Three-dimensional printing with sacrificial materials for soft matter manufacturing

Three-dimensional printed titanium pseudo-prosthesis for the treatment of a tumoral bone defect

Objective To explore the application value of three-dimensional (3D) printing in skull base tumor resection. Methods Fourteen patients accepted resection of skull base tumors in our hospital from May 2016 to November 2017 were chosen in our study; before surgery, solid models of the tumors, having bones of the skull base, tumor tissues and main blood supply arteries, were established by 3D printing; resection was simulated in these models and the surgical approaches and surgical methods were determined accordingly. The disease history, preoperative and postoperative imaging data were analyzed retrospectively. Results The mean time for making a solid model of the tumors was 18.5 h, and the cost was about 5,000 Yuan. Postoperative CT and MR imaging showed that total excision was achieved in 8 patients, subtotal excision was achieved in 5 patients, and one with tumor of the jugular foramen achieved total excision of the intracranial tumor and subtotal excision of the extracranial tumor. One patient had large hemispheric infarction after operation and decompressive craniectomy was performed; the other 13 patients recovered well without serious complications or death. Conclusion The 3D printing technique can assist the preoperative simulation and formulation of skull base tumor resection, and improve the efficiency and safety of the operation. Key words: Three-dimensional printing; Tumor of base of skull; Tumor resection

3D printing of very soft elastomer and sacrificial carbohydrate glass/elastomer structures for robotic applications

Objective: To investigate reduction and fixation of complex acetabular fractures using three-dimensional (3D) printing technique and personalized acetabular wing-plate via lateral-rectus approach. Methods: From March to July 2016, 8 patients with complex acetabular fractures were surgically managed through 3D printing personalized acetabular wing-plate via lateral-rectus approach at Department of Orthopedics, the Third Affiliated Hospital of Southern Medical University. There were 4 male patients and 4 female patients, with an average age of 57 years (ranging from 31 to 76 years). According to Letournel-Judet classification, there were 2 anterior+ posterior hemitransverse fractures and 6 both-column fractures, without posterior wall fracture or contralateral pelvic fracture. The CT data files of acetabular fracture were imported into the computer and 3D printing technique was used to print the fractures models after reduction by digital orthopedic technique. The acetabular wing-plate was designed and printed with titanium. All fractures were treated via the lateral-rectus approach in a horizontal position after general anesthesia. The anterior column and the quadrilateral surface fractures were fixed by 3D printing personalized acetabular wing-plate, and the posterior column fractures were reduction and fixed by antegrade lag screws under direct vision. Results: All the 8 cases underwent the operation successfully. Postoperative X-ray and CT examination showed excellent or good reduction of anterior and posterior column, without any operation complications. Only 1 case with 75 years old was found screw loosening in the pubic bone with osteoporosis after 1 month's follow-up, who didn't accept any treatment because the patient didn't feel discomfort. According to the Matta radiological evaluation, the reduction of the acetabular fracture was rated as excellent in 3 cases, good in 4 cases and fair in 1 case. All patients were followed up for 3 to 6 months and all patients had achieved bone union. According to the modified Merle D'Aubigné and Postel scoring system, 5 cases were excellent, 2 cases were good, 1 case was fair. Conclusions: Surgical management of complex acetabular fracture via lateral-rectus approach combine with 3D printing personalized acetabular wing-plate can effectively improve reduction quality and fixation effect. It will be truly accurate, personalized and minimally invasive.

Background: An increasing number of reconstructive surgeons are using modern imaging technologies for preoperative planning and intraoperative surgical guidance. Conventional imaging modalities such as CT and MRI are relatively affordable and widely accessible and offer powerful functionalities. In the first of a two-part series, we evaluate established three-dimensional (3D) imaging and printing techniques based on CT and MRI used in plastic and reconstructive surgery. Method: A review of the published English literature dating from 1950 to 2017 was taken using databases such as PubMed, MEDLINE®, Web of Science and EMBASE. Result: In plastic and reconstructive surgery, the most commonly used, free software platforms are 3D Slicer (Surgical Planning Laboratory, Boston, MA, USA) and OsiriX (Pixmeo, Geneva, Switzerland). Perforator mapping using 3D-reconstructed images from computed tomography angiography (CTA) and magnetic resonance angiography (MRA) is commonly used for preoperative planning. Three- dimensional volumetric analysis using current software techniques remains labour-intensive and reliant on operator experience. Three-dimensional printing has been investigated extensively since its introduction. As more free open-source software suites and affordable 3D printers become available, 3D printing is becoming more accessible for clinicians. Conclusion: Numerous studies have explored the application of 3D-rendered conventional imaging modalities for perforator mapping, volumetric analysis and printing. However, there is a lack of comprehensive review of all established 3D imaging and printing techniques in a language suitable for clinicians.

To describe the technique and utility of three-dimensional (3D) printing for orbital and peri-orbital masses and discuss other potential applications for 3D printing. Three dogs with a chronic history of nonpainful exophthalmos. Computed tomography (CT) and subsequent 3D printing of the head was performed on each case. CT confirmed a confined mass, and an ultrasound-guided biopsy was obtained in each circumstance. An orbitotomy was tentatively planned for each case, and a 3D print of each head with the associated globe and mass was created to assist in surgical planning. In case 1, the mass was located in the cranioventral aspect of the right orbit, and the histopathologic diagnosis was adenoma. In case 2, the mass was located within the lateral masseter muscle, ventral to the right orbit between the zygomatic arch and the ramus of the mandible. The histopathologic diagnosis in case 2 was consistent with a lipoma. In case 3, the mass was located in the ventral orbit, and the histopathologic diagnosis was histiocytic cellular infiltrate. Three-dimensional printing in cases with orbital and peri-orbital masses has exceptional potential for improved surgical planning and provides another modality for visualization to help veterinarians, students, and owners understand distribution of disease. Additionally, as the techniques of 3D printing continue to evolve, the potential exists to revolutionize ocular surgery and drug delivery.

Osteogenesis of 3D printed porous Ti6Al4V implants with different pore sizes.

Fabrication of three dimensional printed tablets in flexible doses: A comprehensive study from design to evaluation

4D printing: Pragmatic progression in biofabrication

ABSTRACTThe distribution of fibers in the composite (which takes into account both their locations and orientations) is one of the important factors that affect the mechanical properties of FRCs. However, this parameter depends on various factors during composite fabrication, and controlling the distribution of fibers in the produced material represents a significant challenge. In this study, the applicability of three-dimensional (3D) printing technique for controlling fiber distributions was evaluated. The fibers fabricated using a 3D printer were placed inside a mold to produce cementitious composites. Three-point bending tests were conducted and the results of the experiment were discussed.

In the last decade, an emerging three-dimensional (3D) printing technique named freeform 3D printing has revolutionized the biomedical engineering field by allowing soft matters with or without cells to be printed and solidified with high precision regardless of their poor self-supportability. The key to this freeform 3D printing technology is the supporting matrices that hold the printed soft ink materials during omnidirectional writing and solidification. This approach not only overcomes structural design restrictions of conventional layer-by-layer printing but also helps to realize 3D printing of low-viscosity or slow-curing materials. This article focuses on the recent developments in freeform 3D printing of soft matters such as hydrogels, cells, and silicone elastomers, for biomedical engineering. Herein, we classify the reported freeform 3D printing systems into positive, negative, and functional based on the fabrication process, and discuss the rheological requirements of the supporting matrix in accordance with the rheological behavior of counterpart inks, aiming to guide development and evaluation of new freeform printing systems. We also provide a brief overview of various material systems used as supporting matrices for freeform 3D printing systems and explore the potential applications of freeform 3D printing systems in different areas of biomedical engineering.

Breast imaging technology plays an important role in breast cancer planning and treatment. Recently, three-dimensional (3D) printing technology has become a trending issue in phantom constructions for medical applications, with its advantages of being customizable and cost-efficient. However, there is no current practice in the field of multi-purpose breast phantom for quality control (QC) in multi-modalities imaging. The purpose of this study was to fabricate a multi-purpose breast phantom with tissue-equivalent materials via a 3D printing technique for QC in multi-modalities imaging. We used polyvinyl chloride (PVC) based materials and a 3D printing technique to construct a breast phantom. The phantom incorporates structures imaged in the female breast such as microcalcifications, fiber lesions, and tumors with different sizes. Moreover, the phantom was used to assess the sensitivity of lesion detection, depth resolution, and detectability thresholds with different imaging modalities. Phantom tissue equivalent properties were determined using computed tomography (CT) attenuation [Hounsfield unit (HU)] and magnetic resonance imaging (MRI) relaxation times. The 3D-printed breast phantom had an average background value of 36.2 HU, which is close to that of glandular breast tissue (40 HU). T1 and T2 relaxation times had an average relaxation time of 206.81±17.50 and 20.22±5.74 ms, respectively. Mammographic imaging had improved detection of microcalcification compared with ultrasound and MRI with multiple sequences [T1WI, T2WI and short inversion time inversion recovery (STIR)]. Soft-tissue lesion detection and cylindrical tumor contrast were superior with mammography and MRI compared to ultrasound. Hemispherical tumor detection was similar regardless of the imaging modality used. We developed a multi-purpose breast phantom using a 3D printing technique and determined its value for multi-modal breast imaging studies.

Three-dimensional (3D) printing is an exciting form of manufacturing technology that has transformed the way we can treat various medical pathologies. Also known as additive manufacturing, 3D printing fuses materials together in a layer-by-layer fashion to construct a final 3D product. This technology allows flexibility in the design process and enables efficient production of both off-the-shelf and personalized medical products that accommodate patient needs better than traditional manufacturing processes. In the field of orthopaedic surgery, 3D printing implants and instrumentation can be used to address a variety of pathologies that would otherwise be challenging to manage with products made from traditional subtractive manufacturing. Furthermore, 3D bioprinting has significantly impacted bone and cartilage restoration procedures and has the potential to completely transform how we treat patients with debilitating musculoskeletal injuries. Although costs can be high, as technology advances, the economics of 3D printing will improve, especially as the benefits of this technology have clearly been demonstrated in both orthopaedic surgery and medicine as a whole. This review outlines the basics of 3D printing technology and its current applications in orthopaedic surgery and ends with a brief summary of 3D bioprinting and its potential future impact.

Objectives: Three-dimensional (3D) printing has gained significance for human health-care applications in recent years. Some of these applications include obtaining models which mimic anatomical parts. One other parallel development in the biological research area is the development of 3D cell cultures. Such cultures are now becoming the material of choice for in vitro experiments, fast replacing the traditional adherent/monolayer 2D culture approaches. We present here, a method to obtain 3D prints of 3D aggregates of three human cancer cell lines. Such 3D prints can be useful models to understand solid tumor morphologies and also as effective teaching models. Materials and Methods: Photomicrographs of the 3D aggregates of the human cancer cell lines SiHa, MCF-7, and A549 (human cervical cancer, breast cancer, and non-small cell lung cancer cell lines, respectively) were obtained using inverted phase contrast microscopy. Conversion of normal jpeg images into 3D files was performed using the lithophane method and CAD files obtained. The CAD files thus generated were used to print the objects using the Stratasys Polyjet J750 3D Printer. Results: We could obtain 3D prints of SiHa, MCF-7, and A549 (human cervical cancer, breast cancer, and non-small cell lung cancer cell lines, respectively) 3D aggregates/spheroids. Conclusion: It is hoped that this approach will be useful for studying solid tumor morphologies in finer details. Furthermore, other benefits of such 3D prints would be in them being excellent models for teaching purposes.

BackgroundDifficult airway may result in significant morbidity and mortality. Proficient airway evaluation, therefore, is one of the key elements in the safe conduct of anesthesia. A three-dimensional (3D) printing model was recently introduced for medical application. 3D printing is a fast, convenient, and relatively affordable technique. We present a case in which a 3D-printed airway model was successfully used for airway evaluation.Case presentationA 77-year-old man who had previously undergone total laryngectomy was scheduled for resection of a pelvic mass. The condition of his airway, however, complicated the procedure. Routine methods to evaluate his airway were not suitable. Therefore, the patient’s computed tomography imaging data were used to generate stereolithography files and then to print out 3D models of his trachea. These 3D models enhanced our understanding of his tracheal morphology. They helped us devise a preanesthesia plan and effectively execute it without complications.Conclusion3D printing models allow better understanding of morphological changes in the airway and aid preanesthesia planning. The successful outcome of our case suggests 3D printing is a potent tool for evaluating difficult and more widespread use is encouraged.