Kontinkangas campus infrastructure for biomedical research

Kontinkangas campus infrastructure for biomedical research provides open access equipment, services, technical help, and scientific expertise for various technologies in biomedicine for conducting high-quality research. Biomedical research infrastructures are offered by the BCO Core Facilities, Faculty of Medicine, and Faculty of Biochemistry and Molecular Medicine and are available in different application areas; in vivo models, biological imaging, clinical cohorts, bio- and databanks, molecular and cell biology, and in vitro technologies.

In vivo models

Echocardiography (Faculty of Medicine)

Flexivent respiratory function (FBMM)

Generation and analysis of transgenic mice (BCO)

IVIS in vivo imaging system (BCO, OULAC)

Metabolism cages (Faculty of Medicine)

Oulu Laboratory Animal Centre (OULAC)

Biological imaging

Advanced light microscopy (BCO)

Computed tomography and x-ray microscopy (Faculty of Medicine)

Cryo TEM (FBMM)

Electron microscopy (BCO)

Incucyte live cell imaging (Faculty of Medicine)

Clinical cohorts, bio- and databanks

Biobank Borealis of Northern Finland (Faculty of Medicine, PPSHP)

Northern Finland Birth Cohorts/Arctic Biobank (Faculty of Medicine)

Molecular biology technologies

Biocomputing (BCO)

DNA/RNA sequencing (BCO)

Histological techniques (Faculty of Medicine)

Optical genome mapping (Faculty of Medicine)

Optical tweezers (FBMM)

Optical Tweezer (OT) and its bio-photonics applications

‘Optical tweezer’ is an optical set up, which forms a tightly focused laser beam that can trap and levitate dielectric microscopic particles e.g., biological cells or micro beads, without making a mechanical contact with the trapped entity.

A tightly focused laser with a Gaussian beam profile, near its focal point/ beam waist can approximated to be a harmonic oscillator (a coil spring is an example of a harmonic oscillator). In the ray optics regime, it obeys Hooke’s law. A dielectric particle near the beam waist experiences an unbalanced scattering force and gradient force towards the beam focus, it pushes the dielectric particle towards the trap center. The scattering and gradient forces are in equilibrium, when the dielectric particle is stably trapped in the tweezer. A calibrated tweezer can be used to directly measure forces of a microscopic system.

In biophotonics, the major applications of the tweezers are to study the physical properties of biological entities, such as the adhesion/cohesion forces between two biological cells, elasticity of protein strands or cells, to study the visco-elastic properties of a sample using microscopic probes or micro beads, etc. The microbeads or cells can be trapped in the tweezer and move, and confine spatially.

Technical specifications of the Kontinkangas OT-Axiovert 100M system.

The tabletop optical tweezer is built integrated to Axiovert 100M inverted microscope; operated in brightfield mode for the tweezer-based studies. The optical tweezers system consists of 856nm and 975nm lasers (lasers are operated such that, up to 110mW laser power reaches the sample plane). Both wavelengths belong to the biological window spectral regime (700-1100nm), where the optical absorption in minimal. The lasers are redirected to the back aperture of a 100x,1.4 oil objective through a beam expander that expands the beam diameter filling the back aperture of the objective. 975nm laser is reflected via a 2D galvo mirror system. The 2D galvo mirror system enables software-controlled movement of the 975nm laser beam (hence the beam focus) in a 2D plane (~25x25 μm2 area in the sample plane). In addition to the beam steering using 2D galvo mirror, motorized XY scanning stage and motorized focus control facilitates three-dimensional relative movement between the OT and the sample under study, using software control. Imaging is done with a high-speed, monochromatic CMOS camera (75-1300 frames per second is achievable with Matlab image acquisition toolbox), which can also be used for passive calibration techniques of the tweezer, and to capture high frequency movements such as Brownian motion, at a resolution 1pixel ~ 99.5nm.

Using 100x, 1.4NA oil objective, a polystyrene microbead as small as ~500nm and a biological cell as big as 15-20um can be trapped in the tweezer and moved either by beam steering or by moving the motorized microscopic stage. Based on the type of studies, Brownian motion-based calibration (example: for 1um micro bead) or drag force-based calibration (example: 7um micro bead or a biological cell) can be done.

Contact person:

Jeena Ainikkal Velayudhan, e-mail: jeena.ainikkalvelayudhan@oulu.fi

Proteomics and protein analysis (BCO)

Structural biology (BCO)

Cell biology and in vitro technologies

3D Bioprinting (FBMM)

Application

Bioprinting/Tissue engineering comprises three primary components used with the aim of restoring, maintaining, or replacing organs. It can be used to print hard tissue (Bone) and different soft tissues based on bioink and cell type.

What is Bioprinting?

Bioprinting technologies are mainly divided into three categories, inkjet-based bioprinting, pressure-assisted bioprinting, and laser-assisted bioprinting, based on their underlying printing principles. These various printing technologies have their advantages and limitations. The device we have in BCO works based on pressure assistance, the most common method for biological purposes. Basically, 3D bioprinting is a technology where cell-laden bioinks (biomaterials mixed with living cells) are deposited (printed) in 3D to construct a natural tissue-like structure.

Our device features

Modulus:

The product is provided by Brinter company (https://www.brinter.com/) which has a variety of modulus including (1) Digital Pneuma Triaxial Pro – with Microfluidics, (2) Visco Tool Bio, (3) Pneuma Tool Cooled, (4) Visco Tool Heated, (5) Micro Droplet Tool.
Photocuring LEDs allow UV (365 nm) and blue light (405 nm) photocuring of photosensitive bioinks during or after the printing with the possibility to adjust curing intensity, time, and distance.
Optional UV/Vis light module comes with UV-C germicidal LEDs emitting light at 265 nm and can be used for automatic disinfection of the Petri dishes, well-plates or the entire print bed before starting the actual printing process.

Bioink:

Any kind of biocompatible material (natural based or synthetic) which can maintain its 3D structure after being printed can be used as a bioink. Bioink selection is highly dependent on the tissue we aim to mimic and print. Cell viability of the cells in the bioink, mechanical properties, biodegradation rate, electro conductance (for neural tissue engineering aspects), response to temperature, and many other parameters should be taken into account. The most common bioinks are (1) Alginate (2) Gelatin/methacrylate, (3) Collagen/methacrylate (4) Nanocellulose, (5) Polyethylene glycol (PEG), and PEGDA which are commercially available. There is a possibility also to mix one’s extracted ECM with the above bioink and print them.

Printing process

The final structure should be designed in CAD software like SOLID WORK, Fusion 360, or other online 3D sketch software. The design (STL file) will be imported to the Brinter-software where we can manipulate the printing process parameters and the software generate the G codes and the printing process starts!

Contact person: Hasan Ansarizadeh, e-mail: hasan.ansarizadeh@oulu.fi

	Channel	Excitation	Emission
Fluorescence	Green	440–480 nm	504–544 nm
Excitation/Emission	Red	565–605 nm	625–705 nm
Dual Color Module 4614