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.

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.

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.

Lignin/poly(butylene succinate) composites with antioxidant and antibacterial properties for potential biomedical applications.

Lignin (LIG) is a renewable biopolymer with well-known antimicrobial and antioxidant properties. In the present work LIG was combined with poly(butylene succinate) (PBS), a biocompatible/biodegradable polymer, to obtain composites with antimicrobial and antioxidant properties. Hot melt extrusion was used to prepare composites containing up to 15% (w/w) of LIG.

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.

Antioxidant PLA Composites Containing Lignin for 3D Printing Applications: A Potential Material for Healthcare Applications.

Lignin (LIG) is a natural biopolymer with well-known antioxidant capabilities. Accordingly, in the present work, a method to combine LIG with poly(lactic acid) (PLA) for fused filament fabrication applications (FFF) is proposed. For this purpose, PLA pellets were successfully coated with LIG powder and a biocompatible oil (castor oil).

Synthesis and Characterization of Lignin Hydrogels for Potential Applications as Drug Eluting Antimicrobial Coatings for Medical Materials.

Lignin is the second most abundant biopolymer on the planet. It is a biocompatible, cheap, environmentally friendly and readily accessible material. It has been reported that these biomacromolecules have antimicrobial activities.

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.

Synthesis and characterization of hyaluronic acid hydrogels crosslinked using a solvent-free process for potential biomedical applications.

Hyaluronic acid (HA) is a natural linear polysaccharide that has been used extensively in the biomedical field as it is a biocompatible, biodegradable, nontoxic and non-immunogenic polymer with high water affinity. Besides, the presence of multiple acid and hydroxyl groups in the HA molecule makes it an ideal candidate for chemical modification. The present paper describes the synthesis and characterization of HA-based hydrogels.

Anti-Adherent Biomaterials for Prevention of Catheter Biofouling.

Medical device-associated infections present a leading global healthcare challenge, and effective strategies to prevent infections are urgently required. Herein, we present an innovative anti-adherent hydrogel copolymer as a candidate catheter coating with complementary hydrophobic drug-carrying and eluting capacities. The amphiphilic block copolymer, Poloxamer 188, was chemically-derivatized with methacryloyl moieties and copolymerized with the hydrogel monomer, 2-hydroxyethyl methacrylate.

Photochemically Controlled Drug Dosing from a Polymeric Scaffold.

Purpose: To develop the first photoactive biomaterial coating capable of controlled drug dosing via inclusion of synthesised drug-3,5-dimethoxybenzoin (DMB) conjugates in a poly(2-methyoxyethyl acrylate) (pMEA) scaffold.

Methods: Flurbiprofen- and naproxen-DMB conjugates were prepared via esterification and characterised via NMR spectroscopy and mass spectrometry following chromatographic purification. Conjugate photolysis was investigated in acetonitrile solution and within the pMEA matrix following exposure to low-power 365 nm irradiation.

An Infection-Responsive Approach To Reduce Bacterial Adhesion in Urinary Biomaterials.

Infection is an inevitable consequence of chronic urinary catheterization with associated problems of recurrent catheter encrustation and blockage experienced by approximately 50% of all long-term catheterized patients. In this work, we have exploited, for the first time, the reported pathogen-induced elevation of urine pH as a trigger for "intelligent" antimicrobial release from novel hydrogel drug delivery systems of 2-hydroxyethyl methacrylate and vinyl-functionalized nalidixic acid derivatives, developed as candidate infection-resistant urinary catheter coatings. Demonstrating up to 20-fold faster rates of drug release at pH 10, representing infected urine pH, than at pH 7 and achieving reductions of up to 96.

Hydrogel-Forming Microneedle Arrays Made from Light-Responsive Materials for On-Demand Transdermal Drug Delivery.

We describe, for the first time, stimulus-responsive hydrogel-forming microneedle (MN) arrays that enable delivery of a clinically relevant model drug (ibuprofen) upon application of light. MN arrays were prepared using a polymer prepared from 2-hydroxyethyl methacrylate (HEMA) and ethylene glycol dimethacrylate (EGDMA) by micromolding. The obtained MN arrays showed good mechanical properties.

Infection-responsive drug delivery from urinary biomaterials controlled by a novel kinetic and thermodynamic approach.

Purpose: The pH-dependent physicochemical properties of the antimicrobial quinolone, nalidixic acid, were exploited to achieve 'intelligent' drug release from a potential urinary catheter coating, poly(2-hydroxyethylmethacrylate) (p(HEMA)), in direct response to the elevated pH which occurs at the onset of catheter infection.

Methods: p(HEMA) hydrogels, and reduced-hydrophilicity copolymers incorporating methyl methacrylate, were loaded with nalidixic acid by a novel, surface particulate localization method, and characterized in terms of pH-dependent drug release and microbiological activity against the common urease-producing urinary pathogen Proteus mirabilis.

Results: The pH-dependent release kinetics of surface-localized nalidixic acid were 50- and 10-fold faster at pH 9, representing the alkaline conditions induced by urease-producing urinary pathogens, compared to release at pH 5 and pH 7 respectively.