3D Printing of Biodegradable Scaffolds for Tissue Engineering Applications

With the recent improvements in three dimensional (3D) printing technologies, the potential for tissue engineering and regenerative medicine have significantly improved. One key idea in tissue engineering is to specifically design scaffolds to aid in the healing process by being incorporated into the body’s own tissue. The overall goal of this project is to investigate 3D printable scaffold design to access suitability for tissue replacement. This was accomplished by analyzing the effect of the material used to create the scaffolds, pore size, and pore shape on mechanical stiffness and cell culturability. Based on published literature, it was determined that, depending upon the desired tissue type, the best pore shapes are circles, squares, and hexagons. This study focused on designing numerous scaffolds by varying the parameters listed above, and then printing 3D biodegradable (PLA & TPU) scaffolds to be cultured, mechanically tested and evaluated. The scaffolds were cultured with endothelial cell lines to ensure cell survivability on the 3D printed material. After cell culturing protocol, cell attachment and viability were assessed and cell density recorded. The mechanical tests were performed using a standard tension test machine in order to gather stiffness and strength data. By analyzing our results, we will be able to make recommendations regarding which pore shape, size, and porosity will yield the most anatomically compliant results for the desired tissue

Minutes of the Meeting of the Board of Directors of Fannie Mae - on the OFHEO

Also participating were Mr. Smith, Messrs. Levin and Weber, and Ms. Kappler of Fannie Mae, and Messrs. Brome and loffe of Cravath, Swaine Moore LLP as counsel to the non-management directors. Messrs. Williams and Duncan of Fannie Mae were present for parts of the meeting

Treating Causes Not Symptoms : Basic Income as a Public Health Measure

New research funded by the National Institute for Health and Social Care Research (NIHR) has found that a Basic Income scheme could potentially save the NHS tens of billions of pounds. ‘Treating causes not symptoms: Basic Income as a public health measure’ uses a range of economic and health modelling, public opinion surveys and community consultation to present cutting-edge evidence on the impact of Basic Income schemes

The impact of surgical delay on resectability of colorectal cancer: An international prospective cohort study

AIM: The SARS-CoV-2 pandemic has provided a unique opportunity to explore the impact of surgical delays on cancer resectability. This study aimed to compare resectability for colorectal cancer patients undergoing delayed versus non-delayed surgery. METHODS: This was an international prospective cohort study of consecutive colorectal cancer patients with a decision for curative surgery (January-April 2020). Surgical delay was defined as an operation taking place more than 4 weeks after treatment decision, in a patient who did not receive neoadjuvant therapy. A subgroup analysis explored the effects of delay in elective patients only. The impact of longer delays was explored in a sensitivity analysis. The primary outcome was complete resection, defined as curative resection with an R0 margin. RESULTS: Overall, 5453 patients from 304 hospitals in 47 countries were included, of whom 6.6% (358/5453) did not receive their planned operation. Of the 4304 operated patients without neoadjuvant therapy, 40.5% (1744/4304) were delayed beyond 4 weeks. Delayed patients were more likely to be older, men, more comorbid, have higher body mass index and have rectal cancer and early stage disease. Delayed patients had higher unadjusted rates of complete resection (93.7% vs. 91.9%, P = 0.032) and lower rates of emergency surgery (4.5% vs. 22.5%, P < 0.001). After adjustment, delay was not associated with a lower rate of complete resection (OR 1.18, 95% CI 0.90-1.55, P = 0.224), which was consistent in elective patients only (OR 0.94, 95% CI 0.69-1.27, P = 0.672). Longer delays were not associated with poorer outcomes. CONCLUSION: One in 15 colorectal cancer patients did not receive their planned operation during the first wave of COVID-19. Surgical delay did not appear to compromise resectability, raising the hypothesis that any reduction in long-term survival attributable to delays is likely to be due to micro-metastatic disease

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Non-linear Dynamics of the Trapped Quantum Vortex

Nanomechanical resonators have recently been studied as high-sensitivity probes of fluid dynamics in superfluid helium. When turbulence is introduced to such a system, quantum vortices may form and become trapped by the resonator, either completely surrounding the oscillating beam (a fully trapped vortex) or surrounding only part of it (a partially trapped vortex). Fully trapped vortices have been studied using the model of a linear harmonic oscillator behaviour with great success. However, in the presence of a partially trapped vortex, the oscillators have been found to behave non-linearly. We analysed the non-linear response of a doubly clamped nanobeam resonator submerged in helium-4 at 10 mK in the presence of a partially trapped vortex. Our analysis demonstrates that the observed non-linearities are caused by the dynamics of the vortex line. N. M. acknowledges the financial support of the US-UK Fulbright Program

Plasma-Modified ACT Can Be Used to Monitor Bivalirudin (Angiomax

Heparin-induced thrombocytopenia (HIT) is a problem of growing significance and concern, affecting an estimated 1–3% of patients among those receiving an estimated 10 million heparin exposures annually in the United States. The prevalence of heparin antibodies has been reported as at least 12.7% in the general cardiac surgery population before surgery and 42% following surgery (1). Various management techniques for anticoagulation in these patients have been proposed. Many of these alternative agents present additional risks for bleeding and efficacy and, furthermore, require the use of nonconventional monitoring assays to assess the level of anticoagulation achieved adequately. We report here the successful use of bivalirudin anticoagulation on pump, with no additional morbidity, and the first reported use of the plasma-modified ACT (activated clotting time) test, a simple modification of the standard ACT assay, to monitor the anticoagulant effect of bivalirudin

Feasibility of MR imaging/MR spectroscopy-planned focal partial salvage permanent prostate implant (PPI) for localized recurrence after initial PPI for prostate cancer.

PurposeTo assess the feasibility of magnetic resonance imaging (MRI)-planned partial salvage permanent prostate implant (psPPI) among patients with biopsy-proven local recurrence after initial PPI without evidence of distant disease.Methods and materialsFrom 2003-2009, 15 patients underwent MRI/magnetic resonance spectroscopy (MRS) planning for salvage brachytherapy (psPPI, I-125 [n=14; 144 Gy]; Pd-103 [n=1; 125 Gy]) without hormone therapy. Full dose was prescribed to areas of recurrence and underdosage, without entire prostate implantation. Limiting urethral and rectal toxicity was prioritized. Follow-up was from salvage date to prostate-specific antigen (PSA) concentration failure (Phoenix criteria = nadir + 2.0; ASTRO = 3 consecutive rises), recurrence, distant metastases, or last follow-up PSA level. Progression-free survival (PFS) was defined as no PSA failure or biopsy-proven recurrence without all-cause mortality. Toxicity was scored using Common Terminology Criteria for Adverse Events version 4.0.ResultsAt salvage, median age was 68 years, and PSA concentration was 3.5 ng/mL (range, 0.9-5.6 ng/mL). Abnormal MRI/MRS findings were evident in 40% of patients. Biopsy-proven recurrences consisted of a single focus (80%) or 2 foci (20%). At recurrence, Gleason score was 6 (67%) or ≥7 (27%). Median interval between initial and salvage implantation was 69 months (range, 28-132 months). psPPI planning characteristics limited doses to the rectum (mean V100 = 0.5% [0.07 cc]) and urethra (V100 = 12% [0.3 cc]). At median follow-up (23.3 months; range, 8-88 months), treatment failure (n=2) resulted only in localized recurrence; both patients underwent second psPPI with follow-up PSA tests at 12 and 26 months, resulting in 0.6 and 0.7 ng/mL, respectively. American Society for Radiation Oncology PFS rates at 1, 2, and 3 years were 86.7%, 78.4%, and 62.7%, respectively, with 5 patients for whom treatment failed (n=3 with negative transrectal ultrasound-guided biopsy results). Phoenix PFS rates at 1, 2, and 3 years were 100%, 100%, and 71.4%. 73%, respectively; achieved PSA nadir of &lt;0.5 ng/mL; and 47% of patients had a nadir of &lt;0.1 ng/mL. Treatment-related toxicity was minimal, with no operative interventions, fistulas, or other grade ≥3 gastrointestinal (GI)/genitourinary (GU) toxicity. Thirteen percent had grade 1 GI and 33% had grade 2 GU toxicities. Postsalvage, 20% of patients had no erectile dysfunction, 67% of patients had medication-responsive erectile dysfunction, and 13% of patients had erectile dysfunction refractory to medication.ConclusionsFocal psPPI with MR-planning in highly selected patients is feasible with short-term control comparable to conventional salvage, with less toxicity. Longer follow-up is needed to confirm its impact on quality of life and treatment

Feasibility of MR imaging/MR spectroscopy-planned focal partial salvage permanent prostate implant (PPI) for localized recurrence after initial PPI for prostate cancer.

PurposeTo assess the feasibility of magnetic resonance imaging (MRI)-planned partial salvage permanent prostate implant (psPPI) among patients with biopsy-proven local recurrence after initial PPI without evidence of distant disease.Methods and materialsFrom 2003-2009, 15 patients underwent MRI/magnetic resonance spectroscopy (MRS) planning for salvage brachytherapy (psPPI, I-125 [n=14; 144 Gy]; Pd-103 [n=1; 125 Gy]) without hormone therapy. Full dose was prescribed to areas of recurrence and underdosage, without entire prostate implantation. Limiting urethral and rectal toxicity was prioritized. Follow-up was from salvage date to prostate-specific antigen (PSA) concentration failure (Phoenix criteria = nadir + 2.0; ASTRO = 3 consecutive rises), recurrence, distant metastases, or last follow-up PSA level. Progression-free survival (PFS) was defined as no PSA failure or biopsy-proven recurrence without all-cause mortality. Toxicity was scored using Common Terminology Criteria for Adverse Events version 4.0.ResultsAt salvage, median age was 68 years, and PSA concentration was 3.5 ng/mL (range, 0.9-5.6 ng/mL). Abnormal MRI/MRS findings were evident in 40% of patients. Biopsy-proven recurrences consisted of a single focus (80%) or 2 foci (20%). At recurrence, Gleason score was 6 (67%) or ≥7 (27%). Median interval between initial and salvage implantation was 69 months (range, 28-132 months). psPPI planning characteristics limited doses to the rectum (mean V100 = 0.5% [0.07 cc]) and urethra (V100 = 12% [0.3 cc]). At median follow-up (23.3 months; range, 8-88 months), treatment failure (n=2) resulted only in localized recurrence; both patients underwent second psPPI with follow-up PSA tests at 12 and 26 months, resulting in 0.6 and 0.7 ng/mL, respectively. American Society for Radiation Oncology PFS rates at 1, 2, and 3 years were 86.7%, 78.4%, and 62.7%, respectively, with 5 patients for whom treatment failed (n=3 with negative transrectal ultrasound-guided biopsy results). Phoenix PFS rates at 1, 2, and 3 years were 100%, 100%, and 71.4%. 73%, respectively; achieved PSA nadir of &lt;0.5 ng/mL; and 47% of patients had a nadir of &lt;0.1 ng/mL. Treatment-related toxicity was minimal, with no operative interventions, fistulas, or other grade ≥3 gastrointestinal (GI)/genitourinary (GU) toxicity. Thirteen percent had grade 1 GI and 33% had grade 2 GU toxicities. Postsalvage, 20% of patients had no erectile dysfunction, 67% of patients had medication-responsive erectile dysfunction, and 13% of patients had erectile dysfunction refractory to medication.ConclusionsFocal psPPI with MR-planning in highly selected patients is feasible with short-term control comparable to conventional salvage, with less toxicity. Longer follow-up is needed to confirm its impact on quality of life and treatment