Mannosylated gelatin nanoparticles enhanced inactivated PRRSV targeting dendritic cells and increased T cell immunity.

The objective of the present work was to evaluate the efficacy of a novel antigen carrier using mannosylated gelatin nanoparticles with entrapped inactivated porcine reproductive and respiratory syndrome virus (PRRSV) in inducing T cell mediated immunity in vitro. Gelatin nanoparticles (GNP) were modified with mannose to form mannosylated gelatin nanoparticles (MnGNP), which can efficiently and specifically target monocyte derived dendritic cells (MoDCs). The inactivated PRRSV was encapsulated in the MnGNP and GNP, referred to as MnGNP-PRRSV and GNP-PRRSV, respectively. All these prepared nanometer particles were characterized for size, surface charge, drug encapsulation efficiency, and drug release. The efficacy of MnGNP in targeting MoDCs was investigated, as well as the subsequent MoDCs maturation and T cell mediated cytotoxicity. The developed MnGNP-PRRSV particle was characterized with a nanometric size of 302.67 ±â€¯3.2 nm, surface charge of 23.81 ±â€¯1.26 mV, and PRRSV encapsulation efficiency of 63.2 ±â€¯1.85 %. The maximum uptake of MnGNP in MoDCs in vitro was 15.5 times higher than GNP with a shorter reaction time that peaked 4 h earlier. The uptake of MnGNP-PRRSV induced maturation of MoDCs and significantly enhanced expression of SWC-3a, CD80, CD1, SLA I, SLA II on MoDCs, compared to PRRSV (p < 0.001). The cytokine secretion of IL-1ß, IL-6, IL-10, and IL-12 was also increased in MoDCs when treated with MnGNP-PRRSV, compared to PRRSV (p < 0.05). The matured MoDCs triggered T lymphocytes in autologous peripheral blood mononuclear cells (PBMCs) activation, proliferation, and differentiation into effector cytotoxic T lymphocyte, suggesting increased amount of activated T cells after MnGNP-PRRSV treatment. Additionally, the function of T cells to kill PRRSV infected cells was 83.98 ±â€¯2.62 % when triggered by MnGNP-PRRSV, compared to 60 ±â€¯4.7 % in PRRSV group (p < 0.001). These results indicate that MnGNP with entrapped inactivated PRRSV can effectively and specifically target dendritic cells for maturation and activation, and subsequently improve T cell activation, proliferation and function to kill PRRSV infected cells.

Allergic reactions to colloid fluids in anesthesia.

Allergic reactions in anesthesia are a rare event, however, might be life threatening when occurred. Clinical manifestations may not be indicative at first, and difficult to differentiate from different situations during operation and anesthesia. Colloids represent a group of fluids often used during perioperative period that, among other adverse reactions, have an allergic potential. Albumin is a natural colloid that has the lowest incidence of these reactions. However, it is found as an additional substance in other blood products, and, therefore, has to be taken into consideration if anaphylaxis occurs. Dextrans cause the most severe reactions due to dextran reactive antibodies. Pretreatment with Dextran 1 may inhibit the reaction. Gelatins have the highest incidence of anaphylaxis among colloids. Patients with history of allergy to some food, vaccines, cosmetics containing gelatin are at greater perioperative risk for anaphylaxis. Not to forget, gelatins are also a part of topical haemostatic agents used in surgery. Testing for colloid allergies is limited due to their pathophysiologic mechanism, so the clinical assessment is usually essential. Treatment of anaphylaxis caused by colloids is the same as for any other cause. This is a review of the most common colloids and their association with allergic reactions in everyday practice.

Diagnosis and management of hypersensitivity reactions to vaccines.

INTRODUCTION: Many countries in Europe now recommend and enforce mandatory vaccinations to improve vaccination coverage. Thus, the number of adverse events following immunization (AEFI) may show an increase. Among these events, severe hypersensitivity reactions to vaccines are rare. However, it is important that they be identified and recognized so that they may be adequately managed. AREAS COVERED: The literature search was undertaken through PubMed and Embase to identify English-language papers focusing on hypersensitivity to vaccines. EXPERT OPINION: Hypersensitivity reactions following vaccinations are rare and are classified according to their chronology and extension: immediate when they occur within the first 4 hours following administration and non-immediate when they occur later. Local reactions are the most common adverse event following injection of vaccines and generally do not require any allergy workup. Immediate reactions, however, are potentially IgE-mediated and require an allergy workup. In general, a previously known food allergy (i.e., egg or milk) is not a contraindication to immunizations. Patients with a known allergy to gelatin, yeast, latex, antibiotics, or other specific components of vaccines require an allergy workup before administration of the vaccine.

Preventing iatrogenic gelatin anaphylaxis.

OBJECTIVE: To assess the iatrogenic risks of gelatin allergy and identify resources for patient management. DATA SOURCES: A literature review was performed using PubMed and public databases provided by the National Library of Medicine. STUDY SELECTIONS: Reports of iatrogenic gelatin allergy associated with vaccines, hemostatic agents, intravenous colloids, medicinal capsules, and intraoperative surgical supplies. RESULTS: Gelatin ingredients may not be identified by electronic medical record safeguards, and an exhaustive listing of potential iatrogenic exposures is elusive. The National Library of Medicine AccessGUDID (https://accessgudid.nlm.nih.gov/) can be a useful resource in evaluating medical devices for gelatin content. Unexpected sources of iatrogenic gelatin exposure include hemostatic agents, vascular grafts, intravascular cannulas, bone replacement implants, and emergency resuscitation fluids. CONCLUSION: Vigilance is important within medical systems to avoid inadvertent gelatin exposure when caring for patients with gelatin allergy. Additional safeguards are needed to remove latent health care system errors that fail to prevent gelatin administration in this at-risk population.

Safe administration of a gelatin-containing vaccine in an adult with galactose-α-1,3-galactose allergy.

Immunoglobulin (Ig) E antibodies to galactose-α-1,3-galactose (α-Gal) are associated with delayed anaphylaxis to mammalian food products and gelatin-based foods (Commins et al., J Allergy Clin Immunol 2009;123:426; Caponetto et al., J Allergy Clin Immunol Pract 2013;1:302). We describe a patient with α-Gal allergy who successfully tolerated the live zoster vaccine and we review anaphylactic reactions reported to this vaccine. Our patient, who tolerated a vaccine containing the highest gelatin content, is reassuring but continued safety assessment of gelatin-containing vaccines for this patient cohort is recommended as there are multiple factors for this patient cohort that influence the reaction risk.

Immune and inflammatory role of hydroxyethyl starch 130/0.4 and fluid gelatin in patients undergoing coronary surgery.

OBJECTIVES: Compare the effects on inflammatory (TNF-α, IL-6, IL-8 and IL-10) and immunologic (CD3(+), CD4(+), CD8(+), CD11b(+), CD16(+)/56(+) T cells and total lymphocyte concentration) variables of hydroxyethyl starch 130/0.4, 4% modified fluid gelatin, or crystalloid when used as volume replacement fluids for acute normovolemic hemodilution (a blood conservation technique) in coronary artery bypass graft patients. METHODS: Thirty patients undergoing coronary artery bypass graft surgery were randomized to receive Isolyte S® (Group ISO), 6% hydroxyethyl starch 130/0.4 (Group HES) or 4% modified gelatin solution (Group GEL) for acute normovolemic hemodilution. Blood samples were taken immediately after induction of anaesthesia (T0), and 2 h (T1), 12 h (T2), 24 h (T3), and 48 h (T4) after separation from cardiopulmonary bypass. TNF-α, IL-6, IL-8 and IL-10 levels were determined with commercially available ELISA kits. CD3(+) (mature T cells), CD4(+) (T helper cells), CD8(+) (suppressor cytotoxic T cells), CD16(+)/56(+) (natural killer lymphocytes), and CD11b(+) (Mac-1, adhesion receptor) levels were measured using flow-cytometry reagents. The CD4(+):CD8(+) ratio was calculated. RESULTS: Between-group comparisons showed significantly higher levels of TNF-α at T1 (2 h after weaning from cardiopulmonary bypass) in Group HES compared to Group ISO (p=0.003). IL-8 was significantly lower in Group HES than Group GEL at T1 (p=0.0005). IL-10 was significantly higher in Group HES than in Group GEL at T1 (p=0.0001). The CD4(+):CD8(+) ratio in Group ISO was significantly lower than that in Group HES at T2 (p=0.003). CD11b(+) levels in Group HES were also higher than those in Group GEL and group ISO at T2, but not significantly. CD16/56(+) levels in Group HES were higher than those in Group GEL at T2 (p<0.003). No excessive hemorrhage occurred in any patient. Mediastinal drainage during the first 24 h after surgery in Group HES (347±207 mL) was not significantly different from that of Group GEL (272±177 mL) or Group ISO (247±109) (p>0.05). CONCLUSION: Hydroxyethyl starch 130/0.4 reduced pro-inflammatory responses and increased anti-inflammatory responses to a greater degree than gelatin solution and isolyte S®. The use of hydroxyethyl starch, compared to gelatin solution and isolyte S®, resulted in less decrease in the CD4(+):CD8(+) ratio, suggesting less immunosuppression.

[A case of anaphylaxis induced by gelatin-contained gel capsule cold medicine].

We report here a 20-year old woman who referred to our clinic for identify the responsible antigen of anaphylaxis. Five days before the reaction, she had a cold and had taken a gel capsule cold medicine, Stona IB Gel®. On the day of the reaction, she took a dose of Stona IB Gel® after eating yogurt. Five minutes after oral administration, she developed a heat sensation and pruritus on her neck, with flushing, abdominal pains, breathing difficulties, and syncope. The specific IgE antibodies measured by ImmunoCAP® were all negative except for gelatin. Prick-prick skin testing revealed positive responses to Stona IB Gel®, gelatin KS and gelatin RP600, of which the latter two were included in the Stona IB Gel® capsule. From these test results, she was diagnosed with anaphylaxis due to gelatin, and to date she has had no further allergic symptoms since avoiding foods containing gelatin. In infancy she had received four vaccinations against diphtheria, pertussis and tetanus, which contained gelatin as a stabilizer. However, she had not developed allergic symptoms until this time. We hypothesize that she might be sensitized to gelatin by taking Stona IB Gel® during the preceding 4 days. This is the first case of anaphylaxis from the ingestion of an oral medication containing gelatin in Japan. Allergic reactions to gelatin are comparatively rare, but according to the past reports, the reactions were severe. Since many kinds of foods, cosmetics, pharmaceutical products, and medication contain gelatin, it is important to be aware of gelatin allergy.

Biocompatibility and inflammatory response in vitro and in vivo to gelatin-based biomaterials with tailorable elastic properties.

Hydrogels prepared from gelatin and lysine diisocyanate ethyl ester provide tailorable elastic properties and degradation behavior. Their interaction with human aortic endothelial cells (HAEC) as well as human macrophages (Mɸ) and granulocytes (Gɸ) were explored. The experiments revealed a good biocompatibility, appropriate cell adhesion, and cell infiltration. Direct contact to hydrogels, but not contact to hydrolytic or enzymatic hydrogel degradation products, resulted in enhanced cyclooxygenase-2 (COX-2) expression in all cell types, indicating a weak inflammatory activation in vitro. Only Mɸ altered their cytokine secretion profile after direct hydrogel contact, indicating a comparably pronounced inflammatory activation. On the other hand, in HAEC the expression of tight junction proteins, as well as cytokine and matrix metalloproteinase secretion were not influenced by the hydrogels, suggesting a maintained endothelial cell function. This was in line with the finding that in HAEC increased thrombomodulin synthesis but no thrombomodulin membrane shedding occurred. First in vivo data obtained after subcutaneous implantation of the materials in immunocompetent mice revealed good integration of implants in the surrounding tissue, no progredient fibrous capsule formation, and no inflammatory tissue reaction in vivo. Overall, the study demonstrates the potential of gelatin-based hydrogels for temporal replacement and functional regeneration of damaged soft tissue.

Immunocompatibility evaluation of hydrogel-coated polyimide implants for applications in regenerative medicine.

Immunocompatibility of gelatin-based hydrogels to be applied as implant coatings for local regenerative treatment has been studied. First, the bio- and immuno-acceptability of the methacrylamide-modified gelatin hydrogels per se was screened. The results indicated that the hydrogels support cell growth. Metabolic activity of normal cells and permanent cell lines representing various cell types (endothelial, epithelial, fibroblast, and monocyte/macrophage) cultivated on the gelatin hydrogels was moderately lower compared to cells cultivated on tissue culture plastic. The cells cultivated on the hydrogels produced identical cytokines as the control cells although at lower levels. Importantly, no inflammatory activity, measured by nitric oxide and pro-inflammatory cytokine (IL-1α, IL-6, and TNFα) production, was observed in peritoneal cells and monocyte/macrophage RAW 264.7 cell line cultivated on the hydrogels. Finally, polyimide (PI) implantable membranes were surface-modified with gelatin hydrogels and screened for their in vivo immunocompatibility. Their histological examination performed after subcutaneous implantation in mice produced a sound proof of immunoacceptability. Normal tissue repair, mild cellular infiltration and edema mainly induced by the surgery were observed after 2 and 6 days. No adverse tissue responses were induced by the implants. Analysis performed after 4 and 9 weeks indicated areas of foreign body granuloma without formation of a fibrous capsule.

Positively charged cholesterol-recombinant human gelatins foster the cellular uptake of proteins and murine immune reactions.

PURPOSE: Recombinant human gelatins with defined molecular weights were modified with cholesterol to make them amphiphilic in nature. We investigated the feasibility of these modified human gelatins acting as a carrier of antigenic proteins for inducing cellular immunity. The aim of this study was to synthesize novel and effective compounds for vaccine delivery in vivo. METHODS: Two types of cholesterol-modified gelatin micelles, anionic cholesterol-modified gelatin (aCMG) and cationic-cholesterol modified gelatin (cCMG), were synthesized using different cholesterol derivatives such as the cholesterol-isocyanate (Ch-I) for aCMG and amino-modified cholesterol for cCMG. One was anionic and the other cationic, and therefore they differed in terms of their zeta potential. The aCMG and cCMG were characterized for their size, zeta potential, and in their ability to form micelles. Cytotoxicity was also evaluated. The modified human gelatins were then investigated as a carrier of antigenic proteins for inducing cellular immunity both in vitro in DC 2.4 cells, a murine dendritic cell line, as well as in vivo. The mechanism of entry of the polymeric micelles into the cells was also evaluated. RESULTS: It was found that only cCMG successfully complexed with the model antigenic protein, fluorescein-isothiocyanate ovalbumin (OVA) and efficiently delivered and processed proteins in DC 2.4 cells. It was hypothesized that cCMG enter the cells predominantly by a caveolae-mediated pathway that required tyrosine kinase receptors on the cell surface. Animal testing using mice showed that the cationic cholesterol-modified gelatin complexed with OVA produced significantly high antibody titers against OVA: 2580-fold higher than in mice immunized with free OVA. CONCLUSION: Conclusively, cCMG has shown to be very effective in stimulating an immune response due to its high efficiency, stability, and negligible cytotoxicity.

Relationship between red meat allergy and sensitization to gelatin and galactose-α-1,3-galactose.

BACKGROUND: We have observed patients clinically allergic to red meat and meat-derived gelatin. OBJECTIVE: We describe a prospective evaluation of the clinical significance of gelatin sensitization, the predictive value of a positive test result, and an examination of the relationship between allergic reactions to red meat and sensitization to gelatin and galactose-α-1,3-galactose (α-Gal). METHODS: Adult patients evaluated in the 1997-2011 period for suspected allergy/anaphylaxis to medication, insect venom, or food were skin tested with gelatin colloid. In vitro (ImmunoCAP) testing was undertaken where possible. RESULTS: Positive gelatin test results were observed in 40 of 1335 subjects: 30 of 40 patients with red meat allergy (12 also clinically allergic to gelatin), 2 of 2 patients with gelatin colloid-induced anaphylaxis, 4 of 172 patients with idiopathic anaphylaxis (all responded to intravenous gelatin challenge of 0.02-0.4 g), and 4 of 368 patients with drug allergy. Test results were negative in all patients with venom allergy (n = 241), nonmeat food allergy (n = 222), and miscellaneous disorders (n = 290). ImmunoCAP results were positive to α-Gal in 20 of 24 patients with meat allergy and in 20 of 22 patients with positive gelatin skin test results. The results of gelatin skin testing and anti-α-Gal IgE measurements were strongly correlated (r = 0.46, P < .01). α-Gal was detected in bovine gelatin colloids at concentrations of approximately 0.44 to 0.52 µg/g gelatin by means of inhibition RIA. CONCLUSION: Most patients allergic to red meat were sensitized to gelatin, and a subset was clinically allergic to both. The detection of α-Gal in gelatin and correlation between the results of α-Gal and gelatin testing raise the possibility that α-Gal IgE might be the target of reactivity to gelatin. The pathogenic relationship between tick bites and sensitization to red meat, α-Gal, and gelatin (with or without clinical reactivity) remains uncertain.

Preparation and validation of a skin model for the evaluation of intradermal powder injection devices.

A very promising novel needle-free application method is epidermal powder immunisation, a method delivering particulate vaccines into the viable epidermis of human skin where a dense network of immunocompetent cells resides. These antigen-presenting cells (Langerhans cells) are able to recognise antigens, process them and present them to naïve T-cells and induce effective immune responses. Powder injection devices are being developed, and their evaluation is essential before applying them on live animals and individuals. An appropriate skin model will accelerate the development of such injection devices. Different films made from gelatin, silicon and agar were prepared and investigated as skin model candidates for the evaluation of powder injection devices. The mechanical properties of the skin model candidates were measured with an indentation method using a texture analyser, and the results were compared to the properties of human skin and pig skin. The indentation behaviour of the model films and the biological skin samples suggest that gelatin films plasticised with glycerol are very well suitable for a skin model. The mechanical properties of gelatin based films can be tailored by changing the glycerol content in the film making it even possible to simulate human skin with different mechanical properties as the mechanical properties depend on the individual, age, sex and site of injection. The stability of the gelatin films was also investigated under long-term storage. In addition, confocal laser scanning microscopy was used as a novel tool to determine the depths and size of fluorescently labelled particles in the gelatin model.

Production and characterization of antibodies against crosslinked gelatin nanoparticles and first steps toward developing an ELISA screening kit.

Nanotechnologies are finding a growing range of applications in the food sector. Nanoparticles are used notably to add vitamins and other nutrients to foods and beverages without affecting taste and color. They are also used to develop new tastes, preserve food texture, control the release of flavors, improve the bioavailability of compounds such as antioxidants and vitamins, and monitor freshness with nanosensors. Crosslinked gelatin nanoparticles are a component of nano-sized carriers for nutrient and supplement delivery in foods and related products. This paper describes the production and characterization of polyclonal antibodies against gelatin nanoparticles. Two immunization schemes were investigated: subcutaneous injection with and without a first intravenous injection. Two enzyme-linked immunosorbent assay formats were used to characterize the antibodies: an inhibition format with an antigen-coated plate for detection of the immune response and a sandwich format for development of the method. The antibodies showed good sensitivity with an IC50 equal to 0.11 ng mL(-1) using indirect ELISA format and a good specificity for the nanomaterials, without significant cross-reactivity against native gelatin. The limit of detection was determined-0.42, 0.27, 0.26, and 0.24 µg mL(-1) for apple, orange juice, milk, and soft drink matrices, respectively. ELISA technology offers rapid, low-cost assays for screening foods, feeds, and beverages. We have studied a prototype ELISA for detection of gelatin-based nanocarrier systems. Fruit juices, milk, and a soft drink were the matrices selected for assay development.