Enhanced antifouling and anti-swarming properties poly (sulfobetaine methacrylate-co-2-hydroxy-3-phenoxypropyl acrylate) hydrogel coatings for urinary catheters.

Catheter-associated urinary tract infection (CAUTI) remains an unsolved challenge to date, particularly with the emergence and rapid spread of antimicrobial-resistant bacterial pathogens. Despite extensive research, a catheter coating that can offer intrinsic resistance to host protein deposition, bacterial biofilm formation, and swarming is still urgently required. Zwitterionic hydrogel coatings due to their superior lubricity and antifouling properties represent a promising candidate, but their weak mechanical stability in water and poor resistance to bacterial swarming migration limit their application in urinary catheters for infection control.

Comparing an Integrated Amphiphilic Surfactant to Traditional Hydrophilic Coatings for the Reduction of Catheter-Associated Urethral Microtrauma.

Hydrophilic-coated intermittent catheters have improved the experience of intermittent urinary catheterization for patients compared to conventional gel-lubricated uncoated catheters. However, the incorporation of polyvinylpyrrolidone (PVP) within hydrophilic coatings can lead to significant issues with coating dry-out. Consequently, increased force on catheter withdrawal may cause complications, including urethral microtrauma and pain.

Use of solid thermolytic salts to facilitate microwave-induced in situ amorphization.

Moisture was frequently used as dielectric heating source in classical microwave-able systems to facilitate microwave-induced in situ amorphization, however such systems may face the potential of drug hydrolysis. In this study, solid thermolytic salts were proposed to function as moisture substitutes and their feasibility and impacts on microwave-induced in situ amorphization were investigated. It was found that NHHCO was a promising solid alkaline salt to facilitate both microwave-induced in situ amorphization and in situ salt formation of acidic indomethacin (IND).

Comparison of Superhydrophilic, Liquid-Like, Liquid-Infused, and Superhydrophobic Surfaces in Preventing Catheter-Associated Urinary Tract Infection and Encrustation.

Over the past decade, superhydrophilic zwitterionic surfaces, slippery liquid-infused porous surfaces, covalently attached liquid-like surfaces, and superhydrophobic surfaces have emerged as the most promising strategies to prevent biofouling on biomedical devices. Despite working through different mechanisms, they have demonstrated superior efficacy in preventing the adhesion of biomolecules (e.g.

Dual stimuli-responsive delivery system for self-regulated colon-targeted delivery of poorly water-soluble drugs.

Inflammatory bowel disease (IBD) are chronic inflammatory conditions which cause significant patient morbidity. Local drug delivery to the colon can improve treatment efficacy and reduce side effects associated with IBD treatment. Smart drug delivery systems are designed to regulate the release of therapeutic agents at the desired site of action.

Understanding the properties of intermittent catheters to inform future development.

Despite the extensive use of intermittent catheters (ICs) in healthcare, various issues persist for long-term IC users, such as pain, discomfort, infection, and tissue damage, including strictures, scarring and micro-abrasions. A lubricous IC surface is considered necessary to reduce patient pain and trauma, and therefore is a primary focus of IC development to improve patient comfort. While an important consideration, other factors should be routinely investigated to inform future IC development.

Probing the interaction of biofilms with plasmonic metal nanoparticles using surface-enhanced Raman spectroscopy.

Biofilms are complex environments where matrix effects from components such as extracellular polymeric substances and proteins can strongly affect SERS performance. Here the interactions between SERS-enhancing Ag and Au particles were studied using biofilms (-biofilms), which were more homogenous than biofilm samples. This allowed systematic quantitative studies, where samples could be accurately diluted and analysed, to be carried out.

Photosensitiser-incorporated microparticles for photodynamic inactivation of bacteria.

Antimicrobial resistance is an ever-growing global concern, making the development of alternative antimicrobial agents and techniques an urgent priority to protect public health. Antimicrobial photodynamic therapy (aPDT) is one such promising alternative, which harnesses the cytotoxic action of reactive oxygen species (ROS) generated upon irradiation of photosensitisers (PSs) with visible light to destroy microorganisms. In this study we report a convenient and facile method to produce highly photoactive antimicrobial microparticles, exhibiting minimal PS leaching, and examine the effect of particle size on antimicrobial activity.

Tetrasodium EDTA for the prevention of urinary catheter infections and blockages.

Long-term catheterised individuals are at significant risk of developing catheter-associated urinary tract infections (CAUTIs), with up to 50% of patients experiencing recurrent episodes of catheter encrustation and blockage. Catheter blockage is a result of accumulation of carbonate apatite and struvite formed upon precipitation of ions within urine due to an infection-induced rise in pH. The aim of this study was to investigate the antimicrobial and anti-encrustation activities of tetrasodium ethylenediaminetetraacetic acid (tEDTA) to evaluate its potential efficacy in preventing CAUTIs and catheter blockages.

Fibrinogen Deposition on Silicone Oil-Infused Silver-Releasing Urinary Catheters Compromises Antibiofilm and Anti-Encrustation Properties.

Slippery silicone-oil-infused (SOI) surfaces have recently emerged as a promising alternative to conventional anti-infection coatings for urinary catheters to combat biofilm and encrustation formation. Benefiting from the ultralow low hysteresis and slippery behavior, the liquid-like SOI coatings have been found to effectively reduce bacterial adhesion under both static and flow conditions. However, in real clinical settings, the use of catheters may also trigger local inflammation, leading to release of host-secreted proteins, such as fibrinogen (Fgn) that deposits on the catheter surfaces, creating a niche that can be exploited by uropathogens to cause infections.

The effects of surfactants on the performance of polymer-based microwave-induced in situ amorphization.

Microwave-induced in situ amorphization is a novel technology for preparing amorphous solid dispersions (ASDs) to address the challenges of their long-term physical stability and downstream processing. To date, only few types of dielectric materials have been reported for microwave-induced in situ amorphization, which restricted the extensive research of this technology. This study aimed to investigate the feasibility and mechanisms of utilizing the non-ionic surfactants, i.

Investigation into the role of the polymer in enhancing microwave-induced in situ amorphization.

Microwave-induced in situ amorphization is an emerging technology to tackle the persistent stability issue of amorphous solid dispersions (ASDs) during manufacture and storage. The aim of this study was to introduce new effective polymeric carriers with diverse properties to microwave-induced in situ amorphization and to better understand their functions in relation to the final dissolution performance of microwaved tablets. Tablets composed of indomethacin (IND) and different polymers were compacted, stored at 75% relative humidity for at least 1 week and microwaved at 1000 W to induce amorphization.

Development of a high-level light-activated disinfectant for hard surfaces and medical devices.

Background: Bacterial spores are an important consideration in healthcare decontamination, with cross-contamination highlighted as a major route of transmission due to their persistent nature. Their containment is extremely difficult due to the toxicity and cost of first-line sporicides.

Methods: Susceptibility of Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa and Escherichia coli to phenothiazinium photosensitizers and cationic surfactants under white- or red-light irradiation was assessed by determination of minimum inhibitory concentrations, minimum bactericidal concentrations and time-kill assays.

Infection-Triggered, Self-Cleaning Surfaces with On-Demand Cleavage of Surface-Localized Surfactant Moieties.

Biofouling of surfaces is a major cause of infection and leads to significant patient morbidity and mortality within healthcare settings. With ever-increasing concerns over antibiotic resistance and associated challenges in eradicating surface-attached biofilm communities, efficacious antifouling materials are urgently required. We herein describe the development of an inherently antiadherent polymer system with the capacity for on-demand cleavage of surface-localized surfactant moieties.

Hot-melt extrusion of photodynamic antimicrobial polymers for prevention of microbial contamination.

Infectious disease outbreaks within healthcare facilities can exacerbate patient illness and, in some cases, can be fatal. Contaminated surfaces and medical devices can act as a reservoir for transmission of pathogens and have been linked to the rising incidence of healthcare-acquired infections. Antimicrobial surfaces can reduce microbial contamination and transmission and have emerged as a crucial component in healthcare infection control in recent years.

Microwave-Induced In Situ Amorphization: A New Strategy for Tackling the Stability Issue of Amorphous Solid Dispersions.

The thermodynamically unstable nature of amorphous drugs has led to a persistent stability issue of amorphous solid dispersions (ASDs). Lately, microwave-induced in situ amorphization has been proposed as a promising solution to this problem, where the originally loaded crystalline drug is in situ amorphized within the final dosage form using a household microwave oven prior to oral administration. In addition to circumventing issues with physical stability, it can also simplify the problematic downstream processing of ASDs.

The design and development of high drug loading amorphous solid dispersion for hot-melt extrusion platform.

Amorphous solid dispersion (ASD) is a formulation strategy extensively used to enhance the bioavailability of poorly water soluble drugs. Despite this, they are limited by various factors such as limited drug loading, poor stability, drug-excipient miscibility and the choice of process platforms. In this work, we have developed a strategy for the manufacture of high drug loaded ASD (HDASD) using hot-melt extrusion (HME) based platform.

Phosphonium Ionic Liquid-Infused Poly(vinyl chloride) Surfaces Possessing Potent Antifouling Properties.

Microbial fouling is a costly issue, which impacts a wide range of industries, such as healthcare, food processing, and construction industries, and improved strategies to reduce the impact of fouling are urgently required. Slippery liquid-infused porous surfaces (SLIPSs) have recently been developed as a bioinspired approach to prevent antifouling. Here, we report the development of slippery, superhydrophilic surfaces by infusing roughened poly(vinyl chloride) (PVC) substrates with phosphonium ionic liquids (PILs).

Multifunctional, Low Friction, Antimicrobial Approach for Biomaterial Surface Enhancement.

Poly(vinyl chloride) (PVC) biomaterials perform a host of life-saving and life-enhancing roles when employed as medical devices within the body. High frictional forces between the device surface and interfacing tissue can, however, lead to a host of complications including tissue damage, inflammation, pain, and infection. We herein describe a versatile surface modification method using multifunctional hydrogel formulations to increase lubricity and prevent common device-related complications.

Time-Resolved Dynamics of Struvite Crystallization: Insights from the Macroscopic to Molecular Scale.

The crystallization of magnesium ammonium phosphate hexahydrate (struvite) often occurs under conditions of fluid flow, yet the dynamics of struvite growth under these relevant environments has not been previously reported. In this study, we use a microfluidic device to evaluate the anisotropic growth of struvite crystals at variable flow rates and solution supersaturation. We show that bulk crystallization under quiescent conditions yields irreproducible data owing to the propensity of struvite to adopt defects in its crystal lattice, as well as fluctuations in pH that markedly impact crystal growth rates.

Nanoscale Hybrid Coating Enables Multifunctional Tissue Scaffold for Potential Multimodal Therapeutic Applications.

Through a nature-inspired layer-by-layer assembly process, we developed a unique multifunctional tissue scaffold that consists of porous polyurethane substrate and nanoscale chitosan/graphene oxide hybrid coating. Alternative layers of drug-laden chitosan and graphene oxide nanosheets were held together through strong electrostatic interaction, giving rise to a robust multilayer architecture with control over structural element orientation and chemical composition at nanoscale. Combined pH-controlled co-delivery of multiple therapeutic agents and photothermal therapy has been achieved by our scaffold system.

Luminescent lanthanide (Eu(iii)) cross-linked supramolecular metallo co-polymeric hydrogels: the effect of ligand symmetry.

Two lanthanide luminescent naphthyl-dipicolinic amide (dpa) methacrylate monomers for the synthesis of grafted supramolecular co-polymer gels (hydrogels), and their use as additional crosslinks in robust covalently cross-linked HEMA hydrogels is presented; the results demonstrate the importance of the ligand symmetry for the Eu(iii) emission from the hydrogels.

The effect of the linker size in C-symmetrical chiral ligands on the self-assembly formation of luminescent triple-stranded di-metallic Eu(iii) helicates in solution.

Chiral lanthanide-based supramolecular structures have gained significant importance in view of their application in imaging, sensing and other functional purposes. We have designed chiral C2-symmetrical ligands (L) based on the use of two 2,6-pyridine-dicarboxylic-amide moieties (pda), that differ from one another by the nature of the diamine spacer groups (from 1,3-phenylenedimethanamine (1(S,S), 2(R,R)) and benzene-1,3-diamine (3(S,S), 4(R,R)) to much bulkier 4,4'-(cyclohexane-1,1-diyl)bis(2,6-dimethylaniline) (5(S,S), 6(R,R))) between these two pda units. The self-assembly between L and Eu(iii) ions were investigated in CH3CN solution at low concentration whereby the changes in the absorbance, fluorescence and Eu(iii)-centred emission spectra allowed us to model the binding equilibria occurring in the solution to the presence of [Eu:L2], [Eu2:L2], [Eu2:L3] assemblies and reveal their high binding constant values.

Use of in vitro and haptic assessments in the characterisation of surface lubricity.

Lubricity is a key property of hydrophilic-coated urinary catheter surfaces. In vitro tests are commonly employed for evaluation of surface properties in the development of novel catheter coating technologies; however, their value in predicting the more subjective feeling of lubricity requires validation. We herein perform a range of in vitro assessments and human organoleptic studies to characterise surface properties of developmental hydrophilic coating formulations, including water wettability, coefficient of friction, dry-out kinetics and lubricity.