Expedient screening for HIV-1 protease inhibitors using a simplified immunochromatographic assay.

A colloidal gold-based immunochromatographic (IC) strip test was developed and validated for the detection of HIV-1 protease (HIV-PR) activity and inhibitory effect of HIV-PR inhibitors (PIs). It is a unique 'two-step' process requiring the combination of proteolysis of HIV-PR and an immunochromatographic reaction. Monoclonal antibodies to the free C-terminus of HIV matrix protein (HIV-MA) conjugated to gold particles and a monoclonal antibody against intact and cleaved forms of the HIV-MA are immobilized on the 'Test'-line of the IC strip.

Transport of dendrimer nanocarriers through epithelial cells via the transcellular route.

The mechanism of transport of G3 PAMAM and surface-modified (with lauroyl chains) G3 PAMAM dendrimer nanocarriers across Caco-2 cell monolayers has been investigated. Flow-cytometry studies following quenching of extracellular fluorescence demonstrated the cellular internalisation of dendrimers. Optical sectioning of cells incubated with fluorescein isothiocyanate (FITC)-conjugated dendrimer and lauroyl-dendrimer using confocal laser scanning microscopy revealed colocalisation of a marker for cell nuclei (4',6-diamidino-2-phenylindole, DAPI) and FITC fluorescence, also suggesting cellular internalisation of dendrimers.

The use of a dendrimer-propranolol prodrug to bypass efflux transporters and enhance oral bioavailability.

The aim of the study was to determine the effects on the transport of propranolol across monolayers of the human colon adenocarcinoma cell line, Caco-2, of forming a prodrug by conjugating to generation 3 (G3) and lauroyl-G3 PAMAM dendrimers. Propranolol is a poorly soluble drug and known substrate of the P-glycoprotein (P-gp) efflux transporter. Propranolol-G3 dendrimer conjugates were synthesised by surface attachment of two, four or six propranolol molecules.

Engineering of dendrimer surfaces to enhance transepithelial transport and reduce cytotoxicity.

Purpose: To evaluate the cytotoxicity, permeation, and transport mechanisms of PAMAM dendrimers and surface-modified cationic PAMAM dendrimers using monolayers of the human colon adenocarcinoma cell line, Caco-2.

Methods: Cytotoxicity was determined using the MTT assay. The effect of dendrimers on monolayer integrity was determined from measurements of transepithelial electrical resistance (TEER) and [14C]mannitol apparent permeability coefficient (Papp).

The influence of surface modification on the cytotoxicity of PAMAM dendrimers.

The influence of surface modification on the cytotoxicity of PAMAM dendrimers was examined using Caco-2 cells. Dendrimers were modified by conjugating either lauroyl chains or polyethylene glycol (PEG) 2000 onto the surface of cationic PAMAM dendrimers (G2, G3, G4). The cytotoxicity of unmodified dendrimers towards Caco-2 cells was appreciably higher for cationic (whole generation) compared with anionic (half generation) dendrimers and for both types increased with increasing size (generation) and concentration.