48 research outputs found
Amphiphilic Polyanhydride Nanoparticles Stabilize \u3ci\u3eBacillus anthracis\u3c/i\u3e Protective Antigen
Advancements towards an improved vaccine against Bacillus anthracis, the causative agent of anthrax, have focused on formulations composed of the protective antigen (PA) adsorbed to aluminum hydroxide. However, due to the labile nature of PA, antigen stability is a primary concern for vaccine development. Thus, there is a need for a delivery system capable of preserving the immunogenicity of PA through all the steps of vaccine fabrication, storage, and administration. In this work, we demonstrate that biodegradable amphiphilic polyanhydride nanoparticles, which have previously been shown to provide controlled antigen delivery, antigen stability, immune modulation, and protection in a single dose against a pathogenic challenge, can stabilize and release functional PA. These nanoparticles demonstrated polymer hydrophobicity-dependent preservation of the biological function of PA upon encapsulation, storage (over extended times and elevated temperatures), and release. Specifically, fabrication of amphiphilic polyanhydride nanoparticles composed of 1,6-bis(p-carboxyphenoxy)hexane and 1,8-bis(p-carboxyphenoxy)-3,6- dioxaoctane best preserved PA functionality. These studies demonstrate the versatility and superiority of amphiphilic nanoparticles as vaccine delivery vehicles suitable for long-term storage
Modeling and Evaluation of a Policy Provisioning Architecture for Mobile Ad-Hoc Networks
Rational Design of Pathogen-Mimicking Amphiphilic Materials as Nanoadjuvants
An opportunity exists today for cross-cutting research utilizing advances in materials science, immunology, microbial pathogenesis, and computational analysis to effectively design the next generation of adjuvants and vaccines. This study integrates these advances into a bottom-up approach for the molecular design of nanoadjuvants capable of mimicking the immune response induced by a natural infection but without the toxic side effects. Biodegradable amphiphilic polyanhydrides possess the unique ability to mimic pathogens and pathogen associated molecular patterns with respect to persisting within and activating immune cells, respectively. The molecular properties responsible for the pathogen-mimicking abilities of these materials have been identified. The value of using polyanhydride nanovaccines was demonstrated by the induction of long-lived protection against a lethal challenge of Yersinia pestis following a single administration ten months earlier. This approach has the tantalizing potential to catalyze the development of next generation vaccines against diseases caused by emerging and re-emerging pathogens
Genetic Interaction Maps in Escherichia coli Reveal Functional Crosstalk among Cell Envelope Biogenesis Pathways
As the interface between a microbe and its environment, the bacterial cell envelope has broad biological and clinical significance. While numerous biosynthesis genes and pathways have been identified and studied in isolation, how these intersect functionally to ensure envelope integrity during adaptive responses to environmental challenge remains unclear. To this end, we performed high-density synthetic genetic screens to generate quantitative functional association maps encompassing virtually the entire cell envelope biosynthetic machinery of Escherichia coli under both auxotrophic (rich medium) and prototrophic (minimal medium) culture conditions. The differential patterns of genetic interactions detected among >235,000 digenic mutant combinations tested reveal unexpected condition-specific functional crosstalk and genetic backup mechanisms that ensure stress-resistant envelope assembly and maintenance. These networks also provide insights into the global systems connectivity and dynamic functional reorganization of a universal bacterial structure that is both broadly conserved among eubacteria (including pathogens) and an important target
Amphiphilic Polyanhydride Nanoparticles Stabilize \u3ci\u3eBacillus anthracis\u3c/i\u3e Protective Antigen
Advancements towards an improved vaccine against Bacillus anthracis, the causative agent of anthrax, have focused on formulations composed of the protective antigen (PA) adsorbed to aluminum hydroxide. However, due to the labile nature of PA, antigen stability is a primary concern for vaccine development. Thus, there is a need for a delivery system capable of preserving the immunogenicity of PA through all the steps of vaccine fabrication, storage, and administration. In this work, we demonstrate that biodegradable amphiphilic polyanhydride nanoparticles, which have previously been shown to provide controlled antigen delivery, antigen stability, immune modulation, and protection in a single dose against a pathogenic challenge, can stabilize and release functional PA. These nanoparticles demonstrated polymer hydrophobicity-dependent preservation of the biological function of PA upon encapsulation, storage (over extended times and elevated temperatures), and release. Specifically, fabrication of amphiphilic polyanhydride nanoparticles composed of 1,6-bis(p-carboxyphenoxy)hexane and 1,8-bis(p-carboxyphenoxy)-3,6- dioxaoctane best preserved PA functionality. These studies demonstrate the versatility and superiority of amphiphilic nanoparticles as vaccine delivery vehicles suitable for long-term storage
Physico-Chemical and Antimicrobial Efficacy of Encapsulated Dhavana Oil: Evaluation of Release and Stability Profile from Base Matrices
Essential oils (EOs) are naturally occurring volatile aromatic compounds extracted from different parts of plants. They are made up of components like terpenes, phenols, etc., and are chemically unstable and susceptible to oxidative deterioration, leading to reduced shelf-life and overall degradation of the product. Encapsulation of EOs in a matrix can prevent degradation of the active ingredient and improve the shelf-life. In this paper, we report encapsulation of Dhavana oil (Artemisia pellen) in a modified starch matrix using a spray-drying technique. Physico-chemical properties of neat and encapsulated Dhavana oil were studied. We selected two powder bases: CaCO3 and TALC and, loaded neat and encapsulated Dhavana oil in it, studied their stability and interaction with the base matrices at 3 °C, 22 °C and 45 °C up to 2 months under closed conditions and one week at 22 °C and 45 °C under open condition. Thermal degradation pattern was studied for neat and encapsulated Dhavana oil and modified starch. Release of primary active component of neat and encapsulated Dhavana oil from the base matrices was evaluated with GCMS. Stability study and release mechanism were elucidated to understand the release pattern in different base powders under similar conditions. Retention of hydroxydhavanone was found to be better in TALC than CaCO3, and therefore, the former can be considered a suitable base matrix for developing a stable powder formulation with an optimum release of the oil. Dhavana oil is known for its anti-microbial activity, and hence, neat and encapsulated Dhavana oil was tested on different bacterial and fungal strains. The encapsulated oil depicted good anti-microbial efficacy against various bacterial and fungal strains, which is a step forward for developing anti-microbial formulations. Thus, the reported work will provide helpful information on cosmetic formulation and, therefore, be useful for perfumery, food, and cosmetic industries
A REVIEW ON - SOLAR CONCENTRATORS, PERFORMANCE OF SOLAR COLLECTORS & ENERGY STORAGE
Parabolic trough concentrators are one type of concentrators which reflects the sunlight on the receiver (Line type) and gives us wet steam for water. It can be tried with any type of fluid. Presently solar collectors are used for residential and commercial use. These solar collectors require high maintenance and high installation cost, solar concentrators help us in these disadvantages. This review paper concentrates on solar concentrators and various fluids that can be used in receiver. It also focuses on surface shape measurement of solar concentrator in solar thermal power application. In order to capture maximum amount of solar energy it is required to orient the concentrator as per the position of the sun i.e. tracking is required .However some of the concentrators do not track and are referred as fixed concentrators. The objective of the project is to track the receiver instead of solar concentrator
Polyanhydride microparticles enhance dendritic cell antigen presentation and activation
The present studies were designed to evaluate the adjuvant activity of polyanhydride microparticles prepared in the absence of additional stabilizers, excipients, or immune modulators. Microparticles composed of varying ratios of either 1,6-bis(p-carboxyphenoxy)hexane (CPH) and sebacic acid (SA) or 1,8-bis(p-carboxyphenoxy)-3,6-dioxaoctane (CPTEG) and CPH were added to in vitro cultures of bone marrow-derived dendritic cells (DCs). Microparticles were efficiently and rapidly phagocytosed by DCs in the absence of opsonization and without centrifugation or agitation. Within 2 h, internalized particles were rapidly localized to an acidic, phagolysosomal compartment. By 48 h, only a minor reduction in microparticle size was observed in the phagolysosomal compartment, indicating minimal particle erosion consistent with being localized within an intracellular microenvironment favoring particle stability. Polyanhydride microparticles increased DC surface expression of MHC II, the co-stimulatory molecules CD86 and CD40, and the C-type lectin CIRE (murine DC-SIGN; CD209). In addition, microparticle stimulation of DCs also enhanced secretion of the cytokines IL-12p40 and IL-6, a phenomenon found to be dependent on polymer chemistry. DCs cultured with polyanhydride microparticles and ovalbumin induced polymer chemistry-dependent antigen-specific proliferation of both CD4+ OT-II and CD8+ OT-I T cells. These data indicate that polyanhydride particles can be tailored to take advantage of the potential plasticity of the immune response, resulting in the ability to induce immune protection against many types of pathogens
A Review on - Solar Concentrators, Performance of Solar Collectors & Energy Storage
Parabolic trough concentrators are one type of concentrators which reflects the sunlight on the receiver (Line type) and gives us wet steam for water. It can be tried with any type of fluid. Presently solar collectors are used for residential and commercial use. These solar collectors require high maintenance and high installation cost, solar concentrators help us in these disadvantages. This review paper concentrates on solar concentrators and various fluids that can be used in receiver. It also focuses on surface shape measurement of solar concentrator in solar thermal power application. In order to capture maximum amount of solar energy it is required to orient the concentrator as per the position of the sun i.e. tracking is required .However some of the concentrators do not track and are referred as fixed concentrators. The objective of the project is to track the receiver instead of solar concentrator
Amphiphilic Polyanhydride Nanoparticles Stabilize <i>Bacillus anthracis</i> Protective Antigen
Advancements toward an improved vaccine against <i>Bacillus
anthracis</i>, the causative agent of anthrax, have focused on
formulations composed of the protective antigen (PA) adsorbed to aluminum
hydroxide. However, due to the labile nature of PA, antigen stability
is a primary concern for vaccine development. Thus, there is a need
for a delivery system capable of preserving the immunogenicity of
PA through all the steps of vaccine fabrication, storage, and administration.
In this work, we demonstrate that biodegradable amphiphilic polyanhydride
nanoparticles, which have previously been shown to provide controlled
antigen delivery, antigen stability, immune modulation, and protection
in a single dose against a pathogenic challenge, can stabilize and
release functional PA. These nanoparticles demonstrated polymer hydrophobicity-dependent
preservation of the biological function of PA upon encapsulation,
storage (over extended times and elevated temperatures), and release.
Specifically, fabrication of amphiphilic polyanhydride nanoparticles
composed of 1,6-bis(<i>p</i>-carboxyphenoxy)hexane and 1,8-bis(<i>p</i>-carboxyphenoxy)-3,6-dioxaoctane best preserved PA functionality.
These studies demonstrate the versatility and superiority of amphiphilic
nanoparticles as vaccine delivery vehicles suitable for long-term
storage