Scale-up of recombinant protein purification by hydrophobic interaction chromatography

Liposomal Recombinant Human Superoxide Dismutase for the Treatment of Peyronie's Disease: A Randomized Placebo-Controlled Double-Blind Prospective Clinical Study

OBJECTIVE

To demonstrate the efficacy and safety of a topical gel containing liposomally encapsulated recombinant human Superoxide Dismutase (lrhSOD) in the treatment of painful Peyronie's Disease. The theoretical background is that lrhSOD, by scavenging of free oxygen radicals, might interrupt inflammatory cascades and thereby limit further disease progression.

METHODS

In a placebo-controlled randomized clinical trial, 39 patients with Peyronie's Disease and significant pain symptoms were treated with lrhSOD or placebo for a 4 week period. At this time, statistical evaluation of pain resolution was performed as primary study endpoint. Patients then were continued in a cross-over study design to ensure a total of 8 weeks of lrhSOD therapy for all study participants. Pain, plaque and curvature assessment was performed at study entry and every 4 weeks until week 12.

RESULTS

LrhSOD treatment resulted in a statistically significant reduction of pain (p=0.017) compared to placebo already after 4 weeks. At week 12 pain was significantly reduced in 89% of patients who all had received 8 weeks of lrhSOD therapy at that time. Response to other disease parameters was assessed at week 12: plaque size was reduced in 47% of patients, as was plaque consistence in 38%. Penile curvature was improved at 5-30 degrees in 23% of patients. The expected spontaneous disease progression rate of up to 40%, as reported by several investigators, was significantly reduced to <10% under lrhSOD therapy, and patients satisfaction was high, also consequent to the lack of therapy-related side effects observed in the present study.

CONCLUSION

LrhSOD is an easily administrable, safe and effective local therapeutic for the painful phase of Peyronie's Disease.

Enhanced protein loading into liposomes by the multiple crossflow injection technique

Methods for encapsulation of a drug into liposomes should preferably result in a high encapsulation efficiency and a high encapsulation capacity. Our studies were focussed on the establishment of an efficient encapsulation procedure of the radical scavenging protein, rh-Cu/Zn-SOD, into liposomes with the cross flow injection method. Limitations to increase the encapsulation efficiency are caused by the enclosed aqueous volume, by the lipid concentration, the aspired vesicle size and the final ethanol concentration. Our research was performed to maximize the encapsulation following several strategies of injecting higher lipid concentrations into the aqueous phase. The one way triple technique, a sophisticated preparation procedure is presented, which enables three times higher encapsulation rates in comparison to standard procedures. Additionally, scalability studies demonstrate reproducibility independent of the preparation volume. Vesicle size distribution and encapsulation efficiency remain constant. Furthermore, special attention is paid on reproducibility of prepared liposomes, scale-up and on long term stability of the lipid vesicles.

Developments in biotechnological research in Austria

Austria is a small European country with a small number of universities and biotechnological industries, but with great efforts in the implementation of environmental consciousness and corresponding legal standards. This review attempts to describe the biotechnological landscape of Austria, thereby focusing on the highlights in research by industry, universities, and research laboratories, as published during 1990 to early 1995. These will include microbial metabolite (organic acids, antibiotics) and biopolymer (polyhydroxibutyrate, S-layers) production; enzyme (cellulases, hemicellulases, ligninases) technology and biocatalysis; environmental biotechnology; plant breeding and plant protection; mammalian cell products; fermenter design; and bioprocess engineering.

Purification of human recombinant superoxide dismutase by isoelectric focusing in a multicompartment electrolyzer with zwitterionic membranes

Human recombinant superoxide dismutase (SOD), purified to homogeneity, is resolved by both conventional isoelectric focusing and immobilized pH gradients into three bands, with isoelectric points (pIs) in the pH range 4.8 to 5.1, the pI 4.80 form representing the minor component. Due to the fact that this enzyme is expressed in E. coli, N-terminal acetylation or glycosylation should be ruled out. When purified by small-scale preparative isoelectric focusing in immobilized pH gradient gels, it was found that, upon subsequent analysis, the pI 5.07 form would band in the same position, but the intermediate pI 4.92 band would split into the upper (pI 5.07) and the lower (pI 4.80) species, in nearly the same amounts, whereas the lowest pI component would always generate both the intermediate and upper forms. Enzymatic essays pointed out that these three isoforms had nearly the same specific activity, slightly higher than that of the starting material. Metal analysis indicated that all three forms contained the same metal/protein ratio, approaching the value Cu2Zn2-SOD, as reported in the literature. Circular dichroism spectra of the pI 4.80 and 5.07 forms showed the same profile in the 190-240 nm range, but marked differences in the 250-350 nm region. Treatment with EDTA produces 1-2 additional, slightly higher pI isoforms, whereas treatment with KCN generates a number of higher pI components, reaching pI values as high as pH 7, with nearly complete disappearance of the three major SOD isoforms. It is concluded that these three isoforms could represent interconvertible species, the highest pI component representing the most stable conformer.

Hydrophobic interaction chromatography for isolation and purification of Equ.cl, the horse major allergen

Equ.cl, the horse (Equus caballus) major allergen, was identified in a partially purified extract obtained from a crude aqueous horse dander extract, by acetonic precipitation and a salting-out process. It was isolated and purified by size-exclusion chromatography followed by hydrophobic interaction chromatography. Equ.cl appeared as an almost pure protein in a fraction eluted at 1.2 M ammonium sulphate from a phenyl Superose column. It is a single peptide with a relative molecular mass of 20,000 and a pI of ca. 3.9.