Enhancement of Rotavirus Immunogenicity by Microencapsulation

Offit, Paul A.; Khoury, C A; Moser, Charlotte A.; Clark, H Fred; Kim, J E; Speaker, Tully J.

doi:10.1006/viro.1994.1463

Cited by 66 publications

(21 citation statements)

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“…It is well known that viruses are typically damaged irreversibly by exposure to low pH, organic solvents, dehydration, and heat (32,33,45). The current experiment showed that the viability of free phage Felix O1 was rapidly lost upon exposure to a simulated acidic gastric environment and, to a lesser extent, upon exposure to bile salts.…”

Section: Discussionmentioning

confidence: 99%

“…In addition, the microencapsulation of viruses has been studied as an effective adjuvant system to induce specific immune responses via mucosal routes (32). Development of oral microencapsulated forms for delivering viral vaccines with spermine-alginate (29,33), poly(DL-lactide-co-glycolide) (39), and chitosan-bile salt microspheres (25) has been reported in previous studies. However, in terms of the development of a suitable methodology and encapsulation matrix for use with phage, these approaches have some limitations such as the involvement of organic solvents (39), low encapsulation efficiency, and poor protective effects upon exposure to gastric acid (29), which make them unsuitable for microencapsulation of phage for oral delivery.…”

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confidence: 99%

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Microencapsulation of Bacteriophage Felix O1 into Chitosan-Alginate Microspheres for Oral Delivery

Pacan

Wang

et al. 2008

Appl Environ Microbiol

247

188

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This paper reports the development of microencapsulated bacteriophage Felix O1 for oral delivery using a chitosan-alginate-CaCl 2 system. In vitro studies were used to determine the effects of simulated gastric fluid (SGF) and bile salts on the viability of free and encapsulated phage. Free phage Felix O1 was found to be extremely sensitive to acidic environments and was not detectable after a 5-min exposure to pHs below 3.7. In contrast, the number of microencapsulated phage decreased by 0.67 log units only, even at pH 2.4, for the same period of incubation. The viable count of microencapsulated phage decreased only 2.58 log units during a 1-h exposure to SGF with pepsin at pH 2.4. After 3 h of incubation in 1 and 2% bile solutions, the free phage count decreased by 1.29 and 1.67 log units, respectively, while the viability of encapsulated phage was fully maintained. Encapsulated phage was completely released from the microspheres upon exposure to simulated intestinal fluid (pH 6.8) within 6 h. The encapsulated phage in wet microspheres retained full viability when stored at 4°C for the duration of the testing period (6 weeks). With the use of trehalose as a stabilizing agent, the microencapsulated phage in dried form had a 12.6% survival rate after storage for 6 weeks. The current encapsulation technique enables a large proportion of bacteriophage Felix O1 to remain bioactive in a simulated gastrointestinal tract environment, which indicates that these microspheres may facilitate delivery of therapeutic phage to the gut.

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Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

Microencapsulation of Bacteriophage Felix O1 into Chitosan-Alginate Microspheres for Oral Delivery

Pacan

Wang

et al. 2008

Appl Environ Microbiol

247

188

View full text Add to dashboard Cite

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“…Different materials such as Chitosan-bile salt [28], spermine-alginate [35,36], or also PLGA [49] have been tested. Ma et al [31] used a chitosan-alginate-CaCl 2 system for microencapsulation of the Salmonella-specific bacteriophage Felix O1.…”

Section: Artificially Vectorized Bacteriophagesmentioning

confidence: 99%

A Question of Attire: Dressing Up Bacteriophage Therapy for the Battle Against Antibiotic-Resistant Intracellular Bacteria

Nieth

Verseux

Römer

2014

Springer Science Reviews

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More and more bacteria are developing severe antibiotic resistance. Among them are important intracellular pathogens such as Mycobacterium tuberculosis. Alternatives to classical antibiotics are urgently needed and bacteriophage therapy is a promising candidate for alternative or supplemental treatment. Until now, bacteriophages have been thought to be non-suitable for therapy against intracellular pathogens. Still, a few studies have been carried out to assess the efficacy of bacteriophage therapy against intracellular pathogens both in vitro and in vivo, with variable results. Recently, some successful studies have been conducted, in which bacteriophages were carried into infected cells by different bacterial vectors and killed intracellular pathogens. In this review, we aim to recapitulate the existing literature on bacteriophage therapy of intracellular pathogens and discuss possible ways of bacteriophage entry into infected cells, including different Trojan horse strategies and the question of whether free bacteriophages are able to enter mammalian cells. Finally, we sum up attempts of bacteriophage microencapsulation and speculate about the advantages of artificial vectorization for efficient and targeted intracellular delivery.

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“…Feces, nasal and saliva swabs were collected, placed in 0.5 ml washing buffer [PBS containing 5%(w/w) Phenylmethanesulfonyl fluoride (PMSF), 0.2%(w/w) trypsin soybean inhibitor, 0.2%(w/w) gelatin], and spun at 6,000 g for 1 min. The washing buffer collected was maintained at -20°C [19]. All the pigs were slaughtered, and their lungs removed and examined for lesions on day 68 [11,26].…”

Section: Preparation Of Microspheresmentioning

confidence: 99%

Protective Effects of Oral Microencapsulated Mycoplasma hyopneumoniae Vaccine Prepared by Co-Spray Drying Method.

et al. 2003

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ABSTRACT. The efficacy of Mycoplasma hyopneumoniae oral vaccine was investigated in microsphere dosage form. A co-spray drying process was used to apply an encapsulating material, Eudragit L30 D-55, to microspheres containing Mycoplasma hyopneumoniae antigens. The microspheres were generally effective (>93%) with protein release at pH 7.4, but almost none were released at pH 1.2, for 3 hr in an in vitro dissolution test. An SPF-swine model was used to evaluate the effectiveness of the microspheres as an oral vaccine, and the related immune responses. The serum's systemic IgG against M. hyopneumoniae was evoked by ELISA analysis, after a 2nd immunization of all pigs. The vaccinated groups' mean lesion score was significantly lower after the Mycoplasma hyopneumoniae challenge than that of the nonvaccinated/challenged groups (P<0.05). This study strongly suggests that the oral microspheres vaccine prepared by a co-spray drying method can provide effective protection against M. hyopneumoniae infection in pigs. KEY WORDS: co-spray drying, microsphere, Mycoplasma hyopneumoniae, oral vaccine.J. Vet. Med. Sci. 65(1): 69-74, 2003 Mycoplasma hyopneumoniae is widely recognized as a potent pathogen for mycoplasmal pneumonia in swine [2], colonizing the respiratory epithelia and compromising integrity by inducing an inflammatory response [20]. The pathogen also causes significant economic losses by reducing body weight and prolonging periods between feeds [22]. Although some drugs and antibiotics are effective in vitro against M. hyopneumoniae, reducing the disease's clinical signs [12], they have not yet been proven effective in eliminating the pathogen in vivo. Vaccination is an essential strategy in controlling mycoplasmal pneumonia. M. hyopneumoniae infects the ciliated epithelial cells of the respiratory tract [6], and a mucosal immune response may therefore be important in the prevention and control of M. hyopneumoniae-induced pneumonia [23]. The concept of a common mucosal immune system has been supported by several oral immunization reports [8,13]. Numerous experimental systems have proven that oral immunization can induce antibody secretion into the mucus on these surfaces [8,16,18], and is almost completely restricted to the secretory form of IgA. Oral immunization causes this IgA antibody to be secreted from the GALT to distant mucosal tissue, including the salivary, mammary, respiratory, intestine and genital mucosal tissue, protecting these areas from pathogen invasion [5,14].Microspheres have recently received widespread interest as vehicles for the controlled release of drug or bioactive agents; resisting degradation in gastric acid, they can release drugs in the intestines [1]. Oral antigen delivery by pHdependent microspheres can improve local and systemic immune responses [4,16], serving as a potent mucosal immunogen. It is essential to develop a new, simple and effective vaccine process. Microsphere oral vaccines have been previously developed in our laboratory via a novel cospray-drying process [16]. C...

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Enhancement of Rotavirus Immunogenicity by Microencapsulation

Cited by 66 publications

References 0 publications

Microencapsulation of Bacteriophage Felix O1 into Chitosan-Alginate Microspheres for Oral Delivery

Microencapsulation of Bacteriophage Felix O1 into Chitosan-Alginate Microspheres for Oral Delivery

A Question of Attire: Dressing Up Bacteriophage Therapy for the Battle Against Antibiotic-Resistant Intracellular Bacteria

Protective Effects of Oral Microencapsulated Mycoplasma hyopneumoniae Vaccine Prepared by Co-Spray Drying Method.

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