial fibrillary acidic protein (GFAP) and NF200-stained tissue sections were used to evaluate axonal regeneration and astrological scar distribution. Our results indicated that spinal cord DC scaffolds have good histocompatibility and spatial structure, and can promote the proliferation of adherent OECs. In animal experiments, scaffolds carrying OECs have better axon regeneration promoting protein expression than the SCI model, and improve the proliferation and distribution of astrocytes at the site of injury. These results proved that the spinal cord DC scaffold with OECs can promote axon regeneration at the site of injury, providing a new basis for clinical application.

FGF10 Enhances Peripheral Nerve Regeneration via the Preactivation of the PI3K/Akt Signaling-Mediated Antioxidant Response.

The process of axonal regeneration after peripheral nerve injury (PNI) is slow and mostly incomplete. Previous studies have investigated the neuroprotective effects of fibroblast growth factor 10 (FGF10) against spinal cord injury and cerebral ischemia brain injury. However, the role of FGF10 in peripheral nerve regeneration remains unknown. In this study, we aimed to investigate the underlying therapeutic effects of FGF10 on nerve regeneration and functional recovery after PNI and to explore the associated mechanism. Our results showed that FGF10 administration promoted axonal regeneration and functional recovery after nerve damage. Moreover, exogenous FGF10 treatment also prevented SCs from excessive oxidative stress-induced apoptosis, which was probably related to the activation of phosphatidylinositol-3 kinase/protein kinase B (PI3K/Akt) signaling. The inhibition of the PI3K/Akt pathway by the specific inhibitor LY294002 partially reversed the therapeutic effects of FGF10 both in vivo and in vitro. Thus, from our perspective, FGF10 may be a promising therapeutic drug for repairing sciatic nerve damage through countering excessive oxidative stress-induced SC apoptosis.

Fibroblast growth factor 21 facilitates peripheral nerve regeneration through suppressing oxidative damage and autophagic cell death.

Seeking for effective drugs which are beneficial to facilitating axonal regrowth and elongation after peripheral nerve injury (PNI) has gained extensive attention. Fibroblast growth factor 21 (FGF21) is a metabolic factor that regulates blood glucose and lipid homeostasis. However, there is little concern for the potential protective effect of FGF21 on nerve regeneration after PNI and revealing related molecular mechanisms. Here, we firstly found that exogenous FGF21 administration remarkably promoted functional and morphologic recovery in a rat model of sciatic crush injury, manifesting as persistently improved motor and sensory function, enhanced axonal remyelination and regrowth and accelerated Schwann cells (SCs) proliferation. Furthermore, local FGF21 application attenuated the excessive activation of oxidative stress, which was accompanied with the activation of nuclear factor erythroid-2-related factor 2 (Nrf-2) transcription and extracellular regulated protein kinases (ERK) phosphorylation. We detected FGF21 also suppressed autophagic cell death in SCs. Additionally, treatment with the ERK inhibitor U0126 or autophagy inhibitor 3-MA partially abolishes anti-oxidant effect and reduces SCs death. Taken together, these results indicated that the role of FGF21 in remyelination and nerve regeneration after PNI was probably related to inhibit the excessive activation of ERK/Nrf-2 signalling-regulated oxidative stress and autophagy-induced cell death. Overall, our work suggests that FGF21 administration may provide a new therapy for PNI.

[MIPPO and ORIF for the treatment of elderly proximal humerus fractures of type Neer II:a case control study].

OBJECTIVE: To compare the clinical efficacy of minimally invasive percutaneous plate osteosynthesis(MIPPO)and open reduction and internal fixation (ORIF) in treating senile NEER IIproximal humerus fractures. METHODS: From March 2014 to March 2016, 46 elderly patients with Neer II proximal humerus fractures were retrospectively reviewed. Among them, 20 patients in MIPPO group included 9 males and 11 females with an average age of (70.4±4.4) years old; while 26 patients in ORIF group included 11 males and 15 females with an average age of (70.9±4.0) years old. The length of hospital stay, times of fluoroscopy, beginning time of function rehabilitation, healing time of fracture, Constant Murley score of the shoulder joint at 3, 6, 12 months after operation and complications were observed and compared. RESULTS: All patients were followed up for 12 to 24 months with an average of 16.8±3.7. The healing time of fracture, beginning time of function rehabilitation in MIPPO group were(13.0±0.8) weeks, (3.0±0.9) days respectively and shorter than those in ORIF group which were (13.8±1.4) weeks and(6.8±1.3) days. The times of fluoroscopy in MIPPO group was 19.2±3.7 and more than that in ORIF group which was 12.1±3.4. At 3 and 6 months after operation, Constant Murley score in MIPPO group were 81.3±3.9, 86.6±5.4 and more than that in ORIF group which were 69.5±6.6, 80.5±6.7. There were no differences between two groups in the length of hospital stay, Constant Murley score at 12 months after operation and grading at the final follow-up. There was one fracture redisplacement in each group. And 1 case of axillary nerve injury in MIPPO group, 2 cases of delayed union in ORIF group. No incision infection, screw loosening or plate break was found. CONCLUSIONS: MIPPO and ORIF are both effective in treating Neer II proximal humeral fractures. MIPPO technique has the advantages of faster recovery, earlier rehabilitative exercise and better shoulder function. The disadvantages are more exposure to radiationd and the possibility of axillary nerve injure.

Effect of decellularized spinal scaffolds on spinal axon regeneration in rats.

A series of complex influencing factors lead to failure of neural regeneration after spinal cord injury (SCI). Up to now, there is no robust treatment that can restore the loss of function caused by injury. Because damaged spinal axons do not spontaneously regenerate in their naturally inhibitory microenvironments, biomaterials that induce neural regeneration to appear as attractive treatments to improve the microenvironmental conditions after SCI. In this study, we report the novel use of decellularized (DC) scaffolds to provide contact guidance for axonal regrowth in vivo. The idea is that the scaffolds comprise some cytokines and a physical compartment that may facilitate regeneration. To evaluate the efficacy of scaffolds in supporting neural regeneration after SCI, the scaffold was implanted into an injured spinal cord of the rat. The injured spinal scaffolds showed a significant increase of the expression of GAP43, NF200, and Nestin in the scaffold implant groups compared with controls without the scaffold. In addition, the motor function has a better recovery. Together, these results demonstrate that spinal acellular scaffold is capable of promoting axonal regeneration after SCI and may serve as a potential tool in the treatment of SCI. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 698-705, 2018.

Network Location-Aware Service Recommendation with Random Walk in Cyber-Physical Systems.

Cyber-physical systems (CPS) have received much attention from both academia and industry. An increasing number of functions in CPS are provided in the way of services, which gives rise to an urgent task, that is, how to recommend the suitable services in a huge number of available services in CPS. In traditional service recommendation, collaborative filtering (CF) has been studied in academia, and used in industry. However, there exist several defects that limit the application of CF-based methods in CPS. One is that under the case of high data sparsity, CF-based methods are likely to generate inaccurate prediction results. In this paper, we discover that mining the potential similarity relations among users or services in CPS is really helpful to improve the prediction accuracy. Besides, most of traditional CF-based methods are only capable of using the service invocation records, but ignore the context information, such as network location, which is a typical context in CPS. In this paper, we propose a novel service recommendation method for CPS, which utilizes network location as context information and contains three prediction models using random walking. We conduct sufficient experiments on two real-world datasets, and the results demonstrate the effectiveness of our proposed methods and verify that the network location is indeed useful in QoS prediction.