Valentin Jossen

Valentin Jossen
Lonza Bioscience · Ibex

Dr.

About

48
Publications
10,335
Reads
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491
Citations
Additional affiliations
December 2021 - present
Lonza
Position
  • Senior Researcher
February 2016 - November 2021
Zurich University of Applied Sciences
Position
  • Research Associate
November 2012 - January 2016
Zurich University of Applied Sciences
Position
  • Research Assistant
Education
January 2016 - February 2020
Technical University of Berlin
Field of study
  • PhD-Thesis "Bioengineering aspects of microcarrier-based hMSC expansions in different single-use bioreactors"
September 2012 - July 2014
Zurich University of Applied Science
Field of study
  • Pharmaceutical Biotechnology
September 2009 - September 2012
Zurich University of Applied Science
Field of study
  • Biotechnology

Publications

Publications (48)
Article
In recent years, the use of hMSCs, which may be isolated from adipose tissue among others, for the treatment of diseases has increased significantly. The cell quantities required for such therapeutic approaches, between 1012 and 1013, have thus far been predominantly produced using commercially available multi-tray systems, such as the Cell Factory...
Article
Full-text available
Human adipose stem cells (hASCs) are promising candidates for cell-based therapies, butthey need to be efficiently expandedin vitroas they cannot be harvested in sufficient quantities.Recently, dynamic bioreactor systems operated with microcarriers achieved considerable high celldensities. Thus, they are a viable alternative to static planar cultiv...
Article
Cellular agriculture is the controlled and sustainable manufacture of agricultural products with cells and tissues without plant or animal involvement. Today, microorganisms cultivated in bioreactors already produce egg and milk proteins, sweeteners, and flavors for human nutrition as well as leather and fibers for shoes, bags, and textiles. Furthe...
Article
Full-text available
Adipose tissue is an abundant source of stem cells. However, liposuction cannot yield cell quantities sufficient for direct applications in regenerative medicine. Therefore, the development of GMP-compliant ex vivo expansion protocols is required to ensure the production of a “cell drug” that is safe, reproducible, and cost-effective. Thus, we deve...
Article
Full-text available
Stirred single-use bioreactors in combination with microcarriers (MCs) have established themselves as a technology that has the potential to meet the demands of current and future cell therapeutic markets. However, most of the published processes have been performed using fetal bovine serum (FBS) containing cell culture medium and non-biocompatible...
Article
Full-text available
Oxygen supply in aerobic bioprocesses is of crucial importance. For this reason, this paper presents the oxygen demand of different cells and summarizes experimental and numerical possibilities for the determination of oxygen transfer in bioreactors. The focus lies on the volumetric oxygen mass transfer coefficient (kLa) calculation using computati...
Article
Human mesenchymal stem cells (hMSCs) are a valuable source of cells for clinical applications (e.g., treatment of acute myocardial infarction or inflammatory diseases), especially in the field of regenerative medicine. However, for autologous (patient-specific) and allogeneic (off-the-shelf) hMSC-based therapies, in vitro expansion is necessary pri...
Article
Full-text available
Human Adipose Tissue Stem Cells (hASCs) are a valuable source of cells for clinical applications (e.g., treatment of acute myocardial infarction and inflammatory diseases), especially in the field of regenerative medicine. However, for autologous (patient-specific) and allogeneic (off-the-shelf) hASC-based therapies, in-vitro expansion is necessary...
Thesis
Human mesenchymal stem cells (hMSCs) are a valuable cell source for the treatment of degenerative diseases. For the mass expansion of hMSCs, Single-use (SU) bioreactors in combination with microcarriers (MCs) represent a suitable solution. In the present thesis, different aspects of the MC-based expansion of hMSCs in different SU bioreactors were i...
Chapter
This chapter aims to give an overview of instrumented single‐use bioreactor (SUB) types that are currently available commercially. Based on the milestones in the development of SUBs, it focuses on the three most often applied types: wave‐mixed, stirred, and orbitally shaken versions. Their typical working principles are explained, possible fields o...
Article
Full-text available
Human adipose tissue-derived stromal/stem cells (hASCs) are a valuable source of cells for clinical applications, especially in the field of regenerative medicine. Therefore, it comes as no surprise that the interest in hASCs has greatly increased over the last decade. However, in order to use hASCs in clinically relevant numbers, in vitro expansio...
Article
Full-text available
The power input in stirred bioreactors is an important scaling-up parameter and can be measured through the torque that acts on the impeller shaft during rotation. However, the experimental determination of the power input in small-scale vessels is still challenging due to relatively high friction losses inside typically used bushings, bearings and...
Article
Full-text available
Human mesenchymal stem cell (hMSC)-based therapies are of increasing interest in the field of regenerative medicine. As economic considerations have shown, allogeneic therapy seems to be the most cost-effective method. Standardized procedures based on instrumented single-use bioreactors have been shown to provide billion of cells with consistent pr...
Article
Zusammenfassung de Einweg‐Bioreaktoren sind in der Entwicklung und Produktion von monoklonalen Antikörpern angekommen. Studien belegen, dass sie richtig ausgewählt und eingesetzt sicherere, schnellere, grünere und kleinere Produktionsverfahren als ihre wiederverwendbaren Gegenspieler erlauben und zu Kosteneinsparungen beitragen. In der Inokulumprod...
Chapter
It is undisputed that stirred bioreactors are the most common type of bioreactors for submerged bioprocesses. Stirred bioreactors for biopharmaceuticals, which represent the strongest-growing branch of modern biotechnological products, are the focus of our chapter. They are available in working volumes from milliliters up to 70 m 3 and are used for...
Article
Full-text available
Power input is an important engineering and scale-up/down criterion in stirred bioreactors. However, reliably measuring power input in laboratory scale systems is still challenging. Even though torque measurements have proven to be suitable in pilot scale systems, sensor accuracy, resolution and errors from relatively high levels of friction inside...
Article
Full-text available
pH value and the concentration of dissolved oxygen (DO) are key parameters to monitor and control cell growth in cultivation studies. Reliable, robust and accurate methods to measure these parameters in cultivation systems in real time guarantee high product yield and quality. This mini-review summarises the current state of the art of pH and DO se...
Article
Full-text available
The potential of human mesenchymal stem cells (hMSCs) for allogeneic cell therapies has created a large amount of interest. However, this presupposes the availability of efficient scale-up procedures. Promising results have been reported for stirred bioreactors that operate with microcarriers. Recent publications focusing on microcarrier-based stir...
Article
Spinner flasks are often used for microcarrier-based cultivations of human mesenchymal stem cells (hMSCs). Normally, they are not equipped with pH and dissolved Oxygen (DO) probes. This application note describes the cultivation of hMSCs in single-use spinner flasks equipped with optical pH (SP-HP8) and DO (SP-PSt3) sensors for the first time. Whil...
Article
Full-text available
Spinner flasks are often used for microcarrie-based cultivations of human mesenchymal stem cells (hMSCs). Normally, they are not equipped with pH and dissolved oxygen (DO) probes. This application note describes the cultivation of hMSCs in single-use spinner flasks equipped with optical pH (SP-HP8) and DO (SP-PSt3) sensors for the first time. While...
Poster
BIOCHEMICAL ENGINEERING AND CELL CULTIVATION TECHNIQUE μCT-imaging Meshing (fluid domain) Simulation process Simulation results Cultivation studies μCT-imaging and geometry reconstruction • μCT investigations of the HA-scaffold were performed with a step width (d step) of 8 μm in order to capture the complex surface structure (Fig. 1) • IMARIS soft...
Article
Background: To improve cultivation conditions for human bone-marrow-derived mesenchymal stem cells, we redesigned the commercially available UniVessel® SU bioreactor using results obtained from computational fluid dynamics. The goal was to produce ≥1 × 109 cells and to achieve expansion factors ≥30. Screening studies suggested that microcarrier sol...
Article
Suspension cultures, in which human mesenchymal stem cells (hMSCs) are cultivated on microcarriers in scalable single-use stirred bioreactor types, have been shown to be a promising alternative to planar flask cultures. However, stirred single-use bioreactors were originally developed for production processes with robust, permanent cell lines. hMSC...
Article
Full-text available
The book serves as a good starting point for anyone interested in the application of tissue engineering. It offers a colorful mix of topics, which explain the obstacles and possible solutions for TE applications. The first part covers the use of adult stem cells and their applications. The following chapters offer an insight into the development of...
Poster
References [1] Schop D, Janssen F, Expansion of human mesenchymal stromal cells on microcarriers, growth and metabolism. J Tissue Eng Regen Med. 4(2), 131-140 (2010). [2] Kaiser S, Jossen V, Schirmaier C, Eibl D, Brill S, van den Bos C, Eibl R, Fluid flow and cell proliferation of mesenchymal adipose-derived stem cells in small-scale, stirred, sinl...
Article
Full-text available
Suspension cultures, in which human mesenchymal stem cells are cultivated on microcarriers in scalable single-use stirred bioreactor types, have been shown to be a promising alternative to planar flask cultures. However, stirred single-use biore-actors were originally developed for production processes with robust, permanent cell lines. Human mesen...
Article
The fluid flow and suspension characteristics inside small-scale, stirred, single-use bioreactors were investigated experimentally and by means of computational fluid dynamics. The required impeller speed for homogenous suspension were determined for two microcarrier types. The shear stress level and turbulence distribution were predicted using a n...

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