scholarly journals 3221 Optimization of chondrogenesis on 3-dimensionally printed porous tissue bioscaffolds for auricular tissue engineering

2019 ◽  
Vol 3 (s1) ◽  
pp. 18-18
Author(s):  
Brian Chang ◽  
Zahra Nourmahammadi ◽  
Ashley Cornett ◽  
Isabelle Lombaert ◽  
David Zopf

OBJECTIVES/SPECIFIC AIMS: This study’s aims are to optimize the isolation and growth of chondrocytes from pig auricular cartilage; to identify the ideal seeding conditions onto 3D printed auricular bioscaffolds to maximize chondrocyte growth; and to investigate what quantity and types of host tissue can grow on the bioscaffold. Primary outcomes will include comparisons between different seeding conditions in various objective measures of bioscaffold growth and survival as listed in the methods section. Secondary outcomes will include continued optimization of bioscaffolds to minimize extrusion rates and maximize morphologic and histologic similarity to human auricular cartilage. METHODS/STUDY POPULATION: For chondrocyte-seeded scaffolds, cartilage will be collected from freshly harvested porcine auricular tissue and digested in type II collagenase. Chondrocytes derived from the harvest will be seeded into auricular PCL scaffolds using a type I collagen/hyaluronic acid composite gel, which has been previously shown to support chondrogenesis. For scaffolds containing cartilage, punch biopsies will be collected and embedded in specific areas of the scaffold previously shown to experience excessive stress/strain compared to the rest of the construct. From there, five of each chondrocyte-seeded bioscaffolds, chondrocyte-unseeded bioscaffolds, and cartilage-containing bioscaffolds will be implanted into athymic rats. Total follow up will be for six months, with outcomes as measured by clinical assessments, morphologic measurements, radiological imaging, histological analysis, biomechanical evaluation, and photodocumentation. Once these measures are obtained, we will work closely with Dr. Myra Kim, an adjunct professor with the Biostatistics Department, to appropriately analyze differences between the models. RESULTS/ANTICIPATED RESULTS: We believe that while all scaffolds (chondrocyte-seeded, chondrocyte-unseeded, and cartilage-containing) will be structurally sound, the chondrocyte-seeded scaffolds and cartilage-containing scaffolds will exhibit improved soft tissue coverage and have lower exposure and fracture rates. Additionally, between the two, we posit that there will not be appreciable differences histologically, radiologically, or morphologically. DISCUSSION/SIGNIFICANCE OF IMPACT: Auricular reconstruction is a geometrically complex and technically challenging problem. Reconstruction hinges on the physical characteristics of the deformity, patient preferences, and reconstructive materials available. The current gold standard for auricular reconstruction uses autologous rib cartilage as foundational support for overlying soft tissue and these techniques involve freehand carving of the cartilage, requiring high levels of technical skill. Harvesting the materials for this procedure is invasive, and the outcomes of the surgery are largely variable and sometimes undesirable. As alternatives, implantable scaffolds including those made from high density porous polyethylene (commercially referred to as MedPor) have been investigated. However, many of these have proven inadequate due to factors including infection, extrusion, and morphologic and biomechanical dissimilarity from native tissue. 3D printing represents an exciting new avenue through which to address many of these difficulties. Our group has previously demonstrated the successful design, production, and implantation of 3D-printed models: in auricular reconstruction, we have demonstrated the successful creation and implementation of a 3D printed ear scaffold into an athymic rodent model. We now turn our attention to optimization of seeding of our ear scaffold with chondrocytes derived from porcine auricular cartilage or with cartilage punch biopsies, all while maintaining emphasis on regulatory feasibility. With success in this arena, we will be able to provide a much less invasive and technically challenging alternative to the current gold standard, create patient-specific bioscaffolds which are more form fitting and individualized, and provide children with ear malformations better alternatives and treatments for their conditions.

2021 ◽  
Vol 11 ◽  
Author(s):  
Yeonho Choi ◽  
Ik Jae Lee ◽  
Kwangwoo Park ◽  
Kyung Ran Park ◽  
Yeona Cho ◽  
...  

This study aims to confirm the usefulness of patient-specific quality assurance (PSQA) using three-dimensional (3D)-printed phantoms in ensuring the stability of IORT and the precision of the treatment administered. In this study, five patient-specific chest phantoms were fabricated using a 3D printer such that they were dosimetrically equivalent to the chests of actual patients in terms of organ density and shape around the given target, where a spherical applicator was inserted for breast IORT treatment via the INTRABEAM™ system. Models of lungs and soft tissue were fabricated by applying infill ratios corresponding to the mean Hounsfield unit (HU) values calculated from CT scans of the patients. The two models were then assembled into one. A 3D-printed water-equivalent phantom was also fabricated to verify the vendor-provided depth dose curve. Pieces of an EBT3 film were inserted into the 3D-printed customized phantoms to measure the doses. A 10 Gy prescription dose based on the surface of the spherical applicator was delivered and measured through EBT3 films parallel and perpendicular to the axis of the beam. The shapes of the phantoms, CT values, and absorbed doses were compared between the expected and printed ones. The morphological agreement among the five patient-specific 3D chest phantoms was assessed. The mean differences in terms of HU between the patients and the phantoms was 2.2 HU for soft tissue and −26.2 HU for the lungs. The dose irradiated on the surface of the spherical applicator yielded a percent error of −2.16% ± 3.91% between the measured and prescribed doses. In a depth dose comparison using a 3D-printed water phantom, the uncertainty in the measurements based on the EBT3 film decreased as the depth increased beyond 5 mm, and a good agreement in terms of the absolute dose was noted between the EBT3 film and the vendor data. These results demonstrate the applicability of the 3D-printed chest phantom for PSQA in breast IORT. This enhanced precision offers new opportunities for advancements in IORT.


2021 ◽  
Vol 11 ◽  
Author(s):  
Zeping Yu ◽  
Wenli Zhang ◽  
Xiang Fang ◽  
Chongqi Tu ◽  
Hong Duan

Background and PurposePelvic tumor involving Type I + IV resections are technically challenging, along with various reconstructions methods presenting unsatisfactory outcomes and high complication rates. Since predominating studies preferred adopting pedicle screw-rod system (PRSS) to address this issue, we designed a novel three-dimensional-printed, multimodality imaging (3DMMI) based endoprosthesis with patient-specific instrument (PSI) assistance to facilitate the surgical reconstruction of pelvic tumor involving Enneking Type I + IV resection. We aimed to investigate the clinical effectiveness of this novel endoprosthesis and compare it with PRSS in Type I + IV reconstruction.MethodsWe retrospective studied 28 patients for a median follow-up of 47 months (range, 10 to 128 months) in this study with either 3D-printed endoprosthesis reconstruction (n = 10) or PRSS reconstruction (n = 18) between January 2000 and December 2017. Preoperative 3DMMI technique was used for tumor evaluation, PSI design, virtual surgery, and endoprosthesis fabrication. Clinical, oncological outcomes, functional assessments, and complications were analyzed between the two groups.ResultsMinor surgical trauma with mean operative duration of 251 ± 52.16 minutes (p = 0.034) and median intraoperative hemorrhage of 2000ml (range, 1600, 4000ml) (p = 0.032) was observed in endoprosthesis group. Wide margins were achieved in 9 patients of the endoprosthesis group compared with 10 in the PRSS group (p = 0.09). The 1993 version of the Musculoskeletal Tumor Society score (MSTS-93) was 23.9 ± 3.76 in endoprosthesis group, which was higher than PRSS group (p = 0.012). No statistical significance was found in relapse between two groups (p = 0.36). Complications were observed in two patients in endoprosthesis group compared with 12 patients in PRSS group (p = 0.046).ConclusionThe novel design of this 3D-printed endoprosthesis, together with 3DMMI and PSI assisted, is technically accessible with favorable clinical outcomes compared with PRSS. Further study is essential to identify its long-term outcomes.


2015 ◽  
Vol 42 (6Part2) ◽  
pp. 3188-3188
Author(s):  
E Ehler ◽  
D Sterling ◽  
P Higgins

2020 ◽  
Vol 24 (06) ◽  
pp. 667-675
Author(s):  
Violeta Vasilevska Nikodinovska ◽  
Slavcho Ivanoski ◽  
Milan Samardziski ◽  
Vesna Janevska

AbstractBone and soft tissue tumors are a largely heterogeneous group of tumors. Biopsy of musculoskeletal (MSK) tumors is sometimes a challenging procedure. Although the open biopsy is still considered the gold standard for the biopsy of MSK lesions, core needle biopsy can replace it in most cases, with similar accuracy and a low complication rate. The biopsy should be performed in a tertiary sarcoma center where the multidisciplinary team consists of at minimum a tumor surgeon, an MSK pathologist, and an MSK radiologist who can assess all steps of the procedure. Several factors can influence the success of the biopsy including the lesion characteristics, the equipment, and the method used for the procedure. This review highlights some of the important aspects regarding the biopsy of the MSK tumors, with special attention to imaging a guided core needle biopsy and highlighting some of the recent advancements and controversies in the field.


Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1021
Author(s):  
Bernhard Dorweiler ◽  
Pia Elisabeth Baqué ◽  
Rayan Chaban ◽  
Ahmed Ghazy ◽  
Oroa Salem

As comparative data on the precision of 3D-printed anatomical models are sparse, the aim of this study was to evaluate the accuracy of 3D-printed models of vascular anatomy generated by two commonly used printing technologies. Thirty-five 3D models of large (aortic, wall thickness of 2 mm, n = 30) and small (coronary, wall thickness of 1.25 mm, n = 5) vessels printed with fused deposition modeling (FDM) (rigid, n = 20) and PolyJet (flexible, n = 15) technology were subjected to high-resolution CT scans. From the resulting DICOM (Digital Imaging and Communications in Medicine) dataset, an STL file was generated and wall thickness as well as surface congruency were compared with the original STL file using dedicated 3D engineering software. The mean wall thickness for the large-scale aortic models was 2.11 µm (+5%), and 1.26 µm (+0.8%) for the coronary models, resulting in an overall mean wall thickness of +5% for all 35 3D models when compared to the original STL file. The mean surface deviation was found to be +120 µm for all models, with +100 µm for the aortic and +180 µm for the coronary 3D models, respectively. Both printing technologies were found to conform with the currently set standards of accuracy (<1 mm), demonstrating that accurate 3D models of large and small vessel anatomy can be generated by both FDM and PolyJet printing technology using rigid and flexible polymers.


Polymers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1910
Author(s):  
Hun-Jin Jeong ◽  
Se-Won Lee ◽  
Myoung Wha Hong ◽  
Young Yul Kim ◽  
Kyoung Duck Seo ◽  
...  

The meniscus has poor intrinsic regenerative capability, and its injury inevitably leads to articular cartilage degeneration. Although there are commercialized off-the-shelf alternatives to achieve total meniscus regeneration, each has its own shortcomings such as individualized size matching issues and inappropriate mechanical properties. We manufactured a polycaprolactone-based patient-specific designed framework via a Computed Tomography scan images and 3D-printing technique. Then, we completed the hybrid-scaffold by combining the 3D-printed framework and mixture micro-size composite which consists of polycaprolactone and sodium chloride to create a cell-friendly microenvironment. Based on this hybrid-scaffold with an autograft cell source (fibrochondrocyte), we assessed mechanical and histological results using the rabbit total meniscectomy model. At postoperative 12-week, hybrid-scaffold achieved neo-meniscus tissue formation, and its shape was maintained without rupture or break away from the knee joint. Histological and immunohistochemical analysis results showed obvious ingrowth of the fibroblast-like cells and chondrocyte cells as well as mature lacunae that were embedded in the extracellular matrix. Hybrid-scaffolding resulted in superior shape matching as compared to original meniscus tissue. Histological analysis showed evidence of extensive neo-meniscus cell ingrowth. Additionally, the hybrid-scaffold did not induce osteoarthritis on the femoral condyle surface. The 3D-printed hybrid-scaffold may provide a promising approach that can be applied to those who received total meniscal resection, using patient-specific design and autogenous cell source.


2021 ◽  
pp. 155633162199633
Author(s):  
Mehran Ashouri-Sanjani ◽  
Shima Mohammadi-Moghadam ◽  
Parisa Azimi ◽  
Navid Arjmand

Background: Pedicle screw (PS) placement has been widely used in fusion surgeries on the thoracic spine. Achieving cost-effective yet accurate placements through nonradiation techniques remains challenging. Questions/Purposes: Novel noncovering lock-mechanism bilateral vertebra-specific drill guides for PS placement were designed/fabricated, and their accuracy for both nondeformed and deformed thoracic spines was tested. Methods: One nondeformed and 1 severe scoliosis human thoracic spine underwent computed tomographic (CT) scanning, and 2 identical proportions of each were 3-dimensional (3D) printed. Pedicle-specific optimal (no perforation) drilling trajectories were determined on the CT images based on the entry point/orientation/diameter/length of each PS. Vertebra-specific templates were designed and 3D printed, assuring minimal yet firm contacts with the vertebrae through a noncovering lock mechanism. One model of each patient was drilled using the freehand and one using the template guides (96 pedicle drillings). Postoperative CT scans from the models with the inserted PSs were obtained and superimposed on the preoperative planned models to evaluate deviations of the PSs. Results: All templates fitted their corresponding vertebra during the simulated operations. As compared with the freehand approach, PS placement deviations from their preplanned positions were significantly reduced: for the nonscoliosis model, from 2.4 to 0.9 mm for the entry point, 5.0° to 3.3° for the transverse plane angle, 7.1° to 2.2° for the sagittal plane angle, and 8.5° to 4.1° for the 3D angle, improving the success rate from 71.7% to 93.5%. Conclusions: These guides are valuable, as the accurate PS trajectory could be customized preoperatively to match the patients’ unique anatomy. In vivo studies will be required to validate this approach.


2021 ◽  
Author(s):  
Mariya S. Pravdivtseva ◽  
Eva Peschke ◽  
Thomas Lindner ◽  
Fritz Wodarg ◽  
Johannes Hensler ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
A. M. Zamarayeva ◽  
K. Gopalan ◽  
J. R. Corea ◽  
M. Z. Liu ◽  
K. Pang ◽  
...  

AbstractWe have developed a process for fabricating patient specific Magnetic Resonance Imaging (MRI) Radio-frequency (RF) receive coil arrays using additive manufacturing. Our process involves spray deposition of silver nanoparticle inks and dielectric materials onto 3D printed substrates to form high-quality resonant circuits. In this paper, we describe the material selection and characterization, process optimization, and design and testing of a prototype 4-channel neck array for carotid imaging. We show that sprayed polystyrene can form a low loss dielectric layer in a parallel plate capacitor. We also demonstrate that by using sprayed silver nanoparticle ink as conductive traces, our devices are still dominated by sample noise, rather than material losses. These results are critical for maintaining high Signal-to-Noise-Ratio (SNR) in clinical settings. Finally, our prototype patient specific coil array exhibits higher SNR (5 × in the periphery, 1.4 × in the center) than a commercially available array designed to fit the majority of subjects when tested on our custom neck phantom. 3D printed substrates ensure an optimum fit to complex body parts, improve diagnostic image quality, and enable reproducible placement on subjects.


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