Nanoparticulate CpG immunotherapy in RAO-affected horses: phase I and IIa study

Background

Recurrent airway obstruction (RAO), an asthma‐like disease, is 1 of the most common allergic diseases in horses in the northern hemisphere. Hypersensitivity reactions to environmental antigens cause an allergic inflammatory response in the equine airways. Cytosine‐phosphate‐guanosine‐oligodeoxynucleotides (CpG‐ODN) are known to direct the immune system toward a Th1‐pathway, and away from the pro‐allergic Th2‐line (Th2/Th1‐shift). Gelatin nanoparticles (GNPs) are biocompatible and biodegradable immunological inert drug delivery systems that protect CpG‐ODN against nuclease degeneration. Preliminary studies on the inhalation of GNP‐bound CpG‐ODN in RAO‐affected horses have shown promising results.

Objectives

The aim of this study was to evaluate the clinical and immunological effects of GNP‐bound CpG‐ODN in a double‐blinded, placebo‐controlled, prospective, randomized clinical trial and to verify a sustained effect post‐treatment.

Animals and Methods

Twenty‐four RAO‐affected horses received 1 inhalation every 2 days for 5 consecutive administrations. Horses were examined for clinical, endoscopic, cytological, and blood biochemical variables before the inhalation regimen (I), immediately afterwards (II), and 4 weeks post‐treatment (III).

Results

At time points I and II, administration of treatment rather than placebo corresponded to a statistically significant decrease in respiratory effort, nasal discharge, tracheal secretion, and viscosity, AaDO₂ and neutrophil percentage, and an increase in arterial oxygen pressure.

Conclusion and Clinical Importance

Administration of a GNP‐bound CpG‐ODN formulation caused a potent and persistent effect on allergic and inflammatory‐induced clinical variables in RAO‐affected horses. This treatment, therefore, provides an innovative, promising, and well‐tolerated strategy beyond conventional symptomatic long‐term therapy and could serve as a model for asthma treatment in humans.

A novel technique for selective NF-kappaB inhibition in Kupffer cells: contrary effects in fulminant hepatitis and ischaemia-reperfusion

BACKGROUND AND AIMS

The transcription factor nuclear factor kappa B (NF-kappaB) has risen as a promising target for anti-inflammatory therapeutics. In the liver, however, NF-kappaB inhibition mediates both damaging and protective effects. The outcome is deemed to depend on the liver cell type addressed. Recent gene knock-out studies focused on the role of NF-kappaB in hepatocytes, whereas the role of NF-kappaB in Kupffer cells has not yet been investigated in vivo. Here we present a novel approach, which may be suitable for clinical application, to selectively target NF-kappaB in Kupffer cells and analyse the effects in experimental models of liver injury.

METHODS

NF-kappaB inhibiting decoy oligodeoxynucleotides were loaded upon gelatin nanoparticles (D-NPs) and their in vivo distribution was determined by confocal microscopy. Liver damage, NF-kappaB activity, cytokine levels and apoptotic protein expression were evaluated after lipopolysaccharide (LPS), d-galactosamine (GalN)/LPS, or concanavalin A (ConA) challenge and partial warm ischaemia and subsequent reperfusion, respectively.

RESULTS

D-NPs were selectively taken up by Kupffer cells and inhibited NF-kappaB activation. Inhibition of NF-kappaB in Kupffer cells improved survival and reduced liver injury after GalN/LPS as well as after ConA challenge. While anti-apoptotic protein expression in liver tissue was not reduced, pro-apoptotic players such as cJun N-terminal kinase (JNK) were inhibited. In contrast, selective inhibition of NF-kappaB augmented reperfusion injury.

CONCLUSIONS

NF-kappaB inhibiting decoy oligodeoxynucleotide-loaded gelatin nanoparticles is a novel tool to selectively inhibit NF-kappaB activation in Kupffer cells in vivo. Thus, liver injury can be reduced in experimental fulminant hepatitis, but increased at ischaemia-reperfusion.

Incorporation of biodegradable nanoparticles into human airway epithelium cells-in vitro study of the suitability as a vehicle for drug or gene delivery in pulmonary diseases

PURPOSE

Nanoparticles are able to enhance drug or DNA stability for purposes of optimised deposition to targeted tissues. Surface modifications can mediate drug targeting. The suitability of nanoparticles synthesised out of porcine gelatin, human serum albumin, and polyalkylcyanoacrylate as drug and gene carriers for pulmonary application was investigated in vitro on primary airway epithelium cells and the cell line 16HBE14o-.

METHODS

The uptake of nanoparticles into these cells was examined by confocal laser scan microscopy (CLSM) and flow cytometry (FACS). Further the cytotoxicity of nanoparticles was evaluated by an LDH-release-test and the inflammatory potential of the nanoparticles was assessed by measuring IL-8 release.

RESULTS

CLSM and FACS experiments showed that the nanoparticles were incorporated into bronchial epithelial cells provoking little or no cytotoxicity and no inflammation as measured by IL-8 release.

CONCLUSIONS

Based on their low cytotoxicity and the missing inflammatory potential in combination with an efficient uptake in human bronchial epithelial cells, protein-based nanoparticles are suitable drug and gene carriers for pulmonary application.

Preparation of avidin-labeled protein nanoparticles as carriers for biotinylated peptide nucleic acid

The possibility of preparing protein nanoparticles followed by covalent linkage of avidin was investigated. Free sulfhydryl groups were introduced onto the surface of protein nanoparticles either by aldehyde quenching with cysteine or reaction of free amino groups with 2-iminothiolane. The number of primary amino groups and sulfhydryl groups on the surface of the resulting particles was quantified with site-specific reagents. Avidin was attached to the surface of the thiolated nanoparticles via a bifunctional spacer which reacted in a first step with amino groups of avidin and in a second step with the sulfhydryl groups introduced onto the surface of the nanoparticles. Biotinylated peptide nucleic acid (PNA) as a model compound for biotinylated drugs was effectively coupled to the nanoparticles by complex formation with the covalently attached avidin. Since the formation of the interaction between biotin and avidin is very rapid and stable a highly effective drug carrier system for biotinylated compounds such as PNAs was achieved.

Preparation of avidin-labelled gelatin nanoparticles as carriers for biotinylated peptide nucleic acid (PNA)

The possibility of preparing uniform nanoparticles consisting of proteins such as gelatin followed by covalent linkage of avidin was investigated. Gelatin nanoparticles were prepared by two step desolvation. Functional groups at the surface of the particulate system were quantified with site-specific reagents. The surface of the nanoparticles was thiolated and avidin was covalently attached to the nanoparticles via a bifunctional spacer at high levels. Biotinylated peptide nucleic acid (PNA) was effectively complexed by the avidin-conjugated nanoparticles. Avidin-conjugated protein nanoparticles should prove as potential carrier system for biotinylated drug derivatives in antisense therapy.

Desolvation process and surface characterisation of protein nanoparticles

The objective of the present study was to characterise and optimise the desolvation process of human serum albumin (HSA) for the preparation of nanoparticles and to characterise the resulting colloidal system. Following the desolvation of the protein, the resulting nanoparticles were stabilised by the addition of varying amounts of glutaraldehyde or by heat denaturation. The particle size, zeta potential, and the number of available amino groups on the surface of the nanoparticles were determined. The amino groups were quantified by a spectrophotometric method using 2,4, 6-trinitrobenzenesulfonic acid (TNBS). The results indicated that the particle size depended mainly on the amount of desolvating agent added, but not on the amount of cross-linker or the kind of cross-linking procedure. Increasing amounts of glutaraldehyde reduced the number of amino groups on the surface of HSA nanoparticles and also decreased the zeta potential of the carrier system. The temperature and heat denaturation time only had an influence on the stability of the nanoparticles but not on the amount of amino groups or the particle size. It was shown that heat denatured HSA nanoparticles possessed the greatest number of amino groups on their surface. Additional experiments for the characterisation of gelatin A and B nanoparticles were performed.

[Anterior high-frequency capsulotomy: advantages and problems]

METHODS

Since the clinical test phase, the author performed consistently more than 500 capsulotomies in his cataract surgeries by means of a radio-frequency current, using an instrument developed by Klöti et al. Some problems in the application of the instrument and their possible solution are discussed from the practical view of the user.

CONCLUSIONS

The method proved as easy and safe to use especially in certain difficult cases. The main problem seems to be a reduced stability of the anterior capsular rim compared to the cases performed by capsulorhexis.

[Anterior high frequency capsulotomy. II. Clinico-surgical experiences]

Using an instrument developed by Klöti, the author performed anterior capsulotomy by means of a radio-frequency current in 21 cases of extracapsular cataract extraction. This group is compared with 21 control cases. The advantages and limits of this technique are discussed. The procedure was found to be simple and very helpful to the surgeon. There was no evidence of any damage to structures in the patient's eye.

[Computer as replacement for the current medical record? Introduction of a pilot project of the St. Gallen ophthalmology clinic]

Computerized data processing is more and more used in hospitals and medical offices. There are no doubts about the usefulness of a computer for administrative tasks. At our Dept. of Ophthalmology we started a pilot project to enter the medical records into the computer. The pros and cons of such an information system are discussed. Entering medical records into the computer did not prove to be definite advantage for the physician.

[Unusual cases of coronary death]

Stenosing coronary artery sclerosis is the most common cause of sudden unexpected death. In this report we present three exceptions: 1. A mycotic coronary aneurysm ruptures and results in pericardial tamponade; 2. in a young woman Takayasu aortitis encroaches on the ostium and mainstem of the left coronary; 3. fibromuscular dysplasia of the right coronary artery causes death in a 56-year-old male.