3D Printing in Medicine for Preoperative Surgical Planning: A Review

Three-Dimensional Printed Model of the Mediastinum for Cardiothoracic Surgery Resident Education

Background

Mediastinoscopy remains an important component of lung cancer staging. The development of endobronchial ultrasonography has meant residents perform fewer mediastinoscopies. We hypothesized that a 3-dimensional printed model of the mediastinum would be an effective tool for teaching residents the anatomy and techniques for mediastinoscopy.

Methods

A color model of the mediastinum was 3-dimensionally printed based on segmented computed tomographic images. For 2 years, residents and attendings were asked to provide a skills assessment after every mediastinoscopy. During the second year, all residents received standardized instruction for mediastinoscopy using the 3-dimensional model. Skills assessments were compared between the residents taught with and without the 3-dimensional model.

Results

There were 49 resident and 65 attending surveys completed. Residents taught with the 3-dimensional model were more likely to answer that they could identify normal anatomy "well"/"very well" compared with residents taught without the model (86% vs 52%, P = .015). Residents taught with the 3-dimensional model more frequently answered they were able to perform an uncomplicated mediastinoscopy "well"/ "very well" (59% vs 31%, P = .079) compared with residents taught without the 3-dimensional model, although this was not significant. Attendings were equally likely to answer "well"/"very well" that residents taught with the 3-dimensional model could identify normal anatomy (52% vs 55%, P > .99) and perform an uncomplicated mediastinoscopy (48% vs 43%, P = .79) compared with those taught without the model.

Conclusions

A 3-dimensional printed model of the mediastinum may be an effective tool for teaching mediastinoscopy.

Medical 3D Printing Using Material Jetting: Technology Overview, Medical Applications, and Challenges

Material Jetting (MJT) 3D printing (3DP) is a specific technology that deposits photocurable droplets of material and colored inks to fabricate objects layer-by-layer. The high resolution and full color capability render MJT 3DP an ideal technology for 3DP in medicine as evidenced by the 3DP literature. The technology has been adopted globally across the Americas, Europe, Asia, and Australia. While MJT 3D printers can be expensive, their ability to fabricate highly accurate and multi-color parts provides a lucrative opportunity in the creation of advanced prototypes and medical models. The literature on MJT 3DP has expanded greatly as of late, in part aided by the lowering costs of the technology, and this report is the first review to document the applications of MJT in medicine. Additionally, this report portrays the technological information behind MJT 3DP, cases involving fabricated MJT 3DP models from the University of Cincinnati 3DP lab, as well as the challenges of MJT in a clinical setting, including cost, expertise in managing the machines, and scalability issues. It is expected that MJT 3DP, as imaging and segmentation technologies undergo future improvement, will be best poised with representing the voxel-level-variations captured by radiologic-image-sets due to its capacity for voxel-level-control.

Evaluating the Educational Impact of 3D-Printed Models in Cervical Laminoplasty Training: A Survey-Based Study

Background and objective The complexities of spinal surgery, particularly the intricacies of cervical pathology, demand precision and expertise in surgical interventions. Cervical laminoplasty is a procedure that requires meticulous execution and a profound understanding of delicate anatomical structures. Recognizing the limitations of traditional training methods, this study highlights the transformative impact of integrating 3D modeling and printing technologies into medical education. These technologies provide an immersive, interactive, and highly detailed training platform, enabling aspiring surgeons to visualize, dissect, and practice procedures in a risk-free environment. Beyond education, 3D models enhance patient-doctor communication, enable precise preoperative planning, facilitate custom implant design, and support a personalized approach to spinal surgery. Collectively, these advancements hold the promise of reducing surgical errors and improving outcomes. Materials and methods Thirty-eight participants, including neurosurgeons, residents, and medical doctors, were enrolled in this study. High-resolution CT scans, obtained with informed consent to ensure confidentiality and ethical compliance, were used to create the 3D models. These models, printed with polylactic acid (PLA) filament and refined through post-processing, achieved high anatomical accuracy and quality. The training program combined lectures, live demonstrations, and hands-on sessions with 3D models. Participants' experiences and perceptions were evaluated through a survey, focusing on the models' utility and realism in advancing surgical skills. Results The participants overwhelmingly praised the 3D models for their utility in helping to understand cervical laminoplasty concepts and enhancing their learning compared to traditional methods. The models were particularly valued for their accurate representation of anatomical structures and improved visualization of surgical steps. Notably, 81.6% of participants found the models extremely beneficial in planning surgical approaches. The survey results unanimously highlighted the transformative potential of 3D models in medical education. Participants strongly recommended their integration into training programs and preoperative planning processes, emphasizing their ability to elevate the learning experience and improve surgical preparedness. Conclusions Our findings show that 3D modeling significantly enhances training in cervical laminoplasty by providing superior learning tools and improving anatomical visualization compared to conventional methods. The unanimous endorsement from participants underscores the adaptability and precision of 3D models in medical education and preoperative planning. As an indispensable resource in modern medical training, these models represent a pivotal advancement in preparing surgeons for the complexities of spinal surgery.

Development of Tailored Porous Ti6Al4V Materials by Extrusion 3D Printing

Nowadays, metallic bone replacement is in high demand due to different issues, like sicknesses and accidents. Thus, bone implants are fabricated with tailored properties and microstructure for long-term use in the human body. To improve such implants, 3D printing is the most promising technique. Therefore, this work aims to evaluate the fabrication of porous materials by extrusion 3D printing of Ti6Al4V. Cylindrical samples were fabricated from pellets for metal injection molding of Ti6Al4V powders, creating hexagonal channels with three different sizes. The densification kinetics was evaluated by dilatometry tests, which enabled following the densification of the samples during the sintering cycle. Subsequently, the samples were characterized by scanning electron microscopy and X-ray computed tomography to analyze their microstructure. Compression tests evaluated the mechanical strength of sintered samples. It was found that the hexagonal shape during printing is better defined as the channel size increases. The results show similar behavior for each of the channel sizes during sintering; however, greater densification is obtained as the channel size decreases. Additionally, microporosity is obtained at the particle level, which is completely interconnected, ensuring the passage of fluids through the entire sample. On the other hand, as the channel size increases, Young's modulus and yield strength are considerably reduced. The main conclusion is that parts with two scales of porosity can be designed by the 3D printing extrusion process.

Utilizing a Fully Digital Approach for Oral Squamous Cell Carcinoma Treatment and Zygomatic Implant-Based Rehabilitation for Maxillary Defects

This clinical report details the functional and esthetic rehabilitation of a patient with a severe maxillary defect secondary to subtotal maxillectomy for oral squamous cell carcinoma using a maxillary prosthesis anchored by 4 zygomatic implants. The procedure involved meticulous subtotal maxillectomy and defect repair with zygomatic implant support, incorporating advanced digital surgical methods, including 3D reconstruction, computer-guided surgery, and photogrammetry (Icam4D). A 3D finite element analysis was conducted to assess the method's efficacy in analyzing stress distribution around the zygomatic implants. The patient expressed high satisfaction with the prosthesis's functionality, esthetics, speech, and swallowing capabilities, underscoring the value of zygomatic implant-supported maxillofacial prosthetics. This synergy of advanced planning, surgical precision, and biomechanical analysis marks a significant advancement in maxillofacial prosthetics.

Three-Dimensional Printing in Spinal Surgery

OBJECTIVES

Carry out an update and systematic review on the use of three-dimensional printing (3DP) in spinal surgery.

METHODS

A systematic literature review was performed using the PubMed database in March 2024. "Spine surgery" and "3DP" were the search terms. Only articles published from 2014 to 2024 and clinical trails were selected for inclusion. Non-English or Spanish articles were excluded. This review complied with the Preferred Reported Items for Systematic Reviews and Meta-Analysis guideline.

RESULTS

Ten articles were included after screening and evaluation. The majority of the studied diseases were deformities (n = 3) and traumas (n = 3), followed by degenerative diseases (n = 2). Two articles dealt with surgical techniques. Six articles studied the creation of personalized guides for inserting screws; 2 were about education, one related to educating patients about their disease and the other to teaching residents surgical techniques; 2 other articles addressed surgical planning, where biomodels were printed to study anatomy and surgical programming.

CONCLUSIONS

3DP is one of the most-used tools in spine surgeries, but there are still randomized articles available on the subject. Using this technology seems to have a positive effect on patient education regarding their disease and surgical planning.

Personalized Biomodel of the Cervical Spine for Laboratory Laminoplasty Training

OBJECTIVE

The use of biomodels in the laboratory for studying and training cervical laminoplasty has not yet been reported. We propose the use of a cervical spine biomodel for surgical laminoplasty training.

METHODS

This is an experimental study. Ten 3D identical cervical spine biomodels were printed based on computed tomography (CT) and magnetic resonance imaging scans of a patient diagnosed with spondylotic cervical myelopathy. The additive manufacturing method used fused deposition modeling and polylactic acid (PLA) was selected as the raw material. The sample was divided into 2 groups: control (n = 5; the biomodels were submitted to CT scanning) and open-door (n = 5; the biomodels were submitted to open-door laminoplasty and postoperative CT). The area and anteroposterior diameter of the vertebral canal were measured on CT scans.

RESULTS

Printing each piece took 12 hours. During the surgical procedure, there was sufficient support from the biomodels to keep them immobilized. Using the drill was feasible; however continuous irrigation was mandatory to prevent plastic material overheating. The raw material made the biomodel CT study possible. The vertebral canal dimensions increased 24.80% (0.62 cm2) in area and 24.88% (3.12 mm) in anteroposterior diameter CONCLUSIONS: The cervical spine biomodels can be used for laminoplasty training, even by using thermosensitive material such as PLA. The use of continuous irrigation is essential while drilling.

Sensitivity of Frequency Domain Near Infrared Spectroscopy for Neurovascular Structure Detection in Biotissue Volume: Numerical Modeling Results

Through numerical modeling, it has been determined that near infrared spectroscopy with a frequency domain approach can detect neurovascular structures with diameters from 0.5 mm at source-detector distances of 5-8 mm, depending on optical parameters and technical implementation of the method. Among the five classical machine learning methods considered, quadratic discriminant analysis is the most effective for detection. Furthermore, it has been demonstrated that the use of a photomultiplier tube and the registration of both amplitude and phase signal components exhibit the highest sensitivity. Spectroscopy can rival modern ultrasound for detecting arterial vessels. A cross-shaped probe configuration improves sensitivity, and the ratio of reduced scattering coefficient values at different wavelengths is informative for blood-filled vessel detection. These findings are consistent with and significantly extend previous experimental in vivo and in situ studies and could be valuable for intraoperative diagnostic tasks, particularly in neurosurgery.

Assessment of Obesity as Risk Factor of Lumbar Disc Surgery: Retrospective Analysis of 598 Cases and Simulated Surgery on 3D-Printed Models

(1) Background: Obesity poses known risks in surgery, including a prolonged operation time and postoperative complications. Given the rising obesity rates and frequent lumbar disc surgeries, understanding these risks is crucial. This study aims to assess the impact of obesity on operation duration and postoperative complications in lumbar disc prolapse surgery. (2) Methods: We retrospectively analyzed 598 patients with monosegmental disc herniation, correlating their body mass index (BMI) as a surrogate parameter for obesity with operation time. Excluding complex cases (multi-segmental herniations or recurrent herniations), complication rates and hospital stays were recorded. Simulated surgeries on 3D-printed models of varying obesity levels examined operation times and instrument suitability. (3) Results: Of these patients, 438 patients had a BMI of <30, and 160 patients had a BMI of ≥30. Complication rates showed no significant differences between groups. Linear regression analysis failed to establish a sole dependency of operation time on BMI, with R2 = 0.039 for the normal-weight group (BMI < 30) and R2 = 0.059 for the obese group (BMI ≥ 30). The simulation operations on the 3D-printed models of varying degrees of obesity showed a significant increase in the simulated operation time with higher levels of obesity. A geometrically inadequate set of surgical instruments was assumed to be a significant factor in the simulated increase in operating time. (4) Conclusions: While various factors influence operation time, obesity alone does not significantly increase it. However, simulated surgeries highlighted the impact of obesity, particularly on instrument limitations. Understanding these complexities is vital for optimizing surgical outcomes in obese patients.

Microwave-Induced Processing of Free-Standing 3D Printouts: An Effortless Route to High-Redox Kinetics in Electroanalysis

3D-printable composites have become an attractive option used for the design and manufacture of electrochemical sensors. However, to ensure proper charge-transfer kinetics at the electrode/electrolyte interface, activation is often required, with this step consisting of polymer removal to reveal the conductive nanofiller. In this work, we present a novel effective method for the activation of composites consisting of poly(lactic acid) filled with carbon black (CB-PLA) using microwave radiation. A microwave synthesizer used in chemical laboratories (CEM, Matthews, NC, USA) was used for this purpose, establishing that the appropriate activation time for CB-PLA electrodes is 15 min at 70 °C with a microwave power of 100 W. However, the usefulness of an 80 W kitchen microwave oven is also presented for the first time and discussed as a more sustainable approach to CB-PLA electrode activation. It has been established that 10 min in a kitchen microwave oven is adequate to activate the electrode. The electrochemical properties of the microwave-activated electrodes were determined by electrochemical techniques, and their topography was characterized using scanning electron microscopy (SEM), Raman spectroscopy, and contact-angle measurements. This study confirms that during microwave activation, PLAs decompose to uncover the conductive carbon-black filler. We deliver a proof-of-concept of the utility of kitchen microwave-oven activation of a 3D-printed, free-standing electrochemical cell (FSEC) in paracetamol electroanalysis in aqueous electrolyte solution. We established satisfactory limits of linearity for paracetamol detection using voltammetry, ranging from 1.9 μM to 1 mM, with a detection limit (LOD) of 1.31 μM.

Review of recent advances in bone scaffold fabrication methods for tissue engineering for treating bone diseases and sport injuries

Despite advancements in medical care, the management of bone injuries remains one of the most significant challenges in the fields of medicine and sports medicine globally. Bone tissue damage is often associated with aging, reduced quality of life, and various conditions such as trauma, cancer, and infection. While bone tissue possesses the natural capacity for self-repair and regeneration, severe damage may render conventional treatments ineffective, and bone grafting may be limited due to secondary surgical procedures and potential disease transmission. In such cases, bone tissue engineering has emerged as a viable approach, utilizing cells, scaffolds, and growth factors to repair damaged bone tissue. This research shows a comprehensive review of the current literature on the most important and effective methods and materials for improving the treatment of these injuries. Commonly employed cell types include osteogenic cells, embryonic stem cells, and mesenchymal cells, while scaffolds play a crucial role in bone tissue regeneration. To create an effective bone scaffold, a thorough understanding of bone structure, material selection, and examination of scaffold fabrication techniques from inception to the present day is necessary. By gaining insights into these three key components, the ability to design and construct appropriate bone scaffolds can be achieved. Bone tissue engineering scaffolds are evaluated based on factors such as strength, porosity, cell adhesion, biocompatibility, and biodegradability. This article examines the diverse categories of bone scaffolds, the materials and techniques used in their fabrication, as well as the associated merits and drawbacks of these approaches. Furthermore, the review explores the utilization of various scaffold types in bone tissue engineering applications.

Multiscale embedded printing of engineered human tissue and organ equivalents

Creating tissue and organ equivalents with intricate architectures and multiscale functional feature sizes is the first step toward the reconstruction of transplantable human tissues and organs. Existing embedded ink writing approaches are limited by achievable feature sizes ranging from hundreds of microns to tens of millimeters, which hinders their ability to accurately duplicate structures found in various human tissues and organs. In this study, a multiscale embedded printing (MSEP) strategy is developed, in which a stimuli-responsive yield-stress fluid is applied to facilitate the printing process. A dynamic layer height control method is developed to print the cornea with a smooth surface on the order of microns, which can effectively overcome the layered morphology in conventional extrusion-based three-dimensional bioprinting methods. Since the support bath is sensitive to temperature change, it can be easily removed after printing by tuning the ambient temperature, which facilitates the fabrication of human eyeballs with optic nerves and aortic heart valves with overhanging leaflets on the order of a few millimeters. The thermosensitivity of the support bath also enables the reconstruction of the full-scale human heart on the order of tens of centimeters by on-demand adding support bath materials during printing. The proposed MSEP demonstrates broader printable functional feature sizes ranging from microns to centimeters, providing a viable and reliable technical solution for tissue and organ printing in the future.

Biofabrication methods for reconstructing extracellular matrix mimetics

In the human body, almost all cells interact with extracellular matrices (ECMs), which have tissue and organ-specific compositions and architectures. These ECMs not only function as cellular scaffolds, providing structural support, but also play a crucial role in dynamically regulating various cellular functions. This comprehensive review delves into the examination of biofabrication strategies used to develop bioactive materials that accurately mimic one or more biophysical and biochemical properties of ECMs. We discuss the potential integration of these ECM-mimics into a range of physiological and pathological in vitro models, enhancing our understanding of cellular behavior and tissue organization. Lastly, we propose future research directions for ECM-mimics in the context of tissue engineering and organ-on-a-chip applications, offering potential advancements in therapeutic approaches and improved patient outcomes.

Advanced Strategies for the Fabrication of Multi-Material Anatomical Models of Complex Pediatric Oncologic Cases

The printing and manufacturing of anatomical 3D models has gained popularity in complex surgical cases for surgical planning, simulation and training, the evaluation of anatomical relations, medical device testing and patient-professional communication. 3D models provide the haptic feedback that Virtual or Augmented Reality (VR/AR) cannot provide. However, there are many technologies and strategies for the production of 3D models. Therefore, the aim of the present study is to show and compare eight different strategies for the manufacture of surgical planning and training prototypes. The eight strategies for creating complex abdominal oncological anatomical models, based on eight common pediatric oncological cases, were developed using four common technologies (stereolithography (SLA), selectie laser sinterning (SLS), fused filament fabrication (FFF) and material jetting (MJ)) along with indirect and hybrid 3D printing methods. Nine materials were selected for their properties, with the final models assessed for application suitability, production time, viscoelastic mechanical properties (shore hardness and elastic modulus) and cost. The manufacturing and post-processing of each strategy is assessed, with times ranging from 12 h (FFF) to 61 h (hybridization of FFF and SLS), as labor times differ significantly. Cost per model variation is also significant, ranging from EUR 80 (FFF) to EUR 600 (MJ). The main limitation is the mimicry of physiological properties. Viscoelastic properties and the combination of materials, colors and textures are also substantially different according to the strategy and the intended use. It was concluded that MJ is the best overall option, although its use in hospitals is limited due to its cost. Consequently, indirect 3D printing could be a solid and cheaper alternative.

A survey regarding the organizational aspects and quality systems of in-house 3D printing in oral and maxillofacial surgery in Germany

PURPOSE

The aim of the study was to get a cross-sectional overview of the current status of specific organizational procedures, quality control systems, and standard operating procedures for the use of three-dimensional (3D) printing to assist in-house workflow using additive manufacturing in oral and maxillofacial surgery (OMFS) in Germany.

METHODS

An online questionnaire including dynamic components containing 16-29 questions regarding specific organizational aspects, process workflows, quality controls, documentation, and the respective backgrounds in 3D printing was sent to OMF surgeons in university and non-university hospitals as well as private practices with and without inpatient treatment facilities. Participants were recruited from a former study population regarding 3D printing; all participants owned a 3D printer and were registered with the German Association of Oral and Maxillofacial Surgery.

RESULTS

Sixty-seven participants answered the questionnaires. Of those, 20 participants ran a 3D printer in-unit. Quality assurance measures were performed by 13 participants and underlying processes by 8 participants, respectively. Standard operating procedures regarding computer-aided design and manufacturing, post-processing, use, or storage of printed goods were non-existent in most printing units. Data segmentation as well as computer-aided design and manufacturing were conducted by a medical doctor in most cases (n = 19, n = 18, n = 8, respectively). Most participants (n = 8) stated that "medical device regulations did not have any influence yet, but an adaptation of the processes is planned for the future."

CONCLUSION

The findings demonstrated significant differences in 3D printing management in OMFS, especially concerning process workflows, quality control, and documentation. Considering the ever-increasing regulations for medical devices, there might be a necessity for standardized 3D printing recommendations and regulations in OMFS.

Towards Polycaprolactone-Based Scaffolds for Alveolar Bone Tissue Engineering: A Biomimetic Approach in a 3D Printing Technique

The alveolar bone is a unique type of bone, and the goal of bone tissue engineering (BTE) is to develop methods to facilitate its regeneration. Currently, an emerging trend involves the fabrication of polycaprolactone (PCL)-based scaffolds using a three-dimensional (3D) printing technique to enhance an osteoconductive architecture. These scaffolds are further modified with hydroxyapatite (HA), type I collagen (CGI), or chitosan (CS) to impart high osteoinductive potential. In conjunction with cell therapy, these scaffolds may serve as an appealing alternative to bone autografts. This review discusses research gaps in the designing of 3D-printed PCL-based scaffolds from a biomimetic perspective. The article begins with a systematic analysis of biological mineralisation (biomineralisation) and ossification to optimise the scaffold's structural, mechanical, degradation, and surface properties. This scaffold-designing strategy lays the groundwork for developing a research pathway that spans fundamental principles such as molecular dynamics (MD) simulations and fabrication techniques. Ultimately, this paves the way for systematic in vitro and in vivo studies, leading to potential clinical applications.

Rhabdomyosarcoma: Current Therapy, Challenges, and Future Approaches to Treatment Strategies

Rhabdomyosarcoma is a rare cancer arising in skeletal muscle that typically impacts children and young adults. It is a worldwide challenge in child health as treatment outcomes for metastatic and recurrent disease still pose a major concern for both basic and clinical scientists. The treatment strategies for rhabdomyosarcoma include multi-agent chemotherapies after surgical resection with or without ionization radiotherapy. In this comprehensive review, we first provide a detailed clinical understanding of rhabdomyosarcoma including its classification and subtypes, diagnosis, and treatment strategies. Later, we focus on chemotherapy strategies for this childhood sarcoma and discuss the impact of three mechanisms that are involved in the chemotherapy response including apoptosis, macro-autophagy, and the unfolded protein response. Finally, we discuss in vivo mouse and zebrafish models and in vitro three-dimensional bioengineering models of rhabdomyosarcoma to screen future therapeutic approaches and promote muscle regeneration.

Diverse Applications of Three-Dimensional Printing in Biomedical Engineering: A Review

A three-dimensional (3D) printing is a robotically controlled state-of-the-art technology that is promising for all branches of engineering with a meritorious emphasis to biomedical engineering. The purpose of 3D printing (3DP) is to create exact superstructures without any framework in a brief period with high reproducibility to create intricate and complex patient-tailored structures for organ regeneration, drug delivery, imaging processes, designing personalized dose-specific tablets, developing 3D models of organs to plan surgery and to understand the pathology of disease, manufacturing cost-effective surgical tools, and fabricating implants and organ substitute devices for prolonging the lives of patients, etc. The formulation of bioinks and programmed G codes help to obtain precise 3D structures, which determines the stability and functioning of the 3D-printed structures. Three-dimensional printing for medical applications is ambitious and challenging but made possible with the culmination of research expertise from various fields. Exploring and expanding 3DP for biomedical and clinical applications can be life-saving solutions. The 3D printers are cost-effective and eco-friendly, as they do not release any toxic pollutants or waste materials that pollute the environment. The sampling requirements and processing parameters are amenable, which further eases the production. This review highlights the role of 3D printers in the health care sector, focusing on their roles in tablet development, imaging techniques, disease model development, and tissue regeneration.

3D-printed external fixation guide combined with video-assisted thoracoscopic surgery for the treatment of flail chest: a technical report and case series

Background

Flail chest is a common and serious traumatic condition in thoracic surgery. The treatment of flail chest often includes open reduction and internal fixation, which is relatively traumatic, complicated, and expensive. As three-dimensional (3D) printing technology is widely used in the clinical field, the application of 3D-printed products to chest trauma will become a new treatment option. To date, the use of 3D-printed external fixation guides for flail chests has not been reported. Thus, we aimed to assess the short-term efficacy of a new technology that treated flail chests with an individualized 3D-printed external fixation guide combined with video-assisted thoracoscopic surgery (VATS).

Patients and methods

A retrospective analysis was performed on patients with flail chest treated with this new technique at our center from January 2020 to December 2022. The following parameters were included: operative time, thoracic tube extraction time, intensive care unit time, thoracic volume recovery rate, visual analog scale score 1 month postoperatively, and postoperative complication rate. All patients were followed up for at least 3 months.

Results

Five patients (mean age: 45.7 years) were enrolled; they successfully underwent surgery without chest wall deformity and quickly returned to daily life. The average number of rib fractures was 8.4; all patients had lung contusion, hemopneumothorax, and anomalous respiration. The abnormal breathing of all patients was completely corrected on postoperative day 1, and the chest wall was stable. One case experienced mild loosening of the 3D-printed guide postoperatively; however, the overall stability was not affected. The other four cases did not experience such loosening because we replaced the ordinary silk wire with a steel wire. All cases were discharged from the hospital 2 weeks postoperatively and returned to normal life 1 month after the removal of the 3D-printed guide on average. Only one case developed a superficial wound infection postoperatively, and no perioperative death occurred.

Conclusions

The 3D-printed external fixation guide combined with video-assisted thoracoscopic surgery is a novel technique in the treatment of flail chest and is safe, effective, feasible, and minimally invasive, with satisfactory clinical efficacy.

Tailoring diamondised nanocarbon-loaded poly(lactic acid) composites for highly electroactive surfaces: extrusion and characterisation of filaments for improved 3D-printed surfaces

A new 3D-printable composite has been developed dedicated to electroanalytical applications. Two types of diamondised nanocarbons - detonation nanodiamonds (DNDs) and boron-doped carbon nanowalls (BCNWs) - were added as fillers in poly(lactic acid) (PLA)-based composites to extrude 3D filaments. Carbon black served as a primary filler to reach high composite conductivity at low diamondised nanocarbon concentrations (0.01 to 0.2 S/cm, depending on the type and amount of filler). The aim was to thoroughly describe and understand the interactions between the composite components and how they affect the rheological, mechanical and thermal properties, and electrochemical characteristics of filaments and material extrusion printouts. The electrocatalytic properties of composite-based electrodes, fabricated with a simple 3D pen, were evaluated using multiple electrochemical techniques (cyclic and differential pulse voltammetry and electrochemical impedance spectroscopy). The results showed that the addition of 5 wt% of any of the diamond-rich nanocarbons fillers significantly enhanced the redox process kinetics, leading to lower redox activation overpotentials compared with carbon black-loaded PLA. The detection of dopamine was successfully achieved through fabricated composite electrodes, exhibiting lower limits of detection (0.12 μM for DND and 0.18 μM for BCNW) compared with the reference CB-PLA electrodes (0.48 μM). The thermogravimetric results demonstrated that both DND and BCNW powders can accelerate thermal degradation. The presence of diamondised nanocarbons, regardless of their type, resulted in a decrease in the decomposition temperature of the composite. The study provides insight into the interactions between composite components and their impact on the electrochemical properties of 3D-printed surfaces, suggesting electroanalytic potential.

The Innovation Press: A Primer on the Anatomy of Digital Design in Plastic Surgery

ABSTRACT

Three-dimensional (3D) printing continues to revolutionize the field of plastic surgery, allowing surgeons to adapt to the needs of individual patients and innovate, plan, or refine operative techniques. The utility of this manufacturing modality spans from surgical planning, medical education, and effective patient communication to tissue engineering and device prototyping and has valuable implications in every facet of plastic surgery. Three-dimensional printing is more accessible than ever to the surgical community, regardless of previous background in engineering or biotechnology. As such, the onus falls on the surgeon-innovator to have a functional understanding of the fundamental pipeline and processes in actualizing such innovation. We review the broad range of reported uses for 3D printing in plastic surgery, the process from conceptualization to production, and the considerations a physician must make when using 3D printing for clinical applications. We additionally discuss the role of computer-assisted design and manufacturing and virtual and augmented reality, as well as the ability to digitally modify devices using this software. Finally, a discussion of 3D printing logistics, printer types, and materials is included. With innovation and problem solving comprising key tenets of plastic surgery, 3D printing can be a vital tool in the surgeon's intellectual and digital arsenal to span the gap between concept and reality.

Recent Progress and Trends in the Development of Electrospun and 3D Printed Polymeric-Based Materials to Overcome Antimicrobial Resistance (AMR)

Antimicrobial resistance (AMR) developed by microorganisms is considered one of the most critical public health issues worldwide. This problem is affecting the lives of millions of people and needs to be addressed promptly. Mainly, antibiotics are the substances that contribute to AMR in various strains of bacteria and other microorganisms, leading to infectious diseases that cannot be effectively treated. To avoid the use of antibiotics and similar drugs, several approaches have gained attention in the fields of materials science and engineering as well as pharmaceutics over the past five years. Our focus lies on the design and manufacture of polymeric-based materials capable of incorporating antimicrobial agents excluding the aforementioned substances. In this sense, two of the emerging techniques for materials fabrication, namely, electrospinning and 3D printing, have gained significant attraction. In this article, we provide a summary of the most important findings that contribute to the development of antimicrobial systems using these technologies to incorporate various types of nanomaterials, organic molecules, or natural compounds with the required property. Furthermore, we discuss and consider the challenges that lie ahead in this research field for the coming years.

Use of Virtual Reality and Three-Dimensional Printing in the Surgical Planning of Slide Tracheoplasty

Purpose: To describe our experience using virtual reality (VR) and three-dimensional (3D) printing as complements for the surgical planning process of slide tracheoplasty (ST) in patients with congenital tracheal stenosis (CTS). Description: VR and 3D printing are used for the surgical planning of ST as a therapeutic option in three female patients under five years of age with CTS. Evaluation: We assessed the planned surgical procedure, procedural time, postoperative complications, and outcomes, as well as the main surgeon's experience with the use of the applied technologies. Conclusions: The interaction within the VR environment allowed for collaboration of the surgical plan between surgical staff and enhancement of the radiologist-surgeon communication, while procedural simulation with 3D printing prototypes allowed for refining technical abilities for the surgical interventions. Based on our experience, the application of these technologies have added value to the surgical planning of ST and its outcomes in the treatment of CTS.

3D printed biomedical devices and their applications: A review on state-of-the-art technologies, existing challenges, and future perspectives

3D printing, also known as Additive manufacturing (AM), has emerged as a transformative technology with applications across various industries, including the medical sector. This review paper provides an overview of the current status of AM technology, its challenges, and its application in the medical industry. The paper covers the different types of AM technologies, such as fused deposition modeling, stereolithography, selective laser sintering, digital light processing, binder jetting, and electron beam melting, and their suitability for medical applications. The most commonly used biomedical materials in AM, such as plastic, metal, ceramic, composite, and bio-inks, are also viewed. The challenges of AM technology, such as material selection, accuracy, precision, regulatory compliance, cost and quality control, and standardization, are also discussed. The review also highlights the various applications of AM in the medical sector, including the production of patient-specific surgical guides, prosthetics, orthotics, and implants. Finally, the review highlights the Internet of Medical Things (IoMT) and artificial intelligence (AI) for regulatory frameworks and safety standards for 3D-printed biomedical devices. The review concludes that AM technology can transform the healthcare industry by enabling patients to access more personalized and reasonably priced treatment alternatives. Despite the challenges, integrating AI and IoMT with 3D printing technology is expected to play a vital role in the future of biomedical device applications, leading to further advancements and improvements in patient care. More research is needed to address the challenges and optimize its use for medical applications to utilize AM's potential in the medical industry fully.

The Concept of Scaffold-Guided Bone Regeneration for the Treatment of Long Bone Defects: Current Clinical Application and Future Perspective

The treatment of bone defects remains a challenging clinical problem with high reintervention rates, morbidity, and resulting significant healthcare costs. Surgical techniques are constantly evolving, but outcomes can be influenced by several parameters, including the patient's age, comorbidities, systemic disorders, the anatomical location of the defect, and the surgeon's preference and experience. The most used therapeutic modalities for the regeneration of long bone defects include distraction osteogenesis (bone transport), free vascularized fibular grafts, the Masquelet technique, allograft, and (arthroplasty with) mega-prostheses. Over the past 25 years, three-dimensional (3D) printing, a breakthrough layer-by-layer manufacturing technology that produces final parts directly from 3D model data, has taken off and transformed the treatment of bone defects by enabling personalized therapies with highly porous 3D-printed implants tailored to the patient. Therefore, to reduce the morbidities and complications associated with current treatment regimens, efforts have been made in translational research toward 3D-printed scaffolds to facilitate bone regeneration. Three-dimensional printed scaffolds should not only provide osteoconductive surfaces for cell attachment and subsequent bone formation but also provide physical support and containment of bone graft material during the regeneration process, enhancing bone ingrowth, while simultaneously, orthopaedic implants supply mechanical strength with rigid, stable external and/or internal fixation. In this perspective review, we focus on elaborating on the history of bone defect treatment methods and assessing current treatment approaches as well as recent developments, including existing evidence on the advantages and disadvantages of 3D-printed scaffolds for bone defect regeneration. Furthermore, it is evident that the regulatory framework and organization and financing of evidence-based clinical trials remains very complex, and new challenges for non-biodegradable and biodegradable 3D-printed scaffolds for bone regeneration are emerging that have not yet been sufficiently addressed, such as guideline development for specific surgical indications, clinically feasible design concepts for needed multicentre international preclinical and clinical trials, the current medico-legal status, and reimbursement. These challenges underscore the need for intensive exchange and open and honest debate among leaders in the field. This goal can be addressed in a well-planned and focused stakeholder workshop on the topic of patient-specific 3D-printed scaffolds for long bone defect regeneration, as proposed in this perspective review.

3D and 4D Bioprinting Technologies: A Game Changer for the Biomedical Sector?

Bioprinting is an innovative and emerging technology of additive manufacturing (AM) and has revolutionized the biomedical sector by printing three-dimensional (3D) cell-laden constructs in a precise and controlled manner for numerous clinical applications. This approach uses biomaterials and varying types of cells to print constructs for tissue regeneration, e.g., cardiac, bone, corneal, cartilage, neural, and skin. Furthermore, bioprinting technology helps to develop drug delivery and wound healing systems, bio-actuators, bio-robotics, and bio-sensors. More recently, the development of four-dimensional (4D) bioprinting technology and stimuli-responsive materials has transformed the biomedical sector with numerous innovations and revolutions. This issue also leads to the exponential growth of the bioprinting market, with a value over billions of dollars. The present study reviews the concepts and developments of 3D and 4D bioprinting technologies, surveys the applications of these technologies in the biomedical sector, and discusses their potential research topics for future works. It is also urged that collaborative and valiant efforts from clinicians, engineers, scientists, and regulatory bodies are needed for translating this technology into the biomedical, pharmaceutical, and healthcare systems.

Physico-chemical and Textural Properties of 3D Printed Plant-based and Hybrid Soft Meat Analogs

This study investigated the physico-chemical and textural properties of 3D-printed pea protein-only and pea protein-chicken-based hybrid meat analogs. Both pea protein isolate (PPI)-only and hybrid cooked meat analogs had a similar moisture content of approximately 70%, which was similar to that of chicken mince. However, the protein content increased significantly with the amount of chicken in the hybrid paste undergoing 3D printing and cooking. Significant differences were observed in the hardness values of the non-printed cooked pastes and the 3D printed cooked counterparts, suggesting that the 3D printing process reduces the hardness of the samples and is a suitable method to produce a soft meal, and has significant potential in elderly health care. Scanning electron microscopy (SEM) revealed that adding chicken to the plant protein matrix led to better fiber formation. PPI itself was not able to form any fibers merely by 3D printing and cooking in boiling water. Protein-protein interactions were also studied through the protein solubility test, which indicated that hydrogen bonding was the major bonding that contributed to the structure formation in cooked printed meat analogs. In addition, disulfide bonding was correlated with improved fibrous structures, as observed through SEM.

Modular 3D-printed fluorometer/photometer for determination of iron(ii), caffeine, and ciprofloxacin in pharmaceutical samples

The demand for the development of portable and low-cost analytical devices has encouraged studies employing additive manufacturing techniques, such as 3D-printing. This method can be used to produce components such as printed electrodes, photometers, and fluorometers for low-cost systems that provide advantages including low sample volume, reduced chemical waste, and easy coupling with LED-based optics and other instrumental devices. In the present work, a modular 3D-printed fluorometer/photometer was designed and applied for the determination of caffeine (CAF), ciprofloxacin (CIP), and Fe(ii) in pharmaceutical samples. All the plastic parts were printed separately by a 3D printer, using Tritan as the plastic material (black color). The final size of the modular 3D-printed device was 12 × 8 cm. The radiation sources were light-emitting diodes (LEDs), while a light dependent resistor (LDR) was used as a photodetector. The analytical curves obtained for the device were: y = 3.00 × 10^-4 [CAF] + 1.00 and R ² = 0.987 for caffeine; y = 6.90 × 10^-3 [CIP] - 3.39 × 10^-2 and R ² = 0.991 for ciprofloxacin; and y = 1.12 × 10^-1 [Fe(ii)] + 1.26 × 10^-2 and R ² = 0.998 for iron(ii). The results obtained using the developed device were compared with reference methods, with no statistically significant differences observed. The 3D-printed device was composed of moveable parts, providing flexibility for adaptation and application as a photometer or fluorometer, by only switching the photodetector position. The LED could also be easily switched, permitting application of the device for different purposes. The cost of the device, including the printing and electronic components, was lower than US$10. The use of 3D-printing enables the development of portable instruments for use in remote locations with a lack of research resources.

Patient-Specific 3D Printed Soft Models for Liver Surgical Planning and Hands-On Training

Background: Pre-surgical simulation-based training with three-dimensional (3D) models has been intensively developed in complex surgeries in recent years. This is also the case in liver surgery, although with fewer reported examples. The simulation-based training with 3D models represents an alternative to current surgical simulation methods based on animal or ex vivo models or virtual reality (VR), showing reported advantages, which makes the development of realistic 3D-printed models an option. This work presents an innovative, low-cost approach for producing patient-specific 3D anatomical models for hands-on simulation and training. Methods: The article reports three paediatric cases presenting complex liver tumours that were transferred to a major paediatric referral centre for treatment: hepatoblastoma, hepatic hamartoma and biliary tract rhabdomyosarcoma. The complete process of the additively manufactured liver tumour simulators is described, and the different steps for the correct development of each case are explained: (1) medical image acquisition; (2) segmentation; (3) 3D printing; (4) quality control/validation; and (5) cost. A digital workflow for liver cancer surgical planning is proposed. Results: Three hepatic surgeries were planned, with 3D simulators built using 3D printing and silicone moulding techniques. The 3D physical models showed highly accurate replications of the actual condition. Additionally, they proved to be more cost-effective in comparison with other models. Conclusions: It is demonstrated that it is possible to manufacture accurate and cost-effective 3D-printed soft surgical planning simulators for treating liver cancer. The 3D models allowed for proper pre-surgical planning and simulation training in the three cases reported, making it a valuable aid for surgeons.

Navigating the intersection of 3D printing, software regulation and quality control for point-of-care manufacturing of personalized anatomical models

3D printing technology has become increasingly popular in healthcare settings, with applications of 3D printed anatomical models ranging from diagnostics and surgical planning to patient education. However, as the use of 3D printed anatomical models becomes more widespread, there is a growing need for regulation and quality control to ensure their accuracy and safety. This literature review examines the current state of 3D printing in hospitals and FDA regulation process for software intended for use in producing 3D printed models and provides for the first time a comprehensive list of approved software platforms alongside the 3D printers that have been validated with each for producing 3D printed anatomical models. The process for verification and validation of these 3D printed products, as well as the potential for inaccuracy in these models, is discussed, including methods for testing accuracy, limits, and standards for accuracy testing. This article emphasizes the importance of regulation and quality control in the use of 3D printing technology in healthcare, the need for clear guidelines and standards for both the software and the printed products to ensure the safety and accuracy of 3D printed anatomical models, and the opportunity to expand the library of regulated 3D printers.

A systematic review of the application of 3D-printed models to colorectal surgical training

BACKGROUND

The aim of this review was to explore the role of three-dimensional (3D) printing in colorectal surgical education and procedural simulation, and to assess the effectiveness of 3D-printed models in anatomic and operative education in colorectal surgery.

METHODS

A systematic review of the literature was performed following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to identify relevant publications relating to the use of 3D-printed models in colorectal surgery in an educational context. The search encompassed OVID Medline, Web of Science and EMBASE including papers in English published from 1 January 1995 to 1 January 2023. A total of 1018 publications were screened, and 5 met the criteria for inclusion in this review.

RESULTS

Four distinct 3D models were described across five studies. Two models demonstrated objective benefits in the use of 3D-printed models in anatomical education in academic outcomes at all levels of learner medical experience and were well accepted by learners. One model utilised for preoperative visualisation demonstrated improved operative outcomes in complete mesocolic excision compared with preoperative imaging review, with a 22.1% reduction in operative time (p < 0.001), 9.2% reduction in surgical duration (p = 0.035) and 37.3% reduction in intraoperative bleeding volume amongst novice surgeons (p < 0.01). Technical simulation has been demonstrated in a feasibility context in one model but remains limited in scope and application on account of the characteristics of available printing materials.

CONCLUSIONS

3D printing is well accepted and effective for anatomic education and preoperative procedural planning amongst colorectal surgeons, trainees and medical students but remains a technology in the early stages of its possible application. Technological advancements are required to improve the tissue realism of 3D-printed organ models to achieve greater fidelity and provide realistic colorectal surgical simulations.

Application of 3D Printing in Bone Grafts

The application of 3D printing in bone grafts is gaining in importance and is becoming more and more popular. The choice of the method has a direct impact on the preparation of the patient for surgery, the probability of rejection of the transplant, and many other complications. The aim of the article is to discuss methods of bone grafting and to compare these methods. This review of literature is based on a selective literature search of the PubMed and Web of Science databases from 2001 to 2022 using the search terms “bone graft”, “bone transplant”, and “3D printing”. In addition, we also reviewed non-medical literature related to materials used for 3D printing. There are several methods of bone grafting, such as a demineralized bone matrix, cancellous allograft, nonvascular cortical allograft, osteoarticular allograft, osteochondral allograft, vascularized allograft, and an autogenic transplant using a bone substitute. Currently, autogenous grafting, which involves removing the patient’s bone from an area of low aesthetic importance, is referred to as the gold standard. 3D printing enables using a variety of materials. 3D technology is being applied to bone tissue engineering much more often. It allows for the treatment of bone defects thanks to the creation of a porous scaffold with adequate mechanical strength and favorable macro- and microstructures. Bone tissue engineering is an innovative approach that can be used to repair multiple bone defects in the process of transplantation. In this process, biomaterials are a very important factor in supporting regenerative cells and the regeneration of tissue. We have years of research ahead of us; however, it is certain that 3D printing is the future of transplant medicine.

Three-Dimensional-Printed Splint for Use in Pediatric Mandibular Fracture

Mandibular fractures are the most common type, accounting for about 71% of facial fractures in children. The mandible is the only movable bone in the craniomaxillofacial region. The injury of the mandible has a serious impact on the functions of children's mouth opening, chewing, pronunciation, and occlusion. Therefore, the treatment of children's mandibular fractures is particularly important. Because of the characteristics of children with permanent tooth germ blocking and strong skeletal development, the treatment methods of adults cannot simply be used in children with mandibular fractures. Here, we demonstrate the simple, reliable method using 3-dimensional-printing splint for stability of the fracture segments in pediatric patients.

(Bio)printing in Personalized Medicine—Opportunities and Potential Benefits

The global development of technologies now enters areas related to human health, with a transition from conventional to personalized medicine that is based to a significant extent on (bio)printing. The goal of this article is to review some of the published scientific literature and to highlight the importance and potential benefits of using 3D (bio)printing techniques in contemporary personalized medicine and also to offer future perspectives in this research field. The article is prepared according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Web of Science, PubMed, Scopus, Google Scholar, and ScienceDirect databases were used in the literature search. Six authors independently performed the search, study selection, and data extraction. This review focuses on 3D bio(printing) in personalized medicine and provides a classification of 3D bio(printing) benefits in several categories: overcoming the shortage of organs for transplantation, elimination of problems due to the difference between sexes in organ transplantation, reducing the cases of rejection of transplanted organs, enhancing the survival of patients with transplantation, drug research and development, elimination of genetic/congenital defects in tissues and organs, and surgery planning and medical training for young doctors. In particular, we highlight the benefits of each 3D bio(printing) applications included along with the associated scientific reports from recent literature. In addition, we present an overview of some of the challenges that need to be overcome in the applications of 3D bioprinting in personalized medicine. The reviewed articles lead to the conclusion that bioprinting may be adopted as a revolution in the development of personalized, medicine and it has a huge potential in the near future to become a gold standard in future healthcare in the world.

Exploring the value of three-dimensional printing and virtualization in paediatric healthcare: A multi-case quality improvement study

Background

Three-dimensional printing is being utilized in clinical medicine to support activities including surgical planning, education, and medical device fabrication. To better understand the impacts of this technology, a survey was implemented with radiologists, specialist physicians, and surgeons at a tertiary care hospital in Canada, examining multidimensional value and considerations for uptake.

Objectives

To examine how three-dimensional printing can be integrated into the paediatric context and highlight areas of impact and value to the healthcare system using Kirkpatrick's Model. Secondarily, to explore the perspective of clinicians utilizing three-dimensional models and how they make decisions about whether or not to use the technology in patient care.

Methods

A post-case survey. Descriptive statistics are provided for Likert-style questions, and a thematic analysis was conducted to identify common patterns in open-ended responses.

Results

In total, 37 respondents were surveyed across 19 clinical cases, providing their perspectives on model reaction, learning, behaviour, and results. We found surgeons and specialists to consider the models more beneficial than radiologists. Results further showed that the models were more helpful when used to assess the likelihood of success or failure of clinical management strategies, and for intraoperative orientation. We demonstrate that three-dimensional printed models could improve perioperative metrics, including a reduction in operating room time, but with a reciprocal effect on pre-procedural planning time. Clinicians who shared the models with patients and families thought it increased understanding of the disease and surgical procedure, and had no effect on their consultation time.

Conclusions

Three-dimensional printing and virtualization were used in preoperative planning and for communication among the clinical care team, trainees, patients, and families. Three-dimensional models provide multidimensional value to clinical teams, patients, and the health system. Further investigation is warranted to assess value in other clinical areas, across disciplines, and from a health economics and outcomes perspective.

Assessment of a novel patient-specific 3D printed multi-material simulator for endoscopic sinus surgery

Background: Three-dimensional (3D) printing is an emerging tool in the creation of anatomical models for surgical training. Its use in endoscopic sinus surgery (ESS) has been limited because of the difficulty in replicating the anatomical details. Aim: To describe the development of a patient-specific 3D printed multi-material simulator for use in ESS, and to validate it as a training tool among a group of residents and experts in ear-nose-throat (ENT) surgery. Methods: Advanced material jetting 3D printing technology was used to produce both soft tissues and bony structures of the simulator to increase anatomical realism and tactile feedback of the model. A total of 3 ENT residents and 9 ENT specialists were recruited to perform both non-destructive tasks and ESS steps on the model. The anatomical fidelity and the usefulness of the simulator in ESS training were evaluated through specific questionnaires. Results: The tasks were accomplished by 100% of participants and the survey showed overall high scores both for anatomy fidelity and usefulness in training. Dacryocystorhinostomy, medial antrostomy, and turbinectomy were rated as accurately replicable on the simulator by 75% of participants. Positive scores were obtained also for ethmoidectomy and DRAF procedures, while the replication of sphenoidotomy received neutral ratings by half of the participants. Conclusion: This study demonstrates that a 3D printed multi-material model of the sino-nasal anatomy can be generated with a high level of anatomical accuracy and haptic response. This technology has the potential to be useful in surgical training as an alternative or complementary tool to cadaveric dissection.

Virtual surgical planning and 3D printing: Methodology and applications in veterinary oromaxillofacial surgery

Virtual surgical planning is the process of planning and rehearsing a surgical procedure completely within the virtual environment on computer models. Virtual surgical planning and 3D printing is gaining popularity in veterinary oromaxillofacial surgery and are viable tools for the most basic to the most complex cases. These techniques can provide the surgeon with improved visualization and, thus, understanding of the patients' 3D anatomy. Virtual surgical planning is feasible in a clinical setting and may decrease surgical time and increase surgical accuracy. For example, pre-operative implant contouring on a 3D-printed model can save time during surgery; 3D-printed patient-specific implants and surgical guides help maintain normocclusion after mandibular reconstruction; and the presence of a haptic model in the operating room can improve surgical precision and safety. However, significant time and financial resources may need to be allocated for planning and production of surgical guides and implants. The objectives of this manuscript are to provide a description of the methods involved in virtual surgical planning and 3D printing as they apply to veterinary oromaxillofacial surgery and to highlight these concepts with the strategic use of examples. In addition, the advantages and disadvantages of the methods as well as the required software and equipment will be discussed.

Self-Searching Writing of Human-Organ-Scale Three-Dimensional Topographic Scaffolds with Shape Memory by Silkworm-like Electrospun Autopilot Jet

Bioengineered scaffolds satisfying both the physiological and anatomical considerations could potentially repair partially damaged tissues to whole organs. Although three-dimensional (3D) printing has become a popular approach in making 3D topographic scaffolds, electrospinning stands out from all other techniques for fabricating extracellular matrix mimicking fibrous scaffolds. However, its complex charge-influenced jet-field interactions and the associated random motion were hardly overcome for almost a century, thus preventing it from being a viable technique for 3D topographic scaffold construction. Herein, we constructed, for the first time, geometrically challenging 3D fibrous scaffolds using biodegradable poly(ε-caprolactone), mimicking human-organ-scale face, female breast, nipple, and vascular graft, with exceptional shape memory and free-standing features by a novel field self-searching process of autopilot polymer jet, essentially resembling the silkworm-like cocoon spinning. With a simple electrospinning setup and innovative writing strategies supported by simulation, we successfully overcame the intricate jet-field interactions while preserving high-fidelity template topographies, via excellent target recognition, with pattern features ranging from 100's μm to 10's cm. A 3D cell culture study ensured the anatomical compatibility of the so-made 3D scaffolds. Our approach brings the century-old electrospinning to the new list of viable 3D scaffold constructing techniques, which goes beyond applications in tissue engineering.

3D-printed bolus ensures the precise postmastectomy chest wall radiation therapy for breast cancer

Purpose

To investigate the values of a 3D-printed bolus ensuring the precise postmastectomy chest wall radiation therapy for breast cancer.

Methods and materials

In the preclinical study on the anthropomorphic phantom, the 3D-printed bolus was used for dosimetry and fitness evaluation. The dosimetric parameters of planning target volume (PTV) were assessed, including D_min, D_max, D_mean, D_95%, homogeneity index (HI), conformity index (CI), and organs at risk (OARs). The absolute percentage differences (|%diff|) between the theory and fact skin dose were also estimated, and the follow-up was conducted for potential skin side effects.

Results

In preclinical studies, a 3D-printed bolus can better ensure the radiation coverage of PTV (HI 0.05, CI 99.91%), the dose accuracy (|%diff| 0.99%), and skin fitness (mean air gap 1.01 mm). Of the 27 eligible patients, we evaluated the radiation dose parameter (median(min–max): D_min 4967(4789–5099) cGy, D_max 5447(5369–5589) cGy, D_mean 5236(5171–5323) cGy, D_95% 5053(4936–5156) cGy, HI 0.07 (0.06–0.17), and CI 99.94% (97.41%–100%)) and assessed the dose of OARs (ipsilateral lung: D_mean 1341(1208–1385) cGy, V₅ 48.06%(39.75%–48.97%), V₂₀ 24.55%(21.58%–26.93%), V₃₀ 18.40%(15.96%–19.16%); heart: D_mean 339(138–640) cGy, V₃₀ 1.10%(0%–6.14%), V₄₀ 0.38%(0%–4.39%); spinal cord PRV: D_max 639(389–898) cGy). The skin doses in vivo were D_theory 208.85(203.16–212.53) cGy, D_fact 209.53(204.14–214.42) cGy, and |%diff| 1.77% (0.89–2.94%). Of the 360 patients enrolled in the skin side effect follow-up study (including the above 27 patients), grade 1 was the most common toxicity (321, 89.2%), some of which progressing to grade 2 or grade 3 (32, 8.9% or 7, 1.9%); the radiotherapy interruption rate was 1.1%.

Conclusion

A 3D-printed bolus can guarantee the precise radiation dose on skin surface, good fitness to skin, and controllable acute skin toxicity, which possesses a great clinical application value in postmastectomy chest call radiation therapy for breast cancer.

3D printed scaffold design for bone defects with improved mechanical and biological properties

Bone defect treatment is still a challenge in clinics, and synthetic bone scaffolds with adequate mechanical and biological properties are highly needed. Adequate waste and nutrient exchange of the implanted scaffold with the surrounded tissue is a major concern. Moreover, the risk of mechanical instability in the defect area during regular activity increases as the defect size increases. Thus, scaffolds with better mass transportation and mechanical properties are desired. This study introduces 3D printed polymeric scaffolds with a continuous pattern, ZigZag-Spiral pattern, for bone defects treatments. This pattern has a uniform distribution of pore size, which leads to uniform distribution of wall shear stress which is crucial for uniform differentiation of cells attached to the scaffolds. The mechanical, mass transportation, and biological properties of the 3D printed scaffolds are evaluated. The results show that the presented scaffolds have permeability similar to natural bone and, with the same porosity level, have higher mechanical properties than scaffolds with conventional lay-down patterns 0-90° and 0-45°. Finally, human mesenchymal stem cells are seeded on the scaffolds to determine the effects of geometrical microstructure on cell attachment and morphology. The results show that cells in scaffold with ZigZag-Spiral pattern infilled pores gradually, while the other patterns need more time to fill the pores. Considering mechanical, transportation, and biological properties of the considered patterns, scaffolds with ZigZag-Spiral patterns can mimic the properties of cancellous bones and be a better choice for treatments of bone defects.

CT-Derived 3D Printing for Coronary Artery Cannulation Simulator Design Manufacturing

Mastering coronary angiography requires practice. Cadavers and animals do not accurately represent the human anatomical body, and practicing with actual patients has medical safety issues. Simulation offers safe and realistic conditions for cardiology intervention training. In this study, we propose a novel 3D printed simulator that contains physically realistic anatomy and has four access points. It increases safety for patients and students, and production is low-cost. We aimed to make and validate this simulator design as a prototype for coronary cannulation training. It was designed using computed tomography (CT) scan data of aorta, coronary, and heart models, and was printed by 3D printing with resin materials consisting of 75% or 85% clear resin and 25% or 15% flexible resin additive. The simulator was constructed with a camera above the simulator with a degree of LAO of 30°/0°, a display table, and an acrylic box. Twelve validators were interviewed for their expert opinions and analyzed by a qualitative method. They scored the simulator's suitability on a four-point Likert scale questionnaire. They described the simulator as having admirable values for all aspects (85.8%), curriculum suitability (92%), educational importance (94%), accuracy (83%), efficiency (78%), safety (87.5%), endurance (81.2%), aesthetics (80.7%), storage (85.4%), and affordability (85.8%).

From the ground up: understanding the developing infrastructure and resources of 3D printing facilities in hospital-based settings

Background

3D printing is a popular technology in many industries secondary to its ability to rapidly produce inexpensive, high fidelity models/products, mainly through layer-by-layer fusion of various substrate materials. In healthcare, 3D printing has garnered interest for its applications in surgery, simulation, education, and medical device development, and 3D printing facilities are now being integrated into hospital-based settings. Yet, little is known regarding the leadership, resources, outputs, and role of these new onsite entities.

Methods

The purpose of this research was to survey features of North American hospital-based 3D printing facilities to understand their design and utility in anticipation of future expansion. Hospital-based 3D printing labs were recruited through online special interest groups to participate via survey response. Anonymous, voluntary data were collected from 21 facilities over 9 weeks and reported/analyzed in aggregate.

Results

Of the respondents, > 50% were founded in the past 5 years and 80% in the past decade, indicating recent and rapid growth of such facilities. Labs were most commonly found within large, university-affiliated hospitals/health systems with administration frequently, but not exclusively, through radiology departments, which was shown to enhance collaboration. All groups reported collaborating with other medical specialties/departments and image segmentation as part of the workflow, showing widespread interest in high fidelity, personalized medicine applications. Lab leadership was most often multidisciplinary, with physicians present on nearly all leadership teams. Budgets, personnel, and outputs varied among groups, however, all groups reported engagement in multiple 3D printing applications.

Conclusion

This preliminary study provides a foundation for understanding the unique nature of hospital-based 3D printing labs. While there is much to learn about such in-house facilities, the data obtained reveal important baseline characteristics. Further research is indicated to validate these early findings and create a detailed picture of the developing infrastructure of 3D printing in healthcare settings.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41205-022-00147-7.

Characterization of 3D Printed Metal-PLA Composite Scaffolds for Biomedical Applications

Three-dimensional printing is revolutionizing the development of scaffolds due to their rapid-prototyping characteristics. One of the most used techniques is fused filament fabrication (FFF), which is fast and compatible with a wide range of polymers, such as PolyLactic Acid (PLA). Mechanical properties of the 3D printed polymeric scaffolds are often weak for certain applications. A potential solution is the development of composite materials. In the present work, metal-PLA composites have been tested as a material for 3D printing scaffolds. Three different materials were tested: copper-filled PLA, bronze-filled PLA, and steel-filled PLA. Disk-shaped samples were printed with linear infill patterns and line spacing of 0.6, 0.7, and 0.8 mm, respectively. The porosity of the samples was measured from cross-sectional images. Biocompatibility was assessed by culturing Human Bone Marrow-Derived Mesenchymal Stromal on the surface of the printed scaffolds. The results showed that, for identical line spacing value, the highest porosity corresponded to bronze-filled material and the lowest one to steel-filled material. Steel-filled PLA polymers showed good cytocompatibility without the need to coat the material with biomolecules. Moreover, human bone marrow-derived mesenchymal stromal cells differentiated towards osteoblasts when cultured on top of the developed scaffolds. Therefore, it can be concluded that steel-filled PLA bioprinted parts are valid scaffolds for bone tissue engineering.

Design and Mechanical Characterization Using Digital Image Correlation of Soft Tissue-Mimicking Polymers

Present and future anatomical models for biomedical applications will need bio-mimicking three-dimensional (3D)-printed tissues. These would enable, for example, the evaluation of the quality-performance of novel devices at an intermediate step between ex-vivo and in-vivo trials. Nowadays, PolyJet technology produces anatomical models with varying levels of realism and fidelity to replicate organic tissues. These include anatomical presets set with combinations of multiple materials, transitions, and colors that vary in hardness, flexibility, and density. This study aims to mechanically characterize multi-material specimens designed and fabricated to mimic various bio-inspired hierarchical structures targeted to mimic tendons and ligaments. A Stratasys® J750™ 3D Printer was used, combining the Agilus30™ material at different hardness levels in the bio-mimicking configurations. Then, the mechanical properties of these different options were tested to evaluate their behavior under uni-axial tensile tests. Digital Image Correlation (DIC) was used to accurately quantify the specimens' large strains in a non-contact fashion. A difference in the mechanical properties according to pattern type, proposed hardness combinations, and matrix-to-fiber ratio were evidenced. The specimens V, J1, A1, and C were selected as the best for every type of pattern. Specimens V were chosen as the leading combination since they exhibited the best balance of mechanical properties with the higher values of Modulus of elasticity (2.21 ± 0.17 MPa), maximum strain (1.86 ± 0.05 mm/mm), and tensile strength at break (2.11 ± 0.13 MPa). The approach demonstrates the versatility of PolyJet technology that enables core materials to be tailored based on specific needs. These findings will allow the development of more accurate and realistic computational and 3D printed soft tissue anatomical solutions mimicking something much closer to real tissues.

The sustainability of emerging technologies for use in pharmaceutical manufacturing

INTRODUCTION

Sustainability within the pharmaceutical industry is becoming a focal point for many companies, to improve the longevity and social perception of the industry. Both additive manufacturing (AM) and microfluidics (MFs) are continuously progressing, so are far from their optimization in terms of sustainability; hence, it is the aim of this review to highlight potential gaps alongside their beneficial features. Discussed throughout this review also will be an in-depth discussion on the environmental, legal, economic, and social particulars relating to these emerging technologies.

AREAS COVERED

Additive manufacturing (AM) and microfluidics (MFs) are discussed in depth within this review, drawing from up-to-date literature relating to sustainability and circular economies. This applies to both technologies being utilized for therapeutic and analytical purposes within the pharmaceutical industry.

EXPERT OPINION

It is the role of emerging technologies to be at the forefront of promoting a sustainable message by delivering plausible environmental standards whilst maintaining efficacy and economic viability. AM processes are highly customizable, allowing for their optimization in terms of sustainability, from reducing printing time to reducing material usage by removing supports. MFs too are supporting sustainability via reduced material wastage and providing a sustainable means for point of care analysis.