Covering Aluminum Oxide Nanoparticles with Biocompatible Materials to Efficiently Deliver Subunit Vaccines.

Subunit vaccines have advantages of good safety, minimal reactogenicity, and high specificity. However, subunit vaccines also show a crucial disadvantage of poor immunogenicity and, therefore, are often formulated with an adjuvant carrier to form a vaccine adjuvant-delivery system (VADS) to enhance their efficacies. Alums, the coarse aggregates of the insoluble aluminum salts, are the conventional adjuvants and have been widely used in clinical vaccines for a long time. Unfortunately, alums also show two main drawbacks of low potency in eliciting cellular immunity, and high reactogenicity to cause unwanted inflammations. Therefore, herein the phospholipid bilayer-coated aluminum oxide nanoparticles (PLANs) and the PEGylated PLANs (PEG-PLANs) were engineered as a VADS to overcome the drawbacks of both subunit vaccines and coarse alums, while synergizing their functions. In vitro experiments demonstrated that, unlike the micron-sized alums, the nanosized PLANs and PEG-PLANs loaded with model antigen of ovalbumin (OVA) showed a high safety profile and were able to promote APC (antigen-presenting cell) uptake and engender lysosome escape for enhancing the MHC (major histocompatibility complex)-I-antigen display. Subcutaneously administered to mice, PLANs and, especially, PEG-PLANs smoothly trafficked into the draining lymph nodes, wherein the densely clustered immune cells were activated in substantial numbers, leading to robust immunoresponses and efficient production of the anti-antigen antibodies and CD8+ T cells. Thus, the aluminum-based nanocarriers, especially the PEG-PLANs, are a promising VADS possessing the potential of eliciting strong and comprehensive immunity against pathogens.

Preparation of curcumin-hydroxypropyl-ß-cyclodextrin inclusion complex by cosolvency-lyophilization procedure to enhance oral bioavailability of the drug.

The curcumin (CUR)-hydroxypropyl-ß-cyclodextrin (HP-ß-CD) inclusion complex (CUR-HP-ß-CD) was prepared to erase its therapeutic restrictions of poor aqueous solubility and low oral bioavailability. CUR-HP-ß-CD was prepared by a simple procedure of water-ethanol cosolvent incubation-lyophilization which may be suitable for scale up production, and characterized by Fourier transform-infrared spectroscopy (FT-IR), powder X-ray diffractometry (PXRD), differential scanning calorimetry (DSC), phase solubility method and dissolution study; the in vitro cytotoxicity was assayed by MTT, whereas the in vivo pharmacokinetics was tested by HPLC in rats receiving formulations via intravenous and oral administration, respectively. CUR was successfully encapsulated in HP-ß-CD with a loading capacity of about 1:7 of CUR to HP-ß-CD mole ratio, which remarkably enhanced drug water solubility and maintained well the antitumour activity of CUR. The CUR-HP-ß-CD and free CUR have a similar pharmacokinetic behaviour in rats after intravenous administration; however, the oral bioavailability of CUR was enhanced to 2.77-fold by the HP-ß-CD. The CUR-HP-ß-CD can be successfully prepared by a simple method, which may be feasible for industrial scaling up, to remarkably increase drug water solubility and oral bioavailability while maintaining its bioactivity and may be a promising therapeutic preparation.