Research & innovation

Open Flow Microperfusion (OFM)

A Sampling Technology Developed by JOANNEUM RESEARCH HEALTH

Open flow microperfusion (OFM) is a membrane-free, minimally invasive, in vivo sampling technology that allows continuous sampling of interstitial fluid (ISF) for preclinical drug development studies and biomarker research. The decisive advantage of OFM is that it provides direct access to the ISF of various tissues by using membrane-free OFM probes. These membrane-free OFM probes feature an exchange area with no diffusion barrier, and therefore OFM sampling is not restricted by the size or lipophilicity of substances or protein binding effects. This is in contrast to membrane-based probes that allow sampling of low molecular weight or hydrophilic substances only.

Open Flow Microperfusion

OFM is designed for continuous sampling of analytes from the ISF of skin (dermal OFM, dOFM) and adipose tissue (adipose OFM, aOFM).

OFM is capable of sampling lipophilic and hydrophilic compounds, protein-bound and unbound drugs, neurotransmitters, peptides and proteins, antibodies,  nanoparticles and nanocarriers, enzymes and vesicles.

OFM uses probes with macroscopic openings that allow non-selective exchange of substances in a fluid pathway based on convection rather than diffusion, which allows exchange in both directions.

The direct liquid pathway between the probe’s perfusate and the surrounding ISF results in collection of diluted but otherwise unchanged ISF from the investigated target tissues (skin, adipose tissue). Endogenous and exogenous substances present in the ISF can thus be quantified without the risk of investigating an altered sample.


Dermal OFM (dOFM)

dOFM allows the investigation of drug transport in and drug penetration into the dermis after topical or systemic drug application. dOFM is recommended by the U.S. Food and Drug Administration (US FDA) as a novel method for assessment of bioequivalence of topical drugs. dOFM is used to:

  • conduct tissue-specific pharmacokinetic (PK) and pharmacodynamic (PD) studies of drugs.
  • perform head-to-head comparisons of novel topical drug formulations.
  • assess dermal bioavailability.
  • investigate high molecular weight compounds, e.g. antibodies.

Head-to-head settings with OFM have proven particularly useful for evaluating topical generic drug products, which need to demonstrate bioequivalence  to the reference listed drug product to obtain market approval. Applications of dOFM include ex vivo studies with tissue explants and preclinical and clinical in vivo studies.

Adipose OFM (aOFM)

aOFM allows continuous online monitoring of metabolic processes in the subcutaneous adipose tissue, e.g. monitoring of glucose and lactate,    and also larger analytes such as insulin (5.9 kDa).   In addition, the role of polypeptides for metabolic signaling (leptin, cytokine IL-6, TNFα) has been studied with aOFM.  aOFM allows the quantification of proteins (e.g. albumin, size: 68 kDa) in adipose tissue , and thus offers possibility to investigate protein-bound drugs such as highly protein-bound insulin analogues designed for a prolonged, retarded insulin action directly in the adipose tissue.  Most recently, aOFM has been employed to sample agonists to study obesity, lipid metabolism and immune-inflammation. Applications of aOFM include ex vivo studies with tissue explants and preclinical and clinical in vivo studies.

Open Flow Microperfusion

Materials and Methods

Microperfusion Pump for Preclinical OFM Studies – MPP102PC

OFM achieves stable recovery of ISF samples by using a specialized peristaltic OFM pump. Power supply with main supply or primary battery

  • Push and pull option integrated in one pump
  • 2 independent controllable pump heads
  • 6 channels
  • Up to 3 push and 3 pull channels
  • Standard flow rates: 0.1 – 10 μl/min
  • No flow-rate calibration necessary
  • Typical operating time (with a new battery): up to 48 hours at 1.0μl/min and up to 24 hours at 10μl/min.
  • Display: LCD with backlight
  • Dimensions: 130 x 92 x 34.5mm
  • ​Total weight: 295g excl. battery and accessories.
  • ​Ambient operating temperature: 5 to 40°C
  • Attachable to large animals (dog, pig & primate)
  • Power supply via battery or 230V AC power cord
  • Compatible with low bind tubing sets
  • CE-marked

Perfusate Bag – 10 mL

Pack of 3.

  • For use with Microperfusion Pump
  • Ready for connection to up to 3 push channels
  • To be used with single channel or 3 channel tubing 
  • Perfusate not included
  • Gamma-irradiated (sterile)Video

dOFM/aOFM Probe for Skin and Adipose Tissue

Pack of 3.

  • Inert & low adsorptive polymer, outer diameter 0.55 mm; inner diameter 0.40 mm, exchange area 15 mm; Shaft length: 200 mm
  • Includes Mandrel (stainless steel)
  • Gamma-irradiated (sterile)
  • Video
OFM Tubing

OFM Tubing and Accessories

Pack of 3 or 6 

  • Low-bind tubing designed specifically for OFM studies. Compared to traditional FEP or PEEK tubing, this fluoropolymer tubing is less gas permeable and minimizes air bubbles, which optimizes the flow and results in increased recovery rates. Additionally this tubing shows less adsorption.
  • OFM-PP2-100-LB Universal Push-Pull Low-Bind Tubing (3/PK)
  • OFM-T1-100-LB Low Bind Tubing 0.25mm (6/PK, 100 cm)
  • OFM-T2-100-LB Low Bind Tubing 0.13mm (6/PK, 100 cm)
  • OFM-PS3-75 dOFM 3-channel Push Tubing (3/PK)
  • OFM-PL3-75 dOFM 3-channel Pull Tubing (3/PK) 
  • OFM-PL3-75-LB dOFM 3-channel Pull Low-Bind Tubing (3/PK)

BioToSkin offers a wide choice of ex vivo and in vitro service provision.
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