The Effect of Age on the Regenerative Potential of Adipose Stem-cell-derived Apoptotic Extracellular Vesicles in Rat Skin Wound Healing.

Introduction: Skin, being the body's largest organ, is susceptible to injuries. Despite the adoption of common treatments such as debridement, wound dressing, and infection control measures for skin injuries, the outcomes remain unsatisfactory, especially in diabetic patients or elderly patients. The use of adipose stem cell-derived apoptotic extracellular vesicles (apoEVs-ASCs) has been shown great therapeutic potential in wound repair. The effect of the donor age on the biological properties and functions of apoEVs-ASCs has not been reported. Methods: In this study, we isolated apoEVs-ASCs from young and aged rats. Transmission electron microscopy (TEM) and nanoparticle tracking analysis (NTA) were applied for the characteristics of apoEVs-ASCs. For aged and young apoEVs-ASCs groups, the proliferative and migration abilities in vitro, and wound healing function in vivo were contrastively evaluated and quantified for statistical analysis. Results: Our results showed that both young and aged apoEVs-ASCs induced skin healing and reduced scar formation. In addition, young apoEVs-ASCs had significantly higher proliferation, migration of fibroblasts and endothelial cells, and increased neo-angiogenesis ability, when compared with that of aged apoEVs-ASCs. Conclusion: Young apoEVs-ASCs should be employed for wound repair, which is associated with its superior promoting effect on wound healing.

Peptide-Based Coacervate Protocells with Cytoprotective Metal-Phenolic Network Membranes.

Protocells have garnered considerable attention from cell biologists, materials scientists, and synthetic biologists. Phase-separating coacervate microdroplets have emerged as a promising cytomimetic model because they can internalize and concentrate components from dilute surrounding environments. However, the membrane-free nature of such coacervates leads to coalescence into a bulk phase, a phenomenon that is not representative of the cells they are designed to mimic. Herein, we develop a membranized peptide coacervate (PC) with oppositely charged oligopeptides as the molecularly crowded cytosol and a metal-phenolic network (MPN) coating as the membrane. The hybrid protocell efficiently internalizes various bioactive macromolecules (e.g., bovine serum albumin and immunoglobulin G) (>90%) while also resisting radicals due to the semipermeable cytoprotective membrane. Notably, the resultant PC@MPNs are capable of anabolic cascade reactions and remain in discrete protocellular populations without coalescence. Finally, we demonstrate that the MPN protocell membrane can be postfunctionalized with various functional molecules (e.g., folic acid and fluorescence dye) to more closely resemble actual cells with complex membranes, such as recognition molecules, which allows for drug delivery. This membrane-bound cytosolic protocell structure paves the way for innovative synthetic cells with structural and functional complexity.

Should preoperative computed tomography be routine examination for cervicofacial space infections?

BACKGROUND: Cervicofacial space infections are potentially life-threatening, which require accurate diagnosis, early incision, and adequate drainage. The utilization of computed tomography (CT) in cervicofacial space infections has significantly increased for its advantages in the evaluation of abscesses, its availability, and low cost. However, the clinical value of preoperative CT imaging in cervicofacial space infections remains controversial for its poor specificity, radiation exposure, potential complications, and extra cost. We, therefore, investigated whether CT examination should be used as a routine examination in the treatment of patients with cervicofacial space infections. METHODS: A retrospective study of all patients affected by cervicofacial space infections that received incision and drainage surgery from Jan 2016 to Dec 2020 was performed at West China Hospital of Stomatology at Sichuan University. Patients were divided into two groups: the group with preoperative CT and without preoperative CT. Outcomes, including reoperation rate, missed diagnosis rate, days of symptom relief, length of stay, duration of surgery, and total cost of hospitalization, were analyzed. RESULTS: Out of n = 153 patients, 108 patients underwent surgery with preoperative CT and 45 patients without preoperative CT. The reoperation rate in the preoperative CT group (6/108, 5.6%) was significantly lower (P = 0.00) than that in the group without preoperative CT (10/45, 22.2%). Significant reduction of missed diagnosis rate (P = 0.00), days of symptom relief (P = 0.01), length of stay(P = 0.03), and duration of surgery (P = 0.01) were detected in the preoperative CT group. The results demonstrated that the utilization of preoperative CT can reduce the missed diagnosis rate and repeated surgery complications. CONCLUSIONS: We recommend preoperative CT as a routine examination in cervicofacial space infections.

Prevalence and Risk Factors for Chronic Maxillary Sinusitis After Surgery for Mid-Facial Fracture: A Cross-Sectional Study.

ABSTRACT: Posttraumatic chronic maxillary sinusitis deleteriously affects the life quality of patients with recurrent episodes and related discomfort. However, few studies have been performed to investigate the prevalence of chronic maxillary sinusitis after surgery of mid-facial fracture and related risk factors. The early prevention and cure of posttraumatic chronic maxillary sinusitis have received little attention. This study aimed to investigate the prevalence of chronic maxillary sinusitis after surgery for mid-facial fracture and to identify related risk factors. The authors retrospectively collected the medical history, radiographic examination, and clinical examination of patients with mid-facial fracture (experimental group) and patients with mandibular cyst (control group) in our department between January 2015 and December 2020. A total of 298 patients (416 maxillary sinuses) in the experimental group and 172 patients (344 maxillary sinuses) in the control group were included for analyses. The prevalence of chronic maxillary sinusitis in the experimental group and control group were, respectively, 9.14% and 2.04% ( P < 0.05). History of sinusitis/rhinitis (odds ratio = 63.70, P = 0.000) was an independent risk factor for posttraumatic chronic maxillary sinusitis. In conclusion, these findings showed that the prevalence of chronic maxillary sinusitis after surgery for midfacial fracture was significantly higher than that in the control group and long-term follow-up may be beneficial for these patients. Moreover, patients with a history of sinusitis/rhinitis should be informed of the increased risk.

Multifunctional polymeric nanocapsules with enhanced cartilage penetration and retention for osteoarthritis treatment.

Osteoarthritis (OA) is a prevalent joint disease characterized by cartilage degeneration and subchondral bone homeostasis imbalance. Effective topical OA therapy is challenging, as therapeutic drugs often suffer from insufficient penetration and rapid clearance. We develop miniature polydopamine (PDA) nanocapsules (sub-60 nm), which are conjugated with collagen-binding polypeptide (CBP) and loaded with an anabolic drug (i.e., parathyroid hormone 1-34, PTH 1-34) for efficient OA treatment. Such multifunctional polymeric nanocapsules, denoted as PDA@CBP-PTH, possess deformability when interacting with the dense collagen fiber networks, enabling the efficient penetration into 1 mm cartilage in 4 h and prolonged retention within the joints up to 28 days. Moreover, PDA@CBP-PTH nanocapsules exhibit excellent reactive oxygen species scavenging property in chondrocytes and enhance the anabolism in subchondral bone. The nanosystem, as dual-mode treatment for OA, demonstrates rapid penetration, long-lasting effects, and combinational therapeutic impact, paving the way for reversing the progression of OA for joint health care.

Multifunctional Metal-Phenolic Composites Promote Efficient Periodontitis Treatment via Antibacterial and Osteogenic Properties.

Periodontitis, a complex inflammatory disease initiated by bacterial infections, presents a significant challenge in public health. The increased levels of reactive oxygen species and the subsequent exaggerated immune response associated with periodontitis often lead to alveolar bone resorption and tooth loss. Herein, we develop multifunctional metal-phenolic composites (i.e., Au@MPN-BMP2) to address the complex nature of periodontitis, where gold nanoparticles (AuNPs) are coated by metal-phenolic networks (MPNs) and bone morphogenetic protein 2 (BMP2). In this design, MPNs exhibit remarkable antibacterial and antioxidant properties, and AuNPs and BMP2 promote osteogenic differentiation of bone marrow mesenchymal stem cells under inflammatory conditions. In a rat model of periodontitis, treatment with Au@MPN-BMP2 leads to notable therapeutic outcomes, including mitigated oxidative stress, reduced progression of inflammation, and the significant prevention of inflammatory bone loss. These results highlight the multifunctionality of Au@MPN-BMP2 nanoparticles as a promising therapeutic approach for periodontitis, addressing both microbial causative factors and an overactivated immune response. We envision that the rational design of metal-phenolic composites will provide versatile nanoplatforms for tissue regeneration and potential clinical applications.

I want to go there too! Tourism destination envy in social media marketing.

Envy has been widely discussed as a type of consumption motivation and a consumer attitude towards specific consumer goods in the context of social media. However, research on envy in tourism consumption decision-making is still relatively scarce. Accordingly, adopting social cognitive theory while considering benign envy, this study discusses the impact of social media content on consumers' destination envy and behavioural intention during the COVID-19 pandemic. Using a survey of 320 Chinese tourists who travelled to Macao, this paper develops and tests a conceptual framework. The results show that destination envy plays an intermediary role between social media content and consumer behavioural intention. Our findings thus integrate disparate literature streams while shedding light on the impacts of social media content on tourism consumers' travel decisions during the COVID-19 era.

How does the use of simultaneous contrast illusion on product-background color combination nudge consumer behavior? A behavioral and event-related potential study.

Color, as one of the most critical visual factors influencing consumer decisions, has been widely used in e-commerce marketing. However, the effects of product-background saturation combination on consumers' willingness to purchase products with different heaviness attributes (e.g., heaviness-positive products or heaviness-negative products) have not been conclusively determined. The current study demonstrated the effects of product-background saturation combination on product heaviness perception and its downstream consequences. Based on behavioral method, study 1 showed that a patch of color placed in a pale background (the saturation of the background is lower than the saturation of the color patch) was perceived as visually heavier than that in a colorful background (the saturation of the background is higher than the saturation of the color patch). Study 2 applied event-related potentials (ERPs) method to explore the underlying neural mechanisms of how the interactions between the presentation modes and the product types affect consumer decisions. Behaviorally, compared to the colorful background, the pale background would lead to a higher purchase rate for the heaviness-positive products, whereas the opposite results were found for the heaviness-negative products. Furthermore, for both the heaviness-positive and heaviness-negative products, a shorter reaction time would be observed in the pale background condition than in the colorful background condition. Neurophysiologically, the pale background would result in smaller N2 component and larger P3 component compared to the colorful background for the heaviness-positive products, while the reverse held for the heaviness-negative products. Smaller N2 component implies decreased perceptual conflicts and larger P3 component implies increased decision confidence, suggesting that e-retailers should present heaviness-positive products with pale backgrounds and heaviness-negative products with colorful backgrounds.

What motivates farmers to adopt low-carbon agricultural technologies? Empirical evidence from thousands of rice farmers in Hubei province, central China.

Low-carbon agriculture is essential for protecting the global climate and sustainable agricultural economics. Since China is a predominantly agricultural country, the adoption of low-carbon agricultural technologies by local farmers is crucial. The past literature on low-carbon technologies has highlighted the influence of demographic, economic, and environmental factors, while the psychological factors have been underexplored. A questionnaire-based approach was used to assess the psychological process underlying the adoption of low-carbon agricultural technologies by 1,114 Chinese rice farmers in this paper, and structural equation modeling (SEM) was empirically employed to test our theoretical model. The results indicated that farmers' low-carbon production attitude and behavioral efficiency perception directly and positively affected the adoption of low-carbon agricultural technologies and indirectly affected it via low-carbon production intention. Besides, production implementation cost and socio-environmental factor could moderate the direct effects of low-carbon production attitude, behavioral efficiency perception, and low-carbon production intention on farmers' adoption of low-carbon agricultural technologies. In this respect, socio-environmental factor yielded more significant moderating effects. Additionally, this research provides policy implications for promoting low-carbon agricultural technologies in developing countries and regions.

Influence of incentive mechanism and fit degree on user's environmental behavior-Taking Alipay "Ant Forest" in China as an example.

How to use game elements to motivate users and influence their behavior has become a new research trend, which is vital for enhancing the willingness of potential platform users to participate in environmental protection. This paper aims to analyze the influence of incentive mechanism and fit degree on user's environmental behavior based on the stimulus-organism-response theory and self-determination theory. The questionnaire data of 500 users was collected and the impact of incentives on user's environmental behavior was analyzed by structural equation modeling. The results show that economic, value, and social incentives have a significant impact on user's environmental behavior. Besides, the value and social incentives of "Ant Forest" game platform positively influence user fit (conscious participation, enthusiasm, and platform interaction), but the impact of economic incentive on platform interaction is not statistically significant. From the perspective of user fit, "Ant Forest" game platform can positively promote users to adopt environmental behavior, because it explores users' needs from their perspective to give full play to the role of game incentives on users' environmental behavior. Additionally, this research provides the practical implications for managers exploring the effects of co-creation processes in developing countries and regions.

Risk Factors for Maxillary Sinus Pathology after Surgery for Midfacial Fracture: A Multivariate Analysis.

This study aimed to determine the incidence of maxillary sinus pathology in patients with a midfacial fracture who underwent osteosynthesis surgery and evaluate the associated risk factors. We conducted a retrospective case-control analysis of patients with midfacial fractures involving a maxillary sinus wall who were treated with open reduction and internal fixation (ORIF) between January 2015 and December 2020. Fracture reduction, the number of screws implanted in the maxillary sinus, and the number of screws penetrating the maxillary sinus, etc., were examined as potential risk factors. Maxillary sinus pathology on postoperative CT was considered the primary outcome for case-control analysis. Binary logistic regression was used to identify variables associated with postoperative maxillary sinus pathology. Thereafter, propensity score matching (PSM) was used to extract confounding factors. A total of 262 patients (totaling 372 maxillary sinuses) were included for analysis. PSM yielded 178, 246, and 70 matched sinuses, respectively, depending on the potential risk factors. Postoperative maxillary sinus pathology was visualized in 218 of the 372 maxillary sinuses (58.60%). The risk factors for postoperative maxillary sinus pathology included the number of screws penetrating the maxillary sinus (odds ratio (OR), 1.124; p = 0.007), an imperfect maxillary sinus wall fracture reduction (OR, 2.901; p = 0.021), and the number of sinus walls involved (OR, 1.383; p = 0.011). After PSM, postoperative maxillary sinus pathology was still more prevalent in sinuses with multiple maxillary sinus wall fractures (64.04% vs. 48.31%, p = 0.034), sinuses with more screws penetrating the maxillary sinus (64.23% vs. 50.41%, p = 0.028), and sinuses with an imperfect reduction (80% vs. 51.43%, p = 0.012). In conclusion, maxillary sinus pathology is common after the ORIF of midfacial fractures. Patients with a fracture of multiple maxillary sinus walls require a close follow-up. Screw penetration of the maxillary sinus should be avoided to prevent maxillary sinus pathology after a midfacial fracture ORIF.

Xenogeneic stem cell transplantation: Research progress and clinical prospects.

Organ transplantation is the ultimate treatment for end-stage diseases such as heart and liver failure. However, the severe shortage of donor organs has limited the organ transplantation progress. Xenogeneic stem cell transplantation provides a new strategy to solve this problem. Researchers have shown that xenogeneic stem cell transplantation has significant therapeutic effects and broad application prospects in treating liver failure, myocardial infarction, advanced type 1 diabetes mellitus, myelosuppression, and other end-stage diseases by replacing the dysfunctional cells directly or improving the endogenous regenerative milieu. In this review, the sources, problems and solutions, and potential clinical applications of xenogeneic stem cell transplantation will be discussed.

Osteoinductive and antimicrobial mechanisms of graphene-based materials for enhancing bone tissue engineering.

Graphene-based materials (GMs) have great application prospects in bone tissue engineering due to their osteoinductive ability and antimicrobial activity. GMs induce osteogenic differentiation through several mechanisms and pathways in bone tissue engineering. First of all, the surface and high hardness of the porous folds of graphene or graphene oxide (GO) can generate mechanical stimulation to initiate a cascade of reactions that promote osteogenic differentiation without any chemical inducers. In addition, change of the extracellular matrix (ECM), regulation of macrophage polarization, the oncostatin M (OSM) signaling pathway, the MAPK signaling pathway, the BMP signaling pathway, the Wnt/ß-catenin signaling pathway, and other pathways are involved in GMs' regulation of osteogenesis. In bone tissue engineering, GMs prevent the formation of microbial biofilms mainly through preventing microbial adhesion and killing them. The former is mainly achieved by reducing surface free energy (SFE) and increasing hydrophobicity. The latter mainly includes oxidative stress and photothermal/photodynamic effects. Graphene and its derivatives (GDs) are mainly combined with bioactive ceramic materials, metal materials and macromolecular polymers to play an antimicrobial effect in bone tissue engineering. Concentration, number of layers, and type of GDs often affect the antimicrobial activity of GMs. In this paper, we reviewed relevant osteoinductive and antimicrobial mechanisms of GMs and their applications in bone tissue engineering.

Effect of metformin on stem cells: Molecular mechanism and clinical prospect.

Metformin is a first-line medication for type II diabetes. Numerous studies have shown that metformin not only has hypoglycemic effects, but also modulates many physiological and pathological processes ranging from aging and cancer to fracture healing. During these different physiological activities and pathological changes, stem cells usually play a core role. Thus, many studies have investigated the effects of metformin on stem cells. Metformin affects cell differentiation and has promising applications in stem cell medicine. It exerts anti-aging effects and can be applied to gerontology and regenerative medicine. The potential anti-cancer stem cell effect of metformin indicates that it can be an adjuvant therapy for cancers. Furthermore, metformin has beneficial effects against many other diseases including cardiovascular and autoimmune diseases. In this review, we summarize the effects of metformin on stem cells and provide an overview of its molecular mechanisms and clinical prospects.