Ultra-fine silver nanoparticles dispersed in mono-dispersed amino functionalized poly glycidyl methacrylate based microspheres as an effective anti-bacterial agent

Updated review of wet pack complications in pulse vacuum pressure steam sterilisation processes in central sterile supply departments

The quality of sterilisation and disinfection in a central sterile supply department is directly related to the quality of the hospital services and the patients' safety. Wet packs occasionally occur following the process of pressure steam sterilisation; reducing this occurrence is an important issue. Therefore, the causes of wet pack following sterilisation were analysed to identify the influencing factors and suggest improvements to prevent its occurrence. Understanding the sterilisation process and possible causes of exposure helps with risk assessment and identifying necessary corrective measures.

Recent Development of Polydopamine Anti-Bacterial Nanomaterials

Polydopamine (PDA), as a mussel-inspired material, exhibits numerous favorable performance characteristics, such as a simple preparation process, prominent photothermal transfer efficiency, excellent biocompatibility, outstanding drug binding ability, and strong adhesive properties, showing great potential in the biomedical field. The rapid development of this field in the past few years has engendered substantial progress in PDA antibacterial materials. This review presents recent advances in PDA-based antimicrobial materials, including the preparation methods and antibacterial mechanisms of free-standing PDA materials and PDA-based composite materials. Furthermore, the urgent challenges and future research opportunities for PDA antibacterial materials are discussed.

Immobilization of Cu (II) via a graphene oxide-supported strategy for antibacterial reutilization with long-term efficacy

The past several decades have witnessed tremendous research to discover ways for controlling heavy metal pollution, but most of the strategies do not involve reuse of the captured heavy metals. Herein, we propose a graphene oxide -based strategy for the effective removal of Cu²⁺ ions from water, coupled with their reuse as an antibacterial agent. Using GO nanosheets as an adsorbent and nanosupport, the Cu²⁺ ions were effectively extracted from water (>99.9%) and reduced in situ to copper nanoparticles (Cu NPs) containing both crystalline Cu and Cu₂O. The as-captured Cu NPs showed efficient in vitro antibacterial ability against Escherichia coli, reducing the bacteria from 10⁹ to 10¹ CFU mL^-1 by using ¹ mg mL^-1 Cu NPs/GO NSs for 1 h. The minimum inhibitory concentration determined to be only 16 μg mL^-1. For practical applications, Cu recovered from wastewater could reduce bacteria by 8 log CFU in 1 h. The recovered Cu was still able to reduce the bacteria by 7 log CFU after 2 months of storage in an argon atmosphere. This strategy of extracting heavy metals and subsequently reutilizing to kill bacteria will be of great significance for environmental remediation and public healthcare.

Poly(glycidyl methacrylate) macromolecular assemblies as biocompatible nanocarrier for the antimicrobial lysozyme

The antimicrobial lysozyme (Lys) was electrostatically incorporated to negatively charged crosslinked poly(glycidyl methacrylate) (c-PGMA) macromolecular assemblies. The resulting material was characterized by AFM, infrared spectra, water contact angle measurements and the staining with the primary amino specific dye fluorescamine. c-PGMA nanoparticles were successfully loaded with Lys reaching ratios of 27.3 ± 4.0 and 22.5 ± 1.7 mg Lys/g polymer for c-PGMA suspensions and functionalized glass substrates, respectively. Lys-loaded c-PGMA caused clear inhibition zones on S. aureus and E. coli in comparison to neat c-PGMA. c-PGMA functionalized surfaces were intrinsically resistant to colonization, but the incorporation of Lys added resistance to bacterial attachment and allowed keeping surfaces clean of bacterial cells for both strains. A relatively rapid release (24 h) of Lys was observed at physiological pH (7.4). In addition, c-PGMA functionalized substrates could be reloaded several times without losing capacity. c-PGMA macromolecular assemblies did not display cytotoxicity to human dermal fibroblasts as shown in 24 h MTT assays. This work demonstrated that c-PGMA assemblies display durable antibacterial activity, biocompatibility, and full reloading capacity with antimicrobial peptides. c-PGMA functionalized materials have potential application as nanocarriers for anti-infective uses.

Microporous poly(glycidyl methacrylate-co-ethylene glycol dimethyl acrylate) microspheres: synthesis, functionalization and applications

As a new kind of functional material, micron-sized porous polymer microspheres are a hot research topic in the field of polymer materials.

Antimicrobial magnetic poly(GMA) microparticles: synthesis, characterization and lysozyme immobilization

Micron-sized magnetic particles currently find a wide range of applications in many areas including biotechnology, biochemistry, colloid sciences and medicine. In this study, magnetic poly(glycidyl methacrylate) microparticles were synthesized by providing a polymerization around Fe(II)-Ni(II) magnetic double salt. Adsorption of lysozyme protein from aqueous systems was studied with these particles. Adsorption studies were performed with changing pH values, variable amount of adsorbent, different interaction times and lysozyme amounts. The adsorption capacity of the particles was investigated, and a value of about 95.6 mg lysozyme/g microparticle was obtained. The enzyme activity of the immobilized lysozyme was examined and found to be more stable and reusable compared to the free enzyme. The immobilized enzyme still showed 80% activity after five runs and managed to maintain 78% of its initial activity at the end of 60 days. Besides, in the antimicrobial analysis study for six different microorganisms, the minimum inhibitory concentration value of lysozyme immobilized particles was calculated as 125 μg/mL like free lysozyme. Finally, the adsorption interaction was found to be compatible with the Langmuir isotherm model. Accordingly, it can be said that magnetic poly(GMA) microparticles are suitable materials for lysozyme immobilization and immobilized lysozyme can be used in biotechnological studies.

Durable flame retardant polyacrylonitrile fabric via UV-induced grafting polymerization and surface chemical modification

To improve the flame retardancy of polyacrylonitrile (PAN) fabric, glycidyl methacrylate (GMA) was firstly grafted onto the surface of PAN fabric. Then, the GMA grafted PAN fabric (PAN-g-GMA) was chemically modified with hydrazine hydrate and phosphorus acid in sequence to obtain ammoniated PAN-g-GMA fabric (Am-PAN-g-GMA) and flame retardant PAN fabric (FR-PAN), respectively. The structures, thermal properties and combustion characteristics of the samples were researched in detail. The results indicate that the fire retardant PAN fabric has good char-forming ability. Cone calorimeter tests show that the total heat release (THR) of FR-PAN declines by 38.4%, while the peak heat release rate (PHRR) of FR-PAN decreases by 60.2%. Moreover, the total smoke production (TSP) and the peak smoke production rate (PSPR) of FR-PAN dropped from 1.5 m² and 0.06 m² s⁻¹ for the control sample to 0.4 m² and 0.01 m² s⁻¹, respectively, indicating excellent smoke repression performance. The LOI value of FR-PAN fabric was 29.3% after 30 washing cycles showing good washing resistance and excellent flame retardant durability.

A durable flame retardant PAN fabric was prepared via UV-induced grafting polymerization and chemical modification. The flame retardant performance of the fabric was greatly improved.