Annals of 3D printed medicine最新文献

Nephron-sparing surgery (NSS) for Wilms Tumor patients has a positive surgical margin rate of 15.7–36.4%. Innovative approaches may reduce the occurrence of positive surgical margins in NSS and prevent these children from having additional radiotherapy and chemotherapy. The feasibility of performing mock surgery on patient-specific hydrogel phantoms of the kidney, tumor, and arterial vasculature for preoperative simulation of NSS was assessed in two patients. The development of patient-specific phantoms allowed the surgeon to practice surgery. Moreover, phantom specimens were assessed using MRI to understand the location and size of the smallest surgical margin. Surgeons reported that simulation surgery helped perform NSS safely and improved intraoperative tumor localization and resection planning. The technique is considered feasible and useful when preparing for NSS. In the future, this technique may further help to achieve negative surgical margins in NSS and may also allow the use of NSS in patients typically regarded as ineligible for this procedure.

Introduction: The objective of this investigation is to examine a wide array of commonly accessible 3D print filaments and assess their radiographic fidelity in vertebral models.

Material and methods: Solid cylinders were 3D printed on an Ultimaker S5 (Ultimaker B.V., Utrecht, Netherlands) in 12 commonly accessible filaments: ABS (Acrylonitrile butadiene styrene), PLA (Polylactic acid), Tough PLA, PP (Poly propylene), Carbon Fiber ABS, Wood fill, PETG (Polyethylene terephthalate glycol), Nylon, PC (Polycarbonate), Bronze fill, TPU 95A (Thermoplastic polyurethane), and CPE (Chlorinated polyethylene). Cylinders were imaged in a CT phantom with anatomic standards. Next, 11 identical L4 human vertebral models were 3D printed in the same materials (omission of TPU 95A). AP and lateral fluoroscopic images were taken of each of the vertebrae and sent to board-certified/board-eligible neurosurgeons, neuroradiologists, and orthopedic spine surgeons for evaluation.

Results: CT imaging of the materials yielded a range of Hounsfield values from –120.6 HU (PP) to 167.76 HU (PETG). The polled experts rated CF ABS as the highest fidelity model (mean 4.069) and Bronze fill as lowest (mean 2.000). All simulated vertebrae in this study ranked higher than Bronze fill (p<0.05). Notably, CF ABS (p=0.0029), ABS (p=0.0075), and CPE (p=0.0182) ranked significantly higher than Tough PLA.

Discussion: It was determined that CT values of examined filaments were not comparable to cortical bone standard but similar to other bone standards. Our results suggest that apart from Bronze fill, educators can create high fidelity fluoroscopic models with print materials such as ABS, CF ABS, and CPE.

The 3–dimensional printing process (3DP) was patented in the 1980s, but the utilization of this process has expanded substantially over the past decade, to which the pharmaceutical industry is a major contributor. With increasing interest, researchers across the globe are striving for the fabrication of novel pharmaceutical dosage forms, especially tailored ones, which can cater to the specific needs of the patient. These dosage forms intend to cater for on–demand manufacturing, personalized medications, enhanced geometry, size, and dosage, and increased bioavailability of the medicinal active. With the emergence of precision medicine in healthcare, the inclusion of additive manufacturing (AM) technologies is deemed imperative for the fabrication of oral dosage forms and polypills, which opens new horizons for the administration of drug combinations and formulations tailored to individual needs. Although the extensive commercialization and acceptance of the AM techniques may disrupt the current healthcare supply chain, it has the potential to curtail the waste produced by expired and unused medications. This article attempts to outline these additive manufacturing techniques of great interest in the pharmaceutical industry while underscoring the current innovative trends pertaining to the 3D printing of pharmaceutical dosage forms, as well as their advantages, limitations, and prospects in the field of research and development. The article also showcases the viability of various 3D printing techniques by citing numerous papers in which said techniques have been successfully exploited to deliver unique pharmaceutical formulations.

Bone defects are associated with trauma, congenital disorders, non-unions, or infections following surgical procedures. Defects which are unable to heal spontaneously are categorized as “critical sized” and are commonly treated using bone grafts in an effort to facilitate bone regeneration and stabilization. Grafting materials can be either natural or synthetic, each having their respective advantages and disadvantages. Synthetic bone grafts are favored due to their ability to be tailored to exhibit desired properties and geometric configurations. β-tricalcium phosphate (β-TCP) is a synthetic grafting material that has been widely utilized for regenerative purposes due to its favorable osteoconductive properties. In combination with 3D printing, grafting materials can be further customized with respect to their macro and micro features. One way to customize devices is by using 3D printing and varying the surface area, by varying the internal component measurements. The objective of this study was to compare the effect of porosity and surface area of 3D printed β-TCP scaffolds with different strut diameters and the effect on cell proliferation in vitro. ß-TCP scaffolds were printed using a custom-built 3D direct-write micro printer with syringes equipped with different extrusion tip diameters (f_diameter: 200 µm, 250 µm and 330 µm). After sintering and post processing, scaffolds were subjected to micro-computed tomography (µCT) and a Scanning Electron Microscope (SEM) to evaluate surface area and porosity, respectively. Compressive strength was assessed using a universal testing machine. Cell proliferation was assessed through cellular viability, using human osteoprogenitor cells. The surface area of the scaffolds was found to increase with smaller strut diameters. Statistically significant differences (p<0.05) were detected for cellular proliferation, between the smallest extrusion diameter, 200 μm, and the largest diameter, 330 μm, after 48-, 72-, and 168-hours. No statistical significances were detected (p>0.05) with regards to the mechanical properties between groups. This study demonstrated that a smaller diameter rod yielded a higher surface area resulting in increased levels of cellular proliferation. Therefore, tailoring rod dimensions has the capacity to enhance cellular adhesion and ultimately, proliferation.

Pre-operative visualization and three-dimensional (3D) printing have gained much interest in the state-of-the-medicine. This technical note describes the technique for searching and resection of superficial cerebral cortical lesions. The method involves the creation of a patient-specific virtual model of cerebral cortex and 3D printing of an individual craniometric ruler (ICR) for skin incision marking. The benefits and limitations of ICR printing versus frameless neuronavigation are discussed. In addition, we outline the usage of surgical guides in the neurosurgical practice.

Biocompatibility is a key characteristic in the design of biomaterial such as implants. The key aspects of surface quality that affect biocompatibility are surface roughness, surface feature, surface chemistry, crystallinity and porosity. The biocompatibility can be assessed in vitro by observing cell behaviour such as cell differentiation, proliferation and viability. Furthermore, surface aspect such as surface roughness induced selective protein adsorption onto the biomaterial surface. The effect of surface quality on protein adsorption is also important to be understood because cells will attach to the protein adsorbed, instead of the material directly. This review paper critically analyses the role of surface quality on biocompatibility of biomaterials based on the information available in literature. For quantitative analyses, in vivo assessment such as osseointegration phenomenon was discussed in detail. Towards that, a systematic review was conducted with chronological development in this field.

Three-dimensional (3D) printing became more widely available in the past decade, its medical applications are rapidly growing. The technology has also a large potential in forensic sciences – including forensic medicine and pathology. A systematic literature search was performed using electronic databases to analyze the current applications of 3D printing in forensic medicine and to reveal the possible directions of development. The first publication regarding 3D printing in the field of forensic medicine and pathology was published in 2011, but publications were scarce until 2017. Publication numbers increased in 2017 and were constant since then. The publications reveal that 3D printing can be used in everyday forensic medical practice for various purposes including injury reconstruction, injury–weapon comparison, presentation, identification and courtroom demonstration and teaching.

The marked developments in the fields of 3D planning and printing in the last few decades, have enabled the application of virtual surgical planning (VSP) toward personalization of surgical procedures and implants. Augmented reality superimposes digital content on the real-world reality. The aim of this technical note was to introduce the use of AR to evaluate and guide the insertion and positioning of a patient specific implant (PSI) for orbital floor blow-out fracture reconstruction. A 31-year-old, healthy male was injured and suffered from left orbital floor blow-out fracture. DICOM images of the CT scan were obtained for segmentation and for VSP, PSI design and 3D Printing. Patients’ file with the 3D objects was uploaded to AR software. The patient's left orbital floor was approached via the trans-conjunctival incision, PSI titanium plate was set in place and using AR Special head-mounted displays (HoloLens 1, Microsoft) the correct planned position of the plate was confirmed. The post-operative CT scan showed a <0.3 mm discrepancy in all axes of the plate in relation to the planned position. AR application in medicine and in maxillofacial surgery bears great potential, However, further investigation of this technology is required

Off the shelf, universal hinged leg braces are large, awkward looking devices that are often uncomfortable for the user. With the use of 3D printed components it is possible to modify and streamline the traditional leg brace design making it compact, lightweight, and comfortable. A customizable 3D printed orthotic leg brace is presented that provides the user with assisted mobility in addition to an increased degree of rigidity. The 3D printed frame lattice structure of the brace is tailored around the dimensions of the user's leg. The movement assist mechanism consists of dual mechatronic linear actuators mounted on the brace that aid the leg in flexion and extension during the gait cycle. The brace is a lightweight, independently functioning device that will provide increased mobility for the user.

Background

Additive manufacturing (AM) is a fast-developing technology with possible applications in cardiology. Existing research has identified two general factors that can influence implementing AM in cardiology: economics and technology.

Objective

In this study we aimed to identify barriers and facilitators to implementing AM in cardiology.

Methods

We conducted a multiple case study of two Swedish cardiac surgery departments representing implementers and non-implementers of AM. We interviewed key stakeholders (n=8) who had been or were involved in implementing AM in cardiology or AM in general at the hospitals: cardiologists, physicians working with AM but not specialized in cardiology such as radiologists, company representatives, and individuals involved in the 3D-printing facilities. A combination of an inductive and deductive approach was used to analyze the interviews.

Results

Several barriers and facilitators influenced implementing AM in cardiology. Most barriers (n=4) were related to innovation factors, whereas most facilitators (n=4) were related to healthcare professionals. No barriers and facilitators were related to patients.

Conclusion

Our findings show that AM in cardiology is in its very early phases in both hospitals and mostly the work of a few individuals. In the two hospitals studied, there were some unique differences in terms of barriers that could explain the low level of implementation. These barriers could be important to address when supporting implementation of AM at hospitals where AM use is still low.