An intranasal cationic liposomal polysaccharide vaccine elicits humoral immune responses against Streptococcus pneumoniae.

Diseases caused by S. pneumoniae are the leading cause of child mortality. As antibiotic resistance of S. pneumoniae is rising, vaccination remains the most recommended solution. However, the existing pneumococcal polysaccharides vaccine (Pneumovax® 23) proved only to induce T-independent immunity, and strict cold chain dependence of the protein conjugate vaccine impedes its promotion in developing countries, where infections are most problematic. Affordable and efficient vaccines against pneumococcus are therefore in high demand. Here, we present an intranasal vaccine Lipo+CPS12F&αGC, containing the capsular polysaccharides of S. pneumoniae 12F and the iNKT agonist α-galactosylceramide in cationic liposomes. In BALB/cJRj mice, the vaccine effectively activates iNKT cells and promotes B cells maturation, stimulates affinity-matured IgA and IgG production in both the respiratory tract and systemic blood, and displays sufficient protection both in vivo and in vitro. The designed vaccine is a promising, cost-effective solution against pneumococcus, which can be expanded to cover more serotypes and pathogens.

Improving swallowing function with thickening agents in post-stroke oropharyngeal dysphagia: a real-world experience.

INTRODUCTION: Post-stroke dysphagia (PSD) is a widely prevalent and possibly life-threatening consequence that may lead to aspiration pneumonia, malnutrition, dehydration, and higher mortality risk. Recommending thickened fluids (TF) is a longstanding practice in the management of dysphagia. Augmenting liquid viscosity with a xanthan gum-based thickener benefits patients with PSD by aiding in the enhancement of bolus control, facilitating improved coordination in the swallowing mechanism, and lowering the risk of aspiration. Despite the widespread use of TF, limited high-quality evidence supports its benefits in PSD. CASE REPORT: This manuscript presents the clinical experience with four varied cases of PSD. A comprehensive approach to management with TF decreased the risk of aspiration pneumonia and facilitated effective management of dietary recommendations both during hospitalization and after discharge (all Cases). In addition, TF maintained nutrition and hydration in patients with multiple hospital admissions (Case 2), maintained hydration in those unable to engage in swallow rehabilitation due to complex medical conditions (Cases 2, 3, and 4), and those who needed slow and longer recovery due to long-term risk of silent aspiration (Cases 2, 3, and 4). In one case (Case 4), the use of TF was extended for more than two years post-stroke with no reported incidence of chest infection. CONCLUSION: In routine clinical practice, a comprehensive management approach with xanthan gum-based TFs reduces the risk of aspiration and aspiration pneumonia in patients with PSD while maintaining nutritional and hydration and improving swallowing function based on formal instrumental assessments. This clinical experience highlights the pivotal role of instrumental assessment, patient education, and informed decision-making to optimize outcomes with TF.

Enhancing the oral bioavailability of fisetin: polysaccharide-based self nano-emulsifying spheroids for colon-targeted delivery.

Fisetin (FS) is a flavonoid that possesses antioxidant and anti-inflammatory properties against ulcerative colitis. FS shows poor dissolution rate and permeability. An attempt has been made to develop colon-targeted solid self-nanoemulsifying drug delivery systems (S-SNEDDS) of FS. Initially, liquid (L) SNEDDS were prepared by loading FS into isotropic mixture of L-SNEDDS was prepared using Labrafil M 1944 CS, Transcutol P, and Tween 80. These L-SNEDDS were further converted into solid (S) SNEDDS by mixing the isotropic mixture with 1:1:1 ratio of guar gum (GG), xanthan gum (XG) and pectin (PC) [GG:XG:PC (1:1:1)]. Aerosil-200 (A-200) was added to enhance their flow characteristics. Further, they were converted into spheroids by extrusion-spheronization technique. The solid-state characterization of S-SNEDDS was done by SEM, DSC, and PXRD, which revealed that the crystalline form of FS was converted into the amorphous form. In the dissolution study, S-SNEDDS spheroids [GG:XG:PC (1:1:1)] exhibited less than 20% drug release within the first 5 h, followed by rapid release of the drug between the 5th and 10th h, indicating its release at colonic site. The site-specific delivery of FS to colon via FS-S-SNEDDS spheroids was confirmed by conducting pharmacokinetic studies on rats. Wherein, results showed delay in absorption of FS loaded in spheroids up to 5 h and achievement of Cmax at 7h, whereas L-SNEDDS showed rapid absorption of FS. Furthermore, FS-L-SNEDDS and FS-S-SNEDDS spheroids [GG:XG:PC (1:1:1)] increased oral bioavailability of FS by 6.86-fold and 4.44-fold, respectively, as compared to unprocessed FS.

Multidimensional opioid abuse deterrence using a nanoparticle-polymer hybrid formulation.

Misuse of prescription opioid drugs is the leading cause of the opioid crisis and overdose-related death. Abuse deterrent formulations (ADFs) have been developed to discourage attempts to tamper with the formulation and alter the ingestion methods. However, abusers develop complex extraction strategies to circumvent the ADF technologies. For comprehensive deterrence of drug abuse, we develop tannic acid nanoparticles (NPs) that protect encapsulated opioids from solvent extraction and thermal challenge (crisping), complementing the existing formulation strategy to deter injection abuse. Here, we develop a hybrid ADF tablet (NP-Tab), consisting of iron-crosslinked tannic acid NPs encapsulating thebaine (model opioid compound), xanthan gum, and chitosan (gel-forming polymers), and evaluate its performance in common abuse conditions. NP-Tab tampered by crushing and suspended in aqueous solvents forms an instantaneous gel, which is difficult to pull or push through a 21-gauge needle. NPs insulate the drug from organic solvents, deterring solvent extraction. NPs also promote thermal destruction of the drug to make crisping less rewarding. However, NP-Tab releases thebaine in the simulated gastric fluid without delay, suggesting that its analgesic effect may be unaffected if consumed orally as prescribed. These results demonstrate that NP-Tab can provide comprehensive drug abuse deterrence, resisting aqueous/organic solvent extraction, injection, and crisping, while retaining its therapeutic effect upon regular usage.

Potential antitumor and anti-inflammatory activities of an extracellular polymeric substance (EPS) from Bacillus subtilis isolated from a housefly.

Bacillus subtilis, a probiotic, has been applied in the medical, food, and feed industries among others. However, the mechanisms of its benefits to hosts are not yet fully understood. Here the characterization and bioactivities of an extracellular polymeric substance (EPS) from Bacillus subtilis were investigated to reveal its partial mechanisms and provide the theoretical basics for further development and utilization of Bacillus subtilis. In this study, the novel strain Bacillus subtilis xztubd1 (GenBank: MG458322.1) was isolated from a housefly's body, identified according to phenotypical and genotypical analyses, and found to produce large amounts of an EPS. Through ultraviolet spectroscopy and Fourier transform infrared spectroscopy (FTIR spectroscopy), the EPS was found to contain a variety of chemical functional groups, such as O-H groups, C=C, C=O, CH3, C-O-H and C-O-C bonds, and alpha-type pyranose. Furthermore, the in vitro antioxidant activity of the EPS on DPPH radicals at a concentration of 90 µg/ml was 62%; on the superoxide radical at a concentration of 90 µg/ml, this value was 75%; and on hydroxyl radicals at a concentration of 90 µg/ml, the activity was 54%. EPS also enhanced significantly phagocytosis, lysozyme activity in macrophages, IL-2 content in mice and inhibited dramatically the growth of HeLa cells. These results showed that the EPS with reductive groups have the strong capacity to scavenge reactive oxygen species (ROS), reinforce the immune system and inhibit the growth of cancer cell, which helps theirs hosts defence against many diseases, including inflammation and cancer. The EPS from Bacillus subtilis has the potential to be an anticancer and anti-inflammatory drug candidate in the pharmaceutical industries, which provide scientific evidence for the development and utilization of probiotic-derived medicines.

Gellan gum/alginate-based Ca-enriched acellular bilayer hydrogel with robust interface bonding for effective osteochondral repair.

The treatment of osteochondral (OC) defects remains challenging because of the lack of economical and feasible therapeutic strategies for OC repair and reconstruction. In this study, we report an integrated bilayer hydrogel with robust interface binding force (40 kPa) by facilitating the diffusion of calcium ions to the secondary crosslink of the bilayer hydrogel, in which gellan gum and sodium alginate acted as the chondral layer, gellan gum and hydroxyapatite acted as subchondral layer. This integrated construct has high cytocompatibility, and can seed with mesenchymal stem cells (MSCs) related to different functional protein expression for cartilage and bone formation, respectively. Furthermore, in the rabbit critical-sized osteochondral defect model (4.0 mm in diameter and 8.0 mm in depth), the calcium enriched hydrogel act as a calcium reservoir, promote neovascularization at week 4, and repair the critical defect at week 8, demonstrating the feasible preparation of an acellular hydrogel for OC repair.

Protection by vaccination of children against typhoid fever with a Vi-tetanus toxoid conjugate vaccine in urban Bangladesh: a cluster-randomised trial.

BACKGROUND: Typhoid fever remains a major cause of morbidity and mortality in low-income and middle-income countries. Vi-tetanus toxoid conjugate vaccine (Vi-TT) is recommended by WHO for implementation in high-burden countries, but there is little evidence about its ability to protect against clinical typhoid in such settings. METHODS: We did a participant-masked and observer-masked cluster-randomised trial preceded by a safety pilot phase in an urban endemic setting in Dhaka, Bangladesh. 150 clusters, each with approximately 1350 residents, were randomly assigned (1:1) to either Vi-TT or SA 14-14-2 Japanese encephalitis (JE) vaccine. Children aged 9 months to less than 16 years were invited via parent or guardian to receive a single, parenteral dose of vaccine according to their cluster of residence. The study population was followed for an average of 17·1 months. Total and overall protection by Vi-TT against blood culture-confirmed typhoid were the primary endpoints assessed in the intention-to-treat population of vaccinees or all residents in the clusters. A subset of approximately 4800 participants was assessed with active surveillance for adverse events. The trial is registered at www.isrctn.com, ISRCTN11643110. FINDINGS: 41 344 children were vaccinated in April-May, 2018, with another 20 412 children vaccinated at catch-up vaccination campaigns between September and December, 2018, and April and May, 2019. The incidence of typhoid fever (cases per 100 000 person-years) was 635 in JE vaccinees and 96 in Vi-TT vaccinees (total Vi-TT protection 85%; 97·5% CI 76 to 91, p<0·0001). Total vaccine protection was consistent in different age groups, including children vaccinated at ages under 2 years (81%; 95% CI 39 to 94, p=0·0052). The incidence was 213 among all residents in the JE clusters and 93 in the Vi-TT clusters (overall Vi-TT protection 57%; 97·5% CI 43 to 68, p<0·0001). We did not observe significant indirect vaccine protection by Vi-TT (19%; 95% CI -12 to 41, p=0·20). The vaccines were well tolerated, and no serious adverse events judged to be vaccine-related were observed. INTERPRETATION: Vi-TT provided protection against typhoid fever to children vaccinated between 9 months and less than 16 years. Longer-term follow-up will be needed to assess the duration of protection and the need for booster doses. FUNDING: The study was funded by the Bill & Melinda Gates Foundation.

Formulation development and in-vitro evaluation of gastroretentive drug delivery system of loxoprofen sodium: A natural excipients based approach.

The limitations of conventional type delivery systems to retain drug (s) in the stomach has resulted in the development of novel gastroretentive drug delivery system. We developed single-layer effervescent floating tablets of loxoprofen sodium for prolong delivery in the stomach using natural polymers xanthan gum, guar gum and semisynthetic polymer HPMCK4M. All the formulations (F1-F9) were developed by varying concentrations of xanthan gum and HPMCK4M while guar gum concentration was kept constant. Two gas generating agent (s) incorporated were sodium bicarbonate and citric acid. All compendial pre and post-compression tests results were in the acceptable limits. FTIR analysis confirmed drug-polymer compatibility. The in-vitro drug release in simulated conditions i.e., 0.1 N HCl for 12 h revealed orderly increase in total floating time, i.e., less than 6 h for F1 over 12 h for F9. Formulations F1 to F4 were not capable to retard drug release up to 12 h, whereas F5-F7 for 12 h, while F8 and F9 for more than 12 h. Data fitting in various kinetic models showed that drug release best fit in first order kinetic model and F9 in zero order. Based on results data, F7 was the best among all.

Safety and immunogenicity of Vi-typhoid conjugate vaccine co-administration with routine 9-month vaccination in Burkina Faso: A randomized controlled phase 2 trial.

OBJECTIVES: In 2017, the World Health Organisation (WHO) pre-qualified a single-dose typhoid conjugate vaccine (TCV) and identified TCV co-administration studies as a research priority. Accordingly, we tested co-administration of Typbar TCV® (Bharat Biotech International) with measles-rubella (MR) and yellow fever (YF) vaccines. METHODS: We conducted a randomized, double-blind, and controlled, phase 2 trial in Ouagadougou, Burkina Faso. Healthy children aged 9-11 months were randomized 1:1 to receive TCV (Group 1) or control vaccine (inactivated polio vaccine (IPV), Group 2). Vaccines were administered intramuscularly with routine MR and YF vaccines. Safety was assessed by (1) local and systemic reactions on days 0, 3, and 7; (2) unsolicited adverse events within 28 days; and (3) serious adverse events (SAEs) within six months after immunization. RESULTS: We enrolled, randomized, and vaccinated 100 eligible children (49 Group 1 and 51 Group 2). Safety outcomes occurred with similar frequency in both groups: local/solicited reactions (Group 1: 1/49, Group 2: 3/50), systemic/solicited reactions (Group 1: 4/49, Group 2: 9/50), unsolicited adverse events (Group 1: 26/49, Group 2: 33/51), and SAEs (Group 1: 2/49, Group 2: 3/51). TCV conferred robust immunogenicity without interference with MR or YF vaccines. CONCLUSION: TCV can be safely co-administered with MR and YF vaccines to children at the 9-month vaccination visit.

Protective effects of sulfated polysaccharide from Enterobacter cloacae Z0206 against DSS-induced intestinal injury via DNA methylation.

We previously obtained and characterized a novel sulfated derivative of the exopolysaccharides from Enterobacter cloacae Z0206 (SEPS). This study aimed at investigating the effects and mechanism of SEPS against dextran sulfate sodium (DSS) induced intestinal injury. The results showed that SEPS increased the proliferation and survival of intestinal epithelial cells during DSS stimulation. Furthermore, SEPS maintained the barrier function and inflammatory response via JAK2 and MAPK signaling to protect against DSS-induced intestinal injury. Mechanistically, SEPS elevated the DNA methylation in the promoter region to negatively regulate the JAK2 and MAPKs expression. Thus, the current study shows the potential effects and mechanism of SEPS on DSS-induced intestinal epithelial cell injury.

Ebosin Ameliorates Psoriasis-Like Inflammation of Mice via miR-155 Targeting tnfaip3 on IL-17 Pathway.

Psoriasis is a recurrent autoimmune skin disease with aberrant regulation of keratinocytes and immunocytes. There is no universally accepted single treatment available for psoriasis, and the establishment of a common treatment option to control its signs and symptoms is urgently needed. Here, we found Ebosin, a novel exopolysaccharide isolated from Streptomyces sp. 139 by our lab, not only could ameliorate inflammation in LPS-induced keratinocytes through IKK/NF-kapaB pathway, but also attenuate psoriatic skin lesions and reduce inflammatory factors expression in imiquimod (IMQ)-mediated psoriatic mice. Except for inhibiting the expression of epidermal differentiation related proteins, Ebosin significantly increased the percentage of CD4+Foxp3+CD25+ Tregs and decreased CD4+IL17A+ Th17 cells in psoriatic mice. Furthermore, we demonstrate that Ebosin significantly suppressed the IL-17 signaling pathway via A20 (encoded by tnfaip3) in vivo. As the direct binding of tnfaip3 to miR-155 has been demonstrated by luciferase reporter assay, and Ebosin has been demonstrated to inhibit miR-155 level in vitro and in vivo, our study first indicates that Ebosin reduces inflammation through the miR-155-tnfaip3-IL-17 axis and T cell differentiation in a psoriasis-like model. Thus, we conclude that Ebosin can act as a promising therapeutic candidate for the treatment of psoriasis.

Novel Gellan Gum-Based In Situ Nanovesicle Formulation of Docetaxel for Its Localized Delivery Using Depot Formation.

In the present study, different in situ hydrogel formulations of docetaxel (DTX) based on biocompatible polymers such as Hyaluronic Acid (HA), poloxamer-407, chitosan and gellan gum were formulated to increase its therapeutic efficacy and reduce toxicity. DTX was loaded in nanovesicles (20 mg/mL equivalent to commercial strength) and further incorporated into the hydrogel bases to possess a dual rationale of protection against burst release and enhanced solubility of the drug. The optimized hydrogel formulation (NV-TPGS-3-GG-4) showed ideal rheological behavior and in situ characteristics at 37±0.5°C with sustained release of more than 144 h. The optimized formulation had instant in vitro gelation (2.8±0.3 min) with good injectability in comparison to the conventional commercial DTX injectable formulation having instant release (<2 h). Additionally, developed formulation exhibited an improved biodisponibility (25.1±0.2 h) in comparison to the commercially available formulation (1.7±0.1 h). The Solid Tumor Carcinoma model in Swiss albino mice revealed that the optimized formulation (based on gellan gum) showed better tumor reduction (85.7±1.2%) and lower toxicity as compared to the commercial formulation (77.3±1.3%). Pharmacokinetic and biodistribution studies demonstrated 3 to 4 times higher localization of drug in tumors. Our findings suggested that injectable gellan gum-based in situ hydrogel formulation can be an effective delivery system for DTX with enhanced solubility, reduced toxicity, and better targeting to the tumors for improved therapeutics.Graphical abstract.

Effect of hydrocolloid coatings (Basil seed gum, xanthan, and methyl cellulose) on the mass transfer kinetics and quality of fried potato strips.

In this research, the effect of different temperatures (160, 180, and 190 °C) and hydrocolloid coatings (Basil seed gum [BSG], xanthan gum [XG], methylcellulose [MC], BSG-XG, and BSG-MC mixtures) were investigated on the physicochemical properties (oil uptake, moisture loss, color, microscopic structure, activation energy, and texture), mass transfer kinetic of fried potato strips in deep-fat frying, and oil partitions using frying and postfrying cooling phase. An increase in frying time reduced the moisture content and hardness of potato strips; however, the oil content and color difference increased. The oil content in the coated samples had lower rates than that in the noncoated ones. The treated samples using BSG-xanthan mixture (50:50) and BSG had the lowest oil uptake at 0.13% and 0.14% Dry basis (d.b.), respectively. The maximum and minimum values of effective moisture diffusivity were measured in control and samples coated with BSG-XG and BSG, respectively. As frying temperature increased, the specific rate of oil uptake increased and the equilibrium oil content decreased. Overall, BSG-XG mixture-coated potato strips can be used as a promising product due to absorbing the lowest oil rate and being similar to the control in terms of organoleptic properties.

Saccharide dosage content of meningococcal polysaccharide conjugate vaccines determined using WHO International Standards for serogroup A, C, W, Y and X polysaccharides.

Potency of meningococcal polysaccharide-protein conjugate vaccines relies on the polysaccharide content to prevent meningitis. NIBSC, as the official national control laboratory in UK, analysed ten different mono- and multi-meningococcal conjugate vaccines, using established International Standards for meningococcal serogroups A, C, W, Y and X, by resorcinol or HPAEC-PAD assay. Most saccharide contents were within ±20% of their claimed content for licensure with taking different O-acetylation levels into consideration, with only MenC content in two vaccines below (by 60% and 54%) the labelled value, however, previous study showed different dosage was not necessarily correlated to the immunogenicity of those vaccines. This study demonstrated the use of International Standards to quantify saccharide content in polysaccharide-based vaccines with different percentage of O-acetylation. These International Standards are suitable to serve as either quantitative standard or calibrator of in-house standards, with supplied stability data.

Appropriate usage of food thickening agents to prevent non-disintegration of magnesium oxide tablets.

Food thickening agents are used to aid the administration of medicine to elderly patients with dysphagia. Magnesium oxide tablets are sometimes administered with food thickening agents. Non-disintegration and disintegration delay of these tablets in the body are problems associated with food thickening agent use. However, the appropriate usage of food thickening agents for administering tablets is not established. Here, the reasons for the non-disintegration of magnesium oxide tablets administered with food thickeners and appropriate usage of food thickeners were examined using a disintegration test of newly opened and moisture-absorbed magnesium oxide tablets. Immersion of magnesium oxide tablets for 10 and 30 min in xanthan and guar gum-based food thickening agents caused disintegration delay and non-disintegration in the first fluid (pH 1.2). However, tablets immersed for 1 min quickly disintegrated. The disintegration of xanthan gum-based food thickening agents was faster than guar gum-based food thickening agents. Moisture absorption by magnesium oxide tablets caused a significant delay in their disintegration in water. The tablets that absorbed moisture disintegrated within 1 min in the first fluid, even when immersed in food thickening agents for a short time. Overall, a short immersion of magnesium oxide tablets in food thickening agents can avoid non-disintegration.

Short Vi-polysaccharide abrogates T-independent immune response and hyporesponsiveness elicited by long Vi-CRM197 conjugate vaccine.

Polysaccharide-protein conjugates have been developed to overcome the T-independent response, hyporesponsiveness to repeated vaccination, and poor immunogenicity in infants of polysaccharides. To address the impact of polysaccharide length, typhoid conjugates made with short- and long-chain fractions of Vi polysaccharide with average sizes of 9.5, 22.8, 42.7, 82.0, and 165 kDa were compared. Long-chain-conjugated Vi (165 kDa) induced a response in both wild-type and T cell-deficient mice, suggesting that it maintains a T-independent response. In marked contrast, short-chain Vi (9.5 to 42.7 kDa) conjugates induced a response in wild-type mice but not in T cell-deficient mice, suggesting that the response is dependent on T cell help. Mechanistically, this was explained in neonatal mice, in which long-chain, but not short-chain, Vi conjugate induced late apoptosis of Vi-specific B cells in spleen and early depletion of Vi-specific B cells in bone marrow, resulting in hyporesponsiveness and lack of long-term persistence of Vi-specific IgG in serum and IgG+ antibody-secreting cells in bone marrow. We conclude that while conjugation of long-chain Vi generates T-dependent antigens, the conjugates also retain T-independent properties, leading to detrimental effects on immune responses. The data reported here may explain some inconsistencies observed in clinical trials and help guide the design of effective conjugate vaccines.

Polysaccharides from fermented Asparagus officinalis with Lactobacillus plantarum NCU116 alleviated liver injury via modulation of glutathione homeostasis, bile acid metabolism, and SCFA production.

Lactic acid bacteria strain (LAB) NCU116 fermented Asparagus officinalis polysaccharides (FAOP) have been proven to cause substantial changes in physicochemical properties such as monosaccharide composition and molecular weight, accounting for their enhanced immune activity than unprocessed Asparagus officinalis polysaccharides (AOP). In the current study, the hepatoprotective effects of FAOP in mice with cyclophosphamide (CTX)-induced hepatotoxicity were investigated. FAOP were more effective than AOP in alleviating CTX-induced hepatic damage, including inhibition of hepatic biochemical markers (ALT, AST, AKP and LDH) and pro-inflammatory cytokines (TNF-α and IL-1ß) as well as reinforcement of antioxidant systems (T-AOC, SOD, CAT, and MDA). In particular, compared with AOP, FAOP showed superior performance by promoting GSH biosynthesis, and normalizing the expression level of bile acid receptors (FXR and SHP) and key enzymes in bile acid synthesis (CYP7A1, CYP8B1 and CYP27A1). Modulation of disordered homeostasis of bile acids by FAOP can be attributed to the upregulation of hepatic short chain fatty acid (SCFA) receptors GPR41 and GPR109A as well as intestinal SCFA production. Furthermore, serum metabolomics study validated the hepatoprotective superiority of FAOP than AOP with evidence from variations in bile acid compositions and the construction of related metabolic pathways. Therefore, LAB NCU116 fermentation of Asparagus officinalis was practical and effective to obtain promising hepatoprotective polysaccharides, which might arise from enhanced SCFA production than unprocessed AOP.

Development of fluorescein isothiocyanate conjugated gellan gum for application of bioimaging for biomedical application.

Herein, gellan gum (GG), a nature-derived polysaccharide, was applied to combine fluorescein isothiocyanate (FITC) to fabricate a bio-imaging material. The synthesis process of the FITC grafted GG (GG-F) and manufacturing method of GG-F scaffolds are presented. Chemical, physicochemical, and mechanical properties were characterized. In vitro study and in vivo study by implanting the GG-F scaffolds under the subcutaneous area of the nude mice were carried out to verify biocompatibility and safety of the material. The emission of the FITC was confirmed with high-resolution confocal laser scanning microscope (SR CLMS) and fluorescence in vivo imaging (FOBI). The results exhibited well-synthesized GG-F and the manufactured GG-F scaffolds showed similar property of GG scaffolds which confirms that the chemical modification does not affect the property of GG scaffolds. The in vitro and in vivo study exhibited biocompatibility of the GG-F material. Overall, the properly blended GG-F in GG did not influence the characteristics of the pristine GG except for the chemical property. Therefore, the GG-F can be applied for the future analysis in verifying the mechanism of GG characters and can be a promising candidate for bio-imaging.

Comparative Study of Immunogenic Properties of Purified Capsular Polysaccharides from Streptococcus suis Serotypes 3, 7, 8, and 9: the Serotype 3 Polysaccharide Induces an Opsonizing IgG Response.

Streptococcus suis is an encapsulated bacterium and one of the most important swine pathogens and a zoonotic agent for which no effective vaccine exists. Bacterial capsular polysaccharides (CPSs) are poorly immunogenic, but anti-CPS antibodies are essential to the host defense against encapsulated bacteria. In addition to the previously known serotypes 2 and 14, which are nonimmunogenic, we have recently purified and described the CPS structures for serotypes 1, 1/2, 3, 7, 8, and 9. Here, we aimed to elucidate how these new structurally diverse CPSs interact with the immune system to generate anti-CPS antibody responses. CPS-stimulated dendritic cells produced significant levels of C-C motif chemokine ligand 3 (CCL3), partially via Toll-like receptor 2 (TLR2)- and myeloid differentiation factor 88-dependent pathways, and CCL2, via TLR-independent mechanisms. Mice immunized with purified serotype 3 CPS adjuvanted with TiterMax Gold produced an opsonizing IgG response, whereas other CPSs or adjuvants were negative. Mice hyperimmunized with heat-killed S. suis serotypes 3 and 9 both produced anti-CPS type 1 IgGs, whereas serotypes 7 and 8 remained negative. Also, mice infected with sublethal doses of S. suis serotype 3 produced primary anti-CPS IgM and IgG responses, of which only IgM were boosted after a secondary infection. In contrast, mice sublethally infected with S. suis serotype 9 produced weak anti-CPS IgM and IgG responses following a secondary infection. This study provides important information on the divergent evolution of CPS serotypes with highly different structural and/or biochemical properties within S. suis and their interaction with the immune system.