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Category: Basic Sciences/Biologics; Basic Sciences/Biologics Introduction/Purpose: Zinc and magnesium are crucial for bone health, and their deficiencies can lead to impaired bone metabolism and repair. Although enhancing their bioavailability has been linked to better fracture healing, their levels during healing have not been studied. We hypothesized that zinc and magnesium levels transiently decrease at the fracture site compared to intact bone. This study is the first to explore temporal trace element levels during the initial stages of fracture healing. The findings will reveal when each element changes its concentration at the fracture site, which is associated with specific functions necessary for appropriate healing. Understanding the connection between trace element concentration and repair processes could lead to more effective treatment or supplementation during fracture healing. Methods: Following induction of a femur fracture in male BB Wistar rats, injured and intact contralateral femurs were harvested at 1- (n=3), 3- (n=4), and 7-days (n=3) after fracture. Fracture segments 10mm in length were resected 5mm from the center of the callus in either direction. Contralateral non-fractured femur segments were resected from the same region within the femoral diaphysis. Samples were analyzed via inductively coupled mass spectrometry using an Agilent ICP-MS 7900 (Agilent Technologies, Santa Clara, CA). Data was converted from ppb to percent weight zinc and magnesium per weight of bone (w/w%). The difference between zinc and magnesium in contralateral intact bone vs. fractured bone was calculated and averaged (∆) for each group. The average % change were also determined. An independent sample two-tailed t-test was performed comparing average w/w% of zinc and magnesium between fracture and contralateral samples. A p-value of < 0.05 was considered significant. Results: After 1-day post-fracture, there was a -29.09 average % change in zinc levels (∆ 6.90x10^-03 ± 5.05x10^-03) (p = 0.033) and a -25.76 average % change in magnesium levels (∆ 1.21x10^-01 ± 7.36x10^-02 w/w%) (p = 0.241) between fractured and non- fractured femurs. After 3-days post-fracture, there was a -22.51 average % change in zinc levels (∆ 5.45x10^-03 ± 3.95x10^-03 w/w%) (p = 0.022) and a -33.07 average % change in magnesium levels (∆ 1.84x10^-01 ± 1.05x10^-01 w/w%) (p = 0.025). After 7- days post-fracture, there was a -9.40 average % change in zinc levels (∆ 1.90x10^-03 ± 3.98x10^-03) (p = 0.377) and a -17.88 average % change in magnesium levels (∆ 9.04x10^-02 ± 1.24x10^-01 w/w%) (p = 0.159) between fractured and non-fractured femurs. Conclusion: Previous research has established the significance of trace elements, namely zinc and magnesium, in the process of fracture healing. Zinc has been shown to improve fracture healing, while magnesium has been found to play a role regulating inflammation during early fracture healing. The findings of this study corroborate our hypothesis that levels of these elements transiently decline following fracture. By evaluating these changes in trace element levels, we can gain a better understanding of their function in the fracture healing process. These observations may offer insight into potential therapeutic approaches utilizing zinc and magnesium for fracture healing in the future.

Abstract Introduction SEL-212 is a developmental treatment for uncontrolled gout characterized by serum uric acid (sUA) levels ≥ 6 mg/dl despite treatment. It comprises a novel PEGylated uricase (SEL-037; also called pegadricase) co-administered with tolerogenic nanoparticles containing sirolimus (rapamycin) (SEL-110; also called ImmTOR®), which mitigates the formation of anti-drug antibodies (ADAs) against uricase and SEL-037 (PEGylated uricase), thereby enabling sustained sUA control (sUA

Abstract The retinal pigmented epithelium (RPE) constitutes the outer blood‐retinal barrier, enables photoreceptor function of the eye, and is constantly exposed to oxidative stress. As such, dysfunction of the RPE underlies pathology leading to development of age‐related macular degeneration (AMD), the leading cause of vision loss among the elderly in industrialized nations. A major responsibility of the RPE is to process photoreceptor outer segments, which relies on the proper functioning of its endocytic pathways and endosomal trafficking. Exosomes and other extracellular vesicles (EVs) from RPE are an essential part of these pathways and may be early indicators of cellular stress. To test the role of small EVs (sEVs) including exosomes, that may underlie the early stages of AMD, we used a polarized primary RPE cell culture model under chronic subtoxic oxidative stress. Unbiased proteomic analyses of highly purified basolateral sEVs from oxidatively stressed RPE cultures revealed changes in proteins involved in epithelial barrier integrity. There were also significant changes in proteins accumulating in the basal‐side sub‐RPE extracellular matrix during oxidative stress, that could be prevented with an inhibitor of sEV release. Thus, chronic subtoxic oxidative stress in primary RPE cultures induces changes in sEV content, including basal‐side specific desmosome and hemidesmosome shedding via sEVs. These findings provide novel biomarkers of early cellular dysfunction and opportunity for therapeutic intervention in age‐related retinal diseases (e.g., AMD).

Abstract Preferential flow reduces water residence times and allows rapid transport of pollutants such as organic contaminants. Thus, preferential flow is considered to reduce the influence of soil matrix-solute interactions during solute transport. While this claim may be true when rainfall directly follows solute application, forcing rapid chemical and physical disequilibrium, it has been perpetuated as a general feature of solute transport—regardless of the magnitude preferential flow. A small number of studies have alternatively shown that preferential transport of strongly sorbing solutes is reduced when solutes have time to diffuse and equilibrate within the soil matrix. Here we expand this inference by allowing solute sorption equilibrium to occur and exploring how physiochemical properties affect solute transport across a vast range of preferential flow. We applied deuterium-labeled rainfall to field plots containing manure spiked with eight common antibiotics with a range of affinity for the soil after 7 days of equilibration with the soil matrix and quantified preferential flow and solute transport using 48 soil pore water samplers spread along a hillslope. Based on > 700 measurements, our data showed that solute transport to lysimeters was similar—regardless of antibiotic affinity for soil—when preferential flow represented less than 15% of the total water flow. When preferential flow exceeded 15%, however, concentrations were higher for compounds with relatively low affinity for soil. We provide evidence that (1) bypassing water flow can select for compounds that are more easily released from the soil matrix, and (2) this phenomenon becomes more evident as the magnitude of preferential flow increases. We argue that considering the natural spectrum preferential flow as an explanatory variable to gauge the influence of soil matrix-solute interactions may improve parsimonious transport models.

Anti-drug antibodies (ADA) induced by biologic drugs may hamper the efficacy of treatment, so inhibiting ADA induction is desirable. Here, in two clinical trials, the authors show that ImmTOR, previously reported to reduce drug immunogenicity in animal studies, helps mitigate ADA induced by pegylated uricase for treating patients with hyperuricemia.

A major barrier to adeno-associated virus (AAV) gene therapy is the inability to re-dose patients due to formation of vector-induced neutralizing antibodies (Nabs). Tolerogenic nanoparticles encapsulating rapamycin (ImmTOR) provide long-term and specific suppression of adaptive immune responses, allowing for vector re-dosing. Moreover, co-administration of hepatotropic AAV vectors and ImmTOR leads to an increase of transgene expression even after the first dose. ImmTOR and AAV Anc80 encoding the methylmalonyl-coenzyme A (CoA) mutase (MMUT) combination was tested in a mouse model of methylmalonic acidemia, a disease caused by mutations in the MMUT gene. Repeated co-administration of Anc80 and ImmTOR was well tolerated and led to nearly complete inhibition of immunoglobulin (Ig)G antibodies to the Anc80 capsid. A more profound decrease of plasma levels of the key toxic metabolite, plasma methylmalonic acid (pMMA), and disease biomarker, fibroblast growth factor 21 (FGF21), was observed after treatment with the ImmTOR and Anc80-MMUT combination. In addition, there were higher numbers of viral genomes per cell (vg/cell) and increased transgene expression when ImmTOR was co-administered with Anc80-MMUT. These effects were dose-dependent, with the higher doses of ImmTOR providing higher vg/cell and mRNA levels, and an improved biomarker response. Combining of ImmTOR and AAV can not only block the IgG response against capsid, but it also appears to potentiate transduction and enhance therapeutic transgene expression in the mouse model.

An industrial drive testing, with a ‘real-machine’ can pave way, for some serious issues to test-bench and motor. A slight disturbance in control logic amid testing, can damage the physical machine or drive. Such dangerous testing conditions can be avoided by supplanting real motor with a power electronic converter based ‘Motor Emulator’ (ME) test-bench system. The conventional ME comprises of two-stage three-phase AC-DC-AC conversion with first-stage AC-DC as emulator and second-stage DC-AC as regenerating unit. This two-stage power conversion, require independent control algorithm, burdening control complexity as well as the number of power electronic switches are quite significant. Hence, to economize and downsize conventional multistage ME system, this paper experimentally validates a common DC-bus-configured ME system with only the AC-DC regenerative emulator stage. A virtually isolated bidirectional two-level three-phase AC-DC converter is proposed as the regenerative emulator converter in a common DC-Bus-configured ME system. The Proposed converter’s operating principle along with mathematical design and control strategy are also presented. To validate the operation of the proposed converter as a common DC-bus-configured emulator, a permanent magnet synchronous motors (PMSM) of 7.5 kW is emulated and its experimental results are presented here.

Category: Diabetes; Basic Sciences/Biologics; Trauma Introduction/Purpose: Prophylactic vancomycin treatment decreases the rates of surgical site and deep infections by >70% for diabetic patients undergoing reconstructive foot and ankle surgery. We aimed to identify whether local vancomycin at a clinically relevant dose impaired fracture healing in diabetic rats. Our hypothesis was that local vancomycin powder to the fracture site would not affect long term healing outcomes, but continuous exposure of vancomycin would inhibit differentiation of osteoblast precursor cells and their osteogenic activity in vitro. The 25 mg/kg vancomycin was a modest increase to routine surgical site vancomycin application of 1-2 grams for a 70 kg. adult (21.42 mg/kg). Determining how vancomycin affects diabetic fracture healing is of clinical interest, particularly considering its prophylactic use in foot and ankle patients. Methods: Following induction of a femur fracture in male BB Wistar type 1 diabetic rats, a longitudinal incision was made in the lateral aspect of the femur. Powdered vancomycin (25mg/kg) was administered to fracture site of treated (n=5), and Sham surgery (n=6) control rats. Femurs harvested at 6 weeks after fracture, were X-ray scored, µCT scanned and tested to failure in torsion. Bone marrow and periosteal cells isolated from diabetic bones and MC3T3 cells were plated for MTT survival and osteogenic assays. After 4 days, beta glycerol phosphate, ascorbic acid and either 0, 50, 500, or 5,000 µg/mL vancomycin were added to the media (n=3 per group). Cells were fixed at 7 and 14 days for alkaline phosphatase (ALP) staining and at 28 days for Alizarin Red S staining. Parametric data were analyzed using student t-tests. Non-parametric data were analyzed using a Kruskal-Wallis ANOVA on RANKs and Tukey post-hoc tests. Results: Radiographic scoring did not show differences between the control (2.28+-1.57) and treatment (3.67+-0.75) groups (p=0.093). BV/TV was similar between the control (61.2+-8.4 %) and treatment (56.5+-5.2 %) groups (p=0.081). Mechanical testing found similar values in normalized torque to failure (69.56+-36.80 vs 50.05+-28.82 %N*mm, p=0.356), and torsional rigidity (105.97+-103.62 vs 48.68+-32.95 %Nmm 2 , p=0.291), for control and treatment groups, respectively. ALP staining was comparable between groups at either 7 (p=0.809) or 14 days (p=0.343) in bone marrow or MC3T3 cells. Alizarin Red S staining found dose- dependent decreases in mineralized nodule formation between the untreated (10.16+-5.01 nodules per 3.8cm 2 ), and 500µg/mL vancomycin (3.16+-2.26 nodules per 3.8cm 2 ) bone marrow groups at 28 days (p=0.026). Periosteal and MC3T3 cell viability were only impaired at the 5000µg/mL vancomycin dose (p=0.001). Conclusion: Our study argues that local application of vancomycin does not affect diabetic fracture healing at clinically relevant doses. We studied a nearly 2-fold higher vancomycin dose than the 'standard' dose of 14.3mg/kg and less than the 143.5mg/kg dose that did not impair rat spine fusion. Although in vitro vancomycin did not affect cell viability and osteogenic staining in periosteal and MC3T3 cells, mineralized nodule formation was dose-dependently inhibited at day 28 in bone marrow cells. Our results bring novel insight into the effects of vancomycin in diabetic fracture healing and the how long-term dosing impacts cell viability and osteoblastogenesis.

The retina and RPE cells are regularly exposed to chronic oxidative stress as a tissue with high metabolic demand and ROS generation. DJ-1 is a multifunctional protein in the retina and RPE that has been shown to protect cells from oxidative stress in several cell types robustly. Oxidation of DJ-1 cysteine (C) residues is important for its function under oxidative conditions. The present study was conducted to analyze the impact of DJ-1 expression changes and oxidation of its C residues on RPE function. Monolayers of the ARPE-19 cell line and primary human fetal RPE (hfRPE) cultures were infected with replication-deficient adenoviruses to investigate the effects of increased levels of DJ-1 in these monolayers. Adenoviruses carried the full-length human DJ-1 cDNA (hDJ) and mutant constructs of DJ-1, which had all or each of its three C residues individually mutated to serine (S). Alternatively, endogenous DJ-1 levels were decreased by transfection and transduction with shPARK7 lentivirus. These monolayers were then assayed under baseline and low oxidative stress conditions. The results were analyzed by immunofluorescence, Western blot, RT-PCR, mitochondrial membrane potential, and viability assays. We determined that decreased levels of endogenous DJ-1 levels resulted in increased levels of ROS. Furthermore, we observed morphological changes in the mitochondria structure of all the RPE monolayers transduced with all the DJ-1 constructs. The mitochondrial membrane potential of ARPE-19 monolayers overexpressing all DJ-1 constructs displayed a significant decrease, while hfRPE monolayers only displayed a significant decrease in their ΔΨm when overexpressing the C2S mutation. Viability significantly decreased in ARPE-19 cells transduced with the C53S construct. Our data suggest that the oxidation of C53 is crucial for regulating endogenous levels of ROS and viability in RPE cells.