Rapid Fabrication of Sterile Medical Nasopharyngeal Swabs by Stereolithography for Widespread Testing in a Pandemic

Multiscale mechanical characterization of biobased photopolymers towards sustainable vat polymerization 3D printing

In vat polymerization (VP) 3D printing, there is an urgent need to expand characterization efforts for resins derived from natural resources to counter the increasing consumption of fossil fuels required to synthesize conventional monomers. Here, we apply multiscale mechanical characterization techniques to interrogate a 3D printed biobased copolymer along a controlled range of monomer ratios. We varied the concentration of two dissimilar monomers to derive structural information about the polymer networks. Current research primarily considers the macroscale, but recent understanding of the process-induced anisotropy in 3D printed layers suggests a multiscale approach is critical. By combining typical macroscopic techniques with micro- and nanoscale analogues, clear correlations in the processing-structure-property relationships appeared. We observed that measured moduli were always greater via surface-localized methods, but property differences between formulations were easier to identify. As researchers continue to develop novel sustainable biopolymers that match or exceed the performance of commercial resins, it is vital to understand the multiscale relationships between the VP process, the structure of the formed polymer networks, and the resultant properties.

Performance evaluation of commercially available swabs for environmental monitoring: Uptake and release efficiency

Safety and the quality of products rely on proper cleanliness procedures and good manufacturing practices in the production environment. The use of swabs for the collection of samples from surfaces has been a common practice in industries, medicine and forensic studies. To accommodate these different purposes, many varieties of swabs have been introduced into the market, and it is important to assess the performance of these swabs before incorporating into an environmental monitoring procedure. The overall effectiveness of a swab is determined by two factors: the number of bacteria that a swab can uptake from a surface and the number of picked-up bacteria the swab can elute into a releasing buffer. This study evaluated the uptake efficiency and release efficiency of four different commercially available swabs: CleanFoam (Texwipes, USA), FLOQSwabs (Copan diagnostic Inc., USA), Hydraflock swabs (Puritan medical products, USA), and Cotton swabs. Cotton swabs showed the highest uptake efficiency (96.5 ± 1.9%), whereas CleanFoam swabs (57.9 ± 20.3%) showed the least. Both flocked (FLOQSwabs and Hydraflock) swabs showed over 80% uptake efficiency. Releasing efficiency of swabs was tested with eight different releasing buffers. Cotton swabs displayed the lowest release efficiency with most of the tested releasing buffers. When employed with Tris HEPES, Tris MOPS, Tris TAPS, FLOQSwabs, and Hydraflock swabs exhibited releasing efficiency of over 75%. The overall efficiency of the swabs was determined using TAPS as the releasing buffer and the values obtained were 80.4 ± 9.8%, 54.7 ± 16.9%, 35.0 ± 12.7% and 25.2 ± 6.9% for Hydraflock swabs, FLOQSwabs, Cotton swabs and Cleanfoam swabs, respectively.

Scanning Electron Microscopy and EDX Spectroscopy of Commercial Swabs Used for COVID-19 Lateral Flow Testing

The chemical composition of COVID test swabs has not been examined beyond the manufacturer's datasheets. The unprecedented demand for swabs to conduct rapid lateral flow tests and nucleic acid amplification tests led to mass production, including 3D printing platforms. Manufacturing impurities could be present in the swabs and, if so, could pose a risk to human health. We used scanning electron microscopy and energy dispersive X-ray (EDX) spectroscopy to examine the ultrastructure of seven assorted brands of COVID test swabs and to identify and quantify their chemical elements. We detected eight unexpected elements, including transition metals, such as titanium and zirconium, the metalloid silicon, as well as post-transition metals aluminium and gallium, and the non-metal elements sulphur and fluorine. Some of the elements were detected as trace amounts, but for others, the amount was close to reported toxicological thresholds for inhalation routes. Experimental studies have shown that the detrimental effects of unexpected chemical elements include moderate to severe inflammatory states in the exposed epithelium as well as proliferative changes. Given the massive testing still being used in the context of the COVID pandemic, we urge caution in continuing to recommend repeated and frequent testing, particularly of healthy, non-symptomatic, individuals.

CFD based analysis of 3D printed nasopharyngeal swabs for COVID-19 diagnostics

BACKGROUND AND OBJECTIVE

Additive manufacturing of nasopharyngeal (NP) swabs using 3D printing technology presents a viable alternative to address the immediate shortage problem of standard flock-headed swabs for rapid COVID-19 testing. Recently, several geometrical designs have been proposed for 3D printed NP swabs and their clinical trials are already underway. During clinical testing of the NP swabs, one of the key criteria to compare the efficacy of 3D printed swabs with traditional swabs is the collection efficiency. In this study, we report a numerical framework to investigate the collection efficiency of swabs utilizing the computational fluid dynamics (CFD) approach.

METHODS

Three-dimensional computational domain comprising of NP swab dipped in the liquid has been considered in this study to mimic the dip test procedure. The volume of fluid (VOF) method has been employed to track the liquid-air interface as the NP swab is pulled out of the liquid. The governing equations of the multiphase model have been solved utilizing finite-volume-based ANSYS Fluent software by imposing appropriate boundary conditions. Taguchi's based design of experiment analysis has also been conducted to evaluate the influence of geometric design parameters on the collection efficiency of NP swabs. The developed model has been validated by comparing the numerically predicted collection efficiency of different 3D printed NP swabs with the experimental findings.

RESULTS

Numerical predictions of the CFD model are in good agreement with the experimental results. It has been found that there prevails huge variability in the collection efficiency of the 3D printed designs of NP swabs available in the literature, ranging from 2 µl to 120 µl. Furthermore, even the smallest alteration in the geometric design parameter of the 3D printed NP swab results in significant changes in the amount of fluid captured.

CONCLUSIONS

The proposed framework would assist in quantifying the collection efficiency of the 3D printed designs of NP swabs, rapidly and at a low cost. Moreover, we demonstrate that the developed framework can be extended to optimize the designs of 3D printed swabs to drastically improve the performances of the existing designs and achieve comparable efficacy to that of conventionally manufactured swabs.

Digital Innovation, Data Analytics, and Supply Chain Resiliency: A Bibliometric-based Systematic Literature Review

In recent times, the literature has seen considerable growth in research at the intersection of digital innovation, data analytics, and supply chain resilience. While the number of studies on the topic has been burgeoning, due to the absence of a comprehensive literature review, it remains unclear what aspects of the subject have already been investigated and what are the avenues for impactful future research. Integrating bibliometric analysis with a systematic review approach, this paper offers the review of 262 articles at the nexus of innovative technologies, data analytics, and supply chain resiliency. The analysis uncovers the critical research clusters, the evolution of research over time, knowledge trajectories and methodological development in the area. Our thorough analysis enriches contemporary knowledge on the subject by consolidating the dispersed literature on the significance of innovative technologies, data analytics and supply chain resilience thereby recognizing major research clusters or domains and fruitful paths for future research. The review also helps improve practitioners' awareness of the recent research on the topic by recapping key findings of a large amount of literature in one place.

On-Site, On-Demand 3D-Printed Nasopharyngeal Swabs to Improve the Access of Coronavirus Disease-19 Testing

Diagnostic testing that facilitates containment, surveillance, and treatment of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), or future respiratory viruses, depends on a sample collection device that efficiently collects nasopharyngeal tissue and that can be manufactured on site when an outbreak or public health emergency is declared by a government. Here two novel stereolithography-based three-dimensional (3D)-printed nasopharyngeal swabs are reported which are made using a biocompatible and sterilizable photoresist. Such swabs are readily manufactured on-site and on-demand to ensure availability, if supply chain shortages emerge. Additionally, the 3D-printed swabs easily adapt to current workflow and testing procedures in hospital clinical laboratories to allow for effortless scaling up of test kits. Finally, the 3D-printed nasopharyngeal swabs demonstrate concordant SARS-CoV-2 testing results between the 3D-printed swabs and the COPAN commercial swabs, and enable detection of SARS-CoV-2 in clinical samples obtained from autopsies.

Establishing a point-of-care additive manufacturing workflow for clinical use

Additive manufacturing, or 3-Dimensional (3-D) Printing, is built with technology that utilizes layering techniques to build 3-D structures. Today, its use in medicine includes tissue and organ engineering, creation of prosthetics, the manufacturing of anatomical models for preoperative planning, education with high-fidelity simulations, and the production of surgical guides. Traditionally, these 3-D prints have been manufactured by commercial vendors. However, there are various limitations in the adaptability of these vendors to program-specific needs. Therefore, the implementation of a point-of-care in-house 3-D modeling and printing workflow that allows for customization of 3-D model production is desired. In this manuscript, we detail the process of additive manufacturing within the scope of medicine, focusing on the individual components to create a centralized in-house point-of-care manufacturing workflow. Finally, we highlight a myriad of clinical examples to demonstrate the impact that additive manufacturing brings to the field of medicine.