Biosafety of drugs, especially blood derivatives and biotechnology-derived products, as well as medical devices is now a fact well rooted in the minds of scientists in charge of the development of those therapeutics and diagnostics. The succession of recent sanitary crisis, mainly linked to viruses such as HIV/AIDS, flu, SRAS, chikungunya or other agents, previously believed to be related to prions (also known as Transmissible Spongiform Encephalopathy (TSE) agents) probably explains this raise in awareness.

Bertin Pharma and its partner Texcell is able to assess:

• The disinfectant properties of new compounds: Virucidal or prionicid activity
• The elimination/inactivation properties of steps included in your purification & manufacturing processes: Viral or prion clearance
• The eventual presence of adventitious agents (virus and/or prions) in your start material, your cell banks or derivatives: Adventitious agent contamination
• The detergent activity of new compounds and the inactivating activity of new physicochemical processes: Decontamination of medical devices

Nevertheless, as a first-line, we propose to compare your product or machine to others using data previously published in scientific journals.

Testing is performed according to the regulatory agencies’ guidelines. However, prions along with viruses are sensitive to environmental factors and to copy «field reality » is also of interest for the spiking of pathogen agent. For prions, considering their extreme resistance, this concept is looked at for medical devices, at least. In fact, the “Standard Prion Protocol” validates the consensual side of the experimental model using Golden Syrian hamsters infected with the experimental 263K scrapie strain and the interest as confirmation of a further evaluation using a second animal model like C57Bl/6 mice infected with the 6PB1 strain, a bovine spongiform encephalopathy strain adapted to mice.

The eventual multiplication of these tests must imperatively go with technological alternatives, susceptible to lower their costs. The interest of in vitro approaches for prions was fully justified even if they did not measure infectivity but only the abnormal pathologic isoform of the prion protein (PrPTSE). Thus, SPI-Bio has developed an in vitro approach constituting help to the decision to pursue or not the explorations toward the in vivo assay (bioassay) and to better understand the mechanism of action of the tested processes or machines.


What is a prion?
Human prion diseases (transmissible spongiform encephalopathy, TSE) including Creutzfeld-Jakob disease (CJD), fatal insomnia and Gerstmann-Sträussler-Scheinker (GSS) disease are invariably fatal. TSE are classified as spontaneous, inherited, and infectious neurodegenerative diseases.

Three infectious forms of human TSE are identified today:

• First, Kuru is a consequence of ritualistic cannibalism in New Guinea.
• Second, iatrogenic CJD is caused by prion-contaminated cadaveric growth hormone and dura-mater grafts.
• Third, the new variant (vCJD) recently developed in Europe by adults exposed to bovine prions from cattle-derived products infected by   bovine spongiform encephalopathy (BSE).

The biological properties i.e. neuropathology and Type 4 PrPsc electrophoretic pattern revealed similarities between BSE and vCJD agents.

The infectious agent responsible of these diseases and neurologic disorders has been called TSE agent or “prion”. The main and perhaps single component is an approximatively 36 kDa host-encoded glycoprotein called PrPsc. This PrPsc corresponds to the post-translationally modified isoform, PrPc. These isoforms differ in the conformation of their polypeptide chains, and the conversion of α-helice into ß-sheets occurs during the formation of PrPsc. These two isoforms of PrP exhibit distinct biochemical properties. PrPsc aggregates in non-denaturing detergents, and is more resistant to protease digestion than PrPc, yielding a N-terminally cleaved core fragment called PrP 27-30 or PrPres.

Your advantages working with us

• More than 20 years experience with prions
• Strong interactions with Regulatory Agencies
• Experimental models according to the « standard protocols  » (Afnor)
• Experimental models as first approach to make a quick decision
• Experimental models closer to your field issues are also available

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Related services
- Preclinical & clinical studies
- Biologics
- Pharmaceutical development & clinical supplies