Fused Deposition Modeling Enables the Low-Cost Fabrication of Porous, Customized-Shape Sorbents for Small-Molecule Extraction

3D Printing and Blue Sustainability: Taking Advantage of Process-Induced Defects for the Metallic Ion Removal from Water

Additive manufacturing (AM), commonly known as 3D printing, allows for the manufacturing of complex systems that are not possible using traditional manufacturing methods. Nevertheless, some disadvantages are attributed to AM technologies. One of the most often referred to is the defects of the produced components, particularly the porosity. One approach to solving this problem is to consider it as a non-problem, i.e., taking advantage of the defects. Commercially, LAY-FOMM®60 polymer was successfully used in AM through a material extrusion process. This filament is a blend of two polymers, one of them soluble in water, allowing, after its removal from the printed components, the increase in porosity. The defects produced were exploited to evaluate the metallic ion removal capacity of manufactured components using non-potable tap water. Two experimental setups, continuous and ultrasound-assisted methods, were compared, concerning their water cleaning capacity. Results revealed that continuous setup presented the highest metallic ion removal capacity (>80%) for the following three studied metallic ions: iron, copper, and zinc. High water swelling capacity (~80%) and the increase in porosity of 3D-printed parts played a significant role in the ion sorption capacity. The developed strategy could be considered a custom and affordable alternative to designing complex filtration/separation systems for environmental and wastewater treatment applications.

Miniaturized 3D-printed hand-operable dispersive sample pretreatment device with replaceable chitosan/polydopamine thin film metal sorbent for enhanced metal analysis

To address the increasing demand for sensitive and selective sample preparation methods for metal analysis; preconcentration of intended analyte from complex sample matrices before analysis is required to improve the performance of analysis instruments. In this study, we have engineered a sustainable and portable syringe-based hand-operable three-dimensionally (3D) printed sample pretreatment apparatus equipped with a replaceable bio-based thin- film metal sorbent. This device effectively addresses the challenges of sample matrix interference in metal analysis. A metal sorbent film composed of chitosan (CS) and polydopamine (PDA) leveraged the diverse functional groups in the CS/PDA matrix to significantly enhance the extraction efficiency for various metals. Our approach demonstrated excellent analytical performance, with coefficients of determination (R2) of 0.9982 for copper (Cu) and 0.996 for chromium (Cr). The method achieved low limits of detection (LOD) of 0.3 μg L-1 for Cr and 0.7 μg L-1 for Cu. Precision and practicality assessments using actual urine samples yielded satisfactory relative standard deviations (RSD%) ranging from of 1.6 %-8.5 % for both metals, indicating minimal interference from the sample matrix. Moreover, our approach exhibited robust performance even after seven consecutive extraction and desorption cycles, highlighting its sustainability and practical applicability for laboratory and on-site sample pretreatment.

Technological Advancement and Trend in Selective Bioanalytical Sample Extraction through State of the Art 3-D Printing Techniques Aiming 'Sorbent Customization as per need'

The inherent complexity of biological matrices and presence of several interfering substances in biological samples make them unsuitable for direct analysis. An effective sample preparation technique assists in analyte enrichment, improving selectivity and sensitivity of bioanalytical method. Because of several key benefits of employing 3D printed sorbent in sample extraction, it has recently gained popularity across a variety of industries. Applications for 3D printing in the field of bioanalytical research have grown recently, particularly in the areas of miniaturization, (bio)sensing, sample preparation, and separation sciences. Due to the high expense of the solid phase microextraction cartridge, researcher approaches in-lab production of sorbent material for the extraction of analyte from biological samples. Owing to its distinct advantages such as low costs, automation capabilities, capacity to produce products in a variety of shapes, and reduction of tedious steps of sample preparation, 3D printed sorbents are gaining increased attention in the field of bioanalysis. It is also reported to offer high selectivity and assist in achieving a much lower limit of detection. In this review, we have discussed current advancements in different types of 3D printed sorbents, production methods, and their applications in the field of bioanalytical sample preparation.

Application of three-dimensional printing technology in environmental analysis: A review

The development of environmental analysis devices with high performance is essential to assess the potential risks of environmental pollutants. However, it is still challenging to develop environmental analysis equipment with miniaturization, portability, and high sensitivity based on traditional processing techniques. In recent years, the popularity of 3D printing technology (3DP) with high precision, low cost, and unlimited design freedom has provided opportunities to solve the existing challenges of environmental analysis. 3D printing has brought solutions to promote the high performance and versatility of environmental analysis equipment by optimizing printing materials, enhancing equipment structure, and integrating multidisciplinary technology. In this paper, we comprehensively review the latest progress in 3D printing in various aspects of environmental analysis procedures, including but not limited to sample collection, pretreatment, separation, and detection. We highlight their advantages and challenges in determining various environmental contaminants through passive sampling, solid-phase extraction, chromatographic separation, and mass spectrometry detection. The manufacturing of 3D-printed environmental analysis devices is also discussed. Finally, we look forward to their development prospects and challenges.

3D printed stir bar sorptive extraction coupled with high performance liquid chromatography for trace estrogens analysis in environmental water samples

BACKGROUND

Any imaginary shape with good preparation reproducibility can be made by 3D printing technology, and it has been applied in various fields. Comparatively, its applications in sample pre-treatment are relatively less, most of which involves making extraction sorbents and producing non-functionalized devices for support assistance. 3D printing has not been applied to fabricate stir bars in stir bar sorptive extraction, mainly due to the lacking of suitable printing feedstocks. This work aimed to fabricate stir bars by 3D printing, reducing the manufacturing cost and steps and improving preparation reproducibility. (90) RESULTS: By using fused deposition modeling technique and porous filament printing feedstock, stir bars were fabricated without any modifications. Adsorption performance of 3D printed stir bars were investigated for substances with different structures and polarities. Five estrogens with adsorption efficiencies of over 80 % were selected as the representatives. The 3D printed stir bars exhibited good preparation reproducibility (2.9-4.4 %) and higher extraction recoveries (73-81 %) for five estrogens than commercial polydimethylsiloxane coated stir bars (13-69 %) in a shorter time (90 vs 120 min). They showed long lifespan (160 times) with good mechanical properties and merited reduced manufacturing cost (0.064 $ per bar) and manual operation. A method of stir bar sorptive extraction coupled with high performance liquid chromatography was proposed for trace analysis of estrogens in environmental water. Under the optimized conditions, the linear ranges for estrogens were 0.5-200 μg/L with LODs of 0.13-0.17 μg/L. (136) SIGNIFICANCE: The feasibility of fused deposition modeling in stir bar fabrication was demonstrated, along with the potential of porous filament printing feedstock as the sorbent for substances with medium polarity. 3D printed stir bars were featured with excellent preparation reproducibility, long lifespan, and good mechanical properties. The stir bar fabrication method can be used for mass production with minimal differences in products performance. (62).

Innovative, simple, and green: A sample preparation method based on 3D printed polymers

The present study evaluates the capability of fifteen 3D printed thermoplastic polymers as novel stationary phases for the extraction of forty-three physicochemically diverse analytes from fortified human oral fluid samples. Prototype extraction devices were prepared in 96-well plate-compatible format using fused deposition modeling 3D printer. The sample preparation was performed with 5-step protocol utilizing 96-well plates and semiautomated benchtop shaker. All resulting extracts were analyzed via high-performance liquid chromatography (operated in reversed-phase gradient elution mode) and tandem mass spectrometry (with electrospray ionization and triple quadrupole mass spectrometer). Exceptionally favorable results were observed for three polymer types: polyamide 6 (reinforced with 15% carbon fiber), LAYFOMM-60 (polyurethane with water-soluble polyvinyl alcohol), and S-FLEX 90A (thermoplastic polyurethane). Furthermore, this study also introduces an automated and repeatable 3D printing method for the fast fabrication of high-throughput, and highly selective sample preparation devices, most of which are ready-to-use without any additional processing or chemical functionalization. As such, the proposed printing method represents a significant step towards the introduction of novel polymeric stationary phases for analytical sample preparation, thus providing laboratory personnel with a method that is safer and more convenient, while minimizing negative environmental impacts.

Application of three dimensional-printed devices in extraction technologies

Sample pretreatment is an important and necessary process in chemical analysis. Traditional sample preparation methods normally consume moderate to large quantities of solvents and reagents, are time- and labor-intensive and can be prone to error (since they usually involve multiple steps). In the past quarter century or so, modern sample preparation techniques have evolved, from the advent of solid-phase microextraction and liquid-phase microextraction to the present day where they are now widely applied to extract analytes from simple as well as complex matrices leveraging on their extremely low solvent consumption, high extraction efficiency, generally straightforward and simple operation and integration of most, if not all, of the following aspects: Sampling, cleanup, extraction, preconcentration and ready-to-inject status of the final extract. One of the most interesting features of the progress of microextraction techniques over the years lies in the development of devices, apparatus and tools to facilitate and improve their operations. This review explores the application of a recent material fabrication technology that has been receiving a lot of interest, that of three-dimensional (3D) printing, to the manipulation of microextraction. The review highlights the use of 3D-printed devices in the extraction of various analytes and in different methods to address, and improves upon some current extraction (and microextraction) problems, issues and concerns.

Analysis of NSAIDs in Rat Plasma Using 3D-Printed Sorbents by LC-MS/MS: An Approach to Pre-Clinical Pharmacokinetic Studies

Analytical sample preparation techniques are essential for assessing chemicals in various biological matrices. The development of extraction techniques is a modern trend in the bioanalytical sciences. We fabricated customized filaments using hot-melt extrusion techniques followed by fused filament fabrication-mediated 3D printing technology to rapidly prototype sorbents that extract non-steroidal anti-inflammatory drugs from rat plasma for determining pharmacokinetic profiles. The filament was prototyped as a 3D-printed sorbent for extracting small molecules using AffinisolTM, polyvinyl alcohol, and triethyl citrate. The optimized extraction procedure and parameters influencing the sorbent extraction were systematically investigated by the validated LC-MS/MS method. Furthermore, a bioanalytical method was successfully implemented after oral administration to determine the pharmacokinetic profiles of indomethacin and acetaminophen in rat plasma. The Cmax was found to be 0.33 ± 0.04 µg/mL and 27.27 ± 9.9 µg/mL for indomethacin and acetaminophen, respectively, at the maximum time (Tmax) (h) of 0.5–1 h. The mean area under the curve (AUC0–t) for indomethacin was 0.93 ± 0.17 µg h/mL, and for acetaminophen was 32.33± 10.8 µg h/mL. Owing to their newly customizable size and shape, 3D-printed sorbents have opened new opportunities for extracting small molecules from biological matrices in preclinical studies.

Analytical Chemistry: Tasks, Resolutions and Future Standpoints of the Quantitative Analyses of Environmental Complex Sample Matrices

Currently, the challenges that analytical chemistry has to face are ever greater and more complex both from the point of view of the selectivity of analytical methods and their sensitivity. This is especially true in quantitative analysis, where various methods must include the development and validation of new materials, strategies, and procedures to meet the growing need for rapid, sensitive, selective, and green methods. In this context, given the International Guidelines, which over time, are updated and which set up increasingly stringent “limits”, constant innovation is required both in the pre-treatment procedures and in the instrumental configurations to obtain reliable, accurate, and reproducible information. In addition, the environmental field certainly represents the greatest challenge, as analytes are often present at trace and ultra-trace levels. These samples containing analytes at ultra-low concentration levels, therefore, require very labor-intensive sample preparation procedures and involve the high consumption of organic solvents that may not be considered “green”. In the literature, in recent years, there has been a strong development of increasingly high-performing sample preparation techniques, often “solvent-free”, as well as the development of hyphenated instrumental configurations that allow for reaching previously unimaginable levels of sensitivity. This review aims to provide an update of the most recent developments currently in use in sample pre-treatment and instrument configurations in the environmental field, also evaluating the role and future developments of analytical chemistry in light of upcoming challenges and new goals yet to be achieved.

Polyamide Noncoated Device for Adsorption-Based Microextraction and Novel 3D Printed Thin-Film Microextraction Supports

Polyamide noncoated device for adsorption-based microextraction (PANDA microextraction) is a brand new, easy to prepare, environmentally friendly, inexpensive, and efficient sample preparation method created entirely with the use of 3D printing. The proposed method is based on the extractive proprieties of the unmodified polyamide and carbon fiber blends and is compared with the highly selective thin-film microextraction (TFME). In addition, 3D printing was used to simplify the process of TFME. Prototype sample preparation devices were evaluated by the extraction of oral fluid spiked with 38 small molecules with diverse chemical natures, such as lipophilicity in the log P range of 0.2–7.2. The samples were analyzed by high-performance liquid chromatography coupled with tandem mass spectrometry. The results indicate that chemically and thermally resistant 3D printed supports can be successfully used as a cost-saving, environmentally friendly solution for the preparation of TFME devices, alternative to the conventional metal supports, with only marginal differences in the extraction yield (mean = 4.0%, median = 1.8%, range = 0.0–22.3%, n = 38). Even more remarkably, in some cases, the newly proposed PANDA microextraction method exceeded the reference TFME in terms of the extraction efficacy and offered excellent sample cleanup as favorable matrix effects were observed (mean = −8.5%, median = 7.5%, range = −34.7–20.0%, n = 20). This innovative approach paves the road to the simplified sample preparation with the use of emerging extractive 3D printing polymers.

Research progress on the biological modifications of implant materials in 3D printed intervertebral fusion cages

Anterior spine decompression and reconstruction with bone grafts and fusion is a routine spinal surgery. The intervertebral fusion cage can maintain intervertebral height and provide a bone graft window. Titanium fusion cages are the most widely used metal material in spinal clinical applications. However, there is a certain incidence of complications in clinical follow-ups, such as pseudoarticulation formation and implant displacement due to nonfusion of bone grafts in the cage. With the deepening research on metal materials, the properties of these materials have been developed from being biologically inert to having biological activity and biological functionalization, promoting adhesion, cell differentiation, and bone fusion. In addition, 3D printing, thin-film, active biological material, and 4D bioprinting technology are also being used in the biofunctionalization and intelligent advanced manufacturing processes of implant devices in the spine. This review focuses on the biofunctionalization of implant materials in 3D printed intervertebral fusion cages. The surface modifications of implant materials in metal endoscopy, material biocompatibility, and bioactive functionalizationare summarized. Furthermore, the prospects and challenges of the biofunctionalization of implant materials in spinal surgery are discussed. Fig.a.b.c.d.e.f.g As a pre-selected image for the cover, I really look forward to being selected. Special thanks to you for your comments.

Efficient Removal of Organic Contaminants from Aqueous Solution by Highly Compressible Reusable Three-Dimensional Printing Sponges

Adsorption is considered to be one of the most effective and economically viable technologies for removing contaminants from the environment. However, the disadvantages of its high-cost complicated process and difficulty in efficient recycling limit its practical application. Herein, a thermoplastic elastomer-polyvinyl alcohol composite (LAY-FOMM 60) sponge three-dimensional structure (3D printing sponge) was fabricated by the fused filament fabrication combined with water erosion technique. The size and shape of the resultant sponge were tailored, and the batch of adsorption/desorption experiments of Rhodamine B (RhB) onto the sponge was performed. The results show that the adsorption of RhB on the 3D printing sponge was mainly via physical adsorption, and pseudo-second-order and Langmuir models exhibited good correlation with the adsorption kinetic and isotherm data, respectively. Thermodynamic parameters suggest that the adsorption is an endothermic and spontaneous process. It is worth to note that the adsorption/desorption efficiency can be raised by compression. This results in high efficiency and low cost for adsorption/desorption process and benefit for regeneration of the adsorbent. The adsorption capacity was maintained over 85% of the initial capacity after being used for five cycles. The approach provides a simple strategy for manufacturing customizable porous adsorbent materials that meet various water treatment requirements.

Extraction of small molecule from human plasma by prototyping 3D printed sorbent through extruded filament for LC-MS/MS analysis

Analytical sample preparation techniques are regarded as crucial steps for analyzing compounds from different biological matrices. The development of new extraction techniques is a modern trend in the bioanalytical sciences. 3D printed techniques have emerged as a valuable technology for prototyping devices in customized shapes for a cost-effective way to advance analytical sample preparation techniques. The present study aims to fabricate customized filaments through the hot-melt extrusion (HME) technique followed by fused deposition modeling mediated 3D printing process for rapid prototyping of 3D printed sorbents to extract a sample from human plasma. Thus, we fabricated our own indigenous filament using poly (vinyl alcohol), Eudragit® RSPO, and tri-ethyl citrate through HME to prototype the fabricated filament into a 3D printed sorbent for the extraction of small molecules. The 3D sorbent was applied to extract hydrocortisone from human plasma and analyzed using a validated LC-MS/MS method. The extraction procedure was optimized, and the parameters influencing the sorbent extraction were systematically investigated. The extraction recovery of hydrocortisone was found to be >82% at low, medium, and high quality control samples, with a relative standard deviation of <2%. The intra-and inter-day precisions for hydrocortisone ranged from 1.0% to 12% and 2.0%-10.0%, respectively, whereas the intra-and inter-day accuracy for hydrocortisone ranged from 93.0% to 111.0% and 92.0% to 110.0%, respectively. The newly customizable size and shape of the 3D printed sorbent opens new possibilities for extracting small molecules from human plasma.

3D-Printing to Mitigate COVID-19 Pandemic

3D-printing technology provided numerous contributions to the health sector during the recent Coronavirus disease 2019 (COVID-19) pandemic. Several of the 3D-printed medical devices like personal protection equipment (PPE), ventilators, specimen collectors, safety accessories, and isolation wards/ chambers were printed in a short time as demands for these were rising significantly. The review discusses some of these contributions of 3D-printing that helped to protect several lives during this health emergency. By enlisting some of the significant benefits of using the 3D-printing technique during an emergency over other conventional methods, this review claims that the former opens enormous possibilities in times of serious shortage of supply and exceeding demands. This review acknowledges the collaborative approaches adopted by individuals, entrepreneurs, academicians, and companies that helped in forming a global network for delivering 3D-printed medical/non-medical components, when other supply chains were disrupted. The collaboration of the 3D-printing technology with the global health community unfolds new and significant opportunities in the future.

Development and Characterization of Rice Husk and Recycled Polypropylene Composite Filaments for 3D Printing

Nowadays the use of natural fiber composites has gained significant interest due to their low density, high availability, and low cost. The present study explores the development of sustainable 3D printing filaments based on rice husk (RH), an agricultural residue, and recycled polypropylene (rPP) and the influence of fiber weight ratio on physical, thermal, mechanical, and morphological properties of 3D printing parts. Thermogravimetric analysis revealed that the composite's degradation process started earlier than for the neat rPP due to the lignocellulosic fiber components. Mechanical tests showed that tensile strength increased when using a raster angle of 0° than specimens printed at 90°, due to the weaker inter-layer bonding compared to in-layer. Furthermore, inter layer bonding tensile strength was similar for all tested materials. Scanning electron microscope (SEM) images revealed the limited interaction between the untreated fiber and matrix, which led to reduced tensile properties. However, during the printing process, composites presented lower warping than printed neat rPP. Thus, 3D printable ecofriendly natural fiber composite filaments with low density and low cost can be developed and used for 3D printing applications, contributing to reduce the impact of plastic and agricultural waste.

Low-cost and open-source strategies for chemical separations

In recent years, a trend toward utilizing open access resources for laboratory research has begun. Open-source design strategies for scientific hardware rely upon the use of widely available parts, especially those that can be directly printed using additive manufacturing techniques and electronic components that can be connected to low-cost microcontrollers. Open-source software eliminates the need for expensive commercial licenses and provides the opportunity to design programs for specific needs. In this review, the impact of the "open-source movement" within the field of chemical separations is described, primarily through a comprehensive look at research in this area over the past five years. Topics that are covered include general laboratory equipment, sample preparation techniques, separations-based analysis, detection strategies, electronic system control, and software for data processing. Remaining hurdles and possible opportunities for further adoption of open-source approaches in the context of these separations-related topics are also discussed.

Functional 3D printing: Approaches and bioapplications

3D printing technology has become a mature manufacturing technique, widely used for its advantages over the traditional methods, such as the end-user customization and rapid prototyping, useful in different application fields, including the biomedical one. Indeed, it represents a helpful tool for the realization of biodevices (i.e. biosensors, microfluidic bioreactors, drug delivery systems and Lab-On-Chip). In this perspective, the development of 3D printable materials with intrinsic functionalities, through the so-called 4D printing, introduces novel opportunities for the fabrication of "smart" or stimuli-responsive devices. Indeed, functional 3D printable materials can modify their surfaces, structures, properties or even shape in response to specific stimuli (such as pressure, temperature or light radiation), adding to the printed object new interesting properties exploited after the fabrication process. In this context, by combining 3D printing technology with an accurate materials' design, functional 3D objects with built-in (bio)chemical functionalities, having biorecognition, biocatalytic and drug delivery capabilities are here reported.

3D Printed Polyurethane Scaffolds for the Repair of Bone Defects

Critical-size bone defects are those that will not heal without intervention and can arise secondary to trauma, infection, and surgical resection of tumors. Treatment options are currently limited to filling the defect with autologous bone, of which there is not always an abundant supply, or ceramic pastes that only allow for limited osteo-inductive and -conductive capacity. In this study we investigate the repair of bone defects using a 3D printed LayFomm scaffold. LayFomm is a polymer blend of polyvinyl alcohol (PVA) and polyurethane (PU). It can be printed using the most common method of 3D printing, fused deposition modeling, before being washed in water-based solutions to remove the PVA. This leaves a more compliant, micro-porous PU elastomer. In vitro analysis of dental pulp stem cells seeded onto macro-porous scaffolds showed their ability to adhere, proliferate and form mineralized matrix on the scaffold in the presence of osteogenic media. Subcutaneous implantation of LayFomm in a rat model showed the formation of a vascularized fibrous capsule, but without a chronic inflammatory response. Implantation into a mandibular defect showed significantly increased mineralized tissue production when compared to a currently approved bone putty. While their mechanical properties are insufficient for use in load-bearing defects, these findings are promising for the use of polyurethane scaffolds in craniofacial bone regeneration.

Understanding performance of 3D-printed sorbent in study of metabolic stability

Metabolic stability tests are one of the fundamental steps at the preclinical stages of new drug development. Microsomes, used as a typical enzymatic model of liver biotransformation, can be a challenging matrix for analytical scientists due to a high concentration of cellular proteins and membrane lipids. In the work, we propose a new procedure integrating biotransformation reaction with SPME-like protocol for sample clean-up. It is beneficial to increase the overall quality of results in contrary to the typical protein precipitation approach. A set of ten arylpiperazine analogs, six of which are considered promising drug candidates (and four are accepted drugs) were used as a probe to assess the goodness of the newly proposed approach. In order to promote an efficient extraction protocol, a new, miniaturized shape of a sorbent, suitable to perform the extraction in 100 µL of the sample has been designed. Termination of the biotransformation process by protein denaturation with hot water was additionally evaluated. A quantitative structure-property relationship (QSPR) study using Orthogonal Partial Least Squares (OPLS) technique to reveal insights to the sorption mechanism was also performed. The obtained results showed the new 3D-printed sorbent can be an attractive basis for the new sample preparation approach for metabolic stability studies and an alternative for commercially available protocols based on solid-phase microextraction (SPME) or solid-phase extraction (SPE) principles.

The impact of 3D-printed LAY-FOMM 40 and LAY-FOMM 60 on L929 cells and human oral fibroblasts

Objectives

LAY-FOMM is a promising material for FDA-approved Fused Deposition Modeling (FDM) applications in drug delivery. Here we investigated the impact on oral cells.

Materials and methods

We evaluated the impact of 3D-printed LAY-FOMM 40, LAY-FOMM 60, and biocompatible polylactic acid (PLA) on the activity of murine L929 cells, gingival fibroblasts (GF), and periodontal ligament fibroblasts (PDLF) using indirect (samples on cells), direct monolayer culture models (cells on samples), and direct spheroid cultures with resazurin-based toxicity assay, confirmed by MTT and Live-dead staining. The surface topography was evaluated with scanning electron microscopy.

Results

The materials LAY-FOMM 40 and LAY-FOMM 60 led to a reduction in resazurin conversion in L929 cells, GF, and PDLF, higher than the impact of PLA in indirect and direct culture models. Fewer vital cells were found in the presence of LAY-FOMM 40 and 60 than PLA, in the staining in both models. In the direct model, LAY-FOMM 40 and PLA showed less impact on viability in the resazurin-based toxicity assay than in the indirect model. Spheroid microtissues showed a reduction of cell activity of GF and PDLF with LAY-FOMM 40 and 60.

Conclusion

Overall, we found that LAY-FOMM 40 and LAY-FOMM 60 can reduce the activity of L292 and oral cells. Based on the results from the PLA samples, the direct model seems more reliable than the indirect model.

Clinical relevance

A material modification is desired in terms of biocompatibility as it can mask the effect of drugs and interfere with the function of the 3D-printed device.

3D printing in analytical chemistry: current state and future

The rapid development of additive technologies in recent years is accompanied by their intensive introduction into various fields of science and related technologies, including analytical chemistry. The use of 3D printing in analytical instrumentation, in particular, for making prototypes of new equipment and manufacturing parts having complex internal spatial configuration, has been proved as exceptionally effective. Additional opportunities for the widespread introduction of 3D printing technologies are associated with the development of new optically transparent, current- and thermo-conductive materials, various composite materials with desired properties, as well as possibilities for printing with the simultaneous combination of several materials in one product. This review will focus on the application of 3D printing for production of new advanced analytical devices, such as compact chromatographic columns for high performance liquid chromatography, flow reactors and flow cells for detectors, devices for passive concentration of toxic compounds and various integrated devices that allow significant improvements in chemical analysis. A special attention is paid to the complexity and functionality of 3D-printed devices.

3D-Printed Column with Porous Monolithic Packing for Online Solid-Phase Extraction of Multiple Trace Metals in Environmental Water Samples

In this study, we used a multimaterial three-dimensional printing (3DP) technology and porous composite filaments (Lay-Fomm, Gel-Lay, and Lay-Felt) to fabricate solid phase extraction (SPE) columns for the enhanced extraction of multiple metal ions. When employed as sample pretreatment devices in an automatic flow injection analysis/inductively coupled plasma mass spectrometry (ICP-MS) system, these 3D-printed SPE columns performed the near-complete extractions of Mn, Co, Ni, Cu, Zn, Cd, and Pb ions from natural water samples prior to ICP-MS determination. After optimizing the column fabrication, the extraction conditions, and the automatic analysis system, the column packed with the porous composite Lay-Fomm 40 was found to provide the highest extraction performance-the extraction efficiencies of the listed metal ions were all greater than 99.2%, and the detection limits of the method ranged from 0.3 to 6.7 ng L^-1. The detection of these metal ions in several reference materials (CASS-4, SLEW-3, 1640a, and 1643f) validated the reliability of this method; spike analyses of collected water samples (groundwater, river water, and seawater) demonstrated the applicability of the method. The nature of the printing materials enhanced the analytical performance of 3D-printed sample pretreatment devices. Such approaches will be useful to diversify the range of sample preparation schemes and analytical methods enabled by 3DP technologies.

3D Printing in analytical sample preparation

In the last 5 years, additive manufacturing (three-dimensional printing) has emerged as a highly valuable technology to advance the field of analytical sample preparation. Three-dimensional printing enabled the cost-effective and rapid fabrication of devices for sample preparation, especially in flow-based mode, opening new possibilities for the development of automated analytical methods. Recent advances involve membrane-based three-dimensional printed separation devices fabricated by print-pause-print and multi-material three-dimensional printing, or improved three-dimensional printed holders for solid-phase extraction containing sorbent bead packings, extraction disks, fibers, and magnetic particles. Other recent developments rely on the direct three-dimensional printing of extraction sorbents, the functionalization of commercial three-dimensional printable resins, or the coating of three-dimensional printed devices with functional micro/nanomaterials. In addition, improved devices for liquid-liquid extraction such as extraction chambers, or phase separators are opening new possibilities for analytical method development combined with high-performance liquid chromatography. The present review outlines the current state-of-the-art of three-dimensional printing in analytical sample preparation.

Revealing interactions of layered polymeric materials at solid-liquid interface for building solvent compatibility charts for 3D printing applications

Poor stability of 3D printed plastic objects in a number of solvents limits several important applications in engineering, chemistry and biology. Due to layered type of assembling, 3D-printed surfaces possess rather different properties as compared to bulk surfaces made by other methods. Here we study fundamental interactions at the solid-liquid interface and evaluate polymeric materials towards advanced additive manufacturing. A simple and universal stability test was developed for 3D printed parts and applied to a variety of thermoplastics. Specific modes of resistance/destruction were described for different plastics and their compatibility to a representative scope of solvents (aqueous and organic) was evaluated. Classification and characterization of destruction modes for a wide range of conditions (including geometry and 3D printing parameters) were carried out. Key factors of tolerance to solvent media were investigated by electron microscopy. We show that the overall stability and the mode of destruction depend on chemical properties of the polymer and the nature of interactions at the solid-liquid interface. Importantly, stability also depends on the layered microstructure of the sample, which is defined by 3D printing parameters. Developed solvent compatibility charts for a wide range of polymeric materials (ABS, PLA, PLA-Cu, PETG, SBS, Ceramo, HIPS, Primalloy, Photoresin, Nylon, Nylon-C, POM, PE, PP) and solvents represent an important benchmark for practical applications.

Application of 3D-printed scabbard-like sorbent for sample preparation in bioanalysis expanded to 96-wellplate high-throughput format

Modern bioanalysis, which involves the quantitative and qualitative determination of small-molecule endogenous and exogenous substances in biological samples, is a powerful and useful tool that can generate valuable information related to many areas connected with human health and quality of life. Although LC-MS and GC-MS are widely viewed as the gold standards for many bioanalytical tasks, the scientific community has not abandoned its search for newer, more efficient, and more inexpensive methods of performing extraction as a sample preparation step before final analysis. Recent research showing the immense potential of 3D printing compelled our group to explore how this technology could be applied to techniques used in analytical chemistry. In particular, 3D printing offers three promising advantages: availability, low cost of materials and equipment, and the ability to fabricate objects of nearly any shape to suit the needs of a given application. Previously, we demonstrated that a commercial 3D material (LAY-FOMM) can function as a chemically active object that enables the reversible sorption of the antidiabetic drug, glimepiride, and endogenous steroids. In this report, we use a 3D printer to fabricate sorbents with a scabbard-like shape for use with a 96-blade system, which, along with the use of a 96-well plate, allows multiple extractions to be performed simultaneously. In order to assess the relative benefits of this 3D printed approach, we compare the performance of the proposed LAY-FOMM-based sorbent to that of the widely used C18 sorbent. Although the LAY-FOMM sorbent showed lower extraction recovery rates than the C18 sorbent, all of the other validation parameters suggest that it is suitable for use in high-throughput analysis of steroids in human plasma.

Advances in personalized treatment of metastatic spine disease

The spine is one of the most common sites of bony metastases, and its involvement leads to significant patient morbidity. Surgical management in these patients is aimed at improving quality of life and functional status throughout the course of the disease. Resection of metastases often leads to critical size bone defects, presenting a challenge to achieving adequate bone regeneration to fill the void. Current treatment options for repairing these defects are bone grafting and commercial bone cements; however, each has associated limitations. Additionally, tumor recurrence and tumor-induced bone loss make bone regeneration particularly difficult. Systemic therapeutic delivery, such as bisphosphonates, have become standard of care to combat bone loss despite unfavorable systemic side-effects and lack of local efficacy. Developments from tissue engineering have introduced novel materials with osteoinductive and osteoconductive properties which also act as structural support scaffolds for bone regeneration. These new materials can also act as a therapeutic reservoir to sustainably release drugs locally as an alternative to systemic therapy. In this review, we outline recent advancements in tissue engineering and the role of translational research in developing implants that can fully repair bone defects while also delivering local therapeutics to curb tumor recurrence and improve patient quality of life.

Direct photoimmobilization of extraction disks on "green state" 3D printed devices

Post-curing is essential to improve the mechanical properties of 3D printed parts fabricated by stereolithography (SLA), since right after 3D printing they remain in a "green state". It means that the 3D printed parts have reached their final shape, but the polymerization reaction has not been yet completed. Herein, we take advantage of the tacky partially polymerized surface of "green state" SLA 3D printed parts to immobilize extraction disks and miniature magnets, which after UV post-curing, become permanently attached to the 3D printed part resulting in a rotating-disk sorptive extraction device (RDSE). The developed "stick & cure" procedure is reagent-free and does not require any additional preparation time, specialized skills, or instrumentation. As proof of concept, 3D printed RDSE devices with immobilized chelating disks have been applied to the simultaneous extraction of 14 trace metals prior to ICP-OES determination, featuring LODs between 0.03 and 1.27 μg L^-1, and an excellent device-to-device reproducibility (n = 5, RSD = 2.7-8.3%). The developed method was validated using certified wastewater and soil reference samples, and satisfactory spiking recoveries were obtained in the analysis of highly polluted solid waste treatment plant leachates (89-110%). In addition, exploiting the versatility of 3D printing, nine RDSE devices with different shapes were fabricated. Their performance was evaluated and compared for the fast extraction of the highly toxic Cr (VI) as its 1,5-diphenylcarbazide complex in reversed-phase mode, showing different extraction performance on depending on the shape of the 3D printed RDSE device.

Advances in Optical Sensing and Bioanalysis Enabled by 3D Printing

The recent explosion of 3D printing applications in scientific literature has expanded the speed and effectiveness of analytical technological development. 3D printing allows for manufacture that is simply designed in software and printed in-house with nearly no constraints on geometry, and analytical methodologies can thus be prototyped and optimized with little difficulty. The versatility of methods and materials available allows the analytical chemist or biologist to fine-tune both the structural and functional portions of their apparatus. This flexibility has more recently been extended to optical-based bioanalysis, with higher resolution techniques and new printing materials opening the door for a wider variety of optical components, plasmonic surfaces, optical interfaces, and biomimetic systems that can be made in the laboratory. There have been discussions and reviews of various aspects of 3D printing technologies in analytical chemistry; this Review highlights recent literature and trends in their applications to optical sensing and bioanalysis.

Increasing the functionalities of 3D printed microchemical devices by single material, multimaterial, and print-pause-print 3D printing

3D printing has emerged as a valuable approach for the fabrication of fluidic devices and may replace soft-lithography as the method of choice for rapid prototyping. The potential of this disruptive technology is much greater than this - it allows for functional integration in a single, highly automated manufacturing step in a cost and time effective manner. Integration of functionality with a 3D printer can be done through spatial configuration of a single material, inserting pre-made components mid-print in a print-pause-print approach, and/or through the precise spatial deposition of different materials with a multimaterial printer. This review provides an overview on the ways in which 3D printing has been exploited to create and use fluidic devices with different functionality, which provides a basis for critical reflection on the current deficiencies and future opportunities for integration by 3D printing.

Multimaterial 3D Printed Fluidic Device for Measuring Pharmaceuticals in Biological Fluids

Multimaterial 3D printing provides a unique capability for the creation of highly complex integrated devices where complementary functionality is realized using differences in material properties. Using a single and automated print process, microfluidic devices were fabricated containing (i) an optically transparent structure for fluorescence detection, (ii) electrodes for electrokinetic transport, (iii) a primary membrane to remove particulates and macromolecules including proteins, and (iv) a secondary membrane to concentrate small molecule targets. The device was used for the simultaneous extraction and concentration of small molecule pharmaceuticals from urine, which was followed by an on-chip electrophoretic separation of the concentrated targets for quantitative analysis. Owing to the high level of functional integration inside the device, manual handling was minimal and restricted to the introduction of the sample and buffer solutions. The 3D printed sample-in/answer-out device allowed the direct quantification of ampicillin-a small molecule pharmaceutical-in untreated urine within 3 min, down to 2 ppm. These results demonstrate the potential of 3D printing for on-demand fabrication of disposable, functionally integrated devices for low-cost point-of-collection (POC) diagnostics.

Low-Cost Passive Sampling Device with Integrated Porous Membrane Produced Using Multimaterial 3D Printing

Multimaterial 3D printing facilitates the rapid production of complex devices with integrated materials of varying properties and functionality. Herein, multimaterial fused deposition modeling (MM-FDM) 3D printing was applied to the fabrication of low-cost passive sampler devices with integrated porous membranes. Using MM-FDM 3D printing, the device body was produced using black polylactic acid, with Poro-Lay Lay-Felt filament used for the printing of the integrated porous membranes (rubber-elastomeric polymer, porous after removal of a water-soluble poly(vinyl alcohol) component). The resulting device consisted of two interlocking circular frames, each containing the integrated membrane, which could be efficiently sealed together without the need for additional O-rings, and prevented loss of enclosed microparticulate sorbent. Scanning electron microscopy (SEM) analysis of the purified composite filament confirmed the porous properties of the material, an average pore size of ∼30 nm. The printed passive samplers with various membrane thicknesses, including 0.5, 1.0, and 1.5 mm, were evaluated for their ability to facilitate the extraction of atrazine as the model solute onto the internal sorbent, under standard conditions. Gas chromatography-mass spectrometry was used to determine the uptake of atrazine by the device from standard water samples and also to evaluate any chemical leaching from the printed materials. The sampler with 0.5 mm thick membrane showed the best performance with 87% depletion and a sampling rate of 0.19 Ld^-1 ( n = 3, % RSD = 0.59). The results obtained using these printed sampling devices with integrated membranes were in close agreement to devices fitted with a standard poly(ether sulfone) membrane.

Nanoporous 3D-Printed Scaffolds for Local Doxorubicin Delivery in Bone Metastases Secondary to Prostate Cancer

The spine is the most common site of bone metastasis, often originating from prostate, lung, and breast cancers. High systemic doses of chemotherapeutics such as doxorubicin (DOX), cisplatin, or paclitaxel often have severe side effects. Surgical removal of spine metastases also leaves large defects which cannot spontaneously heal and require bone grafting. To circumvent these issues, we designed an approach for local chemotherapeutic delivery within 3D-printed scaffolds which could also potentially serve as a bone substitute. Direct treatment of prostate cancer cell line LAPC4 and patient derived spine metastases cells with 0.01 µM DOX significantly reduced metabolic activity, proliferation, migration, and spheroid growth. We then assessed uptake and release of DOX in a series of porous 3D-printed scaffolds on LAPC4 cells as well as patient-derived spine metastases cells. Over seven days, 60–75% of DOX loaded onto scaffolds could be released, which significantly reduced metabolic activity and proliferation of both LAPC4 and patient derived cells, while unloaded scaffolds had no effect. Porous 3D-printed scaffolds may provide a novel and inexpensive approach to locally deliver chemotherapeutics in a patient-specific manner at tumor resection sites. With a composite design to enhance strength and promote sustained drug release, the scaffolds could reduce systemic negative effects, enhance bone repair, and improve patient outcomes.

One-step three-dimensional printing of enzyme/substrate-incorporated devices for glucose testing

To substantially simplify the fabrication of analytical devices for rapid screening tests, in this study we employed multi-material fused deposition modeling-type three-dimensional printing (3DP) and two functionalized thermoplastic filaments-acrylonitrile butadiene styrene (ABS) incorporating peroxidase-mimicking iron oxide (Fe₃O₄) nanoparticles and polyvinyl alcohol (PVA) infiltrated with the chromogenic substrate o-phenylenediamine (OPD)-for the one-step manufacture of enzyme/substrate-incorporated multi-well plates. Upon contact with samples, these fabricated devices (i) released the chromogenic substrate OPD into the solution, (ii) efficiently catalyzed the oxidation of OPD mediated by the peroxidase substrate H₂O₂, (iii) enabled assays of those substances availably oxidized by their specific oxidases to generate H₂O₂, and (iv) facilitated colorimetric observation by the naked eye or through absorbance measurements after loading into a microplate reader. With glucose oxidase immobilized in each well, samples appropriately diluted could be directly loaded for derivatizing and analyzing glucose without adding any other reagents. After assay optimization, the limits of detection reached as low as 2.8 μM for H₂O₂ and 5.0 μM for glucose; the method's applicability was illustrated in terms of determining glucose concentrations in urine, serum, and plasma samples. These 3D-printed peroxidase mimic/chromogenic substrate-incorporated multi-well plates appear to be highly suitable for rapid and high-throughput screening of glucose in clinical samples. We demonstrate that adequate functionalization of raw materials for 3DP can contribute to the development of novel multifunctional devices with many potential practical applications.

New 3D-printed sorbent for extraction of steroids from human plasma preceding LC-MS analysis

In recent years, there has been an increasing worldwide interest in the use of alternative sample preparation methods that are proceeded by separation techniques. Fused deposition modeling (FDM) is a 3D printing technique that is based the consecutive layering of softened/melted thermoplastic materials. In this study, a group of natural steroids and sexual hormones - namely, aldosterone, cortisol, β-estradiol, testosterone, dihydrotestosterone, and synthetic methyltestosterone and betamethasone - were separated and determined using an optimized high-performance liquid chromatography coupled to mass spectrometry (LC-MS) method in positive ionization mode. 3D-printed sorbents were selected as the pre-concentration technique because they are generally low cost, fast, and simple to make and automate. Furthermore, the use of 3D-printed sorbents helps to minimize potential errors due to their repeatability and reproducibility, and their ability to eliminate carry over by using one printed sorbent for a single extraction of steroids from biological matrices. The extraction procedure was optimized and the parameters influencing 3D-printed Layfomm 60^® based sorbent and LC-MS were studied, including the type of extraction solvent used, sorption and desorption times, temperature, and the salting-out effect. To demonstrate this method's applicability for biological sample analysis, the SPME-LC-MS method was validated for its ability to simultaneously quantify endogenous steroids. This evaluation confirmed good linearity and an R² that was between 0.9970 and 0.9990. The recovery rates for human plasma samples were 86.34-93.6% for the studied steroids with intra- and inter-day RSDs of 1.44-7.42% and 1.44-9.46%, respectively. To our knowledge, this study is the first time that 3D-printed sorbents have been used to extract trace amounts of endogenous low-molecular-weight compounds, such as steroids, from biological samples, such as plasma.

Plasmonic Sensing with 3D Printed Optics

Three-dimensional (3D) printing has undergone an exponential growth in popularity due to its revolutionary and near limitless manufacturing capabilities. Recent trends have seen this technology utilized across a variety of scientific disciplines, including the measurement sciences, but precise fabrication of optical components for high-performance biosensing has not yet been demonstrated. We report here 3D printing of high-quality, custom prisms by stereolithography that enable Kretschmann-configured plasmonic sensing of bacterial toxins. Simple benchtop polishing procedures render a smooth surface that supports propagation of surface plasmon polaritons with a deposited gold layer, which exhibit high bulk refractive index sensitivities and are capable of discriminating trace levels of cholera toxin on a supported lipid membrane interface. Further evidence of the flexibility of this manufacturing technique is demonstrated with printed prisms of varied geometries and in situ monitoring of nanoparticle growth by total internal reflection spectroscopy. This work represents the first example of 3D printed light-guiding sensing platforms and demonstrates the versatility and broad perspective of 3D printing in optical detection.

A Printed Equilibrium Dialysis Device with Integrated Membranes for Improved Binding Affinity Measurements

Equilibrium dialysis is a simple and effective technique used for investigating the binding of small molecules and ions to proteins. A three-dimensional (3D) printer was used to create a device capable of measuring binding constants between a protein and a small ion based on equilibrium dialysis. Specifically, the technology described here enables the user to customize an equilibrium dialysis device to fit their own experiments by choosing membranes of various material and molecular-weight cutoff values. The device has dimensions similar to that of a standard 96-well plate, thus being amenable to automated sample handlers and multichannel pipettes. The device consists of a printed base that hosts multiple windows containing a porous regenerated-cellulose membrane with a molecular-weight cutoff of ∼3500 Da. A key step in the fabrication process is a print-pause-print approach for integrating membranes directly into the windows subsequently inserted into the base. The integrated membranes display no leaking upon placement into the base. After characterizing the system's requirements for reaching equilibrium, the device was used to successfully measure an equilibrium dissociation constant for Zn²⁺ and human serum albumin (K_d = (5.62 ± 0.93) × 10^-7 M) under physiological conditions that is statistically equal to the constants reported in the literature.