The use of nano polymeric self-assemblies based on novel amphiphilic polymers for oral hydrophobic drug delivery.

Purpose: To investigate the use of nano self-assemblies formed by polyallylamine (PAA) modified with 5 or 10% mole fluorenylmethoxy carbonyl (Fmoc5/10), dimethylamino-1-naphthalenesulfonyl (Dansyl5/10) and 5% mole cholesteryl group (Ch5) for oral hydrophobic drug delivery. Methods: Propofol, griseofulvin and prednisolone were loaded into amphiphilic PAAs. Particle size and morphology of drug-loaded self-assemblies were determined using photon correlation spectroscopy and transmission electron microscopy. Solubilising capacity, in vitro drug release and formulation stability were analysed by HPLC, and in vitro biocompatibility studies (haemolysis and cytotoxicity) were carried out on bovine erythrocytes and Caco-2 cells, respectively. Dansyl10 and Ch5 griseofulvin formulations were administered intra-gastrically to rats, and drug plasma levels were analysed by HPLC. Results: Drug-encapsulated self-assemblies typically have hydrodynamic size of 300–400 nm. Dansyl10 exhibited universal drug solubiliser property and had significantly improved prednisolone, griseofulvin and propofol solubility by 145, 557 and 224-fold, respectively. Fmoc polymers resulted in modest drug solubility improvement. These polymers were non-haemolytic, did not enhance cytotoxicity compared to unmodified PAA, and demonstrated significant increase in griseofulvin plasma concentration compared to griseofulvin in water after oral administration. Conclusions: Ch5 and Dansyl10 showed promising potential as nano-carriers for oral hydrophobic drug delivery

Poly(allylamine) magnetomicelles for image guided drug delivery.

Polymeric micelles have received considerable interest for their use as drug delivery vehicles for hydrophobic drug solubilisation. Inorganic metallic nanoparticles have already been exploited clinically in diagnostics for their contrast ability, using magnetic resonance imaging. The combination of these two platforms results in a multifunctional drug carrier for image-guided drug delivery. Here we report the synthesis and evaluation of a new class of poly(allylamine) (PAA) polymer grafted with hydrophobic oxadiazole (Ox) pendant group in a 5% molar monomer: pendant ratio. Further, the thiol-containing pendant group facilitated the attachment of hybrid iron oxide-gold nanoparticles (HNPs) via dative covalent bonding. Physicochemical characterisation of both PAA-Ox5 and PAA-Ox5-HNP polymers was carried out using elemental analysis, nuclear magnetic resonance (NMR), fourier transform infrared spectroscopy (FTIR) and photon correlation spectroscopy (PCS). The drug loading potential of these novel aggregates was investigated, through direct conjugation of hydrophilic and encapsulation of hydrophobic drugs, respectively. The model hydrophobic drugs 2,6- diisopropylphenol (propofol) and (2S,6'R)-7-chloro-2',4,6-trimethoxy-6'-methyl-3H,4'H-spiro[1-benzofuran-2,1'- cyclohex[2]ene]-3,4'-dione (griseofulvin), and the chemotherapeutic agents bisnapthalamidopropyldiaminooctane (BNIPDaoct) and 6-Thioguanine (6-TG) were used. The data showed that the addition of HNPs onto the PAA-Ox5 structure resulted in aggregates of 175 nm in diameter. The PAA-Ox5-HNP nano-aggregates were capable of high drug solubilisation capacities (25.79 mgmL-1, 1.68 mgmL-1 and 0.92 mgmL-1) for propofol, griseofulvin and BNIPDaoct, respectively. 6-TG was also successfully conjugated into the polymer structure (2.8 mgmL-1). In vitro assays on human pancreatic adenocarcinoma cells (BxPC-3) showed increased drug uptake and decreased IC50 values using the novel formulations compared with free drug. This study highlights the potential of PAA-Ox5-HNP as a bi-functional imaging and drug delivery platform

Uptake and transport of novel amphiphilic polyelectrolyte-insulin nanocomplexes by caco-2 cells - towards oral insulin

“The original publication is available at www.springerlink.com”. Copyright SpringerPurpose: The influence of polymer architecture on cellular uptake and transport across Caco-2 cells of novel amphiphilic polyelectrolyte-insulin nanocomplexes was investigated. Method: Polyallylamine (PAA) (15 kDa) was grafted with palmitoyl chains (Pa) and subsequently modified with quaternary ammonium moieties (QPa). These two amphiphilic polyelectrolytes (APs) were tagged with rhodamine and their uptake by Caco-2 cells or their polyelectrolyte complexes (PECs) with fluorescein isothiocyanate-insulin (FITC-insulin) uptake were investigated using fluorescence microscopy. The integrity of the monolayer was determined by measurement of transepithelial electrical resistance (TEER). Insulin transport through Caco-2 monolayers was determined during TEER experiments. Result: Pa and insulin were co-localised in the cell membranes while QPa complexes were found within the cytoplasm. QPa complex uptake was not affected by calcium, cytochalasin D or nocodazole. Uptake was reduced by co-incubation with sodium azide, an active transport inhibitor. Both polymers opened tight junctions reversibly where the TEER values fell by up to 35 % within 30 minutes incubation with Caco-2 cells. Insulin transport through monolayers increased when QPa was used (0.27 ngmL-1 of insulin in basal compartment) compared to Pa (0.14 ngmL-1 of insulin in basal compartment) after 2 hours. Conclusion: These APs have been shown to be taken up by Caco-2 cells and reversibly open tight cell junctions. Further work is required to optimise these formulations with a view to maximising their potential to facilitate oral delivery of insulin.Peer reviewe

Phenomic analysis of chronic granulomatous disease reveals more severe integumentary infections in X-Linked compared with autosomal recessive chronic granulomatous disease

BACKGROUND : Chronic granulomatous disease (CGD) is an inborn error of immunity (IEI), characterised by recurrent bacterial and fungal infections. It is inherited either in an Xlinked (XL) or autosomal recessive (AR) mode. Phenome refers to the entire set of phenotypes expressed, and its study allows us to generate new knowledge of the disease. The objective of the study is to reveal the phenomic differences between XL and AR-CGD by using Human Phenotype Ontology (HPO) terms. METHODS : We collected data on 117 patients with genetically diagnosed CGD from Asia and Africa referred to the Asian Primary Immunodeficiency Network (APID network). Only 90 patients with sufficient clinical information were included for phenomic analysis. We used HPO terms to describe all phenotypes manifested in the patients. RESULTS : XL-CGD patients had a lower age of onset, referral, clinical diagnosis, and genetic diagnosis compared with AR-CGD patients. The integument and central nervous system were more frequently affected in XL-CGD patients. Regarding HPO terms, perianal abscess, cutaneous abscess, and elevated hepatic transaminase were correlated with XL-CGD. A higher percentage of XL-CGD patients presented with BCGitis/BCGosis as their first manifestation. Among our CGD patients, lung was the most frequently infected organ, with gastrointestinal system and skin ranking second and third, respectively. Aspergillus species, Mycobacterium bovis, and Mycobacteirum tuberculosis were the most frequent pathogens to be found. CONCLUSION : Phenomic analysis confirmed that XL-CGD patients have more recurrent and aggressive infections compared with AR-CGD patients. Various phenotypic differences listed out can be used as clinical handles to distinguish XL or AR-CGD based on clinical features.The Society for Relief of Disabled Children and Jeffrey Modell Foundation.https://www.frontiersin.org/journals/immunologydm2022Paediatrics and Child Healt

Dilemmas in the reliable estimation of the in-vitro cell viability in magnetic nanoparticle engineering:which tests and what protocols?

Magnetic nanoparticles [MNPs] made from iron oxides have many applications in biomedicine. Full understanding of the interactions between MNPs and mammalian cells is a critical issue for their applications. In this study, MNPs were coated with poly(ethylenimine) [MNP-PEI] and poly(ethylene glycol) [MNP-PEI-PEG] to provide a subtle difference in their surface charge and their cytotoxicity which were analysed by three standard cell viability assays: 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium [MTS], CellTiter-Blue and CellTiter-Glo (Promega, Southampton, UK) in SH-SY5Y and RAW 264.7 cells The data were validated by traditional trypan blue exclusion. In comparison to trypan blue manual counting, the MTS and Titer-Blue assays appeared to have consistently overestimated the viability. The Titer-Glo also experienced a small overestimation. We hypothesise that interactions were occurring between the assay systems and the nanoparticles, resulting in incorrect cell viability evaluation. To further understand the cytotoxic effect of the nanoparticles on these cells, reactive oxygen species production, lipid peroxidation and cell membrane integrity were investigated. After pegylation, the MNP-PEI-PEG possessed a lower positive surface charge and exhibited much improved biocompatibility compared to MNP-PEI, as demonstrated not only by a higher cell viability, but also by a markedly reduced oxidative stress and cell membrane damage. These findings highlight the importance of assay selection and of dissection of different cellular responses in in-vitro characterisation of nanostructures.Peer reviewedFinal Published versio

Fundamentals of Pharmaceutical Nanoscience

XIV, 598 p. 155 illus., 99 illus. in color.onlin

In Vitro and In Vivo Anticancer Activity of a Novel Nano-sized Formulation Based on Self-assembling Polymers Against Pancreatic Cancer

The original publication is available at www.springerlink.com. Copyright SpringerPurpose: To evaluate the in vitro and in vivo pancreatic anticancer activity of a nano-sized formulation based on novel polyallylamine grafted with 5% mole cholesteryl pendant groups (CH5-PAA). Methods: Insoluble novel anticancer drug, Bisnaphthalimidopropyldiaaminooctane (BNIPDaoct), was loaded into CH5-PAA polymeric self-assemblies by probe sonication. Hydrodynamic diameters and polydispersity index measurements were determined by photon correlation spectroscopy. The in vitro cytotoxicity evaluation of the formulation was carried out by the sulforhodamine B dye assay with human pancreatic adenocarcinoma BxPC-3 cells, while for the in vivo study, Xenograff mice were used. In vitro apoptotic cell death from the drug formulation was confirmed by flow cytometric analysis. Results: The aqueous polymer-drug formulation had a mean hydrodynamic size of 183 nm. The drug aqueous solubility was increased from negligible concentration to 0.3 mg mL−1. CH5-PAA polymer alone did not exhibit cytotoxicity, but the new polymer-drug formulation showed potent in vitro and in vivo anticancer activity. The mode of cell death in the in vitro study was confirmed to be apoptotic. The in vivo results revealed that the CH5-PAA alone did not have any anti-proliferative effect, but the CH5-PAA-drug formulation exhibited similar tumour reduction efficacy as the commercial drug, gemcitabine. Conclusions: The proposed formulation shows potential as pancreatic cancer therapeutics.Peer reviewe

Nano self-assemblies based on cholate grafted poly-L-lysine enhanced the solubility of sterol-like drugs

The physicochemical compatibility between amphiphilic polymers and hydrophobic drugs has been recognized as an important issue for improving the drug solubilisation in polymeric micelle formulations. In this work, poly-L-lysine (PLL) grafted by cholate pendants as the only hydrophobic moiety were synthesized in order to facilitate the solubilisation of sterol drugs. Results showed that micelles formed by cholate grafted PLL encapsulated significantly higher level of prednisolone and estradiol than palmitoylated PLL micelles, whereas the solubilisation capacity of non-sterol drug (griseofulvin) is inefficient for both polymers. This suggests that higher drug-polymer incorporation can be achieved by the inclusion of hydrophobic moieties with similar architecture as the drugs, i.e. 'drug-like' functional groups, which will be useful for the future design of colloidal systems for the encapsulation of specific drug.Peer reviewe

A Novel Application of CORDYCEPIN (Cordycepssinensis Extract): Maintaining Stem Cell Pluripotency and Improving iPS Generation Efficiency

Embryonic stem cells (ES) and induced pluripotnet stem cells (iPS) are both pluripotent stem cells. For mouse stem cells culture technology, leukemia inhibitory factor (LIF) was used to maintain the pluripotency of stem cells in vitro. However, LIF is an expensive reagent. The goal of this study was to find out a pure compound extracted from Chinese herbal medicine that could maintain stem cells pluripotency to replace LIF and improve the iPS generation efficiency. From 20 candidates traditional Chinese medicine we found that Cordycepsmilitaris triggered the up-regulation of stem cells activating genes (Oct4 and Sox2) expression levels in MEF cells. Cordycepin, a major active component of Cordycepsmilitaris, also could up-regulate Oct4 and Sox2 gene expression. Furthermore, we used ES and iPS cells and treated them with different concentrations of Cordycepin (replaced LIF in the culture medium) to test whether it was useful to maintain the pluripotency. The results showed higher expression levels of several stem cells markers in 10 μM Cordycepin-treated ES and iPS cells compared to controls that did not contain LIF, including alkaline phosphatase, SSEA1, and Nanog. Embryonic body formation and differentiation confirmed that 10 μM Cordycepin-containing medium was capable to maintain stem cells pluripotency after four times passages. For mechanism analysis, microarray analysis indicated extracellular matrix and Jak/Stat signaling pathway as the top two deregulated pathways. In ECM pathway, we determined that the integrin αVβ5 expression levels and phosphorylated Src levels increased after Cordycepin treatment. In addition, the phosphorylated Jak2 and phosphorylated Sat3 protein levels were increased after Cordycepin treatment and suppressed with the Jak2 inhibitor, AG490. The expression of cytokines associated with Jak2/Stat3 signaling pathway were also up-regulated by Q-PCR and ELISA assay. Lastly, we used Oct4-GFP MEF cells to test iPS generation efficiency following Cordycepin treatment. We observed that 10 Μm Cordycepin significantly increased the iPS generation efficiency in day 21. In conclusion, we demonstrated Cordycepin could maintain the pluripotency of stem cells through both of ECM and Jak2/Stat3 signaling pathway and improved iPS generation efficiency