Three-dimensional porous scaffolds prepared from regenerated silk fibroin using either an all aqueous process or a process involving an organic solvent, hexafluoroisopropanol (HFIP) have shown promise in cell culture and tissue engineering applications. However, their biocompatibility and in vivo degradation has not been fully established. The present study was conducted to systematically investigate how processing method (aqueous vs. organic solvent) and processing variables (silk fibroin concentration and pore size) affect the short-term (up to 2 months) and longterm (up to 1 year) in vivo behavior of the protein scaffolds in both nude and Lewis rats. The samples were analyzed by histology for scaffold morphological changes and tissue ingrowth, and by real-time RT-PCR and immunohistochemistry for immune responses. Throughout the period of implantation, all scaffolds were well-tolerated by the host animals and immune responses to the implants were mild. Most scaffolds prepared from the all aqueous process degraded to completion between two and six months, while those prepared from organic solvent (hexafluoroisopropanol (HFIP)) process persisted beyond one year. Due to widespread cellular invasion throughout the scaffold, the degradation of aqueous-derived scaffolds appears to be more homogeneous than that of HFIP-derived scaffolds. In general and especially for the HFIP-derived scaffolds, a higher original silk fibroin concentration (e.g. 17%) and smaller pore size (e.g. 100-200 µm) resulted in lower levels of tissue ingrowth and slower degradation. These results demonstrate that the in vivo behavior of the three-dimensional silk fibroin scaffolds is related to the morphological and structural features that resulted from different scaffold preparation processes. The insights gained in this study can serve as a guide for processing scenarios to match desired morphological and structural features and degradation time with tissue-specific applications.

SummaryBackground and objectives Most deaths in autosomal dominant polycystic kidney disease (ADPKD) are attributable to cardiovascular disease (CVD). We examined novel CVD biomarkers in different stages of AD-PKD.Design, setting, participants, & measurements We recruited 50 hypertensive subjects with ADPKD with estimated GFR (eGFR) of Ͼ60 ml/min per 1.73 m 2 ; 52 hypertensive subjects with ADPKD with eGFR of 25 to 60 ml/min per 1.73 m 2 ; 42 normotensive subjects with ADPKD and eGFR of Ͼ60 ml/min per 1.73 m 2 ; and 50 healthy controls. We assayed serum C-reactive protein and IL-6 as markers of inflammation; plasma 8-epi-prostaglandin F 2␣ (8-epi-PGF2␣ ) and superoxide dismutase (SOD) as markers of oxidative stress; and homeostasis model assessment (HOMA) as a measure of insulin resistance. ResultsThe hypertensive ADPKD eGFR of 25 to 60 group had higher levels of C-reactive protein and IL-6 than controls, normotensive ADPKD with eGFR of Ͼ60, and hypertensive ADPKD with eGFR of Ͼ60. The normotensive ADPKD eGFR Ͼ60, hypertensive ADPKD eGFR Ͼ60, and hypertensive ADPKD eGFR 25 to 60 groups had higher 8-epi-PGF 2␣ and lower SOD than controls, with no difference between the ADPKD groups. There was no difference in HOMA levels between any of the groups. Adjustment for age, race, gender, and body mass index did not alter these relationships. ConclusionsInflammation and oxidative stress are evident early in ADPKD even with preserved kidney function. Inflammation exhibits a graded relationship with levels of kidney function, whereas oxidative stress demonstrates a threshold effect. These pathways may be therapeutic targets for CVD risk mitigation.

Morphogenesis of epithelial cells involves processes by which kidney shape and function are regulated. The lack of in vitro models that are sustainable for longer time periods and emulating complex intercellular interactions of the kidney have limited understanding about epithelial tissue morphogenesis and its aberrations in diseases such as autosomal dominant polycystic kidney disease (ADPKD). A sustainable three-dimensional (3D) coculture system for normal and diseased kidney tissues is reported here. Tubule- and ADPKD cyst-derived cells were cultured in extracellular matrix molecules infused into 3D porous silk scaffolds, and these cultures were subsequently extended into a perfusion bioreactor. The results indicated collagen-matrigel-mediated morphogenesis for both (normal and disease) cell types and also supported coculturing with fibroblasts. The structural and functional features of the kidney-like tissue structures were validated based on the distribution of E-cadherin, N-cadherin, Na+ K+ ATPase pump, and cellular uptake of the organic anion (6-carboxy fluorescein). Further, the structures were sustained for longer time periods using a perfusion bioreactor to demonstrate the potential utility of this 3D in vitro coculture system for ADPKD research, other epithelial tissue systems, and for in vitro drug screening.

Opioid analgesics are commonly used post-lung transplant, but have many side effects and are associated with worse outcomes. We conducted a retrospective review of all lung transplant recipients who were treated with a multimodal opioid-sparing pain protocol. The use of liposomal bupivacaine intercostal nerve block was variable due to hospital restrictions. The primary objective was to describe opioid requirements and patient-reported pain scores early post-lung transplant and to assess the impact of intraoperative liposomal bupivacaine intercostal nerve block. We treated 64 lung transplant recipients with our protocol. Opioid utilization decreased to a mean of 43 milligram oral morphine equivalents by postoperative day 4. Median pain scores peaked at 4 on postoperative day 1 and decreased thereafter. Only three patients were discharged home with opioids, all of whom were taking opioid agonist therapy pretransplant for opioid use disorder. Patients who received liposomal bupivacaine intercostal nerve block in the operating room had a significant reduction in opioid consumption over postoperative day 1 through 4 (228 mg vs. 517 mg, P= .032). A multimodal opioid-sparing pain management protocol is feasible and resulted in weaning of opioids prior to hospital discharge.

Systemic vascular dysfunction, manifesting as an increase in AIx and vascular inflammation is evident in young normotensive ADPKD patients with preserved renal function. Vascular inflammation is not associated with elevated AIx in ADPKD.

Objectives Patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection may develop end-stage lung disease requiring lung transplantation. We report the clinical course, pulmonary pathology with radiographic correlation, and outcomes after lung transplantation in three patients who developed chronic respiratory failure due to postacute sequelae of SARS-CoV-2 infection. Methods A retrospective histologic evaluation of explanted lungs due to coronavirus disease 2019 was performed. Results None of the patients had known prior pulmonary disease. The major pathologic findings in the lung explants were proliferative and fibrotic phases of diffuse alveolar damage, interstitial capillary neoangiogenesis, and mononuclear inflammation, specifically macrophages, with varying numbers of T and B lymphocytes. The fibrosis varied from early collagen deposition to more pronounced interstitial collagen deposition; however, pulmonary remodeling with honeycomb change was not present. Other findings included peribronchiolar metaplasia, microvascular thrombosis, recanalized thrombi in muscular arteries, and pleural adhesions. No patients had either recurrence of SARS-CoV-2 infection or allograft rejection following transplant at this time. Conclusions The major pathologic findings in the lung explants of patients with SARS-CoV-2 infection suggest ongoing fibrosis, prominent macrophage infiltration, neoangiogenesis, and microvascular thrombosis. Characterization of pathologic findings could help develop novel management strategies.

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Background Morbidity and mortality rates after lung transplantation remain high compared to other solid organ transplants. In the lung allocation score era, patients given the highest priority on the waitlist are those with the greatest severity of illness, who often require preoperative hospitalization. Material/Methods To determine the association of pre-transplant hospitalization with post-transplant outcomes, we retrospectively evaluated 448 lung transplant recipients at our center between January 2010 and July 2017 (114 hospitalized; 334 outpatient). Results Survival was similar between the groups (hazard ratio 0.93 [95% CI 0.61 to 1.42], p=0.738). However, hospitalized patients had longer hospital and intensive care unit length of stay compared to outpatients – 25 vs. 18 days, (p<0.001) and 9.5 vs. 6 days, (p<0.001), respectively. Hospitalized patients had higher rates of Grade 3 primary graft dysfunction – 29.8% vs. 9.6%, p<0.001 – and remained mechanically ventilated longer – 6 vs. 3 days, p<0.001. A greater percentage of hospitalized patients needed a tracheostomy and a re-operation within 30 days – 39.5% vs. 15.3% (p<0.001) and 22.8% vs. 12.0% (p=0.005) – respectively. After discharge, 28% of hospitalized patients required acute rehabilitation compared with 12% of outpatients (p=0.001). Conclusions While pre-transplant hospitalization is not associated with mortality, it is associated with significant morbidity after transplant.