Jun Shao

Self-nanoemulsifying drug delivery systems (SNEDDS) for oral delivery of protein drugs: I. Formulation development.

The global aim of this research project was to develop a self-nanoemulsifying drug delivery system (SNEDDS) for non-invasive delivery of protein drugs. The specific aim of this study was to develop SNEDDS formulations. An experimental design was adopted to develop SNEDDS. Fluorescent labeled beta-lactamase (FITC-BLM), a model protein, was loaded into SNEDDS through solid dispersion technique. The experimental design provided 720 compositions of different oil, surfactant, and co-surfactant at various ratios, of which 33 SNEDDS prototypes were obtained. Solid dispersion of FITC-BLM in SoyPC prepared was able to dissolve in 16 SNEDDS prototypes (approximately 2200 mU BLM in 1g SNEDDS). SNEDDS NE-12-7 (composition: Lauroglycol FCC, Cremophor EL and Transcutol; ratio: 5:4:3) formed O/W nanoemulsion with mean droplet size in the range of 22-50 nm when diluted with various pH media and different dilution factor with PBS (pH 7.4). The phase diagram of NE-12-7 indicated a broad region of nanoemulsion. BLM-loaded SNEDDS (NE-12-7) stored at 4 degrees C for 12 weeks indicated 10% loss of BLM activity. A SNEDDS was developed to load FITC-BLM into the oil phase which can spontaneously form O/W nanoemulsion upon the addition of water.

Self-nanoemulsifying drug delivery system (SNEDDS) for oral delivery of protein drugs: III. In vivo oral absorption study.

To use self-nanoemulsifying drug delivery system (SNEDDS) to deliver hydrophilic proteins orally. beta-Lactamase (BLM), a 29 kDa protein was used as a model protein, and formulated into the oil phase of a SNEDDS through solid dispersion technique. The oral absorption of BLM in rats when delivered by such a SNEDDS was investigated. Oral delivery of 4500 mU/kg of BLM in SNEDDS nanoemulsion resulted in the relative bioavailability of 6.34%, C(max) of 1.9 mU/ml and mean residence time of 12.12h which was 1.5-, 2.7- and 1.3-fold higher than that by free solution, respectively. Delivery of BLM in the aqueous phase of the nanoemulsion resulted in a PK profile similar to that by the free solution. BLM when loaded in oil phase of SNEDDS, can significantly enhance the oral bioavailability of BLM. SNEDDS has a great potential for oral protein delivery.

Self-nanoemulsifying drug delivery systems (SNEDDS) for oral delivery of protein drugs: II. In vitro transport study

To develop a self-nanoemulsifying drug delivery system (SNEDDS) for protein drugs, and particularly, to test the in vitro transport of beta-lactamase (BLM) by SNEDDS across the cell monolayer. Fluorescently labeled BLM (FITC-BLM), a model protein, formulated into 16 SNEDDS preparations through a solid dispersion technique were studied for transport across MDCK monolayer. All the SNEDDS nanoemulsions resulted in higher transport rate than the free solution. The transport rate by SNEDDS depends on the SNEDDS composition. SNEDDS NE-12-7 (oil: Lauroglycol FCC, surfactant: Cremophor EL and a cosurfactant: Transcutol HP) at the ratio of 5:4:3, rendered the highest transportation rate, 33% as compared to negligible transport by the free solution. FITC-BLM solution mixed with the surfactant and the cosurfactant of SNEDDS NE-12-7 or with blank SNEDDS NE-12-7 increased the transport only by 3.3 and 1.5 folds, respectively, compared to free solution alone. It was found that the monolayer integrity was not compromised in the presence of SNEDDS NE-12-7 or its surfactant/cosurfactant. The SNEDDS significantly increased the transport of FITC-BLM across MDCK monolayer in vitro. SNEDDS may be a potential effective delivery system for non-invasive protein drug delivery.

Biodistribution of indocyanine green-loaded nanoparticles with surface modifications of PEG and folic acid

PURPOSE To establish the biodistribution profile of the PLGA nanoparticles with dual surface modifications of PEG and folic acid (FA) in mice xenografted with MDA-MB-231 human breast cancer cells with high expression of folate receptor (FR); and to illustrate that the modified nanoparticles can target the loaded indocyanine green (ICG) to the tumor with high FR expression. METHODS ICG-loaded nanoparticles were prepared with PLGA (non-modified nanoparticles, NM-NP) or mPEG-PLGA and FA-PLGA (dual modified nanoparticles, DM-NP). Biodistribution of the ICG-loaded nanoparticles (1.25 mg/kg) after i.v. injection was investigated on athymic mice transplanted with MDA-MB-231 tumor. RESULTS ICG concentration in plasma from the DM-NP group was significantly (p<0.05) higher than the NM-NP group from 90 min to the end of the study (12 h). After 4 h, the drug concentration in the tumor tissue from the DM-NP started to be significantly (p<0.05) higher than the NM-NP until 12 h. Compared to the NM-NP, the DM-NP increased the AUC(0-12 h) in plasma by 245% and the AUC(0-12 h) in tumor by 194%, while decreased the AUC(0-12 h) in liver by 13%. CONCLUSION The accumulation of DM-NP into the tumor was significantly higher than NM-NP due to the long circulation and FR-mediated uptake.

An Evidence-based Perspective of Hedyotis Diffusa or Oldenlandia Diffusa (Spreading Hedyotis) for Cancer Patients

Hedyotis diffusa or Oldenlandia diffusa (spreading hedyotis) is one of the most commonly used anticancer herbs. Its clinical use has a history more than several thousand years. It contains flavones, anthraquinones, polysaccharides, and other compounds possessing anticancer activities. In most cases, it is used together with other herbs. About 15% of the anticancer herbal formulas used in China contain this herb. Both pre-clinical and clinical studies have established the efficacy and safety of spreading hedyotis in treating various cancers including stomach cancer, liver cancer, lung cancer, esophagus cancer, and leukemia. It can directly inhibit the growth of various cancer cells and induce apoptosis both in vitro and in vivo. It shows selective cytotoxicity against cancerous cells. It can suppress some oncogenes and up-regulate anti-oncogenes. It also has immune modulation functions against cancer. It enhances the activities of natural killer cells and macrophages, promotes the proliferation of spleen cells, and up-regulates interleukin-2 and tumor necrosis factor-alpha. Clinical outcomes have demonstrated that it can enhance the efficacies and reduce the adverse effects (i.e. white blood cell decrease, nausea/vomit) by the conventional chemotherapies. It is also effective in relieving cancerous pain and fever. The commonly used clinical doses of 30–60 g/day usually do not cause any considerable adverse effects.

Genetically Engineered Normal Flora for Oral Polypeptide Delivery: Dose–Absorption Response

Genetically modified Lactococcus lactis (L. lactis), a probiotic bacterium, able to secrete beta-lactamase (29 kDa), was used as a vector for the oral delivery of beta-lactamase to the rats. Three different doses of L. lactis were administered to the rats, and the resulted beta-lactamase oral bioavailability was studied, and compared to the solution form. The oral administration of 1.2 x 10(7), 3 x 10(7), and 8 x 10(7) colony-forming units of L. lactis led to 145, 209, and 364 mU of beta-lactamase absorbed, and the corresponding bioavailability was 8.7%, 15.5%, and 20.8% based on the in vitro production of beta-lactamase by L. lactis. The oral administration of 504 mU and 1008 mU beta-lactamase free solution resulted in 30 and 47 mU absorbed, a bioavailability of 5.9% and 4.7%, respectively. L. lactis significantly (p < 0.01) increased the oral bioavailability compared to the free solution form. A significant (p < 0.01) increase in the MAT value as compared to the solution, demonstrated that L. lactis can be used as a sustained delivery system. In conclusion, there is a linear relationship between L. lactis dose and these absorption PK parameters within L. lactis dose range of the current study.

Impact of digestion on the transport of dextran-loaded self-emulsified nanoemulsion through MDCK epithelial cell monolayer and rat intestines

Many of the lipids and surfactants used to prepare the self-emulsified nanoemulsion (SEN) are subjected to the gastro-intestinal enzymatic digestion, which may affect the absorption of the loaded drug. The present study was to investigate the impact of such digestion on the transport of hydrophilic macromolecules (10-kDa dextran as the model compound) loaded in SEN through the MDCK cell monolayer and ex-vivo rat intestines. FITC-labeled dextran (FD) was loaded inside the inner oil phase of SEN by the formation of FD-phospholipid solid dispersion (FDPS). After digestion, the droplet size increased from 31.06 ± 2.10 nm to 494.6 ± 22.1 nm, and the FD content in the external aqueous phase increased from 41.6 ± 4.2% to 61.1 ± 4.4%. Compared to the FD solution, SEN without digestion enhanced the transport of FD through MDCK cell monolayer 4.1 times and through rat intestines 3.0-7.4 times. However, the digestion reduced the transport of FD 3.5 times through MDCK cell monolayer and 1.3-2.0 times through rat intestines, compared to that without digestion. This reduction was due to the destruction of lipid nano-droplets and release of FD to the external aqueous phase of SEN. This finding should be considered when SEN is used as a delivery system for hydrophilic macromolecules.

Novel multifunctional near-infrared fluorescent nanoparticles: integrating nanotechnology and biophotonics

The objective of this study is to engineer a novel nanoparticlulate system for use in early tumor diagnosis. Indocyanine green (ICG)-loaded biodegradable nanoparticles were prepared by using biodegradable polymer, poly(DL-lactic-co-glycolic acid) (PLGA). The ICG entrapment, nanoparticle size, shape, zeta potential the release of ICG from nanoparticles was determined. Also, the effect of ICG entrapment on fluorescence spectra of ICG was measured. The engineered nanoparticles were nearly spherical in shape and efficiently entrapped ICG. The release profile of the nanoparticles was exponential. The entrapment of ICG in nanoparticles caused reduction in its peak fluorescence intensity and shifted its wavelength of peak fluorescence to higher values.

Novel near-infrared nanoparticlulate biomarker: preparation and stability studies

Degradation of Indocyanine green (ICG) in aqueous media, limits its application in early tumor diagnosis and therapy. Thus, the objective of this study is to develop biodegradable nanoparticles entrapping ICG and to establish its effectiveness in providing overall stability to ICG. Nanoparticles entrapping ICG were engineered and characterized. The degradation kinetics of ICG in the nanoparticles was investigated in aqueous media. The degradation of ICG in aqueous nanoparticle suspension followed first-order kinetics. Nanoparticles enhanced aqueous, photo and thermal-stability of ICG.