BODIPY-Functionalized Natural Polymer Coatings for Multimodal Therapy of Drug-Resistant Bacterial Infection.

The fact that multidrug resistance (MDR) could induce medical device-related infections, along with the invalidation of traditional antibiotics has become an intractable global medical issue. Therefore, there is a pressing need for innovative strategies of antibacterial functionalization of medical devices. For this purpose, a multimodal antibacterial coating that combines photothermal and photodynamic therapies (PTT/PDT) is developed here based on novel heavy atom-free photosensitizer compound, BDP-6 (a kind of boron-dipyrromethene). The photothermal conversion efficiency of BDP-6 is of 55.9%, which could improve biocompatibility during PTT/PDT process by reducing the exciting light power density. Furthermore, BDP-6, together with oxidized hyaluronic acid, is crosslinked with a natural polymer, gelatin, to fabricate a uniform coating (denoted as polyurethane (PU)-GHB) on the surface of polyurethane. PU-GHB has excellent synergistic in vitro PTT/PDT antibacterial performance against both susceptible bacteria and MDR bacteria. The antibacterial mechanisms are revealed as that hyperthermia could reduce the bacterial activity and enhance the permeability of inner membrane to reactive oxygen species by disturbing cell membrane. Meanwhile, in an infected abdominal wall hernia model, the notable anti-infection performance, good in vivo compatibility, and photoacoustic imaging property of PU-GHB are verified. A promising strategy of developing multifunctional antibacterial coatings on implanted medical devices is provided here.

Infection-responsive long-term antibacterial bone plates for open fracture therapy.

The infections in open fracture induce high morbidity worldwide. Thus, developing efficient anti-infective orthopedic devices is of great significance. In this work, we designed a kind of infection-responsive long-term antibacterial bone plates. Through a facile and flexible volatilization method, a multi-aldehyde polysaccharide derivative, oxidized sodium alginate, was crosslinked with multi-amino compounds, gentamycin and gelatin, to fabricate a uniform coating on Ti bone plates via Schiff base reaction, which was followed by a secondary crosslinking process by glutaraldehyde. The double-crosslinked coating was stable under normal condition, and could responsively release gentamycin by the triggering of the acidic microenvironment caused by bacterial metabolism, owning to the pH-responsiveness of imine structure. The thickness of the coating was ranging from 22.0 µm to 63.6 µm. The coated bone plates (Ti-GOGs) showed infection-triggered antibacterial properties (>99%) and high biocompatibility. After being soaked for five months, it still possessed efficient antibacterial ability, showing its sustainable antibacterial performance. The in vivo anti-infection ability was demonstrated by an animal model of infection after fracture fixation (IAFF). At the early stage of IAFF, Ti-GOGs could inhibit the bacterial infection (>99%). Subsequently, Ti-GOGs could promote recovery of fracture of IAFF. This work provides a convenient and universal strategy for fabrication of various antibacterial orthopedic devices, which is promising to prevent and treat IAFF.

Death education for undergraduate nursing students in the China Midwest region: An exploratory analysis.

AIM: The purpose of this study was to comprehend the need for incorporating death education within the curriculum of undergraduate nursing students and to assess the factors that impact the desire for such education. DESIGN: We enlisted undergraduate nursing students from several nursing colleges located in the central and west region of China. Undergraduate students who fulfilled the eligibility criteria between January and February 2021 were chosen to participate. Data were collected via an online platform called Questionnaire Star. The survey encompassed a general information questionnaire and a scale for assessing the need for education on the topic of death. Descriptive statistical analysis was performed using the SPSS 20.0 software, while multivariate stepwise regression was employed for more complex analysis. Statistical significance was indicated when the p-value was below 0.05, and high statistical significance was noted when the p-value fell below 0.01. METHODS: We designed a descriptive quantitative approach to investigate the need for death education and its associated factors. The research involved 907 undergraduate nursing students from the central and west region of China. The data collection was done through the Questionnaire Star platform. RESULTS: Following the collection of completed surveys, individuals displaying contradictory responses were omitted. Out of 911 surveys disseminated, 907 were successfully collected, resulting in a recovery rate of 99.6%. Among the participants, 769 identified as female, constituting 84.8% of the total, while 138 identified as male, making up 15.2%. The survey findings indicated that factors such as residency, parental educational history and exposure to hospice care education significantly impacted the need for death education among undergraduate nurses (p < 0.05). CONCLUSIONS: Among students pursuing a nursing degree at the undergraduate level, there was a pronounced need for education related to the topic of death. Offering such education to these students is essential, as it helps cultivate a proper understanding of death. This, in turn, contributes to enhancing the overall quality of patient care throughout their life journey. PATIENT OR PUBLIC CONTRIBUTION: A total of 907 nursing undergraduates from central and western China participated in the questionnaire.

Derma-like antibacterial polysaccharide gel dressings for wound care.

Large skin wound infections have high morbidity, which threaten the health of human beings severely. It is essential to develop new wound dressings that can block microbial invasion, eliminate bacteria effectively, adhere to wounds firmly, and have good biocompatibility. In this work, we designed a kind of polysaccharide gel (DLG) dressings with derma-like structure that had good wound care performances. With a facile penetration cross-linking method by the Schiff base reaction between oxidized hyaluronic acid solution and carboxymethyl chitosan solution with higher viscosity, a gradient porous structure was formed inside DLG to mimic the structure of derma, which was due to the simultaneous penetration and reaction processes between two viscous solutions. This derma-like structure endowed the gel dressings with the abilities of self-adhesion to wounds and barriers against bacteria. Through the introduction of cuttlefish juice and gentamycin, the modified gel dressings (DLG-GS) showed mild photothermal effects under the near infrared irradiation at the wavelength of 808 nm, which could reach and maintain the temperature of 45 °C. The mild heat could act together with gentamycin to produce a rapid bactericidal performance within 5 min. Meanwhile, the polysaccharide gel dressings had good biocompatibility. The in vivo anti-infection properties of DLG-GS was demonstrated by an animal model of infected full-thickness skin defect. This strategy provided a feasible solution for the prevention and treatment of infected large wounds. STATEMENT OF SIGNIFICANCE: Derma-like antibacterial gel dressings (DLG-GS) with high bacterial barrier ability, strong tissue adhesive property and good biocompatibility were constructed by a penetration cross-linking method. DLG-GS could eliminate bacterial infection within 5 min due to the rational combination of a mild photothermal effect and antibiotics. DLG-GS showed high anti-infection and wound healing properties in an animal model of infected full-thickness skin defect. This study provides a flexible and universal strategy for the development  of antibacterial wound dressings.

Heparinized anticoagulant coatings based on polyphenol-amine inspired chemistry for blood-contacting catheters.

Blood-contacting catheters occupy a vital position in modern clinical treatment including but not limited to cardiovascular diseases, but catheter-related thrombosis associated with high morbidity and mortality remains a major health concern. Hence, there is an urgent need for functionalized catheter surfaces with superior hemocompatibility that prevent protein adsorption and thrombus formation. In this work, we developed a strategy for constructing a kind of polyphenol-amine coating on the TPU surface (TLA) with tannic acid and lysine via simple dip-coating, inspired by dopamine adhesion. Based on the long-term stability and modifiable properties of TLA coatings, heparin was introduced by an amide reaction to provide anticoagulant activity (TLH). X-ray photoelectron spectroscopy and surface zeta potential measurements fully indicated the successful immobilization of heparin. Water contact angle measurements demonstrated good hydrophilicity and stability for 15 days of TLH coatings. Furthermore, the TLH coatings exhibited significant hemocompatibility and no cytotoxicity. The good antithrombotic properties of the functionalized surfaces were confirmed by an ex vivo blood circulation model. The present work is supposed to find potential clinical applications for preventing surface-induced thrombosis of blood-contacting catheters.