Sarcopenia and anthracycline cardiotoxicity in patients with cancer

BACKGROUND

Several studies have suggested that sarcopenia is associated with an increased treatment toxicity in patients with cancer. The aim of this study is to evaluate the relationship between sarcopenia and anthracycline-related cardiotoxicity.

METHODS

Patients who received anthracycline-based chemotherapy between 2014 and 2018 and had baseline abdominal CT and baseline and follow-up echocardiography after anthracycline treatment were included. European Society of Cardiology ejection fraction criteria and American Society of Echocardiography diastolic dysfunction criteria were used for definition of cardiotoxicity. Sarcopenia was defined on the basis of skeletal muscle index (SMI) and psoas muscle index (PMI) calculated on CT images at L3 and L4 vertebra levels.

RESULTS

A total of 166 patients (75 men and 91 women) were included. Sarcopenia was determined in 33 patients (19.9%) according to L3-SMI, in 17 patients (10.2%) according to L4-SMI and in 45 patients (27.1%) according to PMI. 27 patients (16.3%) developed cardiotoxicity. PMI and L3-SMI were significantly associated with an increased risk of cardiotoxicity (L3-SMI: HR=3.27, 95% CI 1.32 to 8.11, p=0.01; PMI: HR=3.71, 95% CI 1.58 to 8.73, p=0.003).

CONCLUSIONS

This is the first study demonstrating a significant association between CT-diagnosed sarcopenia and anthracycline-related cardiotoxicity. Routine CT scans performed for cancer staging may help clinicians identify high-risk patients in whom closer follow-up or cardioprotective measures should be considered.

3D-Printed Medical-Grade Polycaprolactone (mPCL) Scaffold for the Surgical Treatment of Vaginal Prolapse and Abdominal Hernias

The expected outcome after a scaffold augmented hernia repair is the regeneration of a tissue composition strong enough to sustain biomechanical function over long periods. It is hypothesised that melt electrowriting (MEW) medical-grade polycaprolactone (mPCL) scaffolds loaded with platelet-rich plasma (PRP) will enhance soft tissue regeneration in fascial defects in abdominal and vaginal sheep models. A pre-clinical evaluation of vaginal and abdominal hernia reconstruction using mPCL mesh scaffolds and polypropylene (PP) meshes was undertaken using an ovine model. Each sheep was implanted with both a PP mesh (control group), and a mPCL mesh loaded with PRP (experimental group) in both abdominal and vaginal sites. Mechanical properties of the tissue-mesh complexes were assessed with plunger tests. Tissue responses to the implanted meshes were evaluated via histology, immunohistochemistry and histomorphometry. At 6 months post-surgery, the mPCL mesh was less stiff than the PP mesh, but stiffer than the native tissue, while showing equitable collagen and vascular ingrowth when compared to PP mesh. The results of this pilot study were supportive of mPCL as a safe and effective biodegradable scaffold for hernia and vaginal prolapse repair, hence a full-scale long-term study (over 24-36 months) with an adequate sample size is recommended.

Microporous/Macroporous Polycaprolactone Scaffolds for Dental Applications

This study leverages the advantages of two fabrication techniques, namely, melt-extrusion-based 3D printing and porogen leaching, to develop multiphasic scaffolds with controllable properties essential for scaffold-guided dental tissue regeneration. Polycaprolactone-salt composites are 3D-printed and salt microparticles within the scaffold struts are leached out, revealing a network of microporosity. Extensive characterization confirms that multiscale scaffolds are highly tuneable in terms of their mechanical properties, degradation kinetics, and surface morphology. It can be seen that the surface roughness of the polycaprolactone scaffolds (9.41 ± 3.01 µm) increases with porogen leaching and the use of larger porogens lead to higher roughness values, reaching 28.75 ± 7.48 µm. Multiscale scaffolds exhibit improved attachment and proliferation of 3T3 fibroblast cells as well as extracellular matrix production, compared with their single-scale counterparts (an approximate 1.5- to 2-fold increase in cellular viability and metabolic activity), suggesting that these structures could potentially lead to improved tissue regeneration due to their favourable and reproducible surface morphology. Finally, various scaffolds designed as a drug delivery device were explored by loading them with the antibiotic drug cefazolin. These studies show that by using a multiphasic scaffold design, a sustained drug release profile can be achieved. The combined results strongly support the further development of these scaffolds for dental tissue regeneration applications.

A humanised rat model of osteosarcoma reveals ultrastructural differences between bone and mineralised tumour tissue

Current xenograft animal models fail to accurately replicate the complexity of human bone disease. To gain translatable and clinically valuable data from animal models, new in vivo models need to be developed that mimic pivotal aspects of human bone physiology as well as its diseased state. Above all, an advanced bone disease model should promote the development of new treatment strategies and facilitate the conduction of common clinical interventional procedures. Here we describe the development and characterisation of an orthotopic humanised tissue-engineered osteosarcoma (OS) model in a recently genetically engineered x-linked severe combined immunodeficient (X-SCID) rat. For the first time in a genetically modified rat, our results show the successful implementation of an orthotopic humanised tissue-engineered bone niche supporting the growth of a human OS cell line including its metastatic spread to the lung. Moreover, we studied the inter- and intraspecies differences in ultrastructural composition of bone and calcified tissue produced by the tumour, pointing to the crucial role of humanised animal models.

Adjuvant treatment with paclitaxel plus trastuzumab for node-negative breast cancer: real-life experience

Background: In node-negative HER2-overexpressed breast cancers, adjuvant paclitaxel plus trastuzumab treatment is a successful de-escalation approach with excellent survival outcomes. Methods: All patients with HER2+ breast cancer treated in our centers were retrospectively reviewed. Results: We analyzed 173 patients who were treated with adjuvant paclitaxel plus trastuzumab. The mean tumor size was 2.2 cm. There were eight invasive disease events or death: four distant recurrences (2.3%), three locoregional recurrences (1.7%) and one death without documented recurrence after a 52 month follow-up. The 3-year disease-free survival and recurrence-free interval rate was 96.6%. Conclusion: This real-life experience with adjuvant paclitaxel plus trastuzumab demonstrated few distant recurrences and is compatible with the APT trial findings.

Engineering a 3D bone marrow adipose composite tissue loading model suitable for studying mechanobiological questions

Tissue engineering strategies are widely used to model and study the bone marrow microenvironment in healthy and pathological conditions. Yet, while bone function highly depends on mechanical stimulation, the effects of biomechanical stimuli on the bone marrow niche, specifically on bone marrow adipose tissue (BMAT) is poorly understood due to a lack of representative in vitro loading models. Here, we engineered a BMAT analog made of a GelMA (gelatin methacryloyl) hydrogel/medical-grade polycaprolactone (mPCL) scaffold composite to structurally and biologically mimic key aspects of the bone marrow microenvironment, and exploited an innovative bioreactor to study the effects of mechanical loading. Highly reproducible BMAT analogs facilitated the successful adipogenesis of human mesenchymal bone marrow stem cells. Upon long-term intermittent stimulation (1 Hz, 2 h/day, 3 days/week, 3 weeks) in the novel bioreactor, cellular proliferation and lipid accumulation were similar to unloaded controls, yet there was a significant reduction in the secretion of adipokines including leptin and adiponectin, in line with clinical evidence of reduced adipokine expression following exercise/activity. Ultimately, this innovative loading platform combined with reproducibly engineered BMAT analogs provide opportunities to study marrow physiology in greater complexity as it accounts for the dynamic mechanical microenvironment context.

Abstract PS10-52: Adjuvant treatment with paclitaxel plus trastuzumab for node negative human epidermal growth factor receptor 2-positive breast cancer: Real life experience

BackgroundInvasive breast cancers are characterized by overexpression or amplification of the human epidermal growth factor receptor 2 (HER2) approximately 15 to 25%. Survival outcomes was improved after introduction of Trastuzumab treatment. Trastuzumab treatment was applied mostly with combination chemotherapy regimens at pivotal trials. There were some efforts to avoid the toxicity of combination chemotherapies and reduce the amount of treatment given especially in stage I HER 2 overexpressed breast cancer patients. Adjuvant paclitaxel plus trastuzumab was shown excellent disease free survival (DFS) and overall survival (OS) in node negative, 3 cm and smaller HER 2 overexpressed breast cancer patients. MethodsAll breast cancer patients that treated in Medical Oncology departments of Hacettepe University (Ankara, Turkey), Dr. Abdurrahman Yurtaslan Oncology Training and Research Hospital (Ankara, Turkey), Nicosia Dr. Burhan Nalbantoglu State Hospital (Nicosia, Cyprus) and Near East University (Nicosia, Cyprus) were retrospectively reviewed from patient files, center’s databases and chemotherapy files.ResultsWe retrospectively analyzed 173 patients who treated with adjuvant paclitaxel plus trastuzmab between April 1, 2012 and April 10, 2020. Median age was 52 years (range, 25 to 84 years) and 62.4% had estrogen receptor positive disease. 68.8% of the tumors were high-grade. 14.4% of patients had tumors 1 cm or smaller. 45.0% of patients had tumors larger than 2 cm and 32.3% of patients had tumors larger than 2 cm and up to 3 cm. 12.6% of patients had tumors larger than 3 cm. Mean tumor size was 2.2 cm. 88.4% of patients had N0 disease and 2.9% of patients had microscopic nodal metastasis. 164 of 173 patients completed all 52 weeks of adjuvant treatment. Median follow up of 43 months there were 8 DFS events observed: four distant recurrences (2.3%), three locoregional recurrences (1.7%) and one died without documented recurrence. 3-year DFS rate was 96.6%. There was no recurrences in patients who had tumors 1 cm or smaller. There were 5 DFS events in patients had tumors larger than 2 cm and up to 3 cm subgrup. ConclusionThis real life experience with paclitaxel plus trastuzumab demonstrated few distant recurrences and further supports the APT trial findings.

Table 2. Events Observed for the Disease-free Survival.EventsPatients (N=173)Time to Eventno. (%)moAny recurrence or death8 (4.6)Local or regional recurrenceIpsilateral axilla, HER2-positive2 (1.1)25, 64Ipsilateral breast, HER2-positive1 (0.6)48Distant recurrence4 (2.3)7, 35, 36, 42DeathNot breast-cancer–related1 (0.6)52

Citation Format: Omer Diker, Burak Yasin Aktas, Recep Ak, Bahadir Koylu, Onur Bas, Polat Olgun, Hakan Taban, Deniz Can Guven, Neyran Kertmen, Berna Oksuzoglu, Sercan Aksoy. Adjuvant treatment with paclitaxel plus trastuzumab for node negative human epidermal growth factor receptor 2-positive breast cancer: Real life experience [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS10-52.

Personalized, Mechanically Strong, and Biodegradable Coronary Artery Stents via Melt Electrowriting

Biodegradable coronary artery stents are sought-after alternatives to permanent stents. These devices are designed to degrade after the blood vessel heals, leaving behind a regenerated artery. The original generation of clinically available biodegradable stents required significantly thicker struts (∼150 μm) than nondegradable ones to ensure sufficient mechanical strength. However, these thicker struts proved to be a key contributor to the clinical failure of the stents. A current challenge lies in the fabrication of stents that possess both thin struts and adequate mechanical strength. In this contribution, we describe a method for the bottom-up, additive manufacturing of biodegradable composite stents with ultrathin fibers and superior mechanical properties compared to the base polymer. Specifically, we illustrate that melt electrowriting (MEW) can be used to 3D print composite structures with thin struts (60-80 μm) and a high degree of geometric complexity required for stenting applications. Additionally, this technology allows additive manufacture of personalized stents that are customized to a patient's unique anatomy and disease state. Furthermore, we illustrate that polycaprolactone-reduced graphene oxide nanocomposites have superior mechanical properties compared to original polycaprolactone without detriment to the material's cytocompatibility and that customizable stent-like structures can be fabricated from these materials with struts as thin as 60 μm, well below the target value for clinical use of 80 μm.

Chemoimmunotherapy for the salvage treatment of Ewing sarcoma: A case report

INTRODUCTION

Although, immune check-point inhibitors changed the course of many cancers, the outcomes in sarcomas were rather disappointing with less than 10% response rates. Ewing sarcoma is a poorly differentiated and aggressive tumor mostly seen in the children and adolescents. It's a distinct type of sarcoma with prominent chemosensitivity in the early stages. However, the relapsing disease has a poor prognosis with limited treatment options.

CASE REPORT

Herein, we represent a case of relapsed Ewing sarcoma treated with multiple lines of chemotherapy.Management & outcome: The patient had a very good response to salvage treatment with a combination of paclitaxel and nivolumab which lasted for twelve months after the cessation of treatment.

DISCUSSION

We think that chemotherapy plus immunotherapy can be an option for Ewing sarcoma patients treated with multiple lines of chemotherapy.

Melt Electrowriting of Complex 3D Anatomically Relevant Scaffolds

The manufacture of fibrous scaffolds with tailored micrometric features and anatomically relevant three-dimensional (3D) geometries for soft tissue engineering applications remains a great challenge. Melt electrowriting (MEW) is an advanced additive manufacturing technique capable of depositing predefined micrometric fibers. However, it has been so far inherently limited to simple planar and tubular scaffold geometries because of the need to avoid polymer jet instabilities. In this work, we surmount the technical boundaries of MEW to enable the manufacture of complex fibrous scaffolds with simultaneous controlled micrometric and patient-specific anatomic features. As an example of complex geometry, aortic root scaffolds featuring the sinuses of Valsalva were realized. By modeling the electric field strength associated with the MEW process for these constructs, we found that the combination of a conductive core mandrel with a non-conductive 3D printed model reproducing the complex geometry minimized the variability of the electric field thus enabling the accurate deposition of fibers. We validated these findings experimentally and leveraged the micrometric resolution of MEW to fabricate unprecedented fibrous aortic root scaffolds with anatomically relevant shapes and biomimetic microstructures and mechanical properties. Furthermore, we demonstrated the fabrication of patient-specific aortic root constructs from the 3D reconstruction of computed tomography clinical data.

Characterisation and evaluation of the regenerative capacity of Stro-4+ enriched bone marrow mesenchymal stromal cells using bovine extracellular matrix hydrogel and a novel biocompatible melt electro-written medical-grade polycaprolactone scaffold

Many skeletal tissue regenerative strategies centre around the multifunctional properties of bone marrow derived stromal cells (BMSC) or mesenchymal stem/stromal cells (MSC)/bone marrow derived skeletal stem cells (SSC). Specific identification of these particular stem cells has been inconclusive. However, enriching these heterogeneous bone marrow cell populations with characterised skeletal progenitor markers has been a contributing factor in successful skeletal bone regeneration and repair strategies. In the current studies we have isolated, characterised and enriched ovine bone marrow mesenchymal stromal cells (oBMSCs) using a specific antibody, Stro-4, examined their multipotential differentiation capacity and, in translational studies combined Stro-4+ oBMSCs with a bovine extracellular matrix (bECM) hydrogel and a biocompatible melt electro-written medical-grade polycaprolactone scaffold, and tested their bone regenerative capacity in a small in vivo, highly vascularised, chick chorioallantoic membrane (CAM) model and a preclinical, critical-sized ovine segmental tibial defect model. Proliferation rates and CFU-F formation were similar between unselected and Stro-4+ oBMSCs. Col1A1, Col2A1, mSOX-9, PPARG gene expression were upregulated in respective osteogenic, chondrogenic and adipogenic culture conditions compared to basal conditions with no significant difference between Stro-4+ and unselected oBMSCs. In contrast, proteoglycan expression, alkaline phosphatase activity and adipogenesis were significantly upregulated in the Stro-4+ cells. Furthermore, with extended cultures, the oBMSCs had a predisposition to maintain a strong chondrogenic phenotype. In the CAM model Stro-4+ oBMSCs/bECM hydrogel was able to induce bone formation at a femur fracture site compared to bECM hydrogel and control blank defect alone. Translational studies in a critical-sized ovine tibial defect showed autograft samples contained significantly more bone, (4250.63 mm3, SD = 1485.57) than blank (1045.29 mm3, SD = 219.68) ECM-hydrogel (1152.58 mm3, SD = 191.95) and Stro-4+/ECM-hydrogel (1127.95 mm3, SD = 166.44) groups. Stro-4+ oBMSCs demonstrated a potential to aid bone repair in vitro and in a small in vivo bone defect model using select scaffolds. However, critically, translation to a large related preclinical model demonstrated the complexities of bringing small scale reported stem-cell material therapies to a clinically relevant model and thus facilitate progression to the clinic.

The Patenting and Technological Trends in Hernia Mesh Implants

Described as a projection (prolapse) of tissue through a fascial defect in the abdominal wall, hernias are associated with significant rates of complications, recurrence, and reoperations. This literature review is aimed at providing an overview of the prosthetic surgical meshes used for the repairing of hernia defects. The review was carried out using two specialized online databases: Espacenet, from the European Patent Office (EPO), and WIPO from the World Intellectual Property Organization. Of the 56 patents selected from 2008 to 2018, China was the largest contributor with 55% (31 patents) of the total patent applicant filings, followed by the United States of America (US), with 29% (16 patents). Although the majority of patent applications (39 documents) had at least one company (industry) assigned to the patent application, 4 patents were solely from academic research. Our data showed that only 13 industry applicants have had their products included in the market, and the majority of meshes available on the market are still made from polypropylene. Chemical, physical, and mesh surface modifications have been implemented, and a few reviews describing mesh design, composition, and mechanical properties are available. However, to date, the ideal mesh implant from a clinical point of view has not been developed.

Type II Photoinitiator and Tuneable Poly(Ethylene Glycol)-Based Materials Library for Visible Light Photolithography

Stereolithography (SL) has several advantages over traditional biomanufacturing techniques such as fused deposition modeling, including increased speed, accuracy, and efficiency. While SL has been broadly used in tissue engineering for the fabrication of three-dimensional scaffolds that can mimic the in vivo environment for cell growth and tissue regeneration, lithographic printing is usually performed on single-component materials cured with ultraviolet light, severely limiting the versatility and cytocompatibility of such systems. In this study, we report a highly tunable, low-cost photoinitiator system that we used to establish a systematic library of crosslinked materials based on low molecular weight poly(ethylene glycol) diacrylate. We assessed the physicochemical properties, photocrosslinking efficiency, cost performance, and biocompatibility to demonstrate the capability of manufacturing a multimaterial complex tissue scaffold. [Figure: see text] Impact statement Stereolithography (SL) has advantages over traditional biomanufacturing techniques, including accuracy and efficiency. While SL has been broadly used for fabricating three-dimensional scaffolds that can mimic the in vivo environment for cell growth and tissue regeneration, lithographic printing is usually performed on single-component materials cured with ultraviolet light, severely limiting the versatility and cytocompatibility of such systems. In this study, we report a highly tunable photoinitiator system and establish a systematic library of crosslinked materials based on poly(ethylene glycol) diacrylate. We assessed the physicochemical properties, photocrosslinking efficiency and biocompatibility to demonstrate the capability of manufacturing a multimaterial complex tissue scaffold.

Pembrolizumab- and/or pazopanib-induced remitting seronegative symmetrical synovitis with pitting edema in a patient with renal cell carcinoma

INTRODUCTION

Immune checkpoint inhibitors and angiogenesis inhibitors are novel treatment options for renal cell carcinoma and widely used in clinical practice. They are related with adverse events that occur as a consequence of immune system activation and inhibition of angiogenesis. Herein, we report a rare case of inflammatory arthritis seen in a patient treated with an anti Programmed cell death-1 pembrolizumab and an anti-vascular endothelial growth factor pazopanib.

CASE REPORT

A 60-year-old Caucasian male presented to our clinic with inflammatory arthritis with pitting edema. He had been started on pembrolizumab therapy for metastatic renal cell carcinoma after enrolling in the KEYNOTE-679 study. After six cycles of treatment with pembrolizumab, metastasis had been determined in the lung. Then, the patient's therapy was changed to pazopanib. While the patient was on pazopanib treatment, he noticed a gradual swelling of both hands. Rheumatoid factor, anti-nuclear antibody and anti-cyclic citrullinated peptide were negative. Joint ultrasonography revealed acute tenosynovitis and soft tissue swelling with pitting edema, and a diagnosis of remitting seronegative symmetrical synovitis with pitting edema was made. Management and outcome: He was started on 10 mg prednisolone daily. His symptoms dramatically responded to corticosteroid. He continued to take pazopanib. Then, the patient was discharged with 10 mg prednisolone daily.

DISCUSSION

Pembrolizumab- and/or pazopanib-induced remitting seronegative symmetrical synovitis with pitting edema can be among the rare rheumatic immune-related adverse events that clinicians may encounter as the immune check point inhibitors and anti-VEGF use increases. Corticosteroid therapy can relieve symptoms and cessation of therapy may not be necessary.

The first serological report for genotype C bovine parainfluenza 3 virus in ruminant species of mid-northen Turkey: Traces from the past

Bovine parainfluenza 3 virus (BPI3V)is one of the most important respiratory pathogens and a leading cause of serious respiratory illnesses in cattle, both independent of and in connection with other pathogens involved in the bovine respiratory disease complex (BRDC). In this study, we aimed to identify the historical circulation of genotype C bovine BPI3V (BPI3Vc) in Turkey using the archival serum samples of domestic ruminants that had been collected from six provinces of northern Anatolia in Turkey between 2009-2010. A total of 896 sera from cattle (n=442), sheep (n=330), and goats (n=124) were randomly selected and screened with a virus neutralization test in order to detect antibodies for BPI3Vc. The overall seropositivity rate was 21.09%, with seropositivity rates for cattle, sheep, and goats of 21.04%, 20.00%, and 24.19%, respectively. Neutralizing antibody titers for selected samples ranged between 1/4 to 1/512. This study represents the first serological study conducted using the first BPI3V isolate of Turkey.

Biologically Inspired Scaffolds for Heart Valve Tissue Engineering via Melt Electrowriting

Heart valves are characterized to be highly flexible yet tough, and exhibit complex deformation characteristics such as nonlinearity, anisotropy, and viscoelasticity, which are, at best, only partially recapitulated in scaffolds for heart valve tissue engineering (HVTE). These biomechanical features are dictated by the structural properties and microarchitecture of the major tissue constituents, in particular collagen fibers. In this study, the unique capabilities of melt electrowriting (MEW) are exploited to create functional scaffolds with highly controlled fibrous microarchitectures mimicking the wavy nature of the collagen fibers and their load-dependent recruitment. Scaffolds with precisely-defined serpentine architectures reproduce the J-shaped strain stiffening, anisotropic and viscoelastic behavior of native heart valve leaflets, as demonstrated by quasistatic and dynamic mechanical characterization. They also support the growth of human vascular smooth muscle cells seeded both directly or encapsulated in fibrin, and promote the deposition of valvular extracellular matrix components. Finally, proof-of-principle MEW trileaflet valves display excellent acute hydrodynamic performance under aortic physiological conditions in a custom-made flow loop. The convergence of MEW and a biomimetic design approach enables a new paradigm for the manufacturing of scaffolds with highly controlled microarchitectures, biocompatibility, and stringent nonlinear and anisotropic mechanical properties required for HVTE.

Effect of gelatin source and photoinitiator type on chondrocyte redifferentiation in gelatin methacryloyl-based tissue-engineered cartilage constructs

This work investigates neocartilage formation in bovine and porcine gelatin methacryloyl-based hydrogels photocrosslinked using ultraviolet or visible light photoinitiator systems.

The quest for mechanically and biologically functional soft biomaterials via soft network composites

Developing multifunctional soft biomaterials capable of addressing all the requirements of the complex tissue regeneration process is a multifaceted problem. In order to tackle the current challenges, recent research efforts are increasingly being directed towards biomimetic design concepts that can be translated into soft biomaterials via advanced manufacturing technologies. Among those, soft network composites consisting of a continuous hydrogel matrix and a reinforcing fibrous network closely resemble native soft biological materials in terms of design and composition as well as physicochemical properties. This article reviews soft network composite systems with a particular emphasis on the design, biomaterial and fabrication aspects within the context of soft tissue engineering and drug delivery applications.

Melt Electrospinning Writing of Highly Ordered Large Volume Scaffold Architectures

The additive manufacturing of highly ordered, micrometer-scale scaffolds is at the forefront of tissue engineering and regenerative medicine research. The fabrication of scaffolds for the regeneration of larger tissue volumes, in particular, remains a major challenge. A technology at the convergence of additive manufacturing and electrospinning-melt electrospinning writing (MEW)-is also limited in thickness/volume due to the accumulation of excess charge from the deposited material repelling and hence, distorting scaffold architectures. The underlying physical principles are studied that constrain MEW of thick, large volume scaffolds. Through computational modeling, numerical values variable working distances are established respectively, which maintain the electrostatic force at a constant level during the printing process. Based on the computational simulations, three voltage profiles are applied to determine the maximum height (exceeding 7 mm) of a highly ordered large volume scaffold. These thick MEW scaffolds have fully interconnected pores and allow cells to migrate and proliferate. To the best of the authors knowledge, this is the first study to report that z-axis adjustment and increasing the voltage during the MEW process allows for the fabrication of high-volume scaffolds with uniform morphologies and fiber diameters.

Humanization of bone and bone marrow in an orthotopic site reveals new potential therapeutic targets in osteosarcoma

BACKGROUND

Existing preclinical murine models often fail to predict effects of anti-cancer drugs. In order to minimize interspecies-differences between murine hosts and human bone tumors of in vivo xenograft platforms, we tissue-engineered a novel orthotopic humanized bone model.

METHODS

Orthotopic humanized tissue engineered bone constructs (ohTEBC) were fabricated by 3D printing of medical-grade polycaprolactone scaffolds, which were seeded with human osteoblasts and embedded within polyethylene glycol-based hydrogels containing human umbilical vein endothelial cells (HUVECs). Constructs were then implanted at the femur of NOD-scid and NSG mice. NSG mice were then bone marrow transplanted with human CD34 ⁺ cells. Human osteosarcoma (OS) growth was induced within the ohTEBCs by direct injection of Luc-SAOS-2 cells. Tissues were harvested for bone matrix and marrow morphology analysis as well as tumor biology investigations. Tumor marker expression was analyzed in the humanized OS and correlated with the expression in 68 OS patients utilizing tissue micro arrays (TMA).

RESULTS

After harvesting the femurs micro computed tomography and immunohistochemical staining showed an organ, which had all features of human bone. Around the original mouse femur new bone trabeculae have formed surrounded by a bone cortex. Staining for human specific (hs) collagen type-I (hs Col-I) showed human extracellular bone matrix production. The presence of nuclei staining positive for human nuclear mitotic apparatus protein 1 (hs NuMa) proved the osteocytes residing within the bone matrix were of human origin. Flow cytometry verified the presence of human hematopoietic cells. After injection of Luc-SAOS-2 cells a primary tumor and lung metastasis developed. After euthanization histological analysis showed pathognomic features of osteoblastic OS. Furthermore, the tumor utilized the previously implanted HUVECS for angiogenesis. Tumor marker expression was similar to human patients. Moreover, the recently discovered musculoskeletal gene C12orf29 was expressed in the most common subtypes of OS patient samples.

CONCLUSION

OhTEBCs represent a suitable orthotopic microenvironment for humanized OS growth and offers a new translational direction, as the femur is the most common location of OS. The newly developed and validated preclinical model allows controlled and predictive marker studies of primary bone tumors and other bone malignancies.

Melt Electrospinning Writing of Three-dimensional Poly(ε-caprolactone) Scaffolds with Controllable Morphologies for Tissue Engineering Applications

This tutorial reflects on the fundamental principles and guidelines for electrospinning writing with polymer melts, an additive manufacturing technology with great potential for biomedical applications. The technique facilitates the direct deposition of biocompatible polymer fibers to fabricate well-ordered scaffolds in the sub-micron to micro scale range. The establishment of a stable, viscoelastic, polymer jet between a spinneret and a collector is achieved using an applied voltage and can be direct-written. A significant benefit of a typical porous scaffold is a high surface-to-volume ratio which provides increased effective adhesion sites for cell attachment and growth. Controlling the printing process by fine-tuning the system parameters enables high reproducibility in the quality of the printed scaffolds. It also provides a flexible manufacturing platform for users to tailor the morphological structures of the scaffolds to their specific requirements. For this purpose, we present a protocol to obtain different fiber diameters using melt electrospinning writing (MEW) with a guided amendment of the parameters, including flow rate, voltage and collection speed. Furthermore, we demonstrate how to optimize the jet, discuss often experienced technical challenges, explain troubleshooting techniques and showcase a wide range of printable scaffold architectures.

An Integrated Design, Material, and Fabrication Platform for Engineering Biomechanically and Biologically Functional Soft Tissues

We present a design rationale for stretchable soft network composites for engineering tissues that predominantly function under high tensile loads. The convergence of 3D-printed fibers selected from a design library and biodegradable interpenetrating polymer networks (IPNs) result in biomimetic tissue engineered constructs (bTECs) with fully tunable properties that can match specific tissue requirements. We present our technology platform using an exemplary soft network composite model that is characterized to be flexible, yet ∼125 times stronger (E = 3.19 MPa) and ∼100 times tougher (W_Ext = ∼2000 kJ m^-3) than its hydrogel counterpart.

Via precise interface engineering towards bioinspired composites with improved 3D printing processability and mechanical properties

Precise interface engineering in inorganic–organic hybrid materials enhances both the elastic moduli and toughness of a biodegradable composite, which is of relevance for load-bearing applications in bone tissue engineering.

Periosteum tissue engineering in an orthotopic in vivo platform

The periosteum plays a critical role in bone homeostasis and regeneration. It contains a vascular component that provides vital blood supply to the cortical bone and an osteogenic niche that acts as a source of bone-forming cells. Periosteal grafts have shown promise in the regeneration of critical size defects, however their limited availability restricts their widespread clinical application. Only a small number of tissue-engineered periosteum constructs (TEPCs) have been reported in the literature. A current challenge in the development of appropriate TEPCs is a lack of pre-clinical models in which they can reliably be evaluated. In this study, we present a novel periosteum tissue engineering concept utilizing a multiphasic scaffold design in combination with different human cell types for periosteal regeneration in an orthotopic in vivo platform. Human endothelial and bone marrow mesenchymal stem cells (BM-MSCs) were used to mirror both the vascular and osteogenic niche respectively. Immunohistochemistry showed that the BM-MSCs maintained their undifferentiated phenotype. The human endothelial cells developed into mature vessels and connected to host vasculature. The addition of an in vitro engineered endothelial network increased vascularization in comparison to cell-free constructs. Altogether, the results showed that the human TEPC (hTEPC) successfully recapitulated the osteogenic and vascular niche of native periosteum, and that the presented orthotopic xenograft model provides a suitable in vivo environment for evaluating scaffold-based tissue engineering concepts exploiting human cells.

Effects of quercetin on kidney injury induced by doxorubicin

OBJECTIVES

The anthracycline antitumor drug doxorubicine causes severe nephrotoxicity in a variety of experimental animals and may be nephrotoxic to humans. The aim of present study was to determine the protective effects of quercetin against doxorubicin-induced kidney injury with light microscopy.

METHODS

Forty male Wistar albino rats were divided into four groups: control, doxorubicin, doxorubicin+quercetin and quercetin. A single dose of 20 mg/kg/ i.p. doxorubicin was used to induce injury. Quercetin was administrated orally against doxorubicin toxicity. The kidneys were examined under light microscopy after H-E (hematoxylin-eosin) staining and the changes were scored.

RESULTS

Significant tissue injury was observed in doxorubicin-administered group. Among these injuries, renal tubular dilatation, tubular vacuolar changes, glomerular vacuolization, decrease in bowman space, bowman capsule thickening, and interstitial infiltration were evident. However, the injury induced by doxorubicin was attenuated with quercetin administration.

DISCUSSION

Quercetin decreased doxorubicin-induced kidney damage (Tab. 1, Fig. 4, Ref. 27).

A tattoo pigmented node and breast cancer

Over the last decade, the axillary SLNB has replaced routine ALND for clinical staging in early breast cancer. Studies describe a potential pitfall in the identification of a true sentinel node during surgery due to lymph node pigmentation secondary to migration of tattoo dye. These pigmented “pseudo-sentinel” nodes, if located superficially in the axilla, may mimic the blue sentinel node on visual inspection, therefore missing the true sentinel node and potentially understaging the patient. Here, we present a case report of a breast cancer patient with a tattoo and discuss the importance of tattoo pigment in the LN (Fig. 1, Ref. 8).

The estimation of the volume of sheep mandibular defects using cone-beam computed tomography images and a stereological method

OBJECTIVE

The Cavalieri principle of stereological methods is widely used to estimate the volume of structures. Recently in clinical practice, it has become common to use this approach for daily routine purposes. The Cavalieri principle provides quantitative and unbiased volume estimates which are independent of the observer. In the present study, the efficacy of using the Cavalieri principle to estimate the volume of sheep mandibular defects on cone beam CT (CBCT) scans was tested.

METHODS

24 differently sized defects were created on 4 sheep mandibles. Before the defects were created, the outer boundaries of the defects were determined using plaster casts. CBCT scans of the defects were taken. The scans were reconstructed in the coronal plane and sections of 0.2 mm thickness with 0.2 mm and 0.4 mm intervals were obtained. The volume of each defect was estimated using the Cavalieri principle. The models were created using light-body silicone for the estimation of the actual volume of each defect. They were immersed in water using a pycnometer and the actual volumes were obtained on the basis of the Archimedean principle. The actual and estimated volumes of the defects were compared using the Wilcoxon signed-rank test.

RESULTS

The results showed that the volumes from the Cavalieri estimates did not differ from the actual volumes of the defects (P > 0.05).

CONCLUSION

We concluded that the volume of mandibular defects can be accurately estimated using the Cavalieri principle on images from a CBCT scan.

Chronic prenatal exposure to the 900 megahertz electromagnetic field induces pyramidal cell loss in the hippocampus of newborn rats

Widespread use of mobile phones which are a major source of electromagnetic fields might affect living organisms. However, there has been no investigation concerning prenatal exposure to electromagnetic fields or their roles in the development of the pyramidal cells of the cornu ammonis in postnatal life. Two groups of pregnant rats, a control group and an experimental group, that were exposed to an electromagnetic field were used. For obtaining electromagnetic field offspring, the pregnant rats were exposed to 900 megahertz electromagnetic fields during the 1–19th gestation days. There were no actions performed on the control group during the same period. The offspring rats were spontaneously delivered—control group ( n = 6) and electromagnetic field group ( n = 6). Offspring were sacrificed for stereological analyses at the end of the 4th week. Pyramidal cell number in rat cornu ammonis was estimated using the optical fractionator technique. It was found that 900 megahertz of electromagnetic field significantly reduced the total pyramidal cell number in the cornu ammonis of the electromagnetic field group ( P < 0.001). Therefore, although its exact mechanism is not clear, it is suggested that pyramidal cell loss in the cornu ammonis could be due to the 900 megahertz electromagnetic field exposure in the prenatal period.

Achieving efficient anti-adhesion in re-mediastinoscopy: an experimental study in rats

OBJECTIVE

Re-mediastinoscopy can be a difficult procedure due to fibrosis in the mediastinum. We have investigated the effect of an anti-adhesive barrier agent "hylan B gel" on the formation of adhesions after dissection in the superior mediastinum in a rat model.

METHODS

The study was conducted in 70 male Sprague-Dawley rats weighing 300 g. The strap muscles were divided by a midline cervical incision. The anterior and lateral aspects of the trachea were dissected to the level of the carina. Hylan B gel (Sepragel Sinus, Genzyme Company, Redgefield, NJ, USA) was used to create an anti-adhesive barrier. The rats who were subjected to surgery were sacrificed on postoperative days 14 and 28. All rats were previously divided into 5 groups: Sham group (n = 10); Group 1 (n = 15) surgery alone, sacrificed on day 14; Group 2 (n = 15) surgery and Sepragel, sacrificed on day 14; Group 3 (n = 15) surgery alone, sacrificed on day 28; Group 4 (n = 15) surgery and Sepragel, sacrificed on day 28. Histopathological analysis was performed to study the effect of the anti-adhesive agent. Scores were calculated based on collagen fibrosis, fibroblasts, granulation tissue, muscle alterations/inflammation, histiocytes, mononuclear giant cells, inflammation and vascular proliferation.

RESULTS

Collagen fibrosis and fibroblast scores, which represent adhesions, were significantly higher in Groups 1, 2, 3, 4 than in the Sham group ( P < 0.01). The degree of adhesions on day 14 was found to be higher in Group 1 compared to Group 2 ( P < 0.01). Adhesions on day 28 were higher in Group 3 compared to Group 4 ( P < 0.01). There were no differences between groups with regard to foreign body reactions ( P > 0.05).

CONCLUSION

Adhesions causing technical difficulty during re-mediastinoscopy can be reduced by the application of anti-adhesive agents during the primary procedure.

Histopathological Effects of Bipolar Vessel Sealing Devices on Liver Parenchyma and Comparison with Suture Method: An Experimental Study

BACKGROUND

LigaSureand SurgRx are bipolar vessel sealing devices providing hemostasis by denaturating collagen and elastin from the vessel wall and surrounding connective tissue. We aimed to histopathologically evaluate the lateral injury during rat liver resection with LigaSure and SurgRx.

METHODS

Suture technique was used in group A, LigaSure was used in group B and SurgRx was used in group C to resect one lobe of liver from midline. One of the resected pieces was histopathologically examined the same day and the other piece was left in the animal to be examined at the 7th day. Relaparotomy was performed at the 7th day.

RESULTS

Necrosis, exudate formation, chronic inflammation, histiocytes and fibroblasts scores were significantly lower in SurgRx group compared to the other groups.

CONCLUSION

Our findings suggest that LigaSure and SurgRx can be safely used in liver resection as compared to suture technique while SurgRx was superior than LigaSure in inflammatory response as it causes lower lateral thermal injury and inflammatory scores probably due to its different technical properties.