Influence of various lipid core on characteristics of SLNs designed for topical delivery of fluconazole against cutaneous candidiasis.

Dermal delivery of fluconazole (FLZ) is still a major limitation due to problems relating to control drug release and achieving therapeutic efficacy. Recently, solid lipid nanoparticles (SLNs) were explored for their potential of topical delivery, possible skin compartments targeting and controlled release in the skin strata. The retention and accumulation of drug in skin is affected by composition of SLNs. Hence, the aim of this study was to develop FLZ nanoparticles consisted of various lipid cores in order to optimize the drug retention in skin. SLNs were prepared by solvent diffusion method and characterized for various in vitro and in vivo parameters. The results indicate that the SLNs composed of compritol 888 ATO (CA) have highest drug encapsulation efficiency (75.7 ± 4.94%) with lower particle size (178.9 ± 3.8 nm). The in vitro release and skin permeation data suggest that drug release followed sustained fashion over 24 h. The antifungal activity shows that SLNs made up of CA lipid could noticeably improve the dermal localization. In conclusion, CA lipid based SLNs are represents a promising carrier means for the topical treatment of skin fungal infection as an alternative to the systemic delivery of FLZ.

Structuring polymers for delivery of DNA-based therapeutics: updated insights.

Gene therapy offers greater opportunities for treating numerous incurable diseases from genetic disorders, infections, and cancer. However, development of appropriate delivery systems could be one of the most important factors to overcome numerous biological barriers for delivery of various therapeutic molecules. A number of nonviral polymer-mediated vectors have been developed for DNA delivery and offer the potential to surmount the associated problems of their viral counterpart. To address the concerns associated with safety issues, a wide range of polymeric vectors are available and have been utilized successfully to deliver their therapeutics in vivo. Today's research is mainly focused on the various natural or synthetic polymer-based delivery carriers that protect the DNA molecule from degradation, which offer specific targeting to the desired cells after systemic administration, have transfection efficiencies equivalent to virus-mediated gene delivery, and have long-term gene expression through sustained-release mechanisms. This review explores an updated overview of different nonviral polymeric delivery system for delivery of DNA-based therapeutics. These polymeric carriers have been evaluated in vitro and in vivo and are being utilized in various stages of clinical evaluation. Continued research and understanding of the principles of polymer-based gene delivery systems will enable us to develop new and efficient delivery systems for the delivery of DNA-based therapeutics to achieve the goal of efficacious and specific gene therapy for a vast array of clinical disorders as the therapeutic solutions of tomorrow.

Cationic ligand appended nanoconstructs: a prospective strategy for brain targeting.

The objective of present research was to evaluate the potential of engineered solid lipid nanoparticles (SLNs) as vectors to bypass the blood brain barrier. Anti-cancer agent, doxorubicin (DOX) loaded SLNs were prepared and conjugated with cationic bovine serum albumin (CBSA). The formation of CBSA tethered and plain SLNs were characterized by FTIR, NMR, and TEM analyses. Physicochemical parameters such as particle size/polydispersity index and zeta-potential were also determined. Cellular uptake studies on HNGC-1 cell lines depicted almost six times enhanced uptake of ligand conjugated SLNs as compared to plain DOX solution. Furthermore, CBSA conjugated formulation was more cytotoxic as compared to free drug or unconjugated SLNs. Transendothelial studies showed maximum transcytosis ability of CBSA conjugated SLNs across brain capillary endothelial cells. In vivo pharmacokinetic parameters and biodistribution pattern demonstrated efficiency of the system for spatial and temporal delivery of DOX to brain tissues. Lastly, hematological, nephrotoxic as well as hepatotoxic data suggested CBSA conjugated formulations to be less immunogenic compared to plain formulations.

A magnetic Compton scattering study of Ga rich Co-Ni-Ga ferromagnetic shape memory alloys.

The temperature dependent spin momentum densities of Co(1.8)NiGa(1.2) and Co(2)Ni(0.76)Ga(1.24) alloys have been measured using the magnetic Compton scattering technique. The individual contributions of constituents in the formation of the total spin moment are also calculated using Compton line shape analysis. The magnetic Compton data when compared with the magnetization data obtained using a vibrating sample magnetometer show a negligible orbital contribution. The spin moments deduced from the experimental Compton data are compared with the theoretical results obtained from the full potential linearized augmented plane wave method and are found to be in good agreement. The origin of the magnetism in both alloys is also described in terms of the e(g) and t(2g) contributions of Ni and Co.

Viral protein complexed liposomes for intranasal delivery of hepatitis B surface antigen.

The present work investigates prospective of recombinantly expressed influenza surface protein haemagglutinin (HA) complexed liposomes for intranasal delivery of HBsAg. Liposomes encapsulating HBsAg were prepared and complexed with HA. The prepared formulations were extensively characterized for vesicle size, polydispersity index, entrapment efficiency, HA complexation efficiency, in vitro release, etc. Stability of protein molecules was accessed by SDS-PAGE. The antigenicity of protein HBsAg was determined by EIA and the functional stability of HA was evaluated by haemagglutination assay. Subsequently, in vivo study was carried out to study their feasibility as nasal vaccine carriers. A significant and perdurable immune response was obtained following in vivo administration of the developed formulations that was comparable with alum adsorbed HBsAg administered intramuscularly. The HA complexed liposomal formulations elicited sIgA in mucosal secretions and also demonstrated cellular immune response both of which are not induced in the case of alum adsorbed HBsAg vaccine. Further, the HA complexed liposomes produced higher immune response as compared to plain liposomes that might be due to higher uptake of former as evidenced in microscopy study of nasal tissues. The higher cellular response generated by HA complexed liposomes may be possibly due to characteristic pH dependent fusion property of HA protein.

Novel approaches to oral immunization for hepatitis B.

Hepatitis B is a necroinflammatory liver disease manifested with subacute to acute symptoms, liver cirrhosis, and mortality. Parenteral alum-adsorbed hepatitis B surface antigenic (HBsAg) vaccination, although available, poses serious concerns regarding inability to induce both cell-mediated and mucosal immune response. In this context, oral delivery may be a prospective solution to the issues associated with conventional vaccination. However, the strategy is detrimental to the antigenic substances, suffers various physical/chemical barriers, and impedes poor transcytosis via mucosal route. Therefore, surface-engineered novel carrier-based approaches are reportedly promising for effective HBsAg oral vaccine delivery. This review focuses on the efforts for developing oral mucosal vaccine against hepatitis B, with considerable attention on novel drug delivery systems for spatial distribution of antigenic substance to the immune effector cells and organs.

Lectin anchored PLGA nanoparticles for oral mucosal immunization against hepatitis B.

Present study aimed at exploring the potential of α-l-fucose specific, LTA (Lotus tetragonolobus from Winged or Asparagus pea) as a homing device for nanocarriers to target the M cell for elicitation of strong immune response. LTA grafted poly(lactic-co-glycolic acids) (PLGA) nanoparticles encapsulating hepatitis B surface antigen (HBsAg) was developed and characterized for shape, size, polydispersity index, zeta potential, and antigen loading efficiency. The peyer's patch uptake was studied by using confocal laser scanning microscopy technique using dual staining technique. The immune stimulating potential was assessed by measuring anti-HBsAg titer in serum of balb/c mice. Induction of the mucosal immunity was assessed by estimating secretory immunoglobulin A level in the salivary, intestinal, and vaginal secretion and cytokine (interleukin-2 and interferon-γ) levels in the spleen homogenates. Furthermore, IgG1 and IgG2a isotype were determined to confirm the T(H)1/T(H)2 mixed immune response. The LTA anchored PLGA nanoparticles have demonstrated approximately four-fold increase in the degree of interaction with the bovine submaxillary mucin (BSM). The results demonstrated that LTA anchored PLGA nanoparticles elicited strong mucosal and systemic response and hence could be a promising carrier adjuvant for the M cell targeted oral mucosal immunization against Hepatitis B.

Molecular basis of the mucosal immune system: from fundamental concepts to advances in liposome-based vaccines.

The mucosal immune system, the primary portal for entry of most prevalent and devastating pathogens, is guarded by the special lymphoid tissues (mucosally associated lymphoid tissues) for immunity. Mucosal immune infection results in induction of IgA-manifested humoral immunity. Cell-mediated immunity may also be generated, marked by the presence of CD4(+) Th1 and CD8(+) cells. Furthermore, the immunity generated at the mucosal site is transported to the distal mucosal site as well as to systemic tissues. An understanding of the molecular basis of the mucosal immune system provides a unique platform for designing a mucosal vaccine. Coadministration of immunostimulatory molecules further accelerates functioning of the immune system. Mimicking receptor-mediated binding of the pathogen may be achieved by direct conjugation of antigen with an immunostimulatory molecule or encapsulation in a carrier followed by anchoring of a ligand having affinity to the cells of the mucosal immune system. Nanotechnology has played a significant role in mucosal vaccine development and among the available options liposomes are the most promising. Liposomes are phospholipid bilayered vesicles that can encapsulate protein as well as DNA-based vaccines and offer coencapsulation of adjuvant along with the antigen. At the same, time ligand-conjugated liposomes augment interaction of antigen with the cells of the mucosal immune system and thereby serve as suitable candidates for the mucosal delivery of vaccines. This article exhaustively explores strategies involved in the generation of mucosal immunity and also provides an insight to the progress that has been made in the development of liposome-based mucosal vaccine.

Recent advances in mucosal delivery of vaccines: role of mucoadhesive/biodegradable polymeric carriers.

IMPORTANCE OF THE FIELD: The mucosal delivery of vaccines provides the basis for induction of humoral, cellular and mucosal immune responses against infectious diseases. The delivery of antigens to and through mucosal barriers always remains challenging due to adverse physiological conditions (pH and enzymes) and biological barriers created by tight epithelial junctions restricting transportation of macromolecules. Mucoadhesive and biodegradable polymers offer numerous advantages in therapeutic delivery of proteins/antigens particularly through the mucosal route by protecting antigens from degradation, increasing concentration of antigen in the vicinity of mucosal tissue for better absorption, extending their residence time in the body and/or targeting them to sites of antigen uptake. Furthermore, antigen can be delivered more effectively to the antigen presenting cells by anchoring the ligand having affinity on the surface of carrier for the receptors present on the mucosal epithelial cells. AREAS COVERED IN THIS REVIEW: The present review covers various polymeric carriers, which allow the possibility of modification and manipulation of their properties, thereby, enhancing the effectiveness of mucosal vaccines. This article reviews the recent literature and patents in the field of vaccine delivery using mucoadhesive polymeric carriers. WHAT THE READER WILL GAIN: The reader will gain insights into various natural polymers, synthetic polymers and ligand derived polymeric carrier systems studied to enhance mucosal immunization. TAKE HOME MESSAGE: Biodegradable polymeric carriers represent a promising approach for mucosal delivery of vaccine.

Evaluation of mucoadhesive PLGA microparticles for nasal immunization.

In this study, hepatitis B surface antigen (HBsAg) loaded poly(lactic-co-glycolic acid) (PLGA) microparticles were prepared and coated with chitosan and trimethyl chitosan (TMC) to evaluate the effect of coating material for nasal vaccine delivery. The developed formulations were characterized for size, zeta potential, entrapment efficiency, and mucin adsorption ability. Plain PLGA microparticles demonstrated negative zeta potential. However, coated microparticles showed higher positive zeta potential. Results indicated that TMC microparticles demonstrated substantially higher mucin adsorption when compared to chitosan-coated microparticles and plain PLGA microparticles. The coated and uncoated microparticles showed deposition in nasal-associated lymphoid tissue under fluorescence microscopy. The coated and uncoated microparticles were then administered intranasally to mice. Immune-adjuvant effect was determined on the basis of specific antibody titer observed in serum and secretions using enzyme-linked immunosorbent assay. It was observed that coated particles showed a markedly increased anti-HBsAg titer as compared to plain PLGA microparticles, but the results were more pronounced with the TMC-coated PLGA microparticles.

Targeted nucleic acid delivery to mitochondria.

Mitochondrial genetics has become an emerging area of research in the field of modern therapeutics. Mitochondrial genome is the source of 13 polypeptides which are components of subunits of complexes of electron transport chain and are used in the generation of ATP by oxidative phosphorylation. Any mutation and/or defects in these mitochondrial genes may cause diseases ranging from neurodegenerative diseases, diabetes mellitus to cancer. In an ideal condition mtDNA should be mutation free. There are various mechanisms for the repair of diseased cell or mitochondrial DNA. Nowadays, nucleic acid based therapeutics has become of interest and represent a new area of research. However, problem consistently encountered is safe and effective delivery of DNA to the mitochondria for therapeutic benefits. There are numerous barriers which are to be surpassed for successful delivery of nucleic acid to the cell interior and ultimately to the mitochondria. For efficient and effective DNA delivery to the mitochondrial matrix, a suitable carrier system is required to be designed and developed. In the present review we have discussed briefly about mitochondrial DNA and related diseases, various barriers encountered in the delivery of DNA, internalization processes, delivery strategies and methods for targeted delivery of DNA to the mitochondria.

Development and characterization of novel carrier gel core liposomes based transmission blocking malaria vaccine.

The aim of present work was to investigate the potential utility of novel carrier gel core liposomes for intramuscular delivery of transmission blocking malaria antigen Pfs25 and to evaluate the effect of co-administration of vaccine adjuvant CpGODN on immune enhancement of recombinant protein antigen Pfs25. In the present work we have prepared gel core liposomes containing core of biocompatible polymer poly acrylic acid in phospholipid bilayer by reverse phase evaporation method and characterized for various in vitro parameters. In process stability of the encapsulated antigen was evaluated by SDS-PAGE followed by western blotting. The immune stimulating ability was studied by measuring anti-Pfs25 antibody titer in serum of Balb/c mice following intramuscular administration of various formulations. A Significant and perdurable immune responses was obtained after intramuscular administration of gel core liposomes encapsulated Pfs25 as compared to Pfs25 loaded conventional liposomes. Moreover co-administration of CpGODN in liposomes (conventional and gel core) was found to further increase the immunogenicity of vaccine. The result indicates high potential of gel core liposomes for their use as a carrier adjuvant for intramuscular delivery of recombinant antigen Pfs25 based transmission blocking malaria vaccine.

Development of self-assembled nanoceramic carrier construct(s) for vaccine delivery.

Hydroxyapatite (HA) has been extensively investigated as scaffolds for tissue engineering, as drug delivery agents, as non-viral gene carriers, as prosthetic coatings, and composites. Recent studies in our laboratory demonstrated the immunoadjuvant properties of HA when administered with malarial merozoite surface protein-1(19) (MSP-1(19)). HA nanoceramic carrier was prepared by co-precipitation method that comprises of sintering and spray-drying technique. Prepared systems were characterized for crystallinity, size, shape, and antigen loading efficiency. Small size and large surface area of prepared HA demonstrated good adsorption efficiency of immunogens. Prepared nanoceramic formulations also showed slower in vitro antigen release and slower biodegrability behavior, which may lead to a prolonged exposure to antigen-presenting cells and lymphocytes. Furthermore, addition of mannose in nanoceramic formulation may additionally lead to increased stability and immunological reactions. Immunization with MSP-1(19) in nanoceramic-based adjuvant systems induced a vigorous immunoglobulin G (IgG) response, with higher IgG2a than IgG1 titers. In addition considerable amount of IFN-g and IL-2 was observed in spleen cells of mice immunized with nanoceramic-based vaccines. On the contrary, mice immunized with MSP-1(19) alone or with alum did not exhibit a significant cytotoxic response. The antibody responses to vaccine co-administered with HA was a mixed Th1/Th2 compared to the Th2-biased response obtained with alum. The prepared HA nanoparticles exhibit physicochemical properties that appear promising to make them a suitable immunoadjuvant to be used as antigen carriers for immunopotentiation.

Gel core liposomes: an advanced carrier for improved vaccine delivery.

Many sub-unit vaccines are successful in preventing the occurrence of disease, but their use is largely restrained due to low immunogenicity. Novel carrier-based vaccine could serve as a vaccine adjuvant to overcome low immunogenicity of sub-unit vaccines. The use of liposomes as a delivery system for antigen is well recognized but they are unstable and release of antigen from them cannot be controlled over a prolonged period of time. To overcome the limitation of liposomes, this study has developed gel core liposomes in which a core of polymer was incorporated inside the liposomal vesicles, which serve the function of skeleton and provide mechanical strength to vesicles. In the present investigation BSA-loaded gel core liposomes were prepared by reverse phase evaporation method and characterized for vesicles size, shape, entrapment efficiency, in vitro release and stability studies. The in vivo studies to evaluate antigen presenting potential of the gel-core liposomes was performed in Balb/c mice by measuring the immune response elicited by intramuscular administration of BSA-loaded gel core liposomes and compared with intramuscularly administered BSA-loaded conventional liposomes, alum adsorbed BSA and plain antigen. Results indicate that intramuscular immunization with gel core liposomes induces efficient systemic antibody responses against BSA as compared to other formulations. The gel core liposomal formulation provides good entrapment efficiency, enhanced in vitro stability, prolonged antigen release and effective immunoadjuvant property, justifying its potential for improved vaccine delivery.

Aquasomes--a nanoparticulate approach for the delivery of antigen.

The development of compound that enhances immune responses to recombinant or synthetic epitopes is of considerable importance in vaccine research. Of the many different types of immunopotentiating compounds that have been researched, aquasomes are of considerable promise, because of their potency and adjuvanticity. Aquasomes were prepared by self-assembling of hydroxyapatite by co-precipitation method and thereafter preliminary coated with polyhydroxyl oligomers (cellobiose and trehalose) and subsequently adsorbed with bovine serum albumin (BSA) as a model antigen. The prepared systems were characterized for size, shape, antigen-loading efficiency, in vitro antigen stability, and in vivo performance. BSA-immobilized aquasomes were around 200 nm in diameter and spherical in shape and had approximately 20-30% BSA-loading efficiency. The immunological activity of the formulated aquasomes was compared with plain BSA and better results were observed. Studies also indicated that aquasome formulations could elicit combined T-helper 1 (Th1) and Th2 immune response.

Growth and properties of pulsed laser deposited thin films of Fe(3)O(4) on Si substrates of different orientation.

Fe(3)O(4) thin films were prepared by pulsed laser deposition on Si substrates of different orientations: (111), (100) and (110). X-ray diffraction studies revealed the spinel cubic structure of the films with preferential (111) orientation independent of the substrate orientation. Raman spectroscopy suggests the single-phase growth of Fe(3)O(4) films on these substrates, with minimum full width at half maxima being observed for the film grown on Si(111) substrate. These samples exhibit room-temperature ferromagnetism, as observed by magnetization hysteresis. The magnetization in these films saturates at a magnetic field value of approximately 0.2 T.