PLA Substrates Research Articles

The Deposition of Hydroxyapatite Particles Within an Organic Matrix on the Surface of Poly(lactic acid)

Hydroxyapatite (HAP) is a well-established material in biomedical applications, especially for bone tissue regeneration, dental implants, and drug delivery systems. Recent research emphasizes enhancing the biocompatibility and osteoconductivity of orthopedic implants using HAP. This study explores the potential of combining HAP with a lipid matrix to improve the surface properties and biocompatibility of poly(lactic acid) (PLA)-based, 3D-printed, resorbable bone implants. We utilized the Langmuir–Blodgett method to deposit HAP within a dihexadecyl phosphate (DHP) matrix onto PLA substrates. This study demonstrates that DHP and HAP form stable monolayers at the air/water interface with HAP particles distributed within a homogeneous lipid matrix. The presence of HAP and the resulting changes in surface free energy (SFE) are hypothesized to enhance the biocompatibility of PLA implants. Our findings indicate that films composed of DHP + HAP 5:1 are particularly effective in altering PLA surface characteristics, potentially improving osteointegration, and reducing microbial adherence. Overall, this work highlights that surface modification of PLA with HAP and lipid matrices is the first step towards new, promising, and cost-effective strategies for developing advanced biomaterials for bone regeneration.

Mild Fabrication of Polymeric Porous/Nonporous Micro‐Composite Structures via Enhancing the Photothermal Conversion of Ultrafast Laser

AbstractLocalized foaming of polymers is promising to fabricate polymeric composite structures for applications in biomedical, aerospace, automotive, etc. However, the severe pyrolysis and carbonization of polymer chains during localized foaming may degrade the bulk strength. Herein, a mild localized foaming strategy is proposed to fabricate poly(lactic acid) (PLA) micro‐foams within dense PLA matrices using ultrafast lasers. The PLA substrates doped with graphene (Gr) and azodicarbonamide (AC) are developed for mild foaming. A picosecond laser is applied to pattern PLA micro‐foams on the PLA/Gr/AC substrates to fabricate porous/nonporous micro‐composite structures. The thermal behavior of the PLA/Gr/AC substrates is characterized to evaluate their capability in photothermal conversion and mild foaming during ultrafast laser pulses. To optimize the laser foaming process, the microstructure of the laser‐foamed PLA processed with different laser parameters is studied. It demonstrates that the oxidation of the functional groups dominates the side reactions on the PLA chains with slight variation in molecular weight during laser foaming, indicating that the PLA chains keep almost intact and mild localized foaming is realized. Furthermore, the developed technology is demonstrated for micro‐patterning and texturing, material toughness programming, and shape memory programming, showing promising applications for smart materials, metamaterials, micro‐robotics, and biological scaffolds.

Low-cost saw/sinus-tooth-shaped circular microstrip patch antenna for in-space and satellite applications

Antennas operating in S and C bands are crucial in space satellite applications due to their high bandwidth, which facilitates the swift transmission of large data volumes from space vehicles to Earth. These bands are less affected by atmospheric disturbances and exhibit lower noise levels, ensuring uninterrupted and reliable communication between spacecraft and Earth centers. They are essential for satellite-based remote sensing, analyzing surface properties, transmitting high-resolution images, scientific data, and other information. Additionally, they are used for spacecraft control and navigation, enabling precise mission operations. This study emphasizes user-friendly production antennas with different geometries and distinct feeding techniques, demonstrating various design implementations using CST Microwave Studio software. Innovative manufacturing methods such as 3D printing PLA substrates and using copper tape for antenna elements were explored to optimize costs and production processes. Precise cutting of antenna radiation geometries was achieved using the Cricut machine. Experimental validation through reflection coefficient (S11) measurements with a handheld vector network analyzer confirmed the practical application of theoretical foundations. The study’s novelty lies in examining unconventional materials like PLA filament for antenna substrates, exploring fractalization theory for enhancing bandwidth, and discussing advancements in material science with flexible filaments like TPU. These contributions offer insights into user-friendly antenna production, innovative manufacturing techniques, and theoretical explorations in antenna design, enhancing the efficiency and effectiveness of space satellite communication systems.

Bulge-Free and Homogeneous Metal Line Jet Printing with StarJet Technology.

The technology to jet print metal lines with precise shape fidelity on diverse substrates is gaining higher interest across multiple research fields. It finds applications in additively manufactured flexible electronics, environmentally friendly and sustainable electronics, sensor devices for medical applications, and fabricating electrodes for solar cells. This paper provides an experimental investigation to deepen insights into the non-contact printing of solder lines using StarJet technology, eliminating the need for surface activation, substrate heating, curing, or post-processing. Moreover, it employs bulk metal instead of conventional inks or pastes, leading to cost-effective production and enhanced conductivity. The effect of molten metal temperature, substrate temperature, standoff distance, and printing velocity was investigated on polymer foils (i.e., PET sheets). Robust printing parameters were derived to print uniform, bulge-free, bulk metal lines suitable for additive manufacturing applications. The applicability of the derived parameters was extended to 3D-printed PLA, TPU, PA-GF, and PETG substrates having a much higher surface roughness. Additionally, a high aspect ratio of approx. 16:1 wall structure has been demonstrated by printing multiple metal lines on top of each other. While challenges persist, this study contributes to advancing additively manufactured electronic devices, highlighting the capabilities of StarJet metal jet-printing technology.

Modification of 3D-Printed PLA Structures Using Photo-Iniferter Polymerization: Toward On-Demand Antimicrobial Water Filters.

Water filtration is an important application to ensure the accessibility of clean drinking water. As requirements and contaminants vary on a local level, adjustable filter devices and their evaluation with contaminants are required. Within this work, modular filter devices are designed featuring an adjustable surface functionalization. For this purpose, 3D-printed structures are created consisting of bio-based poly(lactic acid) (PLA) that are manufactured by extrusion printing. The surface of PLA is activated with amino groups that are used to install xanthates as chain transfer agents. Subsequently, photo-iniferter (PI) polymerization is used to create cationic polymer brushes on the surface of PLA substrates. Multiple surface characterization techniques are employed to prove successful growth of polymer brushes on PLA. After initial optimization studies on flat surfaces, filter devices are printed, functionalized, and used to remove bacteria from contaminated water. Significant reduction of the number of microorganisms is detected after filtration (single filtration or cycling) and contaminating organism can also be removed from freshwater samples by simple incubation with a 3D-printed filter. The herein developed setup for producing functional filter devices and probing their performance in affinity filtration is a useful platform technology, enabling the rapid testing of polymer brushes for such applications.

Laser-induced graphitized electrodes enabled by a 3D printer/diode laser setup for voltammetric detection of hormones

Contraceptive pills have helped to shape modern society and their use has become more popular over the years. β-estradiol, one of the molecules present in this type of medication, is considered an endocrine disrupting compound (EDC), being nowadays commonly found in water resources. Due to their adverse effects on human health and the environment, even at trace levels, low-cost and rapid-detection approaches capable of reliably detecting EDCs such as β-estradiol are highly keen. As an alternative to the classic and well-established analytical methods for hormone detection, here we propose a simple and low-cost strategy that relies on the use of laser-induced graphitization (LIG) to manufacture electrodes for voltammetric detection of hormone in river and tap water. The LIG electrodes were produced by attaching a diode laser to a commercially available Fused Deposition Modelling (FDM) 3D printer, in which the laser promoted the controlled ablation of the polyimide film adhered to the PLA substrates. Specifically, the manufacturing steps included the 3D printing of the substrate followed by laser scribing a double-sided tape made of polyimide glued onto the surface of the substrate. The 3D printer was able to control the laser movement at specifics positions to manufacture the carbon-based three-electrode system (TES) layout. The usability of the electrochemical sensor was evaluated towards β-estradiol detection, which presented a linear response from 0.25 to 10 µmol L−1 and a limit of detection (LOD) = 80 nM. Spiked samples using tap water and river water reached 91 and 110% of recovery respectively. Our results suggest the proposed approach as an innovative and versatile way to produce low-cost, easily customizable, and reliable electrochemical sensors based on laser ablation on polyimide films.

Fabrication and biocompatibility analysis of flexible organic light emitting diodes on poly(lactic acid) substrates: toward the development of greener bio‐electronic devices

AbstractThe use of biodegradable and biocompatible materials for electronic applications is a research topic of great interest, offering the possibility to develop bio‐electronic devices and reduce e‐wastes. In this work, poly(lactic acid) (PLA) films were prepared to be employed as substrates in flexible optoelectronic devices and their functionality was tested in indium tin oxide‐free organic light emitting diodes (OLEDs). The PLA substrates were fabricated by extrusion and characterized in terms of morphological, optical and wettability properties. The films showed optical transmittance of about 90% in the visible region and surface roughness of about 12 nm, optical and morphological parameters suitable for OLED applications. Different structures were fabricated on top of the PLA substrates by hybrid technology through solution‐based and thermal evaporation deposition methods. Good electro‐optical properties were detected in iridium complexes‐based devices, with current efficiencies of about 14 and 1 cd/A in structures with tris[2‐phenylpyridinato‐C2,N]iridium(III) (Ir[ppy]3) and bis[2‐(4,6‐difluorophenyl)pyridinato‐C2,N](picolinato)iridium (FIrPic) as emitting layer, respectively. The biocompatibility assay showed that the encapsulated devices do not release toxic substances and their biocompatibility can be improved by selecting different encapsulating glues. The results of this study show the potentiality of PLA as substrate for the fabrication of biocompatible and biodegradable optoelectronic devices opening new routes for the development of advanced bio‐electronic systems.

Discharge Plasma Treatment as an Efficient Tool for Improved Poly(lactide) Adhesive-Wood Interactions.

Poly(lactide) (PLA) films obtained by thermoforming or solution-casting were modified by diffuse coplanar surface barrier discharge plasma (300 W and 60 s). PLA films were used as hot-melt adhesive in joints in oak wood. It was demonstrated that lap shear strength increased from 3.4 to 8.2 MPa, respectively, for the untreated and plasma-treated series. Pull-off tests performed on particleboard for the untreated and treated PLA films showed 100% cohesive failure. Pull-off strength tests on solid oak demonstrated adhesion enhancement from 3.3 MPa with the adhesion failure mode to 6.6 MPa with the cohesion failure mode for untreated and treated PLA. XPS revealed that carbonyl oxygen content increased by two-to-three-fold, which was confirmed in the Fourier-transform infrared spectroscopy experiments of the treated PLA. The water contact angle decreased from 66.4° for the pristine PLA to 49.8° after treatment. Subsequently, the surface free energy increased from 47.9 to 61.05 mJ/m2. Thus, it was clearly proven that discharge air plasma can be an efficient tool to change surface properties and to strengthen adhesive interactions between PLA and woody substrates.

Effect of pH and ionic strength of chitosan/casein and casein/chitosan multilayers on curcumin release

In the present paper the effect of pH and ionic strength on the immobilization and release of curcumin from chitosan and casein polyelectrolyte multilayers (PEMs) was investigated. The investigated PEMs were deposited on polylactic acid (PDLA) substrates. The PLA substrates were charged in a corona discharge system, consisting of a corona electrode, a grounded plate electrode and a grid placed between them. The substrate was charged for 1 minute at room temperature. Positive or negative 5kV voltage was applied to the corona electrode and 1 kV voltage with the same polarity was applied to the grid. Chitosan solutions with different pH and ionic strength were prepared. Layer-by-Layer (LbL) deposition technique was used for the multilayer build-up. For the deposition process was ensured that the first deposited layer always possessed an opposite electric charge to that of the substrate. An investigation of the water uptake properties of the deposited PEM multilayers was carried out. Curcumin was immobilized in the resulting casein layers. The release of the immobilized curcumin from the multilayers in saline buffer was investigated and the effects of the different pH and ionic strengths of the chitosan solutions were determined.

PH-Triggered Adhesiveness and Cohesiveness of Chondroitin Sulfate-Catechol Biopolymer for Biomedical Applications.

Nature provides biomaterials that tend to be effective to control both their adhesive and cohesive properties. A catecholamine motif found in the marine mussels, the mytilus edulis foot protein, can play adhesiveness and cohesiveness. Particularly, acidic pH drives catechol (Cat) to have adhesive function, resulting in surface coating, while basic pH allows to enhance its cohesive properties, resulting in the formation of hydrogels. In this work, we demonstrated the usefulness of Cat-conjugated chondroitin sulfate (CS) as a platform for mesenchymal stem cell culture, utilizing the adhesive property of CS-Cat as coating for different substrates and the cohesive properties as hydrogel for cells encapsulation. To prepare the CS-Cat biopolymer, dopamine (DP) was coupled to the CS by carbodiimide coupling reaction and the Cat content was determined by UV–Vis spectroscopy (4.8 ± 0.6%). To demonstrate the adhesive properties of the biopolymer, PLA, PCL, TiO2, and SiO2 substrates were immersed in CS-Cat solution (pH < 2). Following the coating, the surfaces became highly hydrophilic, exhibiting a contact angle less than 35°. Also, in the presence of an oxidizing agent at pH 8, CS-Cat solution immediately became a hydrogel, as shown by inverted-vial test. Finally, immortalized TERT human mesenchymal stem cells (Y201) confirmed the high cytocompatibility of the biopolymer. The CS-Cat coating significantly enabled the Y201 adhesion onto PLA substrates, while the prepared hydrogel demonstrated to be a suitable environment for the encapsulation of cells as suitable bioink for further bioprinting applications.

Surface modification of PLA nets intended for agricultural applications

Exclusion nets create a physical barrier between pests and crops, serving as a practical tool to reduce pesticide use in a wide variety of crops, and their negative impacts on the environment. While the efficiency of this method has been recently assessed, protection from pests is incomplete, as microorganisms such as fungi are not hindered by netting. In order to avoid favorable conditions for microbial development (e.g. wet leaf surfaces), the present study discusses two hydrophobic surface treatment approaches, each applied to two PLA substrates that can be used as exclusion nets to reduce water ingress on protected fruit trees. Both a commercial exclusion net and a fused deposition modelled (or 3D printed) mesh were treated via solvent-free and solvent-induced modifications. Photo-initiated chemical vapor deposition (PICVD) allowed organic thin film growth on the substrate at near-ambient conditions. Dip-dip-dry (DDD) exploited solvent-induced topology modification to yield hydrophobic PLA samples, showing various microstructures (crazes or hierarchical topology) depending on the substrate properties. Both substrates were efficiently rendered hydrophobic after surface treatments, with water contact angles climbing from 73° to 101° (PICVD) or 143° (DDD) for printed PLA samples, and to 131° (PICVD) or 135° (DDD) for commercial exclusion nets. The hierarchical features present on DDD-treated printed PLA substrates showed potential for molecular adsorption, paving the way for a method to increase the phytosanitary effect of agricultural textiles by active ingredient incorporation (limonene is used here as a test case). Surface properties were characterized with SEM imaging, contact angle measurements, tensile tests and drop penetration assessments (rain simulation).

Investigating Neurogenic Differentiation of Dental Pulp Stem Cells Using PLA and Graphene Thin-Film and Electrospun Fiber Scaffolds in Vitro

Dental pulp derived cells are pluripotent stem cells which can be differentiated along odontogenic, osteogenic, adipogenic, or neurogenic lineages. Odontogenic and osteogenic differentiation, in the absence of dexamethasone, have been shown to be highly dependent on substrate morphology and mechanics. Here we focus on neurogenic differentiation, using the protocol described by A. Arthur et al., and its dependence on substrate nature. DPSCs were cultured on PLA, a biodegradable polymer approved for internal use. The upregulation of genetic markers was compared with that of cells plated on standard TCP. The role of substrate morphology was investigated by plating on electrospun fibers approximately 2.0 ± 1.0 μm in diameter and on spin-cast thin films. The influence of graphene was investigated through the addition of 3% and 10% graphene nanoparticles to the films and fibers respectively. The aspect ratio of the cells was measured using confocal microscopy. Cells grown on graphene containing substrates had larger aspect ratios than their non-graphene counterparts, and cells grown on microfibers were longer than their counterparts on the flat films. But the cell aspect ratio did not necessarily correlate with genetic differentiation. The results after 21 days of incubation indicated that early markers (TBP, β-III tubulin), decreased uniformly on all substrates relative to day 0, with the largest decrease occurring on the PLA flat film with graphene. The late stage marker, NEFM, which indicates differentiation, was upregulated to a significantly larger extent on all PLA substrates. No difference was observed between the fibers and the flat film in the absence of graphene, thus morphology did not play a significant role on this polymer. Addition of graphene did not affect the outcome on the fibers, but significantly suppressed the gene expression on the flat films. These results indicate that PLA is a promising scaffold material for neurogenic differentiation.

Dual effect of dynamic vulcanization of biobased unsaturated polyester: Simultaneously enhance the toughness and fire safety of Poly(lactic acid)

To overcome the inherent flammability and brittleness of biobased and biodegradable poly(lactic acid) (PLA) so as to broaden its applications, a new strategy, introducing a dynamic vulcanization of biobased unsaturated polyester (BUP) in PLA substrates, has been employed to improve the fire safety and toughness of PLA simultaneously for the first time. For toughened PLA by BUP (TPLA), only 20 wt% ammonium polyphosphate (APP) needs to be added for achieving UL 94 V-0 rating and a limiting oxygen index (LOI) value of 27%. In contrast, for PLA without BUP, 20 wt% of APP (PLA/APP20) cannot endow it with a fire safety, and only UL 94 V-2 rating and a LOI value of 24% are obtained. Interestingly, the elongation at break and the notched Izod impact strength of TPLA/APP20 are 107.1% and 15.9 kJ/m2, respectively, being 13.7 and 8.8 times than that of neat PLA; the complex viscosities of TPLA/APP are much higher than that of PLA/APP even near the burning temperature, which can reduce the fluidity and avoid further diffusion of flame with the flow of melt. Further, an open cone calorimeter test, XPS, FT-IR and SEM have been used to find out how the toughening treatment affect the fire safety of PLA/APP. All the results demonstrate that for PLA with low melt viscosity and heavy dripping during burning, the toughening treatment via dynamic vulcanization can quickly promote continuous dense char formation benefiting improving the flame retardant efficiency of APP.

Heparin coating on 3D printed poly (l-lactic acid) biodegradable cardiovascular stent via mild surface modification approach for coronary artery implantation

In the last decade, stent implantation therapy has been widely performed in the clinic. Although the patient's cardiovascular state depends on their age, gender, and health condition, the development of customized individual stents has been limited. Thus, a patient-specific stent manufacturing system should be devised for more successful stent therapy. In this study, we prepared a 3D printed PLA biodegradable polymeric stent using polydopamine (PDA), polyethyleneimine (PEI) and heparin (Hep) chemistry to prevent restenosis and thrombosis with anticoagulation and good blood compatibility. Physico-chemical characterization indicated that pristine PLA substrates were well modified as the amine abundant surface allowed for coating of a large amount of Hep. From in vitro and ex vivo analysis, heparinized 3D PLA stents showed excellent thromboresistance and hemocompatibility functions as well as modulation of smooth muscle cell (SMC) and endothelial cell (EC) proliferation. In an in vivo study, the heparinized 3D PLA stent showed the widest lumen area with the least neointimal hyperplasia and without atherosclerosis or thrombosis. All of these assessments clearly confirmed that our innovative strategy may suggest a useful paradigm as a preparation method for a patient-customized fully biodegradable individual stent for successful implantation therapy. This would find wide utilization for cardiovascular clinical applications.

Photoactive Hybrid Materials with Fractal Designs Produced via 3D Printing and Plasma Grafting Technologies.

The present paper partly aims at exploring the potential of fractal geometry for concrete applications in the field of materials science. It is more specifically a study about the conception of hybrid polymer-based materials with photocatalytic activity. The concept behind this work is to investigate the use of polymer fractal structures manufactured by 3D-printing technology, as a highly ordered substrate with an important surface area to immobilize catalyst nanoparticles, by means of plasma grafting technology. Two types of fractal units, fractal pyramids (fracmids) and fractal cones (fracones), have been described and the former has been extensively characterized on a geometrical aspect. Various complex superstructures have also been described using fractal units as building blocks. 3D structures based on the aforementioned theoretical models have been designed using computer-aided design (CAD). On the basis of CAD models, several structures have been 3D-printed with PLA using fused deposition modeling. PLA substrates have been successfully coated with nanoparticles of ZnO using a combination of core-shell synthesis and plasma grafting. Finally, the photocatalytic activity of a hybrid material has been assessed with a positive outcome, showing the relevance of the concept developed in this study.

Dual RGD-immobilized poly(L-lactic acid) by atmospheric pressure plasma jet for bone tissue engineering.

Surface treatment on PLA substrates by atmospheric pressure plasma jet (APPJ) for polymerization of dual RGD-peptides were investigated. Peptide-modified surfaces have been highlighted as the most promising approach to improve the integration of implants into surrounding bones. By varying the RF power, PLA substrates treated by APPJ process have a tendency to form a hydrophobic surface. The effects on the proliferation and differentiation of MG63 cells were evaluated and osteocalcin (OCN) expression was analyzed using RT-PCR. The water contact angle of the W/APPJ process PLA was approximately 54% of that of the W/O APPJ process PLA substrates. W/APPJ process significantly increased cell proliferation, improved the functionality of the material without using a complicated procedure. We believe that pretreatment using the APPJ processes and dual RGD grafting can be more appropriate than traditional surface modification methods, with more potential for application to bone materials.

Novel solvent bonding method for creation of a three-dimensional, non-planar, hybrid PLA/PMMA microfluidic chip

Fused deposition modeling (FDM) is an approach of 3D printing and has been used in the fabrication of microfluidic systems. Unfortunately, the poor optical transparency of the resulting microfluidic devices makes the characterization and quantification of experiment results difficult. In this study, we developed a method of solvent bonding PMMA and poly(lactic acid) (PLA) thermoplastic materials for the creation of hybrid microfluidic chips. The benefits of the proposed method are as follows: (1) simplified fabrication of complex 3D microfluidic chips; (2) optical characterization and quantification of fabrication results; and (3) the ability to print and embed tubing connectors within the microfluidic chip to facilitate assembly. Three experiments were conducted to evaluate the efficacy of the proposed scheme. We fabricated one microfluidic chip with an S-microchannel to examine the fundamental fabrication results. We also fabricated two application-oriented microfluidic chips respectively featuring a 3D non-planar micromixer and a double emulsion generator. Our experiment results demonstrate the efficacy of this bonding method in the rapid formation of strong bonds (exceeding 13 bars) between PLA and PMMA substrates. The two application examples further demonstrate that the proposed scheme is applicable to the fabrication of complex microfluidic chips quickly and easily without sacrificing their intended functionalities.

Oriented growth and transdifferentiation of mesenchymal stem cells towards a Schwann cell fate on micropatterned substrates

While Schwann cells (SCs) have a significant role in peripheral nerve regeneration, their use in treatments has been limited because of lack of a readily available source. To address this issue, this study focused on the effect of guidance cues by employing micropatterned polymeric films to influence the alignment, morphology and transdifferentiation of bone marrow-derived rat mesenchymal stem cells (MSCs) towards a Schwann cell-like fate. Two different types of polymers, biocompatible polystyrene (PS) and biodegradable poly(lactic acid) (PLA) were used to fabricate patterned films. Percentages of transdifferentiated MSCs (tMSCs) immunolabeled with SC markers (α-S100β and α-p75(NTR)) were found to be similar on patterned versus smooth PS and PLA substrates. However, patterning had a significant effect on the alignment and elongation of the tMSCs. More than 80% of the tMSCs were oriented in the direction of microgrooves (0°-20°), while cells on the smooth substrates were randomly oriented. The aspect ratio [AR, ratio of length (in direction of microgrooves) and breadth (in direction perpendicular to microgrooves)] of the tMSCs on patterned substrates had a value of approximately five, as compared to cells on smooth substrates where the AR was one. Understanding responses to these cues invitro helps us in understanding the behavior and interaction of the cells with the 3D environment of the scaffolds, facilitating the application of these concepts to designing effective nerve guidance conduits for peripheral nerve regeneration.

Reducing Water Vapor Permeability of Poly(lactic acid) Film and Bottle through Layer-by-Layer Deposition of Green-Processed Cellulose Nanocrystals and Chitosan

Layer-by-layer electrostatic self-assembly technique was applied to improve the barrier properties of poly(lactic acid) (PLA) films and bottles. The LbL process was carried out by the alternate adsorption of chitosan (CH) (polycation) and cellulose nanocrystals (CNC) produced via ultrasonic treatment. Four bilayers (on each side) of chitosan and cellulose nanocrystals caused 29 and 26% improvement in barrier properties in case of films and bottles, respectively. According to the results the LbL process with CH and CNC offered a transparent “green” barrier coating on PLA substrates.

Production of outer membrane vesicles by the plague pathogen Yersinia pestis.

Many Gram-negative bacteria produce outer membrane vesicles (OMVs) during cell growth and division, and some bacterial pathogens deliver virulence factors to the host via the release of OMVs during infection. Here we show that Yersinia pestis, the causative agent of the disease plague, produces and releases native OMVs under physiological conditions. These OMVs, approximately 100 nm in diameter, contain multiple virulence-associated outer membrane proteins including the adhesin Ail, the F1 outer fimbrial antigen, and the protease Pla. We found that OMVs released by Y. pestis contain catalytically active Pla that is competent for plasminogen activation and α2-antiplasmin degradation. The abundance of OMV-associated proteins released by Y. pestis is significantly elevated at 37°C compared to 26°C and is increased in response to membrane stress and mutations in RseA, Hfq, and the major Braun lipoprotein (Lpp). In addition, we show that Y. pestis OMVs are able to bind to components of the extracellular matrix such as fibronectin and laminin. These data suggest that Y. pestis may produce OMVs during mammalian infection and we propose that dispersal of Pla via OMV release may influence the outcome of infection through interactions with Pla substrates such as plasminogen and Fas ligand.