PULMONARY DELIVERY OF PNEUMOCCOCAL VACCINE USING NANOCOMPOSITE MICROPARTICLE CARRIERS VIA DRY POWDER INHALATION

S. pneumoniae is one of the most significant human pathogens, causing high morbidity and mortality rates globally. Although there are vaccine available such as PPV 23, PCV7, PCV10, and PCV13, they are ineffective in some situations due to the differing epidemiology of various serotypes depending on the site of infection and the geographical location. Furthermore, they are expensive to produce and distribute. Universal research is presently concentrated on establishing other pneumococcalvaccine approaches such as using pneumococcal surface protein A (PspA) which relate to pathogenesis and are common to all serotypes. In this study polymeric nanoparticles (NPs) encapsulating PspA4Pro were incorporated into microcarriers using L-leucine and spray dried to produce nanocomposite micro#particles (NCMPs) dry powder for inhalation. Parameters for the preparation of protein-loaded polyester poly (Glycerol Adipate-co-ω-Pentadecalactone), (PGA-co-PDL) NCMPs were optimised using Taguchi design and BSA as a model protein, by the double emulsion solvent evaporation method followed by spray drying. Particle size was mainly affected by the polymer mass and small particle size ≤ 500nm was achieved. The most important factor for obtaining a high BSA loading was BSA concentration. The spray drying process was optimised to produce NCMPs with a porous corrugated surface, 50% yield, MMAD of 1.71±0.10 μm and FPF% of 78.57±0.1%. Adsorption of chitosan hydrochloride (CHL) onto PGA-co-PDL NPs can be used assuccessful strategies to produce cationic NPs. Cationic NPs were prepared with similarparticle size to anionic NPs ≤ 500nm. The In vitro aerosolisation performance ofcationic NPs/NCMPs showed FPF% of 46.79±11.21% and MMAD of 1.49±0.29 μm. Further cell viability studies on A549 cell line showed a good profile with a cell viability of 79±4.7% for anionic NPs/NCMPs and 78.85±9.96% for cationic xviii NPs/NCMPs at 2.5 mg/ml concentration after 24 h exposure. The previous results introduced a successful method for preparing anionic and cationic NPs/NCMPs for delivering PspA4Pro as dry powder via inhalation. The particle size of PspAPro4 loaded anionic NPs and cationic NPs were 310±25.3 nm and 409.7±49.5 nm, respectively, to be effectively taken up by dendritic cells (DCs). The PspA4Pro loading in anionic NPs was 65.73±5.6 μg/mg and in cationic NPs was 9.84±1.4 μg/mg. The PspA4Pro released from anionic and cationic NPs/NCMPs preserved its primary and secondary structure as evaluated by SDS-PAGE and circular dichroism. In vitro release studies showed that the anionic NPs/NCMPs formulations achieved a cumulative release of 21.01±1.5% while the cationic NPs/NCMPs formulation released 83.13 ±0.84% after 48 h. DCs uptake studies provide evidence of particles uptake by DCs upon incubation for 1 h as visualized by confocal microscopy. These results indicate the use of optimised methods for developing polymeric based NCMPs for vaccine delivery via inhalation against pneumococcal diseases

Recent Advances Using Supercritical Fluid Techniques for Pulmonary Administration of Macromolecules via Dry Powder Formulations

Growing demands on a suitable formulation method that ensures the stability of the active compound coupled with the limitations of current methods (milling, lyophilization, spray drying, and freeze spray drying) has brought wide attention to supercritical fluid (SCF) technology. Advantages of using the SCF technology comprise its high abilities, adaptability in providing alternative processing methods, high compressibility and diffusivity of the supercritical fluid, capability as an alternative for conventional organic solvents, and the option to attain different processing parameters which would be otherwise difficult to conduct with traditional methods. This review proposes to present an up-to-date outlook on dry powder pulmonary formulations of macromolecules using SCF technology

Bovine serum albumin adsorbed PGA-CO-PDL nanocarriers for vaccine delivery via dry powder inhalation

Purpose: Dry powder vaccine delivery via the pulmonary route has gained significant attention as an alternate route to parenteral delivery. In this study, we investigated bovine serum albumin (BSA) adsorbed poly(glycerol adipate-co-ω-pentadecalactone), PGA-co-PDL polymeric nanoparticles (NPs) within L-leucine (L-leu) microcarriers for dry powder inhalation. Methods: NPs were prepared by oil-in-water single emulsion-solvent evaporation and particle size optimised using Taguchi's design of experiment. BSA was adsorbed onto NPs at different ratios at room temperature. The NPs were spray-dried in aqueous suspension of L-leu (1:1.5) using a Büchi-290 mini-spray dryer. The resultant nanocomposite microparticles (NCMPs) were characterised for toxicity (MTT assay), aerosolization (Next Generation Impactor), in vitro release study and BSA was characterized using SDS-PAGE and CD respectively. Results: NPs of size 128.50∈±∈6.57 nm, PDI 0.07∈±∈0.03 suitable for targeting lung dendritic cells were produced. BSA adsorption for 1 h resulted in 10.23∈±∈1.87 μg of protein per mg of NPs. Spray-drying with L-leu resulted in NCMPs with 42.35∈±∈3.17% yield. In vitro release study at 37°C showed an initial burst release of 30.15∈±∈2.33% with 95.15∈±∈1.08% over 48 h. Aerosolization studies indicated fine particle fraction (FPF%) dae∈<∈4.46 μm as 76.95∈±∈5.61% and mass median aerodynamic diameter (MMAD) of 1.21∈±∈0.67 μm. The cell viability was 87.01∈±∈14.11% (A549 cell line) and 106.04∈±∈21.14% (16HBE14o- cell line) with L-leu based NCMPs at 1.25 mg/ml concentration after 24 h treatment. The SDS-PAGE and CD confirmed the primary and secondary structure of the released BSA. Conclusions: The results suggest that PGA-co-PDL/L-leu NCMPs may be a promising carrier for pulmonary vaccine delivery due to excellent BSA adsorption and aerosolization behaviour

Bovine Serum Albumin Adsorbed PGA-co-PDL Nanocarriers for Vaccine Delivery via Dry Powder Inhalation

PURPOSE: Dry powder vaccine delivery via the pulmonary route has gained significant attention as an alternate route to parenteral delivery. In this study, we investigated bovine serum albumin (BSA) adsorbed poly(glycerol adipate-co-ω-pentadecalactone), PGA-co-PDL polymeric nanoparticles (NPs) within L-leucine (L-leu) microcarriers for dry powder inhalation. METHODS: NPs were prepared by oil-in-water single emulsion-solvent evaporation and particle size optimised using Taguchi’s design of experiment. BSA was adsorbed onto NPs at different ratios at room temperature. The NPs were spray-dried in aqueous suspension of L-leu (1:1.5) using a Büchi-290 mini-spray dryer. The resultant nanocomposite microparticles (NCMPs) were characterised for toxicity (MTT assay), aerosolization (Next Generation Impactor), in vitro release study and BSA was characterized using SDS-PAGE and CD respectively. RESULTSL NPs of size 128.50 ± 6.57 nm, PDI 0.07 ± 0.03 suitable for targeting lung dendritic cells were produced. BSA adsorption for 1 h resulted in 10.23 ± 1.87 μg of protein per mg of NPs. Spray-drying with L-leu resulted in NCMPs with 42.35 ± 3.17% yield. In vitro release study at 37°C showed an initial burst release of 30.15 ± 2.33% with 95.15 ± 1.08% over 48 h. Aerosolization studies indicated fine particle fraction (FPF%) dae < 4.46 μm as 76.95 ± 5.61% and mass median aerodynamic diameter (MMAD) of 1.21 ± 0.67 μm. The cell viability was 87.01 ± 14.11% (A549 cell line) and 106.04 ± 21.14% (16HBE14o- cell line) with L-leu based NCMPs at 1.25 mg/ml concentration after 24 h treatment. The SDS-PAGE and CD confirmed the primary and secondary structure of the released BSA. CONCLUSIONS: The results suggest that PGA-co-PDL/L-leu NCMPs may be a promising carrier for pulmonary vaccine delivery due to excellent BSA adsorption and aerosolization behaviour

Dry powder pulmonary delivery of cationic PGA-co-PDL nanoparticles with surface adsorbed model protein.

Pulmonary delivery of macromolecules has been the focus of attention as an alternate route of delivery with benefits such as; large surface area, thin alveolar epithelium, rapid absorption and extensive vasculature. In this study, a model protein, bovine serum albumin (BSA) was adsorbed onto cationic PGA-co-PDL polymeric nanoparticles (NPs) prepared by a single emulsion solvent evaporation method using a cationic surfactant didodecyldimethylammonium bromide (DMAB) at 2% w/w (particle size: 128.64±06.01nm and zeta-potential: +42.32±02.70mV). The optimum cationic NPs were then surface adsorbed with BSA, NP:BSA (100:4) ratio yielded 10.01±1.19μg of BSA per mg of NPs. The BSA adsorbed NPs (5mg/ml) were then spray-dried in an aqueous suspension of L-leucine (7.5mg/ml, corresponding to a ratio of 1:1.5/NP:l-leu) using a Büchi-290 mini-spray dryer to produce nanocomposite microparticles (NCMPs) containing cationic NPs. The aerosol properties showed a fine particle fraction (FPF, dae<4.46μm) of 70.67±4.07% and mass median aerodynamic diameter (MMAD) of 2.80±0.21μm suggesting a deposition in the respiratory bronchiolar region of the lungs.The cell viability was 75.76±03.55% (A549 cell line) at 156.25μg/ml concentration after 24h exposure. SDS-PAGE and circular dichroism (CD) confirmed that the primary and secondary structure of the released BSA was maintained. Moreover, the released BSA showed 78.76±1.54% relative esterolytic activity compared to standard BSA