Antithrombotic Revascularization Strategy of Bioengineered Liver Using a Biomimetic Polymer.

A bioengineered liver has the potential to save patients with end-stage liver disease, and a three-dimensional decellularized scaffold is a promising approach for practical use. The main challenge in bioengineered liver transplantation is thrombogenicity during blood perfusion. We aimed to apply a novel antithrombotic polymer to revascularize liver scaffolds and evaluate the thrombogenicity and biosafety of the polymer-treated scaffolds. A biomimetic polymer, 2-metacryloyloxyethyl phosphorylcholine (MPC) was prepared for modification of the extracellular matrix in liver scaffolds. The polymer was injected into the rat liver scaffolds' portal vein and could extensively react to the vessel walls. In an ex vivo blood perfusion experiment, we demonstrated significantly less platelet deposition in the polymer-treated scaffolds than nontreated or re-endothelialized scaffolds with human umbilical vein endothelial cells. In the heterotopic transplantation model, liver volume was better maintained in the polymer-treated groups, and platelet deposition was suppressed in these groups. Additionally, the polymer-treated liver scaffolds maintained the metabolic function of the recellularized rat primary hepatocytes during perfusion culture. The MPC polymer treatment efficiently suppressed thrombus formation during blood perfusion in liver scaffolds and maintained the function of recellularized hepatocytes. Revascularizing liver scaffolds using this polymer is a promising approach for bioengineered liver transplantation.

Helminth derivative tuftsin-phopshorylcholine to treat autoimmunity.

Autoimmune diseases (AIDs) affect 5 to 10% of the population. There are more than ∼100 different autoimmune diseases. The AIDs are one of the top 10 causes of death in women under 65; 2nd highest cause of chronic illness; top cause of morbidity in women in the US. The NIH estimates annual direct healthcare costs for autoimmune diseases about $100 billion, in comparison, with cancers investment of $57 billion, heart and stroke cost of $200 billion. The current treatments for autoimmune diseases encompasses: steroids, chemotherapy, immunosuppressants, biological drugs, disease specific drugs (like acethylcholine-estherase for myasthenia gravis). The treatments for autooimmune diseases supress the patient immune network, which leads the patients to be more susceptible to infections. Hence, there is a need to develop immunomodulatory small molecules with minimal side effects to treat autoimmune diseases. The helminths developed secreting compounds which modulate the human defense pathways in order to develop tolerance and survive in the host environment. We have imitated the immunomodulatory activity of the helminth by using a derivative of the helminth secretory molecule. A bi-functional small molecule -tuftsin (T)-phosphorylcholine (PC), coined as TPC, was constructed. This chimeric molecule showed its immunomodulatory activity in 4 murine models of autoimmune diseases, attenuating the clinical score and the inflammatory response by immunomodutating the host immune system. Ex-vivo in human peripheral blood mononuclear cells (PBMCs) and biopsies originated from arteries of patients with giant cell arteritis. This paper decipher the mode of action of TPC immunomodulatory activity. Our data propose the potential for this small molecule to be a novel therapy for patients with autoimmune diseases.

Evidence for biexponential glutamate T2 relaxation in human visual cortex at 3T: A functional MRS study.

Functional magnetic resonance spectroscopy (fMRS) measures dynamic changes in metabolite concentration in response to neural stimulation. The biophysical basis of these changes remains unclear. One hypothesis suggests that an increase or decrease in the glutamate signal detected by fMRS could be due to neurotransmitter movements between cellular compartments with different T2 relaxation times. Previous studies reporting glutamate (Glu) T2 values have generally sampled at echo times (TEs) within the range of 30-450 ms, which is not adequate to observe a component with short T2 (<20 ms). Here, we acquire MRS measurements for Glu, (t) total creatine (tCr) and total N-acetylaspartate (tNAA) from the visual cortex in 14 healthy participants at a range of TE values between 9.3-280 ms during short blocks (64 s) of flickering checkerboards and rest to examine both the short- and long-T2 components of the curve. We fit monoexponential and biexponential Glu, tCr and tNAA T2 relaxation curves for rest and stimulation and use Akaike information criterion to assess best model fit. We also include power calculations for detection of a 2% shift of Glu between compartments for each TE. Using pooled data over all participants at rest, we observed a short Glu T2-component with T2 = 10 ms and volume fraction of 0.35, a short tCr T2-component with T2 = 26 ms and volume fraction of 0.25 and a short tNAA T2-component around 15 ms with volume fraction of 0.34. No statistically significant change in Glu, tCr and tNAA signal during stimulation was detected at any TE. The volume fractions of short-T2 component between rest and active conditions were not statistically different. This study provides evidence for a short T2-component for Glu, tCr and tNAA but no evidence to support the hypothesis of task-related changes in glutamate distribution between short and long T2 compartments.

Stable and Thin-Polymer-Based Modification of Neurovascular Stents with 2-Methacryloyloxyethyl Phosphorylcholine Polymer for Antithrombogenicity.

The advent of intracranial stents has revolutionized the endovascular treatment of cerebral aneurysms. The utilization of stents has rendered numerous cerebral aneurysm amenable to endovascular treatment, thereby obviating the need for otherwise invasive open surgical options. Stent placement has become a mainstream approach because of its safety and efficacy. However, further improvements are required for clinically approved devices to avoid the frequent occurrence of thrombotic complications. Therefore, controlling the thrombotic complications associated with the use of devices is of significant importance. Our group has developed a unique stent coated with a 2-methacryloyloxyethyl phosphorylcholine (MPC)-based polymer. In this study, the surface characteristics of the polymer coating were verified using X-ray photoelectron spectroscopy and atomic force microscopy. Subsequently, the antithrombotic properties of the coating were evaluated by measuring platelet count and thrombin-antithrombin complex levels of whole human blood after 3 h of incubation in a Chandler loop model. Scanning electron microscopy was utilized to examine thrombus formation on the stent surface. We observed that MPC polymer-coated stents significantly reduced thrombus formation as compared to bare stents and several clinically approved devices. Finally, the coated stents were further analyzed by implanting them in the internal thoracic arteries of pigs. Angiographic imaging and histopathological examinations that were performed one week after implantation revealed that the vascular lumen was well maintained and coated stents were integrated within the vascular endothelium without inducing adverse effects. Thus, we demonstrated the efficacy of MPC polymer coating as a viable strategy for avoiding the thrombotic risks associated with neurovascular stents.

Mass Spectrometry Imaging Combined with Sparse Autoencoder Method Reveals Altered Phosphorylcholine Distribution in Imipramine Treated Wild-Type Mice Brains.

Mass spectrometry imaging (MSI) is essential for visualizing drug distribution, metabolites, and significant biomolecules in pharmacokinetic studies. This study mainly focuses on imipramine, a tricyclic antidepressant that affects endogenous metabolite concentrations. The aim was to use atmospheric pressure matrix-assisted laser desorption/ionization (AP-MALDI)-MSI combined with different dimensionality reduction methods to examine the distribution and impact of imipramine on endogenous metabolites in the brains of treated wild-type mice. Brain sections from both control and imipramine-treated mice underwent AP-MALDI-MSI. Dimensionality reduction methods, including principal component analysis, multivariate curve resolution, and sparse autoencoder (SAE), were employed to extract valuable information from the MSI data. Only the SAE method identified phosphorylcholine (ChoP) as a potential marker distinguishing between the control and treated mice brains. Additionally, a significant decrease in ChoP accumulation was observed in the cerebellum, hypothalamus, thalamus, midbrain, caudate putamen, and striatum ventral regions of the treated mice brains. The application of dimensionality reduction methods, particularly the SAE method, to the AP-MALDI-MSI data is a novel approach for peak selection in AP-MALDI-MSI data analysis. This study revealed a significant decrease in ChoP in imipramine-treated mice brains.

Health Technology Assessment of Cardiopulmonary Bypass Circuit with and without Phosphorylcholine Coating: A Retrospective Study on Safety and Efficiency in Cardiac Surgery.

BACKGROUND: Phosphorylcholine has emerged as a potential adjunctive agent in cardiopulmonary bypass (CPB) circuits. Phosphorylcholine serves as a coating for the CPB circuit, potentially enhancing biocompatibility and reducing thrombotic events. However, its impact on specific patient populations and procedural outcomes remains underexplored. MATERIALS AND METHODS: In this retrospective study, we analyzed data from 60 patients who underwent cardiac surgery with CPB, comprising 20 cases each of coronary artery bypass grafting (CABG), mitral valve repair, and aortic valve replacement. The patient cohort was divided into two groups-30 patients whose CPB circuits were coated with phosphorylcholine (phosphorylcholine-coated group) and 30 patients who did not receive phosphorylcholine supplementation or circuit coating. Both groups underwent surgery with identical CPB circuit designs. We assessed the absence of adverse events, safety, and efficacy parameters, including blood loss, clotting, and the structural integrity of the CPB circuit. Additionally, we measured changes in mean albumin levels (g/dL), mean platelet counts (×109/L), and antithrombin III (ATIII) levels before and after CPB. RESULTS: The retrospective analysis revealed an absence of adverse events in both groups. In the phosphorylcholine-coated group compared to the non-phosphorylcholine-coated group, there was a notable difference in the delta change in mean albumin levels (0.87 ± 0.1 vs. 1.65 ± 0.2 g/dL, p-value 0.021), mean platelet counts (42.251 ± 0.121 vs. 54.21 ± 0.194 × 109/L, p-value 0.049), and ATIII levels (16.85 ± 0.2 vs. 31.21 ± 0.3 p-value 0.017). There was a notable reduction in the perioperative consumption of human complex units after CPB (3 vs. 12, p-value 0.019). CONCLUSIONS: Both groups, phosphorylcholine and non-phosphorylcholine, demonstrated the absence of adverse events and that the systems are safe for iatrogenic complication. Our findings suggest that the use of phosphorylcholine coating on the CPB circuit, in the absence of supplementary phosphorylcholine, in cardiac surgery is associated with favorable changes in mean albumin levels, mean platelet counts, and ATIII levels. Further research is warranted to elucidate the full extent of phosphorylcholine's impact on patient outcomes and CPB circuit performance.

Broad specificity of monoclonal IgA (TEPC15-IgA) for enteric bacteria via phosphorylcholine-mediated interaction.

Immunoglobulin A (IgA) is notable for its broad specificity toward multiple bacteria. Phosphorylcholine (PC) plays a role in the infection of pathogenic bacteria carrying PC and in the induction of IgA responses in the host immune system. The commercially available mouse monoclonal IgA, TEPC15-IgA, is a distinctive antibody with specificity for PC, warranting further exploration of its response to PC-bearing enteric bacteria. In this study, using 17 different enteric bacteria, including 3 aerobic and 14 anerobic bacteria that could be cultured in vitro, we confirmed that TEPC15-IgA recognizes 4 bacterial species: Lactobacillus taiwanensis, Limosilactobacillus frumenti, Streptococcus infantis, and Escherichia coli, although reactivity varied. Interestingly, TEPC15-IgA did not react with four of six Lactobacillus species used. Moreover, distinct target molecules associated with PC in L. taiwanensis and L. frumenti were evident, differing in molecular weight. These findings suggest that the natural generation of PC-specific IgA could prevent PC-mediated infections and potentially facilitate the formation of a microflora rich in indigenous bacteria with PC, particularly in the gastrointestinal tract.

Bioinspired zwitterionic triblock copolymers designed for colloidal drug delivery: 2 - Biological evaluation.

In this work, poly(lactide) nanoparticles were equipped with a bioinspired coating layer based on poly[2-(methacryloyloxy)ethyl phosphorylcholine] and then evaluated when administered to the lungs and after intravenous injection. Compared to the plain counterparts, the chosen zwitterionic polymer shell prevented the coated colloidal formulation from aggregation and conditioned it for lower cytotoxicity, protein adsorption, complement activation and phagocytic cell uptake. Consequently, no interference with the biophysical function of the lung surfactant system could be detected accompanied by negligible protein and cell influx into the bronchoalveolar space after intratracheal administration. When injected into the central compartment, the coated formulation showed a prolonged circulation half-life and a delayed biodistribution to the liver. Taken together, colloidal drug delivery vehicles would clearly benefit from the investigated poly[2-(methacryloyloxy)ethyl phosphorylcholine]-based polymer coatings.

Bioinspired zwitterionic triblock copolymers designed for colloidal drug delivery: 1 - Synthesis and characterization.

This study describes the synthesis and characterization of triblock copolymers composed of poly[2-(methacryloyloxy)ethyl phosphorylcholine]-block-poly(propylene glycol)-block-poly[2-(methacryloyloxy)ethyl phosphorylcholine] (PMPC-b-PPG-b-PMPC) intended for, but not limited to, applications in colloidal drug delivery. Atom transfer radical polymerization led to a library of well-defined PMPC-b-PPG-b-PMPC triblock copolymers with varying overall molecular weight (ranging from ∼5 to ∼25 kDa) and composition (weight fraction of the hydrophobic PPG block ranged from ∼10 to ∼50 wt%). The properties of the synthesized triblock copolymers were linked to the PPG to bioinspired PMPC block(s) ratio, where the more hydrophilic species showed adequate aqueous solubility, surface activity and biocompatibility (non-toxicity) in in vitro cell culture. Their amphiphilic nature makes them adsorb efficiently onto polymer nanoparticles, what improves colloidal stability under stress conditions and, furthermore, depletes proteins from unwanted adsorption to the underlying surface. The current findings strengthen our insights into structure-function relationships of PMPC-based coatings leading to protecting shells on relevant polymer nanoparticle formulations. PMPC-b-PPG-b-PMPC triblock copolymers composed of a hydrophobic PPG block of 2-4 kDa flanked by two hydrophilic PMPC blocks each of 5-10 kDa seem to be most promising to enhance colloidal drug delivery vehicles.

Evaluation of the EMBOPIPE flow diverter device: in vivo and in vitro experiments.

BACKGROUND: Although flow diverter device (FDD) has brought revolutionized advances in endovascular treatment of intracranial aneurysms, it also presents considerable drawbacks as well, as the innovation for novel device has never stopped. This preclinical research aims to evaluate the safety and efficacy of a newly developed FDD, the EMBOPIPE, through in vivo and in vitro experiments. METHODS: Aneurysms were induced in 20 New Zealand white rabbits which were randomized to three follow-up groups according to the time elapsed after EMBOPIPE implantation (28, 90, and 180 days). Additional EMBOPIPEs were implanted in the abdominal aorta to cover the renal artery in nine rabbits. Angiography was performed immediately after device placement in all groups. Aneurysm occlusion, patency of renal arteries, and pathological outcomes were assessed. For the in vitro experiments, we measured the thrombogenic potential of EMBOPIPEs (n = 5) compared with bare stents (n = 5) using the Chandler loop model. Evaluation indicators were the platelet counts, macroscopic observations and scanning electron microscopy. RESULTS: EMBOPIPEs were successfully deployed in 19 of 20 rabbit aneurysms (95.0%). The rates of complete or near-complete aneurysm occlusion were 73.3%, 83.3%, and 100% in the 28-, 90-, and 180-day groups, respectively. All renal arteries covered by EMBOPIPEs remained patent, and the mean difference in renal artery diameter before and after the device placement in the three groups was 0.07 mm, 0.10 mm, and 0.10 mm, respectively (p = 0.77). Renal pathology was normal in all cases. The pathological findings of the aneurysms were as follows: thickened and adequate neointimal coverage at the aneurysm neck, minimal inflammatory response, near-complete smooth muscle cell layer, and endothelialization along the device. In vitro experiments showed that the platelet counts were significantly higher in EMBOPIPE blood samples than in bare stent samples and that platelet adhesion to the device was lower in the EMBOPIPE stent struts compared with bare stent struts through macroscopic observations and scanning electron microscopy. CONCLUSIONS: The EMBOPIPE can achieve high rates of aneurysm occlusion while maintaining excellent branch artery patency. It exhibited wonderful pathological results. This novel device with phosphorylcholine surface modification could reduce platelet thrombus attached to the stent struts.

Efficacy and Safety of Artificial Tears Containing Lipidure and Hypromellose for the Treatment of Moderate Dry Eye Disease in Contact Lens Wearers.

Background and Objectives: Dry eye disease (DED) affects 5-50% of the global population and deeply influences everyday life activities. This study compared the efficacy, tolerability, and safety of novel Respilac artificial tears containing lipidure and hypromellose (HPMC) with the widely used Nextal artificial tears, which are also HPMC-based, for the treatment of moderate DED in contact lenses (CL) wearers. Materials and Methods: In a prospective, single-center, randomized investigation, 30 patients aged ≥18 years, diagnosed with moderate DED, and wearing CL were randomly assigned to the Respilac (n = 15) or Nextal group (n = 15). Patients self-administrated one drop of Respilac or Nextal in both eyes three times daily for 21 days. Changes in the endpoint (visual analogue scale (VAS) score for ocular tolerability, symptom assessment in dry eye (SANDE) score, non-invasive first break-up time (NIF-BUT) results, tear analysis value, meibography results, and CL tolerability results were assessed, comparing treatment groups and time-point evaluations. Adverse events (AEs) were also recorded and evaluated. Results: VAS scores decreased with time (p < 0.001) in both groups, showing no statistically significant difference among them (p = 0.13). Improvements were also detected from screening to end-of-treatment, which were indicated by the SANDE scores for severity and frequency (p < 0.001) and by tear analysis results (p < 0.001) with no observed difference between the Nextal and Respilac arms. NIF-BUT, meibography, and CL tolerability values were shown to be non-significantly affected by treatment and time. There were no AEs detected in this study cohort. Conclusions: Respilac was confirmed to be effective, safe, and well-tolerated. Lipidure-based ophthalmic solution was shown not to be inferior to the currently used Nextal, however, showing improvements in DED symptoms. Within the existing literature, our study is one of the first to report that MPC plus HPMC-containing eye drops are an effective option for the treatment of moderate dry eye disease and desiccation damage prevention in contact lens wearers.

Reduction in creatine metabolites in macrophages exposed to small molecule analogues of the anti-inflammatory parasitic worm product ES-62.

ES-62, a protein secreted by Acanthocheilonema viteae, is anti-inflammatory by virtue of covalently attached phosphorylcholine (PC) residues and thus a library of drug-like small molecule analogues (SMAs) based on its PC moieties has been designed for therapeutic purposes. Two members, SMAs 11a and 12b, were previously found to suppress production of pro-inflammatory cytokines by mouse bone marrow-derived macrophages (BMMs) exposed to cytosine-phosphate-guanosine oligodeoxynucleotides (CpG), agonists for Toll-like receptor 9. In order to explore the mechanism of action underlying such activities, an untargeted mass spectrometry-based metabolomics screen was undertaken. Stimulation of BMMs with CpG produced significant metabolic changes relating to glycolysis and the TCA cycle but the SMAs had little impact on this. Also, the SMAs did not promote alterations in metabolites known to be associated with macrophage M1/M2 polarization. Rather, BMMs exposed to SMAs 11a or 12b prior to CpG treatment, or even alone, revealed downregulation of metabolites of creatine, a molecule whose major role is in the transport of high energy phosphate from the mitochondria to the cytosol. These data therefore provide insight into a possible mechanism of action of molecules with significant therapeutic potential that has not previously been described for parasitic worm products.

Solubility determination and thermodynamic model analysis of L-α-glyceryl phosphorylcholine in different organic solvents of 278.15 K to 323.15 K.

L-α-glyceryl phosphorylcholine, also referred to as choline ethanol phosphate and phosphocholine glycerophosphate, is a naturally occurring metabolite of water-soluble phospholipids in animals. This molecular property is important for informing the crystallization and purification of drugs. The solubility of L-α-glyceryl phosphorylcholine was determined in ten pure solvents and three mixed solvents under atmospheric pressure. The experimental results indicate that L-α-glyceryl phosphorylcholine is most soluble in methanol and least soluble in acetone. Additionally, the solubility of L-α-glyceryl phosphorylcholine was found to increase with temperature within the experimental range. Furthermore, the solubility of L-α-glyceryl phosphorylcholine in binary solvents is dependent on the proportion of positive solvent and temperature. The solubility of L-α-glyceryl phosphorylcholine increases with the proportion of positive solvent. XRD and DSC results indicate that the crystal form of L-α-glyceryl phosphorylcholine remains unchanged before and after dissolution in the reagent, and its melting point temperature is 413.15 K. Various models, including the modified Apelblat model, λh model, Jouyban-Acree model, SUN model, and CNIBS/R-K model, were used to fit the solubility data of L-α-glyceryl phosphorylcholine in different solvents. The study found that the modified Apelblat model and CNIBS/R-K model were the most appropriate for fitting the data. The KAT-LSER model was used to analyze the molecular interactions between solvents and solutes, revealing that the solvent step method with non-specific polarity/polarization interaction had the greatest impact on solubility.

Recognition of Highly Branched N-Glycans of the Porcine Whipworm by the Immune System.

Glycans are key to host-pathogen interactions, whereby recognition by the host and immunomodulation by the pathogen can be mediated by carbohydrate binding proteins, such as lectins of the innate immune system, and their glycoconjugate ligands. Previous studies have shown that excretory-secretory products of the porcine nematode parasite Trichuris suis exert immunomodulatory effects in a glycan-dependent manner. To better understand the mechanisms of these interactions, we prepared N-glycans from T. suis and both analyzed their structures and used them to generate a natural glycan microarray. With this array, we explored the interactions of glycans with C-type lectins, C-reactive protein, and sera from T. suis-infected pigs. Glycans containing LacdiNAc and phosphorylcholine-modified glycans were associated with the highest binding by most of these proteins. In-depth analysis revealed not only fucosylated LacdiNAc motifs with and without phosphorylcholine moieties but phosphorylcholine-modified mannose and N-acetylhexosamine-substituted fucose residues, in the context of maximally tetraantennary N-glycan scaffolds. Furthermore, O-glycans also contained fucosylated motifs. In summary, the glycans of T. suis are recognized by both the innate and adaptive immune systems and also exhibit species-specific features distinguishing its glycome from those of other nematodes.

Preparation and Characterization of Acrylic and Methacrylic Phospholipid-Mimetic Polymer Hydrogels and Their Applications in Optical Tissue Clearing.

The 2-methacryloyloxyethyl phosphorylcholine (MPC) polymers are mimetic to phospholipids, being widely used as biocompatible polymers. In our previous study, MPC polymer hydrogels proved more effective for optical tissue clearing compared to acrylamide (AAm) polymer hydrogels. In the present study, 2-acryloyloxyethyl phosphorylcholine (APC) was synthesized and employed to create hydrogels for a comparative analysis with methacrylic MPC-based hydrogels. APC, an acrylic monomer, was copolymerized with AAm in a similar reactivity. In contrast, MPC, as a methacrylic monomer, demonstrated higher copolymerization reactivity than AAm, leading to a spontaneously delayed two-step polymerization behavior. This suggests that the polymer sequences and network structures became heterogeneous when both methacrylic and acrylic monomers, as well as crosslinkers, were present in the copolymerization system. The molecular weight of the APC polymers was considerably smaller than that of the MPC polymers due to the formation of mid-chain radicals and subsequent ß-scission during polymerization. The swelling ratios in water and strain sweep profiles of hydrogels prepared using acrylic and methacrylic compounds differed from those of hydrogels prepared using only acrylic compounds. This implies that copolymerization reactivity influences the polymer network structures and crosslinking density in addition to the copolymer composition. APC-based hydrogels are effective for the optical clearing of tumor tissues and are applicable to both passive and electrophoretic methods.

Adsorption Dynamics of Uremic Toxins to Novel Modified Magnetic Nanoparticles.

Kidney dysfunction leads to the retention of metabolites in the blood compartment, some of which reach toxic levels. Uremic toxins are associated with the progression of kidney disease and other symptoms of kidney failure (i.e., nausea, itchiness, and hypertension). Toxin removal ameliorates symptoms and reduces further organ damage, but membrane-based methods are inadequate for this purpose. Engineered adsorbents may facilitate enhanced removal of retained toxins, especially those bound strongly by proteins. Poly 2-(methacryloyloxy)ethyl phosphorylcholine-co-ß-cyclodextrin (p(MPC-co-PMßCD)) coated magnetic nanoparticles are synthesized, characterized for their physicochemical properties (Fourier-transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), thermogravimetric analysis(TGA), gel permeation chromatography (GPC), and transmission electron microscope (TEM), and evaluated toxin adsorption from a complex solution for the first time to quantify the effects of film chemistry and incubation time on the adsorbed toxinome (the collection of toxins). Uremic toxins are bound by even "low-fouling" polymer films themselves; providing further insight into how small molecule interactions with "low-fouling" films may affect protein-surface interactions. These results suggest a dynamic interaction between toxins and surfaces that is not driven by solution concentration alone. This knowledge will help advance the design of novel adsorbent films for clearing uremic toxins.

Application of phosphorylcholine derivative as mucosal adjuvant enhancing mucosal immune responses in the upper respiratory tract.

OBJECTIVE: A phosphorylcholine (PC)-derivative with high binding ability (PCDB) was intranasally administered to mice with ovalbumin (OVA), and immune responses were investigated to determine whether PCDB has antigenicity and adjuvanticity. METHODS: BALB/c mice were intranasally immunized with PCDB coupled with OVA, unbound PCDB plus OVA, cholera toxin (CT) plus OVA, OVA alone, and PCDB alone. Then, the production of OVA- and PC-specific antibodies in external secretions and serum, and the secretion of cytokines such as IL-4 and IFN-γ from splenic mononuclear cells by stimulation with PCDB and OVA were examined. Furthermore, the secretion of IL-12p40 from CD11c+ cells following stimulation with PCDB was observed to clarify the adjuvant effect of PCDB through TLR4. RESULTS: Intranasal immunization with PCDB plus OVA increased OVA- and PC-specific IgA in external secretions and OVA- and PC-specific antibodies in the serum. The analysis of IgG subclasses specific to OVA and PC showed a higher production of IgG1 than IgG2, and the secretion of both IL-4 and IFN-γ was enhanced. However, IL-12p40 secretion from CD11c+ cells was increased and OVA-specific IgE production was not promoted by PCDB stimulation. CONCLUSION: Intranasal administration of the protein antigen with PCDB enhanced immune responses specific to the mixed antigen and PC. Although PCDB acted to bias the immune response toward the Th2-type, antigen-specific IgE production did not increase. These findings suggest that PCDB has the potential to be a mucosal vaccine with both adjuvanticity and antigenicity without causing side effects due to type I allergy.

Achieving superior anticoagulation of endothelial membrane mimetic coating by heparin grafting at zwitterionic biocompatible interfaces.

Thrombosis and bleeding are common complications of blood-contacting medical device therapies. In this work, an endothelium membrane mimetic coating (PMPCC/Hep) has been created to address these challenges. The coating is fabricated by multi-point anchoring of a phosphorylcholine copolymer (poly-MPC-co-MSA, PMPCC) with carboxylic side chains and end-group grafting of unfractionated heparin (Hep) onto polydopamine precoated blood-contacting material surfaces. The PMPCC coating forms an ultrathin cell outer membrane mimetic layer to resist protein adsorption and platelet adhesion. The tiny defects/pores of the PMPCC layer provide entrances for heparin end-group to be inserted and grafted onto the sub-layer amino groups. The combination of the PMPCC cell membrane mimetic anti-fouling nature with the grafted heparin bioactivity further enhances the anticoagulation performance of the formed endothelium membrane mimetic PMPCC/Hep coating. Compared to conventional Hep coating, the PMPCC/Hep coating further decreases protein adsorption and platelet adhesion by 50 % and 90 %, respectively. More significantly, the PMPCC/Hep coating shows a superior anticoagulation activity, even significantly higher than that of an end-point-attached heparin coating. Furthermore, the blood coagulation function is well preserved in the PMPCC/Hep coating anticoagulation strategy. All the results support that the PMPCC/Hep coating strategy has great potential in developing more efficient and safer blood-contacting medical devices.

A novel family of sugar-specific phosphodiesterases that remove zwitterionic modifications of GlcNAc.

The zwitterions phosphorylcholine (PC) and phosphoethanolamine (PE) are often found esterified to certain sugars in polysaccharides and glycoconjugates in a wide range of biological species. One such modification involves PC attachment to the 6-carbon of N-acetylglucosamine (GlcNAc-6-PC) in N-glycans and glycosphingolipids (GSLs) of parasitic nematodes, a modification that helps the parasite evade host immunity. Knowledge of enzymes involved in the synthesis and degradation of PC and PE modifications is limited. More detailed studies on such enzymes would contribute to a better understanding of the function of PC modifications and have potential application in the structural analysis of zwitterion-modified glycans. In this study, we used functional metagenomic screening to identify phosphodiesterases encoded in a human fecal DNA fosmid library that remove PC from GlcNAc-6-PC. A novel bacterial phosphodiesterase was identified and biochemically characterized. This enzyme (termed GlcNAc-PDase) shows remarkable substrate preference for GlcNAc-6-PC and GlcNAc-6-PE, with little or no activity on other zwitterion-modified hexoses. The identified GlcNAc-PDase protein sequence is a member of the large endonuclease/exonuclease/phosphatase superfamily where it defines a distinct subfamily of related sequences of previously unknown function, mostly from Clostridium bacteria species. Finally, we demonstrate use of GlcNAc-PDase to confirm the presence of GlcNAc-6-PC in N-glycans and GSLs of the parasitic nematode Brugia malayi in a glycoanalytical workflow.

Site-oriented conjugation of poly(2-methacryloyloxyethyl phosphorylcholine) for enhanced brain delivery of antibody.

Antibody therapeutics are limited in treating brain diseases due to poor blood-brain barrier (BBB) penetration. We have discovered that poly 2-methacryloyloxyethyl phosphorylcholine (PMPC), a biocompatible polymer, effectively facilitates BBB penetration via receptor-mediated transcytosis and have developed a PMPC-shell-based platform for brain delivery of therapeutic antibodies, termed nanocapsule. Yet, the platform results in functional loss of antibodies due to epitope masking by the PMPC polymer network, which necessitates the incorporation of a targeting moiety and degradable crosslinker to enable on-site antibody release. In this study, we developed a novel platform based on site-oriented conjugation of PMPC to the antibody, allowing it to maintain key functionalities of the original antibody. With an optimized PMPC chain length, the PMPC-antibody conjugate exhibited enhanced brain delivery while retaining epitope recognition, cellular internalization, and antibody-dependent cellular phagocytic activity. This simple formula incorporates only the antibody and PMPC without requiring additional components, thereby addressing the issues of the nanocapsule platform and paving the way for PMPC-based brain delivery strategies for antibodies.