Fundamental Chemistry Advances Toward the Development of Degradable Polymer-Based Nanoparticles for the Treatment of Infectious Diseases

Microorganisms, including bacteria, viruses, fungi, or parasites, give rise to infectious diseases, which can spread between people, and can even transfer from animals or insects to humans. Infectious diseases are common, sometimes fatal, health issues. To date, the treatment of infectious diseases has largely relied on antibiotics. However, the therapeutic outcomes of current treatments need to be enhanced due to the emergence of drug-resistant microorganisms and the decline in the development of new antibiotics. Nanotechnology could help improve the efficacy of currently available antibiotics via changing the pharmacokinetics and biodistribution of drugs, which could enhance bioavailability, reduce side effects, help overcome physical and biological barriers for the efficient delivery to the site of infection, and so on. This dissertation aims to explore a novel treatment method to treat infectious diseases using degradable polymer-based nanoparticles. In a first project, bacterial adhesin, FimHA-targeted polymeric nanoparticles were developed for the delivery of antimicrobials to bacteria hiding inside the cells by mimicking the bacterial mode of cell invasion in order to treat and eradicate recurrent urinary tract infections. Amidation between carboxylic acids located in the shell of the poly(acrylic acid)-block-polystyrene-based polymeric nanoparticles and primary amine groups of lysine residues on FimHA was employed as the conjugation method. We prepared FimHA-polymeric nanoparticle conjugates with varying amounts of adhesins on the surface without free and/or physically-associated proteins under the improved coupling conditions. In a second direction involving a series of projects, functional polycarbonates were developed in order to expand the pool of degradable polymers and their self-assembled nanostructures, which can be utilized as drug-delivery vehicles. Degradable polycarbonates were synthesized by metal-free organocatalytic ring-opening polymerization of cyclic carbonate monomers. Postpolymerization modifications were also employed to introduce new functionalities onto the same degradable polymer backbone. Water-soluble polycarbonate formed a hydrophilic shell domain of polymeric nanostructures, and reactive aldehyde- and vinyl ether-functionalized polycarbonates were synthesized and their potential for drug delivery systems were demonstrated. In a third direction, advanced mechanistic understanding of organocatalytic ring-opening polymerization (ROP), which is widely used for syntheses of degradable polymers, was gained by specialized NMR spectroscopy studies. The collection of 13C NMR data in real time during polymerization was enhanced via hyperpolarization of nuclear spins. The “living” characteristics of ring-opening polymerization enabled the observation of NMR resonances associated with an intermediate formed during ROP

Multiparametric immunoimaging maps inflammatory signatures in murine myocardial infarction models

In the past 2 decades, research on atherosclerotic cardiovascular disease has uncovered inflammation to be a key driver of the pathophysiological process. A pressing need therefore exists to quantitatively and longitudinally probe inflammation, in preclinical models and in cardiovascular disease patients, ideally using non-invasive methods and at multiple levels. Here, we developed and employe

Cardiac immune cell infiltration associates with abnormal lipid metabolism

CD36 mediates the uptake of long-chain fatty acids (FAs), a major energy substrate for the myocardium. Under excessive FA supply, CD36 can cause cardiac lipid accumulation and inflammation while its deletion reduces heart FA uptake and lipid content and increases glucose utilization. As a result, CD36 was proposed as a therapeutic target for obesity-associated heart disease. However, more recent reports have shown that CD36 deficiency suppresses myocardial flexibility in fuel preference between glucose and FAs, impairing tissue energy balance, while CD36 absence in tissue macrophages reduces efferocytosis and myocardial repair after injury. In line with the latter homeostatic functions, we had previously reported that CD3

The presence of high level soluble herpes virus entry mediator in sera of gastric cancer patients

The development of gastric cancer (GC) is closely related to chronic inflammation caused by Helicobacter pylori infection, and herpes virus entry mediator (HVEM) is a receptor expressed on the surface of leukocytes that mediates potent inflammatory responses in animal models. However, the role of HVEM in human GC has not been studied. Previously, we showed that the interaction of HVEM on human leukocytes with its ligand LIGHT induces intracellular calcium mobilization, which results in inflammatory responses including induction of proinflammatory cytokine production and anti-bacterial activities. In this study, we report that leukocytes from GC patients express lower levels of membrane HVEM (mHVEM) and have lower LIGHT-induced bactericidal activities than those from healthy controls (HC). In contrast, levels of soluble HVEM (sHVEM) in the sera of GC patients were significantly higher than in those of HC. We found that monocyte membrane-bound HVEM is released into the medium when cells are activated by proinflammatory cytokines such as TNF-α and IL-8, which are elevated in the sera of GC patients. mHVEM level dropped in parallel with the release of sHVEM, and release was completely blocked by the metalloprotease inhibitor, GM6001. We also found that the low level of mHVEM on GC patient leukocytes was correlated with low LIGHT-induced bactericidal activities against H. pylori and S. aureus and production of reactive oxygen species. Our results indicate that mHVEM on leukocytes and sHVEM in sera may contribute to the development and/or progression of GC

The First Case of Catheter-related Bloodstream Infection Caused by Nocardia farcinica

Nocardia farcinica is an emerging pathogen in immunocompromised hosts. Even though several species of Nocardia have been reported as causative pathogens of catheter-related blood stream infections (CRBSI), CRBSI caused by N. farcinica has not been reported. A 70-yr-old man with a tunneled central venous catheter (CVC) for home parenteral nutrition was admitted with fever for two days. Norcardia species was isolated from the blood through CVC and peripheral bloods and identified to N. farcinica by 16S rRNA and rpoB gene sequence analyses. This report emphasizes the rapid and correct identification of causative agents in infectious diseases in the selection of antimicrobial agents and the consideration of catheter removal

Reprogramming alveolar macrophage responses to TGF-β reveals CCR2+ monocyte activity that promotes bronchiolitis obliterans syndrome

Bronchiolitis obliterans syndrome (BOS) is a major impediment to lung transplant survival and is generally resistant to medical therapy. Extracorporeal photophoresis (ECP) is an immunomodulatory therapy that shows promise in stabilizing BOS patients, but its mechanisms of action are unclear. In a mouse lung transplant model, we show that ECP blunts alloimmune responses and inhibits BOS through lowering airway TGF-β bioavailability without altering its expression. Surprisingly, ECP-treated leukocytes were primarily engulfed by alveolar macrophages (AMs), which were reprogrammed to become less responsive to TGF-β and reduce TGF-β bioavailability through secretion of the TGF-β antagonist decorin. In untreated recipients, high airway TGF-β activity stimulated AMs to express CCL2, leading to CCR2+ monocyte-driven BOS development. Moreover, we found TGF-β receptor 2-dependent differentiation of CCR2+ monocytes was required for the generation of monocyte-derived AMs, which in turn promoted BOS by expanding tissue-resident memory CD8+ T cells that inflicted airway injury through Blimp-1-mediated granzyme B expression. Thus, through studying the effects of ECP, we have identified an AM functional plasticity that controls a TGF-β-dependent network that couples CCR2+ monocyte recruitment and differentiation to alloimmunity and BOS

Multiparametric Immunoimaging Maps Inflammatory Signatures in Murine Myocardial Infarction Models.

In the past 2 decades, research on atherosclerotic cardiovascular disease has uncovered inflammation to be a key driver of the pathophysiological process. A pressing need therefore exists to quantitatively and longitudinally probe inflammation, in preclinical models and in cardiovascular disease patients, ideally using non-invasive methods and at multiple levels. Here, we developed and employed in vivo multiparametric imaging approaches to investigate the immune response following myocardial infarction. The myocardial infarction models encompassed either transient or permanent left anterior descending coronary artery occlusion in C57BL/6 and Apoe-/-mice. We performed nanotracer-based fluorine magnetic resonance imaging and positron emission tomography (PET) imaging using a CD11b-specific nanobody and a C-C motif chemokine receptor 2-binding probe. We found that immune cell influx in the infarct was more pronounced in the permanent occlusion model. Further, using 18F-fluorothymidine and 18F-fluorodeoxyglucose PET, we detected increased hematopoietic activity after myocardial infarction, with no difference between the models. Finally, we observed persistent systemic inflammation and exacerbated atherosclerosis in Apoe-/- mice, regardless of which infarction model was used. Taken together, we showed the strengths and capabilities of multiparametric imaging in detecting inflammatory activity in cardiovascular disease, which augments the development of clinical readouts.This work was supported by National Institute of Health grants R01HL143814 (to Dr Fayad), P01HL131478 (Drs Fayad and Mulder), P41EB025815 (Drs Liu and Gropler ), R35HL145212 (Dr Liu), and R35HL139598 (Dr Nahrendorf) and award K22CA226040 (Dr Rashidian). This work was also supported by an Innovation Research Fund Basic Research Award from the Dana-Farber Cancer Institute (Dr Rashidian). Dr Maier was supported by Deutsche Forschungsgemeinschaft grants (MA 7059/1 and MA 7059/3-1) and is part of SFB1425 funded by the Deutsche Forschungsgemeinschaft (project no. 422681845). All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.S

Efficacy and safety of entecavir plus carnitine complex (GODEX®) compared to entecavir monotherapy in patient with ALT elevated chronic hepatitis B: randomized, multicenter open-label trials. The GOAL study

Background/AimsCarnitine and vitamin complex (Godex®) is widely used in patients with chronic liver disease who show elevated liver enzyme in South Korea. The purpose of this study is to identify the efficacy and safety of carnitine from entecavir combination therapy in Alanine aminotransferase (ALT) elevated Chronic Hepatitis B (CHB) patients.Methods130 treatment-naïve patients with CHB were enrolled from 13 sites. The patients were randomly selected to the entecavir and the complex of entecavir and carnitine. The primary endpoint of the study is ALT normalization level after 12 months.ResultsAmong the 130 patients, 119 patients completed the study treatment. The ALT normalization at 3 months was 58.9% for the monotherapy and 95.2% for the combination therapy (P<0.0001). ALT normalization rate at 12 months was 85.7% for the monotherapy and 100% for the combination group (P=0.0019). The rate of less than HBV DNA 300 copies/mL at 12 months was not statistically significant (P=0.5318) 75.9% for the monotherapy, 70.7% for the combination and it was. Quantification of HBsAg level was not different from the monotherapy to combination at 12 months. Changes of ELISPOT value to evaluate the INF-γ secretion by HBsAg showed the increasing trend of combination therapy compare to mono-treatment.ConclusionsALT normalization rate was higher in carnitine complex combination group than entecavir group in CHB. Combination group was faster than entecavir mono-treatment group on ALT normalization rate. HBV DNA normalization rate and the serum HBV-DNA level were not changed by carnitine complex treatment

Effects of Printing Parameters on the Fit of Implant-Supported 3D Printing Resin Prosthetics

The purpose of the study was to investigate the influence of 3D printing parameters on fit and internal gap of 3D printed resin dental prosthesis. The dental model was simulated and fabricated for three-unit prostheses with two implants. One hundred prostheses were 3D printed with two-layer thicknesses for five build orientations using a resin (NextDent C&amp;B; 3D systems, Soesterberg, The Netherlands) and ten prostheses were manufactured with a milling resin as control. The prostheses were seated and scanned with micro-CT (computerized tomography). Internal gap volume (IGV) was calculated from 3D reconstructed micro-CT data. IGV, marginal fit, and lengths of internal gaps were measured, and the values were analyzed statistically. For the 3D printed prostheses, IGV was smaller at 45&deg;, 60&deg;, and 90&deg; compared to other build orientations. The marginal fit evaluated by absolute marginal discrepancy was smaller than other build orientations at 45&deg; and 60&deg;. IGV was smaller at 50 &micro;m layer thickness than at 100 &micro;m layer thickness, but the marginal fit was smaller at 100 &micro;m layer thickness than at 50 &micro;m layer thickness. The 3D printed prosthesis had smaller internal gap than the milled prosthesis. The marginal fit of the 3D printed resin prosthesis was clinically acceptable, and build orientation of 45&deg; and 60&deg; would be recommended when considering fit and internal gap