Enhancing stem cell therapy efficacy with functional lignin modified cerium-iron nanozyme through magnetic resonance imaging tracking and apoptosis protection in inflammatory environment.

Stem cell transplantation provides a promising approach for addressing inflammation and functional disorders. Nonetheless, the viability of these transplanted cells diminishes significantly within pathological environments, limiting their therapeutic potential. Moreover, the non-invasive tracking of these cells in vivo remains a considerable challenge, hampering the assessment of their therapeutic efficacy. Transition-metal oxide nanocrystals, known for their unique "enzyme-like" catalytic property and imaging capability, provide a new avenue for clinical application. In this study, the lignin as a biocompatible macromolecule was modified with poly (ethylene glycol) through chain-transfer polymerization, and then it was utilized to incorporate superparamagnetic iron oxide and cerium oxide nanocrystals creating a functional nanozyme. The iron oxide nanocrystals self-assembled into the hydrophobic core of nano system, while the in-situ mineralization of cerium oxide particles was carried out with the assistance of peripheral phenolic hydroxyl groups. The product, cerium­iron core-shell nanozyme, enabled effective stem cells labeling through endocytosis and exhibited catalase and superoxide dismutase activities within the cells. As a result, it could scavenge highly destructive hydroxyl radicals and peroxyl radicals, shielding stem cells from apoptosis in inflammatory environment and maintaining their differentiation ability. Additionally, when these functionalized stem cells were administered to mice with acute inflammation, not only did they alleviate disease symptoms, but they also allowed for the visualization using T2-weighted magnetic resonance imaging. This innovative therapeutic approach provides a new strategy for combatting diseases.

Hydrogel for light delivery in biomedical applications.

Traditional optical waveguides or mediums are often silica-based materials, but their applications in biomedicine and healthcare are limited due to the poor biocompatibility and unsuitable mechanical properties. In term of the applications in human body, a biocompatible hydrogel system with excellent optical transparency and mechanical flexibility could be beneficial. In this review, we explore the different designs of hydrogel-based optical waveguides derived from natural and synthetic sources. We highlighted key developments such as light emitting contact lenses, implantable optical fibres, biosensing systems, luminating and fluorescent materials. Finally, we expand further on the challenges and perspectives for hydrogel waveguides to achieve clinical applications.

Differential mucosal tropism and dissemination of classical and hypervirulent Klebsiella pneumoniae infection.

Klebsiella pneumoniae (Kp) infection is an important healthcare concern. The ST258 classical (c)Kp strain is dominant in hospital-acquired infections in North America and Europe, while ST23 hypervirulent (hv)Kp prevails in community-acquired infections in Asia. This study aimed to develop symptomatic mucosal infection models in mice that mirror natural infections in humans to gain a deeper understanding of Kp mucosal pathogenesis. We showed that cKp replicates in the nasal cavity instead of the lungs, and this early infection event is crucial for the establishment of chronic colonization in the cecum and colon. In contrast, hvKp replicates directly in the lungs to lethal bacterial load, and early infection of esophagus supported downstream transient colonization in the ileum and cecum. Here, we have developed an in vivo model that illuminates how differences in Kp tropism are responsible for virulence and disease phenotype in cKp and hvKp, providing the basis for further mechanistic study.

Nanochitin for sustainable and advanced manufacturing.

Presently, the rapid depletion of resources and drastic climate change highlight the importance of sustainable development. In this case, nanochitin derived from chitin, the second most abundant renewable polymer in the world, possesses numerous advantages, including toughness, easy processability and biodegradability. Furthermore, it exhibits better dispersibility in various solvents and higher reactivity than chitin owing to its increased surface area to volume ratio. Additionally, it is the only natural polysaccharide that contains nitrogen. Therefore, it is valuable to further develop this innovative technology. This review summarizes the recent developments in nanochitin and specifically identifies sustainable strategies for its preparation. Additionally, the different biomass sources that can be exploited for the extraction of nanochitin are highlighted. More importantly, the life cycle assessment of nanochitin preparation is discussed, followed by its applications in advanced manufacturing and perspectives on the valorization of chitin waste.

Association between chronic pain and quality of life in long-term breast cancer survivors: a prospective analysis.

PURPOSE: Pain is a leading cause of disability worldwide and is highly prevalent among breast cancer survivors. Pain and quality of life (QOL) are associated in breast cancer patients undergoing active treatment, but little is known about the relationship between the two in long-term survivors. METHODS: We evaluated associations between pain information collected during a 5-year post-diagnosis follow-up survey and QOL assessed by the SF-36 during a 10-year post-diagnosis survey for 2828 participants in the Shanghai Breast Cancer Survival Study. RESULTS: The mean overall QOL score was 78.7 for the entire study population and decreased as pain severity and frequency measured at the 5-year timepoint increased (none: 81.9, mild: 75.9, moderate/severe: 70.4, infrequent: 76.7, frequent: 72.3; P < 0.001). Significant inverse associations were found between pain and all QOL domains, including pain at 10-years post-diagnosis after multivariate adjustments. Concurrent pain was significantly and strongly associated with QOL. Most of the associations between 5-years post-diagnosis pain and QOL at 10-years post-diagnosis persisted after further adjustment for concurrent pain. CONCLUSIONS: Pain is associated prospectively and concurrently with poor QOL among long-term breast cancer survivors. Programs to manage pain are needed to improve QOL among breast cancer survivors.

Chronic pain and its correlates among long-term breast cancer survivors.

PURPOSE: Chronic pain is a common symptom affecting quality of life for breast cancer survivors. However, its prevalence and correlate factors in long-term breast cancer survivors, particularly Asian women, are understudied. The reported study is to address these knowledge gaps. METHODS: We evaluated pain severity and frequency, and their associations with clinical features and lifestyle factors among 3640 5-year breast cancer survivors who participated in the Shanghai Breast Cancer Survival Study. Demographic, clinical, and lifestyle information was collected at study enrollment, which occurred 6 months post-diagnosis, and pain was assessed at the 5-year post-diagnosis follow-up survey. RESULTS: In total, 42% of participants reported experiencing pain. Pain is more prevalent among survivors with low educational attainment or low income. Multivariable polytomous regression analyses showed that pain was positively associated with metastasis or recurrence (moderate pain OR: 2.17, 95% CI: 1.45, 3.26, frequent pain OR: 1.92, 95% CI: 1.37, 2.70), triple negative status (infrequent pain OR: 1.36, 95% CI: 1.04, 1.78), obesity (frequent pain OR: 1.80, 95% CI: 1.41, 2.31), and multiple comorbidities. Exercise (OR: 0.65, 95%: 0.49, 0.88), chemotherapy (OR: 0.59, 95% CI: 0.41, 0.849), and HER2-positive and ER/PR-negative status (OR: 0.64, 95% CI: 0.43, 0.97) were inversely associated with moderate pain. CONCLUSIONS: Chronic pain is highly prevalent among long-term breast cancer survivors in China and was associated with obesity, physical inactivity, and several clinical factors. IMPLICATIONS FOR CANCER SURVIVORS: This study highlights the importance of promoting weight control and exercise to alleviate chronic pain.

Dynamic Grafting of Carboxylates onto Poly(Vinyl Alcohol) Polymers for Supramolecularly-Crosslinked Hydrogel Formation.

Supramolecular hydrogels have attracted considerable interest due to their unique stimuli-responsive and self-healing properties. However, these hydrogel systems are usually achieved by covalent grafting of supramolecular units onto the polymer backbone, which in turn limits their reprocessability. Herein, we prepared a supramolecular hydrogel system by forming dynamic covalent crosslinks between 4-carboxyphenylboronic acid (CPBA) and polyvinyl alcohol (PVA). The system was then further crosslinked with either calcium ions or branched polyethylenimine (PEI) to generate hydrogels with distinctly different properties. Incorporation of calcium ions resulted in the formation of hydrogels with higher storage modulus of 7290 Pa but without self-healing properties. On the other hand, PEI-crosslinked hydrogel (PVA-CPBA-PEI) exhibited >2000% critical strain value, demonstrated high stability over 52 days and showed sustained antibacterial effect. A combination of supramolecular interactions and dynamic covalent crosslinks can be an alternate strategy to fabricate next-generation hydrogel materials.

PLA-lignin nanofibers as antioxidant biomaterials for cartilage regeneration and osteoarthritis treatment.

BACKGROUND: Osteoarthritis (OA) is common musculoskeletal disorders associated with overgeneration of free radicals, and it causes joint pain, inflammation, and cartilage degradation. Lignin as a natural antioxidant biopolymer has shown its great potential for biomedical applications. In this work, we developed a series of lignin-based nanofibers as antioxidative scaffolds for cartilage tissue engineering. RESULTS: The nanofibers were engineered by grafting poly(lactic acid) (PLA) into lignin via ring-opening polymerization and followed by electrospinning. Varying the lignin content in the system was able to adjust the physiochemical properties of the resulting nanofibers, including fiber diameters, mechanical and viscoelastic properties, and antioxidant activity. In vitro study demonstrated that the PLA-lignin nanofibers could protect bone marrow-derived mesenchymal stem/stromal cells (BMSCs) from oxidative stress and promote the chondrogenic differentiation. Moreover, the animal study showed that the lignin nanofibers could promote cartilage regeneration and repair cartilage defects within 6 weeks of implantation. CONCLUSION: Our study indicated that lignin-based nanofibers could serve as an antioxidant tissue engineering scaffold and facilitate the cartilage regrowth for OA treatment.

Recycling of spent coffee grounds for useful extracts and green composites.

Large amounts of spent coffee grounds (SCGs) are often discarded and there is a need to find alternative disposal methods due to environmental concerns. This project aims to develop sustainable materials by re-purposing spent coffee grounds (SCGs). Oil extraction was performed using different organic solvents and yielded approximately 10% coffee oil. Coffee oil contains potentially useful chemical compounds such as fatty acids and caffeine. They also exhibited antioxidant properties. Extracted SCGs (ESCGs) were blended with epoxy resin to form composites. ESCG composites displayed a general decrease in mechanical properties relative to epoxy. However, improvements were observed when comparing ESCG composites and SCG composites. The greatest improvement belongs to epoxy composite filled with acetone-ESCGs, where the tensile strength, flexural modulus and flexural strength increased to 23.4 MPa, 3.02 GPa and 42.9 MPa respectively. This study presents a way to exploit waste materials which contributes to the goal of sustainability.

Sanitizing agents for virus inactivation and disinfection.

Viral epidemics develop from the emergence of new variants of infectious viruses. The lack of effective antiviral treatments for the new viral infections coupled with rapid community spread of the infection often result in major human and financial loss. Viral transmissions can occur via close human-to-human contact or via contacting a contaminated surface. Thus, careful disinfection or sanitization is essential to curtail viral spread. A myriad of disinfectants/sanitizing agents/biocidal agents are available that can inactivate viruses, but their effectiveness is dependent upon many factors such as concentration of agent, reaction time, temperature, and organic load. In this work, we review common commercially available disinfectants agents available on the market and evaluate their effectiveness under various application conditions. In addition, this work also seeks to debunk common myths about viral inactivation and highlight new exciting advances in the development of potential sanitizing agents.

Formulation of Biocompatible Targeted ECO/siRNA Nanoparticles with Long-Term Stability for Clinical Translation of RNAi.

Nanoparticle based siRNA formulations often suffer from aggregation and loss of function during storage. We in this study report a frozen targeted RGD-polyethylene glycol (PEG)-ECO/siß3 nanoparticle formulation with a prolonged shelf life and preserved nanoparticle functionality. The targeted RGD-PEG-ECO/siß3 nanoparticles are formed by step-wised self-assembly of RGD-PEG-maleimide, ECO, and siRNA. The nanoparticles have a diameter of 224.5 ± 9.41 nm and a zeta potential to 45.96 ± 3.67 mV in water and a size of 234.34 ± 3.01 nm and a near neutral zeta potential in saline solution. The addition of sucrose does not affect their size and zeta potential and substantially preserves the integrity and biological activities of frozen and lyophilized formulations of the targeted nanoparticles. The frozen formulation with as low as 5% sucrose retains nanoparticle integrity (90% siRNA encapsulation), size distribution (polydispersity index [PDI] ≤20%), and functionality (at least 75% silencing efficiency) at -80°C for at least 1 year. The frozen RGD-PEG-ECO/siß3 nanoparticle formulation exhibits excellent biocompatibility, with no adverse effects on hemocompatibility and minimal immunogenicity. As RNAi holds the promise in treating the previously untreatable diseases, the frozen nanoparticle formulation with the low sucrose concentration has the potential to be a delivery platform for clinical translation of RNAi therapeutics.

Patient Demographic and Clinician Factors in Antibiotic Prescribing for Upper Respiratory Tract Infections in the Australian Capital Territory from 2006-2015.

INTRODUCTION: National antibiotic stewardship programs aim to mitigate rising antimicrobial resistance and associated healthcare costs by promoting safe and appropriate antibiotic prescribing. AIM: This study aimed to analyse patient and clinician demographic factors that may influence antibiotic prescribing for Upper Respiratory Tract Infections (URTIs). Trends in antibiotic prescribing patterns were also analysed over the study period. MATERIALS AND METHODS: This retrospective cross-sectional study analysed data from the Australian National University Medical School Clinical Audit Project database, comprising data collected by students during patient encounters over a two week period each April-May between 2006 and 2015 (excluding 2013). Data was collected via standardised survey in multiple healthcare settings and locations in the Australian Capital Territory (ACT) and Southeast New South Wales. (NSW) URTI diagnosis and symptomatology were defined using the International Classification of Disease (ICD-10) and International Classification of Primary Care, version 2 PLUS (ICPC-2+) criteria. RESULTS: URTI accounted for 5.6% (n=698) of total patient encounters (n=12,468), and of these, 42.7% (n=289) were prescribed an antibiotic intervention. Antibiotics were significantly more likely to be prescribed in the hospital setting (44.2%; n=237) compared to community GP (32.1%; n=52; p<0.05) and for patients presenting with localised symptoms (65.9%; n=109) compared to generalised symptoms (33.7%; n=122; p<0.01). No significant association was observed for age, rurality, patient gender, clinical gender or Indigenous status. The most frequently prescribed antibiotic was penicillin (67.8%; n=196). Over the decade of study, antibiotic prescribing for URTIs showed decreasing trend both overall (R2=0.204) and with respect to all demographic factors assessed. CONCLUSION: This study supports the effectiveness to-date of antibiotic stewardship programs in Australia. While continued efforts are required to further mitigate antibiotic resistance, this study suggests target areas may include improving clinician resistance to patient demand for antibiotics and increasing confidence in prescribing for special populations such as Indigenous peoples and the extremes of age.

Characteristics of pectinase treated with ultrasound both during and after the immobilization process.

In this study, ultrasound was applied both during and after the immobilization process and characteristics of different immobilized pectinase samples were studied. When introduced during the immobilization process, ultrasound at an intensity of 9WmL-1 for 20min increased the immobilization yield 92.28% more than the control. When introduced to the already immobilized pectinase, ultrasound at an intensity of 4.5WmL-1 for 10min increased the pectinase activity by 30.05%. Results of scanning electron microscope demonstrated that ultrasound increased surface area and loosened structures of immobilized enzymes. Higher Vmax and lower Km were obtained after ultrasound treatment, indicating the increased catalytic efficiency and enhanced affinity of immobilized pectinase. Furthermore, the optimum temperature and pH for free and immobilized pectinase remained unchanged at 50°C and pH 4. Thermostability, reaction stability and reusability of two ultrasound-treated pectinase enzymes slightly decreased due to structural matrix changes.

Complications associated with tissue anchor migration after vaginal surgery using the tissue fixation system - a case series.

This case series describes eleven women with serious complications related to migration of tissue anchors after vaginal surgery for uterovaginal prolapse and/or urinary incontinence using the tissue fixation system.