In this study, the CaP/pDNA nanoparticles were prepared using Triton X-100/Butanol/Cyclohexane/Water reverse microemulsion system. Optimization of preparation conditions was based on evaluation of particle size by Box-Behnken design method. The particle sizes of the optimized CaP/pDNA nanoparticles were found to be 60.23 ± 4.72 nm, polydispersity index was 0.252 and pDNA encapsulate efficiency was more than 90%. The optimized CaP/pDNA nanoparticles have pH sensitivity and biocompatibility. Further, optimized CaP/pDNA nanoparticles showed higher transfection efficiency.

The highly pathogenic avian influenza H5N1 virus continues to spread globally in domestic poultry with sporadic transmission to humans. The possibility for its rapid transmission to humans raised global fears for the virus to gain capacity for human-to-human transmission to start a future pandemic. Through direct contact with infected poultry, it caused the largest number of reported cases of severe disease and death in humans of any avian influenza strains. For pandemic preparedness, use of safe and effective vaccine adjuvants and delivery systems to improve vaccine efficacy are considered imperative. We previously demonstrated CaPtivate\'s proprietary CaP nanoparticles (CaPNP) as a potent vaccine adjuvant/delivery system with ability to induce both humoral and cell-mediated immune responses against many viral or bacterial infections. In this study, we investigated the delivery of insect cell culture-derived recombinant hemagglutinin protein (HA) of A/H5N1/Vietnam/1203/2004 virus using CaPNP. We evaluated the vaccine immunogenicity in mice following two intramuscular doses of 3 μg antigen combined with escalating doses of CaPNP. Our data showed CaPNP-adjuvanted HA(H5N1) vaccines eliciting significantly higher IgG, hemagglutination inhibition, and virus neutralization titers compared to non-adjuvanted vaccine. Among the four adjuvant doses that were tested, CaPNP at 0.24% final concentration elicited the highest IgG and neutralizing antibody titers. We also evaluated the inflammatory response to CaPNP following a single intramuscular injection in guinea pigs and showed that CaPNP does not induce any systemic reaction or adverse effects. Current data further support our earlier studies demonstrating CaPNP as a safe and an effective adjuvant for influenza vaccines.

Calcium phosphate (CaP) nanoparticles, as a promising vehicle for gene delivery, have been widely used owing to their biocompatibility, biodegradability and adsorptive capacity for nucleic acids. Unfortunately, their utility in vivo has been profoundly restricted due to numerous technical barriers such as the lack of tissue specificity and limited transfection efficiency, as well as uncontrollable aggregation over time. To address these issues, an effective conjugate folate-polyethylene glycol-pamidronate (shortened as FA-PEG-Pam) was designed and coated on the surface of CaP/NLS/pDNA (CaP/NDs), forming a versatile gene carrier FA-PEG-Pam/CaP/NDs. Inclusion of FA-PEG-Pam significantly reduced the size of CaP nanoparticles, thus inhibiting the aggregation of CaP nanoparticles. FA-PEG-Pam/CaP/NDs showed better cellular uptake than mPEG-Pam/CaP/NDs, which could be attributed to the high-affinity interactions between FA and highly expressed FR. Meanwhile, FA-PEG-Pam/CaP/NDs had low cytotoxicity and desired effect on inducing apoptosis (71.1%). Furthermore, FA-PEG-Pam/CaP/NDs showed admirable transfection efficiency (63.5%) due to the presence of NLS peptides. What\'s more, in vivo studies revealed that the hybrid nanoparticles had supreme antitumor activity (IR% = 58.7%) among the whole preparations. Altogether, FA-PEG-Pam/CaP/NDs was expected to be a hopeful strategy for gene delivery.

Herpes simplex viruses 1 and 2 are among the most ubiquitous human infections and persist lifelong in their host. Upon primary infection or reactivation from ganglia, the viruses spread by direct cell-cell contacts (cell-to-cell spread) and thus escape from the host immune response. We have developed a monoclonal antibody (mAb 2c), which inhibits the HSV cell-to-cell spread, thereby protecting from lethal genital infection and blindness in animal models. In the present study we have designed a nanoparticle-based vaccine to induce protective antibody responses exceeding the cell-to-cell spread inhibiting properties of mAb 2c. We used biodegradable calcium phosphate (CaP) nanoparticles coated with a synthetic peptide that represents the conformational epitope on HSV-1 gB recognized by mAb 2c. The CaP nanoparticles additionally contained a TLR-ligand CpGm and were formulated with adjuvants to facilitate the humoral immune response. This vaccine effectively protected mice from lethal HSV-1 infection by inducing cell-to-cell spread inhibiting antibodies.

This research focused on optimizing the preparations of pDNA-loaded calcium phosphate (CaP) nanoparticles by employing a 3-factor, 3-level Box-Behnken design. Results indicated that a Ca/P ratio of 189.56, pH of 7.82, and a stirring speed of 528.83 rpm were the optimum conditions for preparation of the nanoparticles. The size of the optimized CaP/pDNA nanoparticles was 61.3 ± 3.64 nm, with a polydispersity index of 0.341 and an encapsulation efficiency of up to 92.11%. The optimized CaP/pDNA nanoparticles had high transfection efficiency and demonstrated good biocompatibility in vitro. Therefore, the Box-Behnken design method was successful in providing desirable CaP nanoparticle pDNA delivery systems by optimizing the experimental factors.

The aim of this research was transdermal delivery of 5-fluorouracil (5-FU) using dextran-coated cellulose acetate phthalate (CAP) nanoparticulate formulation. CAP nanoparticles were prepared using drug-polymer ratio (1:1 to 1:3) and surfactant ratio (2.5, 5 and 10%). Dextran coating was made using aminodextran. The results showed that the optimized CAP nanoparticles (CNs) and dextran-coated CAP nanoparticles represented core-corona nanoparticles with the mean diameter of 75 ± 3 and 79 ± 2 nm, respectively, and entrapment efficiency was 82.5 ± 0.06 and 78.2 ± 0.12, respectively. Dextran-coated nanoparticles (FDCNs) and CAP nanoparticles (FCNs) showed in vitro 5-FU release upto 31 h and 8 h, respectively. Moreover, the cumulative amount of 5-FU penetrated through excised skin from FDCNs was 2.94 folds than that of the FU cream. Concentration of 5-FU in epidermis and dermis were also studied. In dermis, concentration of 5-FU was found higher in case of FDCN formulation than plain FU cream. FDCNs were found more hemocompatible in comparison to FCNs. The hematological data recommended that FDCNs formulation was less immunogenic compared to FU creams formulation. In blood level study, FDCNs exhibited 153, 12, 16.66 and 16.24-fold higher values for area under the curve, Tmax, Cmax and mean residence time (MRT) compared with those of FU cream, respectively. The in-vitro cytotoxicity was assessed using the MCF-7 by the MTT test and was compared to the plain 5-FU solution. All the detailed evidence showed that FDCNs could provide a promising tuning as a transdermal delivery system of 5-FU.