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1.
Int J Mol Sci ; 23(7)2022 Mar 22.
Article in English | MEDLINE | ID: covidwho-1785725

ABSTRACT

Tumor cells evolve in a complex and heterogeneous environment composed of different cell types and an extracellular matrix. Current 2D culture methods are very limited in their ability to mimic the cancer cell environment. In recent years, various 3D models of cancer cells have been developed, notably in the form of spheroids/organoids, using scaffold or cancer-on-chip devices. However, these models have the disadvantage of not being able to precisely control the organization of multiple cell types in complex architecture and are sometimes not very reproducible in their production, and this is especially true for spheroids. Three-dimensional bioprinting can produce complex, multi-cellular, and reproducible constructs in which the matrix composition and rigidity can be adapted locally or globally to the tumor model studied. For these reasons, 3D bioprinting seems to be the technique of choice to mimic the tumor microenvironment in vivo as closely as possible. In this review, we discuss different 3D-bioprinting technologies, including bioinks and crosslinkers that can be used for in vitro cancer models and the techniques used to study cells grown in hydrogels; finally, we provide some applications of bioprinted cancer models.


Subject(s)
Bioprinting , Neoplasms , Bioprinting/methods , Humans , Hydrogels , Precision Medicine , Printing, Three-Dimensional , Tissue Engineering/methods , Tissue Scaffolds , Tumor Microenvironment
2.
Sensors (Basel) ; 22(6)2022 Mar 19.
Article in English | MEDLINE | ID: covidwho-1765836

ABSTRACT

Detection of bacterial pathogens is significant in the fields of food safety, medicine, and public health, just to name a few. If bacterial pathogens are not properly identified and treated promptly, they can lead to morbidity and mortality, also possibly contribute to antimicrobial resistance. Current bacterial detection methodologies rely solely on laboratory-based techniques, which are limited by long turnaround detection times, expensive costs, and risks of inadequate accuracy; also, the work requires trained specialists. Here, we describe a cost-effective and portable 3D-printed electrochemical biosensor that facilitates rapid detection of certain Escherichia coli (E. coli) strains (DH5α, BL21, TOP10, and JM109) within 15 min using 500 µL of sample, and costs only USD 2.50 per test. The sensor displayed an excellent limit of detection (LOD) of 53 cfu, limit of quantification (LOQ) of 270 cfu, and showed cross-reactivity with strains BL21 and JM109 due to shared epitopes. This advantageous diagnostic device is a strong candidate for frequent testing at point of care; it also has application in various fields and industries where pathogen detection is of interest.


Subject(s)
Biosensing Techniques , Escherichia coli , Bacteria , Biosensing Techniques/methods , Limit of Detection , Printing, Three-Dimensional
3.
Sci Rep ; 12(1): 4132, 2022 03 08.
Article in English | MEDLINE | ID: covidwho-1735286

ABSTRACT

This paper presents a deep learning-driven portable, accurate, low-cost, and easy-to-use device to perform Reverse-Transcription Loop-Mediated Isothermal Amplification (RT-LAMP) to facilitate rapid detection of COVID-19. The 3D-printed device-powered using only a 5 Volt AC-DC adapter-can perform 16 simultaneous RT-LAMP reactions and can be used multiple times. Moreover, the experimental protocol is devised to obviate the need for separate, expensive equipment for RNA extraction in addition to eliminating sample evaporation. The entire process from sample preparation to the qualitative assessment of the LAMP amplification takes only 45 min (10 min for pre-heating and 35 min for RT-LAMP reactions). The completion of the amplification reaction yields a fuchsia color for the negative samples and either a yellow or orange color for the positive samples, based on a pH indicator dye. The device is coupled with a novel deep learning system that automatically analyzes the amplification results and pays attention to the pH indicator dye to screen the COVID-19 subjects. The proposed device has been rigorously tested on 250 RT-LAMP clinical samples, where it achieved an overall specificity and sensitivity of 0.9666 and 0.9722, respectively with a recall of 0.9892 for Ct < 30. Also, the proposed system can be widely used as an accurate, sensitive, rapid, and portable tool to detect COVID-19 in settings where access to a lab is difficult, or the results are urgently required.


Subject(s)
COVID-19/diagnosis , Deep Learning , Molecular Diagnostic Techniques/methods , Nucleic Acid Amplification Techniques/methods , SARS-CoV-2/genetics , Area Under Curve , COVID-19 Testing , Coloring Agents/chemistry , Humans , Molecular Diagnostic Techniques/instrumentation , Nasopharynx/virology , Nucleic Acid Amplification Techniques/instrumentation , Point-of-Care Systems , Printing, Three-Dimensional , RNA, Viral/analysis , RNA, Viral/metabolism , ROC Curve , SARS-CoV-2/isolation & purification , Sensitivity and Specificity
4.
J Dtsch Dermatol Ges ; 20(2): 177-183, 2022 02.
Article in English | MEDLINE | ID: covidwho-1642640

ABSTRACT

BACKGROUND AND OBJECTIVES: The corona pandemic affects many aspects of life - with challenges in medical treatment undoubtedly of paramount importance. However, continuing medical education needs to be consistently provided. During a semester with lockdown-phases and limited student-to-patient-contact availability, we supplied silicone models of primary skin lesions to every student and asked them to evaluate this teaching tool. METHODS: In two anonymous online surveys, we asked students enrolled in dermatology (n = 222) at the Medical Facility of the Ludwig Maximilian University of Munich in the winter semester 2020/2021 - subsequent to online teaching - about their understanding and self-assessment of primary skin lesions before and after receiving silicone models for practice. The models were produced by layering different types of silicone into negative 3D printed molds made from polylactide to attain different degrees of hardness and colors. RESULTS: Data from 211 (95.0 %) and 213 (95.9 %) of the 222 students were analyzed before and after receiving the silicone models, respectively. In all questions the students stated a highly significant improvement in their skills (P < 0.001). The majority of students evaluated the silicone models positively and reported a better understanding and learning of primary skin lesions. CONCLUSIONS: This study demonstrates the benefit of haptic experience in dermatology teaching not only in the time of COVID-19, but also thereafter.


Subject(s)
COVID-19 , Silicones , Communicable Disease Control , Humans , Printing, Three-Dimensional , SARS-CoV-2
5.
J Mater Sci Mater Med ; 33(1): 8, 2022 Jan 04.
Article in English | MEDLINE | ID: covidwho-1602899

ABSTRACT

The collection capacity of common nasopharyngeal swabs and irregularities of medical personnel limit the accuracy of PCR testing. This study describes a newly designed 3D-printed swab that is combined with a 3D-printed cover to prevent the extraction of undesired nasal secretions. This swab improved the accuracy of PCR test results. The results of a series of experiments showed that, because of the mucus extraction effect, 3D-printed swabs can replace ordinary cotton swabs. The crisis of the worldwide medical supply shortage can be ameliorated to a certain extent by applying 3D printing technology.


Subject(s)
COVID-19 Nucleic Acid Testing/instrumentation , Specimen Handling/instrumentation , Biocompatible Materials , Biomechanical Phenomena , COVID-19/diagnosis , COVID-19/virology , Computer Simulation , Equipment Design , Finite Element Analysis , Humans , Materials Testing , Nasopharynx/virology , Printing, Three-Dimensional , Resins, Synthetic , Safety , Tensile Strength , Textiles
6.
PLoS One ; 16(3): e0247575, 2021.
Article in English | MEDLINE | ID: covidwho-1573727

ABSTRACT

INTRODUCTION: The COVID-19 pandemic has led to widespread shortages of N95 respirators and other personal protective equipment (PPE). An effective, reusable, locally-manufactured respirator can mitigate this problem. We describe the development, manufacture, and preliminary testing of an open-hardware-licensed device, the "simple silicone mask" (SSM). METHODS: A multidisciplinary team developed a reusable silicone half facepiece respirator over 9 prototype iterations. The manufacturing process consisted of 3D printing and silicone casting. Prototypes were assessed for comfort and breathability. Filtration was assessed by user seal checks and quantitative fit-testing according to CSA Z94.4-18. RESULTS: The respirator originally included a cartridge for holding filter material; this was modified to connect to standard heat-moisture exchange (HME) filters (N95 or greater) after the cartridge showed poor filtration performance due to flow acceleration around the filter edges, which was exacerbated by high filter resistance. All 8 HME-based iterations provided an adequate seal by user seal checks and achieved a pass rate of 87.5% (N = 8) on quantitative testing, with all failures occurring in the first iteration. The overall median fit-factor was 1662 (100 = pass). Estimated unit cost for a production run of 1000 using distributed manufacturing techniques is CAD $15 in materials and 20 minutes of labor. CONCLUSION: Small-scale manufacturing of an effective, reusable N95 respirator during a pandemic is feasible and cost-effective. Required quantities of reusables are more predictable and less vulnerable to supply chain disruption than disposables. With further evaluation, such devices may be an alternative to disposable respirators during public health emergencies. The respirator described above is an investigational device and requires further evaluation and regulatory requirements before clinical deployment. The authors and affiliates do not endorse the use of this device at present.


Subject(s)
COVID-19/prevention & control , Equipment Design/instrumentation , Filtration/instrumentation , Pandemics/prevention & control , Personal Protective Equipment , Respiratory Protective Devices , Ventilators, Mechanical , Equipment Reuse , Face , Humans , Materials Testing/instrumentation , N95 Respirators , Occupational Exposure/prevention & control , Printing, Three-Dimensional/instrumentation , SARS-CoV-2/pathogenicity
7.
Anal Chim Acta ; 1191: 339372, 2022 Jan 25.
Article in English | MEDLINE | ID: covidwho-1559547

ABSTRACT

The 3D printing technology has gained ground due to its wide range of applicability. The development of new conductive filaments contributes significantly to the production of improved electrochemical devices. In this context, we report a simple method to producing an efficient conductive filament, containing graphite within the polymer matrix of PLA, and applied in conjunction with 3D printing technology to generate (bio)sensors without the need for surface activation. The proposed method for producing the conductive filament consists of four steps: (i) mixing graphite and PLA in a heated reflux system; (ii) recrystallization of the composite; (iii) drying and; (iv) extrusion. The produced filament was used for the manufacture of electrochemical 3D printed sensors. The filament and sensor were characterized by physicochemical techniques, such as SEM, TGA, Raman, FTIR as well as electrochemical techniques (EIS and CV). Finally, as a proof-of-concept, the fabricated 3D-printed sensor was applied for the determination of uric acid and dopamine in synthetic urine and used as a platform for the development of a biosensor for the detection of SARS-CoV-2. The developed sensors, without pre-treatment, provided linear ranges of 0.5-150.0 and 5.0-50.0 µmol L-1, with low LOD values (0.07 and 0.11 µmol L-1), for uric acid and dopamine, respectively. The developed biosensor successfully detected SARS-CoV-2 S protein, with a linear range from 5.0 to 75.0 nmol L-1 (0.38 µg mL-1 to 5.74 µg mL-1) and LOD of 1.36 nmol L-1 (0.10 µg mL-1) and sensitivity of 0.17 µA nmol-1 L (0.01 µA µg-1 mL). Therefore, the lab-made produced and the ready-to-use conductive filament is promising and can become an alternative route for the production of different 3D electrochemical (bio)sensors and other types of conductive devices by 3D printing.


Subject(s)
COVID-19 , SARS-CoV-2 , Electric Conductivity , Humans , Printing, Three-Dimensional , Spike Glycoprotein, Coronavirus
8.
Int J Mol Sci ; 22(23)2021 Nov 24.
Article in English | MEDLINE | ID: covidwho-1542582

ABSTRACT

COVID-19 pandemic and associated supply-chain disruptions emphasise the requirement for antimicrobial materials for on-demand manufacturing. Besides aerosol transmission, SARS-CoV-2 is also propagated through contact with virus-contaminated surfaces. As such, the development of effective biofunctional materials that can inactivate SARS-CoV-2 is critical for pandemic preparedness. Such materials will enable the rational development of antiviral devices with prolonged serviceability, reducing the environmental burden of disposable alternatives. This research reveals the novel use of Laser Powder Bed Fusion (LPBF) to 3D print porous Cobalt-Chromium-Molybdenum (Co-Cr-Mo) superalloy with potent antiviral activity (100% viral inactivation in 30 min). The porous material was rationally conceived using a multi-objective surrogate model featuring track thickness (tt) and pore diameter (ϕd) as responses. The regression analysis found the most significant parameters for Co-Cr-Mo track formation to be the interaction effects of scanning rate (Vs) and laser power (Pl) in the order PlVs>Vs>Pl. Contrastively, the pore diameter was found to be primarily driven by the hatch spacing (Sh). The study is the first to demonstrate the superior antiviral properties of 3D printed Co-Cr-Mo superalloy against an enveloped virus used as biosafe viral model of SARS-CoV-2. The material significantly outperforms the viral inactivation time of other broadly used antiviral metals such as copper and silver, as the material's viral inactivation time was from 5 h to 30 min. As such, the study goes beyond the current state-of-the-art in antiviral alloys to provide extra protection to combat the SARS-CoV-2 viral spread. The evolving nature of the COVID-19 pandemic brings new and unpredictable challenges where on-demand 3D printing of antiviral materials can achieve rapid solutions while reducing the environmental impact of disposable devices.


Subject(s)
Antiviral Agents/pharmacology , Chromium/pharmacology , Cobalt/pharmacology , Molybdenum/pharmacology , Printing, Three-Dimensional , Alloys , COVID-19 , Humans , Porosity , SARS-CoV-2/drug effects , Surface Properties , Virus Inactivation/drug effects
9.
World Neurosurg ; 156: 133-146.e6, 2021 12.
Article in English | MEDLINE | ID: covidwho-1527881

ABSTRACT

BACKGROUND: Intracranial surgery can be complex and high risk. Safety, ethical and financial factors make training in the area challenging. Head model 3-dimensional (3D) printing is a realistic training alternative to patient and traditional means of cadaver and animal model simulation. OBJECTIVE: To describe important factors relating to the 3D printing of human head models and how such models perform as simulators. METHODS: Searches were performed in PubMed, the Cochrane Library, Scopus, and Web of Science. Articles were screened independently by 3 reviewers using Covidence software. Data items were collected under 5 categories: study information; printers and processes; head model specifics; simulation and evaluations; and costs and production times. RESULTS: Forty articles published over the last 10 years were included in the review. A range of printers, printing methods, and substrates were used to create head models and tissue types. Complexity of the models ranged from sections of single tissue type (e.g., bone) to high-fidelity integration of multiple tissue types. Some models incorporated disease (e.g., tumors and aneurysms) and artificial physiology (e.g., pulsatile circulation). Aneurysm clipping, bone drilling, craniotomy, endonasal surgery, and tumor resection were the most commonly practiced procedures. Evaluations completed by those using the models were generally favorable. CONCLUSIONS: The findings of this review indicate that those who practice surgery and surgical techniques on 3D-printed head models deem them to be valuable assets in cranial surgery training. Understanding how surgical simulation on such models affects surgical performance and patient outcomes, and considering cost-effectiveness, are important future research endeavors.


Subject(s)
Head/anatomy & histology , Models, Anatomic , Neurosurgical Procedures/methods , Printing, Three-Dimensional , Craniotomy/methods , Humans
10.
Int J Environ Res Public Health ; 18(21)2021 11 06.
Article in English | MEDLINE | ID: covidwho-1512309

ABSTRACT

This paper presents a complex and extensive experimental evaluation of fine particle emissions released by an FDM 3D printer for four of the most common printing materials (ABS, PLA, PET-G, and TPU). These thermoplastic filaments were examined at three printing temperatures within their recommended range. In addition, these measurements were extended using various types of printing nozzles, which influenced the emissions considerably. This research is based on more than a hundred individual measurements for which a standardized printing method was developed. The study presents information about differences between particular printing conditions in terms of the amount of fine particles emitted as well as the particle size distributions during printing periods. This expands existing knowledge about the emission of ultrafine particles during 3D printing, and it can help reduce the emissions of these devices to achieve cleaner and safer 3D printer operations.


Subject(s)
Air Pollution, Indoor , Particulate Matter , Air Pollution, Indoor/analysis , Particle Size , Particulate Matter/analysis , Printing, Three-Dimensional , Temperature
11.
Clin Infect Dis ; 73(9): e3033-e3035, 2021 11 02.
Article in English | MEDLINE | ID: covidwho-1501006
12.
Clin Infect Dis ; 73(9): e3027-e3032, 2021 11 02.
Article in English | MEDLINE | ID: covidwho-1500994

ABSTRACT

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes coronavirus disease 2019 (COVID-19), can be detected in respiratory samples by real-time reverse transcriptase polymerase chain reaction (RT-PCR) or other molecular methods. Accessibility of diagnostic testing for COVID-19 has been limited by intermittent shortages of supplies required for testing, including flocked nasopharyngeal (FLNP) swabs. METHODS: We developed a 3-dimensional printed nasopharyngeal (3DP) swab as a replacement of the FLNP swab. The performance of 3DP and FLNP swabs were compared in a clinical trial of symptomatic patients at 3 clinical sites (n = 291) using 3 SARS-CoV-2 emergency use authorization tests: a modified version of the Centers for Disease Control and Prevention (CDC) RT-PCR Diagnostic Panel and 2 commercial automated formats, Roche Cobas and NeuMoDx. RESULTS: The cycle threshold-C(t)-values from the gene targets and the RNase P gene control in the CDC assay showed no significant differences between swabs for both gene targets (P = .152 and P = .092), with the RNase P target performing significantly better in the 3DP swabs (P < .001). The C(t) values showed no significant differences between swabs for both viral gene targets in the Roche cobas assay (P = .05 and P = .05) as well as the NeuMoDx assay (P = .401 and P = .484). The overall clinical correlation of COVID-19 diagnosis between all methods was 95.88% (Kappa 0.901). CONCLUSIONS: The 3DP swabs were equivalent to standard FLNP in 3 testing platforms for SARS-CoV-2. Given the need for widespread testing, 3DP swabs printed onsite are an alternate to FLNP that can rapidly scale in response to acute needs when supply chain disruptions affect availability of collection kits.


Subject(s)
COVID-19 Testing , COVID-19 , Humans , Nasopharynx , Printing, Three-Dimensional , SARS-CoV-2 , Specimen Handling
13.
Sci Rep ; 11(1): 21449, 2021 11 02.
Article in English | MEDLINE | ID: covidwho-1500502

ABSTRACT

The World Health Organisation has called for a 40% increase in personal protective equipment manufacturing worldwide, recognising that frontline workers need effective protection during the COVID-19 pandemic. Current devices suffer from high fit-failure rates leaving significant proportions of users exposed to risk of viral infection. Driven by non-contact, portable, and widely available 3D scanning technologies, a workflow is presented whereby a user's face is rapidly categorised using relevant facial parameters. Device design is then directed down either a semi-customised or fully-customised route. Semi-customised designs use the extracted eye-to-chin distance to categorise users in to pre-determined size brackets established via a cohort of 200 participants encompassing 87.5% of the cohort. The user's nasal profile is approximated to a Gaussian curve to further refine the selection in to one of three subsets. Flexible silicone provides the facial interface accommodating minor mismatches between true nasal profile and the approximation, maintaining a good seal in this challenging region. Critically, users with outlying facial parameters are flagged for the fully-customised route whereby the silicone interface is mapped to 3D scan data. These two approaches allow for large scale manufacture of a limited number of design variations, currently nine through the semi-customised approach, whilst ensuring effective device fit. Furthermore, labour-intensive fully-customised designs are targeted as those users who will most greatly benefit. By encompassing both approaches, the presented workflow balances manufacturing scale-up feasibility with the diverse range of users to provide well-fitting devices as widely as possible. Novel flow visualisation on a model face is presented alongside qualitative fit-testing of prototype devices to support the workflow methodology.


Subject(s)
Face/physiology , Personal Protective Equipment , Photogrammetry/methods , COVID-19/prevention & control , COVID-19/virology , Computer-Aided Design , Equipment Design , Face/anatomy & histology , Humans , Printing, Three-Dimensional , SARS-CoV-2/isolation & purification
14.
Molecules ; 26(19)2021 Oct 06.
Article in English | MEDLINE | ID: covidwho-1463769

ABSTRACT

Pristine high-density bulk disks of MgB2 with added hexagonal BN (10 wt.%) were prepared using spark plasma sintering. The BN-added samples are machinable by chipping them into desired geometries. Complex shapes of different sizes can also be obtained by the 3D printing of polylactic acid filaments embedded with MgB2 powder particles (10 wt.%). Our present work aims to assess antimicrobial activity quantified as viable cells (CFU/mL) vs. time of sintered and 3D-printed materials. In vitro antimicrobial tests were performed against the bacterial strains Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Staphylococcus aureus ATCC 25923, Enterococcus faecium DSM 13590, and Enterococcus faecalis ATCC 29212; and the yeast strain Candida parapsilosis ATCC 22019. The antimicrobial effects were found to depend on the tested samples and microbes, with E. faecium being the most resistant and E. coli the most susceptible.


Subject(s)
Anti-Infective Agents/pharmacology , Bacteria/drug effects , Boron Compounds/pharmacology , Fungi/drug effects , Magnesium Compounds/pharmacology , Candida parapsilosis/drug effects , Enterococcus faecalis/drug effects , Enterococcus faecium/drug effects , Escherichia coli/drug effects , Microbial Sensitivity Tests , Polyesters/pharmacology , Printing, Three-Dimensional , Pseudomonas aeruginosa/drug effects , Staphylococcus aureus/drug effects
15.
World Neurosurg ; 156: 133-146.e6, 2021 12.
Article in English | MEDLINE | ID: covidwho-1454572

ABSTRACT

BACKGROUND: Intracranial surgery can be complex and high risk. Safety, ethical and financial factors make training in the area challenging. Head model 3-dimensional (3D) printing is a realistic training alternative to patient and traditional means of cadaver and animal model simulation. OBJECTIVE: To describe important factors relating to the 3D printing of human head models and how such models perform as simulators. METHODS: Searches were performed in PubMed, the Cochrane Library, Scopus, and Web of Science. Articles were screened independently by 3 reviewers using Covidence software. Data items were collected under 5 categories: study information; printers and processes; head model specifics; simulation and evaluations; and costs and production times. RESULTS: Forty articles published over the last 10 years were included in the review. A range of printers, printing methods, and substrates were used to create head models and tissue types. Complexity of the models ranged from sections of single tissue type (e.g., bone) to high-fidelity integration of multiple tissue types. Some models incorporated disease (e.g., tumors and aneurysms) and artificial physiology (e.g., pulsatile circulation). Aneurysm clipping, bone drilling, craniotomy, endonasal surgery, and tumor resection were the most commonly practiced procedures. Evaluations completed by those using the models were generally favorable. CONCLUSIONS: The findings of this review indicate that those who practice surgery and surgical techniques on 3D-printed head models deem them to be valuable assets in cranial surgery training. Understanding how surgical simulation on such models affects surgical performance and patient outcomes, and considering cost-effectiveness, are important future research endeavors.


Subject(s)
Head/anatomy & histology , Models, Anatomic , Neurosurgical Procedures/methods , Printing, Three-Dimensional , Craniotomy/methods , Humans
16.
Adv Mater ; 33(52): e2105361, 2021 Dec.
Article in English | MEDLINE | ID: covidwho-1453531

ABSTRACT

Solid-state optics has been the pillar of modern digital age. Integrating soft hydrogel materials with micro/nanooptics could expand the horizons of photonics for bioengineering. Here, wet-spun multilayer hydrogel fibers are engineered through ionic-crosslinked natural polysaccharides that serve as multifunctional platforms. The resulting flexible hydrogel structure and reversible crosslinking provide tunable design properties such as adjustable refractive index and fusion splicing. Modulation of the optical readout via physical stimuli, including shape, compression, and multiple optical inputs/outputs is demonstrated. The unique permeability of the hydrogels is also combined with plasmonic nanoparticles for molecular detection of SARS-CoV-2 in fiber-coupled biomedical swabs. A tricoaxial 3D printing nozzle is then employed for the continuous fabrication of living optical fibers. Light interaction with living cells enables the quantification and digitalization of complex biological phenomena such as 3D cancer progression and drug susceptibility. These fibers pave the way for advances in biomaterial-based photonics and biosensing platforms.


Subject(s)
Hydrogels/chemistry , Optical Fibers , Optics and Photonics/methods , Polysaccharides/chemistry , Antineoplastic Agents/pharmacology , Antineoplastic Agents/therapeutic use , Biocompatible Materials/chemistry , Biosensing Techniques , COVID-19/diagnosis , COVID-19/virology , Cell Line, Tumor , Cell Proliferation/drug effects , Gold/chemistry , Humans , Metal Nanoparticles/chemistry , Neoplasms/drug therapy , Neoplasms/pathology , Printing, Three-Dimensional , SARS-CoV-2/isolation & purification
17.
Sci Rep ; 11(1): 19347, 2021 09 29.
Article in English | MEDLINE | ID: covidwho-1442810

ABSTRACT

The ongoing COVID-19 pandemic has revealed alarming shortages of personal protective equipment for frontline healthcare professionals and the general public. Therefore, a 3D-printable mask frame was developed, and its air seal performance was evaluated and compared. Personalized masks (PM) based on individual face scans (n = 8) and a statistically shaped mask (SSM) based on a standardized facial soft tissue shape computed from 190 face scans were designed. Subsequently, the masks were additively manufactured, and in a second step, the PM and SSM were compared to surgical masks (SM) and FFP2 masks (FFP2) in terms of air seal performance. 3D-printed face models allowed for air leakage evaluation by measuring the pressure inside the mask in sealed and unsealed conditions during a breathing simulation. The PM demonstrated the lowest leak flow (p < 0.01) of inspired or expired unfiltered air of approximately 10.4 ± 16.4%, whereas the SM showed the highest (p < 0.01) leakage with 84.9 ± 7.7%. The FFP2 and SSM had similar values of 34.9 ± 18.5% leakage (p > 0.68). The developed framework allows for the time- and resource-efficient, on-demand, and in-house production of masks. For the best seal performance, an individually personalized mask design might be recommended.


Subject(s)
COVID-19 , Masks , Personal Protective Equipment , Biometry , Equipment Design , Health Personnel , Humans , Printing, Three-Dimensional , Public Health
20.
Ann Biomed Eng ; 49(12): 3666-3675, 2021 Dec.
Article in English | MEDLINE | ID: covidwho-1391896

ABSTRACT

Early in 2020, the pandemic resulted in an enormous demand for personal protective equipment (PPE), which consists of face masks, face shields, respirators, and gowns. At our institution, at the request of hospital administration, the Lifespan 3D Printing Laboratory spearheaded an initiative to produce reusable N95 masks for use in the hospital setting. Through this article, we seek to detail our experience designing and 3D printing an N95 mask, highlighting the most important lessons learned throughout the process. Foremost among these, we were successful in producing a non-commercial N95 alternative mask which could be used in an era when N95 materials were extremely limited in supply. We identified five key lessons related to design software, 3D printed material airtightness, breathability and humidity dispersal, and ability for communication. By sharing our experience and the most valuable lessons we learned through this process, we hope to provide a helpful foundation for future 3D-printed N95 endeavors.


Subject(s)
COVID-19/prevention & control , N95 Respirators , Printing, Three-Dimensional , COVID-19/epidemiology , Equipment Design , Humans , Pandemics
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