Plasma Polymer Layer Research Articles

Fluorocarbon Plasma-Polymerized Layer Increases the Release Time of Silver Ions and the Antibacterial Activity of Silver-Based Coatings.

Silver-based antibacterial coatings limit the spread of hospital-acquired infections. Indeed, the use of silver and silver oxide nanoparticles (Ag and AgO NPs) incorporated in amorphous hydrogenated carbon (a-C:H) as a matrix demonstrates a promising approach to reduce microbial contamination on environmental surfaces. However, its success as an antibacterial coating hinges on the control of Ag+ release. In this sense, if a continuous release is required, an additional barrier is needed to extend the release time of Ag+. Thus, this research investigated the use of a plasma fluoropolymer (CFx) as an additional top layer to elongate Ag+ release and increase the antibacterial activity due to its high hydrophobic nature. Herein, a porous CFx film was deposited on a-C:H containing Ag and AgO NPs using pulsed afterglow low pressure plasma polymerization. The chemical composition, surface wettability and morphology, release profile, and antibacterial activity were analyzed. Overall, the combination of a-C:H:Ag (12.1 at. % of Ag) and CFx film (120.0°, F/C = 0.8) successfully inactivated 88% of E. coli and delayed biofilm formation after 12 h. Thus, using a hybrid approach composed of Ag NPs and a hydrophobic polymeric layer, it was possible to increase the overall antibacterial activity of the coating.

In Situ Plasma Polymerization of Self-Stabilized Polythiophene Enables Dendrite-Free Lithium Metal Anodes with Ultra-Long Cycle Life.

Constructing a flexible and chemically stable multifunctional layer for the lithium (Li) metal anodes is a highly effective approach to improve the uneven deposition of Li+ and suppress the dendrite growth. Herein, an organic protecting layer of polythiophene is in situ polymerized on the Li metal via plasma polymerization. Compared with the chemically polymerized thiophene (C-PTh), the plasma polymerized thiophene layer (P-PTh), with a higher Young's modulus of 8.1GPa, shows strong structural stability due to the chemical binding of the polythiophene and Li. Moreover, the nucleophilic C─S bond of polythiophene facilitates the decomposition of Li salts in the electrolytes, promoting the formation of LiF-rich solid electrolyte interface (SEI) layers. The synergetic effect of the rigid LiF as well as the flexible PTh-Li can effectively regulate the uniform Li deposition and suppress the growth of Li dendrites during the repeated stripping-plating, enabling the Li anodes with long-cycling lifespan over 8000h (1mAcm-2, 1 mAhcm-2) and 2500h (10mAcm-2, 10 mAhcm-2). Since the plasma polymerization is facile (5-20min) and environmentally friendly (solvent-free), this work offers a novel and promising strategy for the construction of the forthcoming generation of high-energy-density batteries.

Plasma-induced Polymerization and Grafting of Acrylic Acid on the Polypropylene Nonwoven Fabric Using Pulsed Underwater Diaphragm Electrical Discharge

Polypropylene (PP) nonwovens are used in many hygiene, healthcare and medical products due to their low cost, high chemical resistance and inertness. From an economic point of view, PP textiles would be used as an excellent support material in regenerative medicine or tissue engineering, but here surface functionalization is necessary to ensure cell adhesion and proliferation. Acrylic acid (AAc) is an excellent source of carboxylic-rich (-COOH) coatings suitable for this purpose, but their multistep preparation is time-consuming. Plasma polymerization provides an excellent solution to this demanding procedure since the process of polymerization and grafting to the substrate takes place simultaneously. Here, we propose a relatively fast and effective method for AAc plasma polymerization by using a pulsed underwater diaphragm electrical discharge operated in an aqueous solution consisting of AAc. AAc layers are successfully grafted onto PP nonwovens, which are continuously rewound through the slit where the plasma is generated. The presence of plasma polymerized AAc layer in the fibrous structure of PP nonwoven was monitored by SEM, FTIR and XPS measurements. Additionally, the improved wettability and adhesion characteristics were investigated by the critical wetting surface tension (CWST) method, the standard method of strike-through time (STT) and „tape-peel“ test. Resulting AAc modified PP nonwoven possesses hydrophilic character, enhanced adhesion and a considerable amount of -COOH groups on the surface. Although after the washing test the FTIR and XPS results indicated a lower concentration of the carboxylic groups, the CWST and STT measurements confirmed the stable hydrophilic character of the PP nonwovens surface.

Plasma Polymerization of Precipitated Silica for Tire Application.

Pre-treated silica with a plasma-deposited (PD) layer of polymerized precursors was tested concerning its compatibility with Natural Rubber (NR) and its influence on the processing of silica-silane compounds. The modification was performed in a tailor-made plasma reactor. The degree of deposition of the plasma-coated samples was analyzed by ThermoGravimetric Analysis (TGA). In addition, Diffuse Reflectance Infrared Fourier Transform spectroscopy (DRIFTs), X-ray Photoelectron Spectroscopy (XPS), and Transmission Electron Microscopy (TEM) were performed to identify the morphology of the deposited plasma polymer layer on the silica surface. PD silica samples were incorporated into a NR/silica model compound. NR compounds containing untreated silica and in-situ silane-modified silica were taken as references. The silane coupling agent used for the reference compounds was bis-(3-triethoxysilyl-propyl)disulfide (TESPD), and reference compounds with untreated silica having the full amount and 50% of silane were prepared. In addition, 50% of the silane was added to the PD silica-filled compounds in order to verify the hypothesis that additional silane coupling agents can react with silanol groups stemming from the breakdown of the silica clusters during mixing. The acetylene PD silica with 50% reduced silane-filled compounds presented comparable properties to the in-situ silane-modified reference compound containing 100% TESPD. This facilitates processing as lower amounts of volatile organic compounds, such as ethanol, are generated compared to the conventional silica-silane filler systems.

Dual pH- and electro-responsive antibiotic-loaded polymeric platforms for effective bacterial detection and elimination

We describe a multi-tasking flexible system that is able to release a wide spectrum antibiotic (levofloxacin, LVX) under electrostimulation and act as a pH sensor for detecting bacterial infections. Combining anodic polymerization with plasma polymerization processes we engineered dual pH- and electro-responsive polymeric systems. Particularly, the manufactured devices consisted on a layer of poly(hydroxymethyl-3,4-ethylenedioxythiophene) (PHEDOT) loaded with the LVX antibiotic and coated with a plasma polymer layer of poly(acrylic acid) (PAA). The PHEDOT acted as conductive and electro-responsive agent, while the PAA provided pH responsiveness, changing from a compact globular conformation in acid environments to an expanded open coil conformation in alkaline environments. The assembly between the PHEDOT layer and the PAA coating affected the electrochemical response of the former, becoming dependent on the pH detected by the latter. The conformational change experienced by the PAA layer as a function of the pH and the redox properties of PHEDOT were leveraged for the electrochemical detection of bacteria growth and for regulating the release of the LVX antibiotic, respectively. The effectiveness of the system as a stimulus-responsive antibiotic carrier and pH sensor was also investigated on strains of Escherichia coli and Streptococcus salivarius.

Plasma‐coated PCL scaffolds with immobilized platelet‐rich plasma enhance the wound healing in diabetics mice

AbstractCOOH plasma polymer layers deposited onto polycaprolactone (PCL) nanofibers by plasma polymerization of CO2and C2H4in the Ar atmosphere were obtained and tested for diabetic wound healing. Simply by changing the deposition time, very different morphologies of coated PCL nanofibers were achieved. In vivo tests revealed that by applying modified nanofibers for 10 days, wound healing accelerated by 32.1%. Compared to a controlled wound characterized by an acute inflammatory process, wounds covered with nanofibers with platelet‐rich plasma demonstrated complete healing with a high percentage of collagen fibers on Day 19.

Surface nanotopography mediated albumin adsorption, unfolding and modulation of early innate immune responses

Surface roughness plays an important role in regulating protein adsorption to biomaterial surfaces and modulating the subsequent inflammatory response. In this study, we examined the role of surface nanotopography on albumin adsorption, unfolding and subsequent immune responses. To achieve the objectives of the study, we create model surfaces of hill-like nanoprotrusions by covalently immobilizing gold nanoparticles (AuNPs) of predetermined sizes (16, 38, and 68 nm) on a functional plasma polymer layer. The amount of adsorbed albumin increased with the increase in surface area caused by greater surface nanotopography scales. Circular dichroism spectroscopy was used to evaluate albumin conformational changes and pointed to loss of α-helical structure on all model surfaces with the greatest conformational changes found on the smooth surface and the surface with largest nanotopography features. Studies with differentiated THP-1 cells (dTHP-1) demonstrated that immune cells interacted with surface adsorbed albumin via their scavenger receptors, which could bind to exposed peptide sequences caused by surface induced unfolding of the albumin. Pre-adsorption of albumin resulted in an overall decrease in the level of expression of pro-inflammatory cytokines from dTHP-1 cells. On the other hand, pre-adsorption of albumin led in an increase in the production of anti-inflammatory markers, which suggests a switch to the M2 pro-healing phenotype. The knowledge obtained from this study could instruct the design of healthcare materials where the generation of targeted surface nanotopography and pre-adsorption of albumin may enhance the biomaterial biocompatibility and lead to faster wound healing.

Bioactive Plasma Coatings on Orthodontic Brackets: In Vitro Metal Ion Release and Cytotoxicity

The metal ion release characteristics and biocompatibility of meta-based materials are key factors that influence their use in orthodontics. Although stainless steel-based alloys have gained much interest and use due to their mechanical properties and cost, they are prone to localised attack after prolonged exposure to the hostile oral environment. Metal ions may induce cellular toxicity at high dosages. To circumvent these issues, orthodontic brackets were coated with a functional nano-thin layer of plasma polymer and further immobilised with enantiomers of tryptophan. Analysis of the physicochemical properties confirmed the presence of functional coatings on the surface of the brackets. The quantification of metal ion release using mass spectrometry proved that plasma functionalisation could minimise metal ion release from orthodontic brackets. Furthermore, the biocompatibility of the brackets has been improved after functionalisation. These findings demonstrate that plasma polymer facilitated surface functionalisation of orthodontic brackets is a promising approach to reducing metal toxicity without impacting their bulk properties.

Characterization of functionalized coatings prepared from pulsed plasma polymerization

Material assembly based on elastomer part and metallic substrate has been widely used in many industrial sectors. However, the adhesion between the two materials requests specific processes and adhesives. Plasma technology is an interesting way to prepare the assembly since the plasma polymer layers used for the adhesive joint can bear different reactive chemical functions toward the elastomer. Three different plasma coatings are synthesized from acetylene, acrylic acid, and maleic anhydride plasma because of their respective chemical functions able to open the carbon-carbon double bond of the elastomer (rubber, fluoroelastomer). For such a purpose, fine-tuning of plasma parameters was essential to preserve the precursor chemistry and to avoid any degradation. Pulsed plasma discharge was selected, plasma parameters defined thanks to the design of experiment. The different plasma polymers were characterized by FTIR, XPS and NEXAFS spectroscopies and surface energy measurement.

One-step plasma deposited thin SiO x C y films for corrosion resistance of low carbon steel

Tetraethyl orthosilicate (TEOS) was used as a chemical precursor to deposit ultra-thin SiO x C y plasma polymer films onto mild steel surfaces for preventing the corrosion process. The structure–property relationships of the coatings were evaluated by X-ray Photo Spectroscopy (XPS), X-Ray Diffraction (XRD), Fourier Transform InfraRed spectroscopy (ATR-FTIR) and Energy Dispersive X-ray spectroscopy (EDX) completed with Scanning Electron Microscopy (SEM). The SEM micrographs confirmed a pinhole-free surface morphology of the low-pressure deposited plasma polymer films. The TEOS molecules become fragmented in the plasma by numerous collisions with energy-rich electrons and heavier particles. Recombination of fragments and condensation onto the steel substrate is responsible for the formation of organic SiO containing plasma polymer layers. Such thin layers consist of predominantly SiO x structures. Their properties are determined largely by the gap distance between the two samples used as electrodes in the plasma. The efficiency of the corrosion-protecting coating was compared with uncoated samples. The corrosion protection was determined by exposure of samples to 3.5% NaCl aqueous solutions. For this purpose, polarization and Electrochemical Impedance Spectroscopy (EIS) were used to monitor the corrosion. The optimal gap distance between the electrodes was determined for corrosion protection. The best protective efficiency reached more than 97% of the total protection as measured at room temperature.

Development of mass sensitive sensor platform based on plasma polymerization technique: Quartz tuning fork as transducer

This paper describes a modification process of QTFs’ prongs with stable amine containing bilayer plasma polymer film and an application of quartz tuning fork (QTF) as a transducer for biomedical application. To produce stable amine containing film, first, we created plasma polymer films from hexane precursors. We then subjected those films to a second capping layer of ethylenediamine plasma polymer. The film was characterized by contact angle measurement, atomic force microscopy, and X-ray photoelectron spectroscopy. The effect of the interfacial structure onto stability was also analyzed in air. A model protein, BSA, sensing experiments were examined by measuring the shift in the resonance frequency of QTFs. The performance of the proposed sensor was investigated in terms of quality factor. These findings reveal that amine containing bilayer coated QTFs have the potential to be used in mass sensitive biosensor applications for future.

The wrinkling concept applied to plasma‐deposited polymer‐like thin films: A promising method for the fabrication of flexible electrodes

AbstractIn this communication, we report on an innovative solvent‐free method that allows for the design of nano‐/micropatterns with tuneable dimensions. Our approach is based on the spontaneous wrinkling phenomenon taking place in a bilayer system formed by a mechanically responsive bottom plasma polymer layer and a top aluminum thin film. The dimensions of the wrinkles can be adjusted in a wide range (i.e., from nanometer to micrometer range) by modulating the cross‐linking density as well as the thickness of the plasma polymer layer. Finally, it is demonstrated that these wrinkled surfaces could efficiently be used as flexible electrodes. The whole set of our data unambiguously reveals the attractiveness of our method for the fabrication of the micro‐/nanopattern with dimensions on demand.

Flexible Al2O3/plasma polymer multilayer moisture barrier films deposited by a spatial atomic layer deposition process

Al2O3/plasma polymer multilayers were developed and characterized for the moisture barrier films of flexible organic devices. The inorganic Al2O3 thin films were deposited by a spatial atomic layer deposition process and the organic layers were deposited by plasma polymerization in the same chamber using CHF3, benzene, and cyclohexane precursors. The deposition rate, light transmittance, and surface roughness of the plasma polymer films obtained from the three precursors were investigated. The three plasma polymer layers were introduced between Al2O3 layers and their effect on the water permeability and flexibility of each Al2O3/plasma polymer multilayer structure was evaluated. The multilayer structure with hydrocarbon from cyclohexane shows better flexibility than that with fluorocarbon by CHF3 and hydrocarbon by benzene. Polymer interlayers with plasma thicker than 20 nm are necessary for reasonable flexibility. The authors increased the number of layers up to 21 to improve the water permeability and flexibility. The water vapor transmission rate (WVTR) of a 100 nm-thick Al2O3/plasma polymer was reduced to 8.5 × 10−5 g/m2 day with the 21-layer structure. This WVTR value is 58% lower than that of the 100 nm-thick single-layer Al2O3. The WVTR of a 100 nm-thick single-layer Al2O3 increased by 900% when it was bent 1000 times with a bending radius of 1 cm due to film cracks, while, under the same conditions, the 21-layer structure showed only a 32% increase in the WVTR. These results indicate that the nanometer-scale-thick plasma polymer can be an effective solution for multilayer moisture barrier films.

Role of the surface chemistry of plasma polymer layers on their long‐term antifogging behavior

AbstractThe long‐term antifogging capability of plasma coatings obtained from a hydrophilic precursor, such as 2‐(dimethylamino)ethyl methacrylate or acrylic acid, and a hydrophobic monomer, 1H,1H,2H‐perfluoro‐1‐decene (HDFD), deposited on polycarbonate is studied for two different agings. These films, when freshly prepared, show simultaneous hydrophilicity/oleophobicity for HDFD concentrations <50%. They fulfill antifogging criteria: low water contact angle (<20°), high hexadecane contact angle around 70° and preservation of optical transparency after water vapor contact. Depending on their chemical structure, only p‐AA‐co‐HDFD with 20–40% of HDFD retain their antifogging properties after thermal aging, while all of them are altered when dipped in hot water. p‐AA‐co‐HDFD is more efficient than p‐DAME‐co‐HDFD in reducing airborne contamination and improving long‐term antifogging performance.

Thin Plasma-Polymerized Coatings as a Primer with Polyurethane Topcoat for Improved Corrosion Resistance

Use of a plasma-polymerized (pp) layer under a polyurethane (PU) coating on aluminum dramatically improves the corrosion resistance. Compared to conventional polymer coatings, pp coatings are highly cross-linked, have better adhesion to substrates, and result in lower emission of volatile organic contents. Although past research has focused on the properties of comparatively thick pp films and on the use of pp films alone to protect metals, we consider here very thin pp coatings as a primer layer to improve corrosion resistance. Electrochemical impedance spectroscopy combined with salt spray lab tests show that the corrosion resistance of a PU coating on top of a pp coating from hexamethyldisiloxane (HMDSO) is much better than that of a PU coating directly on Al 3003. The relatively poor pull-off adhesion between PU and pp-HMDSO is readily addressed using a gradient coating by depositing a pp maleic anhydride layer over the pp-HMDSO coating or by modifying the surface composition of the pp-HMDSO coating with N2 plasma. X-ray photon spectroscopy analysis of the failure interface from pull-off tests makes clear that failure does not occur at the interface between the pp coating and the metal substrate. Field tests show the performance of the coating system with PU on a gradient coating on Al 3003 to be superior to that of a coating system of PU on chromate-treated Al 3003.

Plasma Polymer Layers with Primary Amino Groups for Immobilization of Nano- and Microparticles

The assembly of nano- and micro-scale building blocks on surface has been the focus of intense interest in materials science for years. In this work, (3-aminopropyl)triethoxysilane (APTES) carrying one primary amino group was deposited on various substrate surfaces using the plasma polymerization method. The key plasma parameters i.e. pressure and power were varied to obtained the highest density of primary amino groups. The influence of such parameters on the characteristics of deposited layers (e.g. chemical structure, adhesion strength, growth rate, etc.) was systemically investigated using various characterization methods such as XPS, FTIR, ellipsometry and so on. Meanwhile, three types of particles (AuNPs, zeolites and gold@zeolites) with sizes from nano- to submicro-range were synthesized and further used as model building blocks. Subsequently, the prepared particles were deposited onto cyclic olefin copolymer (COC) substrate surfaces, which were pre-functionalized by deposition of the plasma polymer layer using the parameters of pressure = 1.0 mbar and power = 30 W. The results confirmed the formation of membrane structures consisting of highly packed particles on the COC surface, and such immobilized structures showed high stability against flowing water, evidencing the good immobilization ability of deposited APTES layers with amino groups.

Improvement in the moisture barrier properties and flexibility by reducing hydrogen dangling bonds in SiNx thin films with plasma surface treatment

In this study, silicon nitride (SiNx) thin films were deposited by inductively coupled plasma chemical vapor deposition using trisilylamine (TSA, N(SiH3)3) and ammonia (NH3) plasma, and their moisture barrier properties were improved by plasma post-treatment. Ar, N2, and O2 plasmas were applied to the SiNx films after deposition. After O2 plasma treatment, the reduction of hydrogen in -NHx was confirmed by FT-IR analysis. Mass spectroscopic results showed a distinct hydrogen peak in the O2 plasma processes. Hydrogen was speculated to be removed from the SiNx surface, and the reduced hydrogen on the surface was attributed to the densification of the SiNx thin films. The increased film density reduced the moisture permeability of the SiNx thin films. The water vapor transmission rate (WVTR) of 120-nm thick single SiNx thin films was reduced by 77% to 3.0 × 10−3 g/m2-day from 1.3 × 10−2 g/m2-day with O2 plasma treatment. The increase of WVTR evaluated using a bending test was adopted to estimate flexibility. The increase of WVTR reduced to 71% in O2-plasma treated SiNx single layers from 88% with untreated SiNx single layers after bending the film at a bending radius of 1.5 cm. Multilayer moisture barrier films were fabricated using the O2-plasma treated SiNx layers and hydrocarbon plasma polymer layers made of cyclohexane plasma to further improve the moisture barrier properties and flexibility. The increase of WVTR reduced by approximately five times in the multilayer structure with O2 plasma treated SiNx/hydrocarbon plasma polymer after the bending test. A WVTR of 7.6 × 10−4 g/m2-day was obtained with an alternating nine-layer structure. In this study, we demonstrated that plasma post-treatment processes can improve the moisture barrier properties and flexibility by reducing the hydrogen dangling bonds and hydrogen concentration inside SiNx thin films.

Interfacial Forces at Layered Surfaces: Substrate Electrical Double-Layer Forces Acting through Ultrathin Polymer Coatings.

Manipulating the surface properties of materials via the application of coatings is a widely used strategy to achieve desired interfacial interactions, implicitly assuming that the interfacial forces of coated samples are determined exclusively by the surface properties of the coatings. However, interfacial interactions between materials and their environments operate over finite length scales. Thus, the question addressed in this study is whether interactions associated with bulk substrate materials could act through thin coatings or, conversely, how thick a coating needs to be to completely screen subsurface forces contributed by underlying substrates. Plasma polymer layers were deposited on silicon wafer substrates from ethanol vapor, with identical chemical composition, ultrasmooth surfaces, and varying thicknesses. Using colloid-probe atomic force microscopy, electrical double-layer forces were determined in solutions of various ionic strengths and fitted using the Derjaguin-Landau-Verwey-Overbeek theory. For the thicker ethanol plasma polymers, the fitted surface potentials reflected the presence of surface carboxylate groups and were invariant with thickness. In contrast, for coatings <18 nm thick, the surface potentials increased steadily with decreasing film thickness; the measured electrical double-layer forces contained contributions from both the coating and the substrate. Theoretical calculations were in agreement with this model. Thus, our observations indicate that the higher surface potential of the underlying SiO2 surface can influence the interactions between a colloid particle and the multilayer structure if coatings are sufficiently thin. Such superposition needs to be factored into the design of coatings aimed at the control of material interactions via surface forces.

Maleic anhydride and acetylene plasma copolymer surfaces for SPR immunosensing

We report on the successful application of carboxyl-rich plasma polymerized (PP) films as a matrix layer for bioreceptor immobilization in surface plasmon resonance (SPR) immunosensing. Composition and chemical properties of the carboxyl-rich PP films deposited from a mixture of maleic anhydride and acetylene were investigated. Changes in the films stored in air, water, and buffer were studied and the involved chemical changes were described. Performance in SPR immunosensing was evaluated on interactions of human serum albumin (HSA) with a specific monoclonal antibody. The comparison with the mixed self-assembled monolayer of mercaptoundecanoic acid and mercaptohexanol (MUA/MCH) and one of the most widely used surfaces for SPR, the 2D and 3D carboxymethylated dextran (CMD), was presented to show the efficacy of plasma polymerized matrix layers for biosensing. The PP film-based SPR immunosensor provided a similar detection limit of HSA (100ng/mL) as MUA/MCH- (100ng/mL) and 3D CMD (50ng/mL)-based sensors. However, the response levels were about twice higher in case of the PP film-based immunosensor than in case of MUA/MCH-based alternative. The PP film surfaces had similar binding capacity towards antibody as the 3D CMD layers. The response of PP film-based sensor towards HSA was comparable to 3D CMD-based sensor up to 2.5μg/mL. For the higher concentrations (> 10μg/mL), the response of PP film-based immunosensor was lower due to inaccessibility of active sites of the immobilized antibody inside the flat PP film surface. We have demonstrated that due to its high stability and cost-effective straightforward preparation, the carboxyl-rich PP films represent an efficient alternative to self-assembled monolayers (SAM) and dextran-based layers in label-free immunosensing. Graphical abstract.

Stimulus-Responsive Antibiotic Releasing Systems for the Treatment of Wound Infections.

There remains an unmet need for innovative treatments for chronic wound infections as they continue to be a financial and social burden on society. Because of the dynamic nature of wounds, this study investigated the utilization of stimulus-responsive plasma polymers for the development of pH- and thermoresponsive antibiotic delivery systems for the treatment of wound infections. Porous silicon films were loaded with the antibiotic levofloxacin (LVX) and subsequently coated with plasma polymer layers: first, poly(1,7-octadiene) (pOCT) for stability, followed by either the temperature-responsive polymer poly N,N-diethylacrylamide (pDEA) or the pH- responsive polymer poly 2-(diethylamino)ethyl methacrylate (pDEAEMA), to fabricate two delivery systems. The delivery systems were thoroughly characterized chemically and physically and tested in vitro through drug release and bacterial zone of inhibition studies. After a 16 h time point, the system containing pDEA achieved 3.2-fold greater release at 45 °C compared to 22 °C, whereas the system containing pDEAEMA achieved a 2.2-fold greater release when exposed to pH 8.5 media compared to pH 6.2 media. Furthermore, both systems retained their antimicrobial activity and demonstrated stimulus-responsive release to form zones of inhibition on relevant wound pathogens, Pseudomonas aeruginosa, Staphylococcus epidermidis and Staphylococcus aureus. Therefore, this proof-of-principle study confirms that stimulus-responsive porous silicon films can be utilized to deliver antibiotic when exposed to physiologically relevant stimuli such as pH and temperature with the potential to be applied to other pharmaceutics.