Layer-by-layer-coated lyotropic liquid crystalline nanoparticles for active tumor targeting of rapamycin

Laminated chitosan-based composite sponges for transmucosal delivery of novel protamine-decorated tripterine phytosomes: Ex-vivo mucopenetration and in-vivo pharmacokinetic assessments

In the current study, laminated chitosan (CS):hydroxypropyl methylcellulose (HPMC) composite sponges were exploited as solid matrices for buccal delivery of tripterine phytosomes functionalized with novel mucopenetrating protamine layer (PRT-TRI-PHY). Tripterine (TRI) is a herbal drug widely investigated as a potential anticancer candidate against various types of cancers. However, clinical use of TRI is handicapped by its low oral bioavailability. To surmount TRI pharmaceutical obstacles, TRI phytosomes (TRI-PHY) were prepared using solvent evaporation technique then coated with a protamine layer via electrostatic assembly process. The developed PRT-TRI-PHY showed a nano-metric size of 250 nm and positive zeta potential (+21.6 mV). Sponges loaded with PRT-TRI-PHY demonstrated a sustained release profile with superior mucoadhesion characteristics compared with the counterparts loaded with uncoated TRI-PHY. The ex-vivo permeation study via chicken pouch mucosa revealed that sponges loaded with PRT-TRI-PHY demonstrated 2.3-folds higher flux value compared with sponges loaded with uncoated TRI-PHY. Additionally, in-vivo pharmacokinetic study in healthy rabbits revealed the significantly higher bioavailability of PRT-TRI-PHY compared with TRI-PHY with relative bioavailability of 244%. Conclusively, mucoadhesive CS-HPMC sponges loaded with a novel mucopenetrating nanocarrier, PRT-TRI-PHY, could significantly improve the absorption of tripterine via buccal mucosa which would be of prime importance for its clinical utility.

Self-assembled phospholipid-based phytosomal nanocarriers as promising platforms for improving oral bioavailability of the anticancer celastrol

Celastrol (CST) is a promising natural drug of herbal origin that gained a great interest in the recent years by virtue of its wide variety of pharmacological actions. Nowadays, CST is extensively studied as a natural anticancer surrogate with a potential activity against various types of cancers. However, CST suffers from many limitations that handicapped its clinical utility such as limited aqueous solubility and poor gastrointestinal absorption which resulted into its low oral bioavailability. This work spotlights, for the first time, development of self-assembled phytosomal nanocarriers (CST-PHY) for improving CST solubility and oral bioavailability. First CST-phospholipid complex was prepared by a simple solvent evaporation technique. Formation of CST-phospholipid complex was confirmed by differential scanning calorimetry (DSC), infrared spectroscopy (IR), powder X-ray diffraction (XRD) and partition coefficient determination. After dispersion into deionized water, CST-phospholipid complex was self-assembled to form CST-PHY. The optimized CST-PHY demonstrated a nanometric particle size of 178.4±7.07nm and a negative zeta potential of -38.7±3.61mV. Comparative in-vitro release study showed the ability of phytosomes to significantly enhance CST release compared with crude drug and physical mixture. Pharmacokinetic studies in rabbits revealed significant improvement in CST-PHY oral bioavailability compared with crude CST evidenced by 4-fold increase in AUC_0-8 and 5-fold increase in C_max of CST-PHY compared with crude CST. Conclusively, the results confirmed the potential of phytosomal nanocarriers to improve CST oral delivery paving the way for its use for oral cancer therapy.

Protein-lipid nanohybrids as emerging platforms for drug and gene delivery: Challenges and outcomes

Nanoparticulate drug delivery systems have been long used to deliver a vast range of drugs and bioactives owing to their ability to demonstrate novel physical, chemical, and/or biological properties. An exponential growth has spurred in research and development of these nanocarriers which led to the evolution of a great number of diverse nanosystems including liposomes, nanoemulsions, solid lipid nanoparticles (SLNs), micelles, dendrimers, polymeric nanoparticles (NPs), metallic NPs, and carbon nanotubes. Among them, lipid-based nanocarriers have made the largest progress whether commercially or under development. Despite this progress, these lipid-based nanocarriers suffer from several limitations that led to the development of many protein-coated lipid nanocarriers. To less extent, protein-based nanocarriers suffer from limitations that led to the fabrication of some lipid bilayer enveloping protein nanocarriers. This review discusses in-depth some limitations associated with the lipid-based or protein-based nanocarriers and the fruitful outcomes brought by protein-lipid hybridization. Also discussed are the various hybridization techniques utilized to formulate these protein-lipid nanohybrids and the mechanisms involved in the drug loading process.