Brinter® bioprinting applications in regenerative medicine

Brinter® offers an accessible way into the fast-growing application field of 3D bioprinting, which has the potential to transform the sciences of regenerative medicine and tissue engineering.

3D bioprinting is a revolutionary technology that will eventually make medical care faster, more effective, and more personalized by enabling researchers to fabricate geometrically well-defined 3D scaffolds seeded with cells in a rapid, inexpensive, and high-throughput manner. Bioprinting organs and tissue patches from a patient’s own cells reduces the chance of rejection and can eliminate the need for organ donors.

Tissue Engineering applications

Traditionally, stem cells have been grown in plastic culture plates as two-dimensional (2D) monolayers. These 2D culture techniques are inherently inefficient, labour-intensive, expensive, and yield limited expansion of stem cells. Moreover, 2D cultures yield heterogeneous populations of stem cells and their derivatives, lacking the intricacy needed to mimic the 3D microenvironment of a stem cell niche responsible for the regulation of stem cell fate.

More recently developed 3D culture methods can control cell fate by recapitulating the physical and biochemical properties of the native microenvironments. However, these prefabricated or rigid 3D scaffolds require cell seeding or migration of cells into the scaffold, yielding a heterogeneous distribution of cells. Moreover, conventional laboratory techniques such as photolithography and stamping for patterning the scaffolds with biologically active molecules are time-consuming, involving several complex fabrication steps performed manually, making fabrication of 3D microenvironments difficult to scale up.

Bioprinting allows researchers to fabricate simplified homocellular tissue models for basic research or to produce more complex scaffolds with controlled spatial heterogeneity of physical properties, cellular composition, and ECM/biomolecule organization.

It allows automated fabrication of spatially defined gradients of immobilized biomolecules in a noncontact manner reducing the risk of cross-contamination originating from the surface and without the need to chemically modify the printable proteins or substrates.

Drug screening applications

Drug development costs are prohibitively expensive, averaging around $2.6 billion for every new drug entering the market. R&D is becoming even more challenging with stricter guidance around animal testing, demanding that the pharmaceutical industry needs more cost-effective alternatives without compromising results.

The results gained from preclinical animal models used to assess the safety and toxicity of new drug candidates translate poorly to humans. Hence, the failure rate for new drugs reaching clinical trials is around 90 per cent, with only one in ten eventually making it to market.

Bioprinted tissue models based on human cells can improve the drug discovery process by eliminating unsafe drug candidates at an earlier stage, thus speeding up the translation of new drugs into clinics. They can also eliminate the need for animal models in drug discovery and cosmetic testing altogether as well as decrease preclinical trial costs.

Similarly, the automatically and reproducibly produced tissue constructs can increase the confidence in safety assessments and guide research projects away from potential hepatic toxicants at an earlier stage.

Cancer research applications

Cancer therapeutics currently have the lowest clinical trial success rate of all major diseases. The majority of cancer research is conducted in mouse models that do not accurately represent human tumor biology.

Hence, better and more affordable preclinical human tissue models accurately representing human cancer pathways in a realistic biological context are highly needed.

Bioprinted in-vitro tumor models based on human cancer cells can accurately reproduce the characteristics of human cancer tissue, which allows studies concerning complex interactions such as cancer cell dynamics during vascularization or metastasis of cancer cells. Bioprinted tumor models created using a patient’s own cancerous cells could also enable future personalization of anti-cancer drugs.

Drug printing applications

The conventional pharmaceutical manufacturing processes for tablets and other oral dosage forms first developed around 200 years ago are cost-effective for large-scale production but are inherently time-consuming, labour-intensive, and dose inflexible.

Tablets are usually mass-manufactured in a few discrete strengths, often based on the dose required for a suitable effect in the majority of the population without regard to individual genetic profile, disease state, gender, age, and weight.

Nor do traditional manufacturing processes easily support early-phase drug development, where doses need to vary according to evolving study needs.

Bioprinting generates new ways to produce prescription pills from sets of biochemical inks customized for each patient. This allows the individualization of medication according to the needs of the patients, their genetic profile, as well as their health condition, moving beyond a “one size fits all” approach towards personalized medicines. Instead of taking many pills a day, future patients could take just one 3D printed composite pill containing multiple drugs, each with a unique release rate.

3D bioprinting of drugs could take place anywhere in the world with access to the active ingredients, supporting on-demand dispensing in various settings, such as pharmacies and hospital wards, which could improve medicine access, reduce medicine wastage, and accelerate discharge times from hospitals.

Bioprinted tissue and organ applications

Organ transplant waiting lists for patients on long-term dialysis or approaching end-stage liver failure represent an economic health burden felt by every health system in the world.

Despite the high (and constantly increasing) number of performed transplantations, these cover less than 10 per cent of patients waiting for donor organs that must be sourced either from living or deceased donors. Furthermore, any patient who finally receives a transplant faces a lifetime on immunosuppressive drugs.

However, a wide variety of tissues, such as blood vessels and neovascularized cartilage, have now been successfully bioprinted, and the vision is to make it possible to 3D bioprint entire functional organs for those in need of organ transplant.

Incorporation of nerves, blood vessels, and lymphatic vessels capable of integrating with host systems will enable the creation of transplantable organs, such as kidneys, lungs, hearts, and livers. Before the transition to clinics, artificial organs will be assessed via animal transplantation.

Nor would bioprinted organs be rejected by the body as they could be fabricated from the patient’s own cells, which would eliminate the detrimental side effects of immunosuppressive drugs as well as the tremendous costs they create for the healthcare system.

Bioprinting techniques

Brinter® 3D bioprinting platforms use revolutionary 3D biomanufacturing technology to drive the field of 3D cell culture models, regenerative medicine and tissue engineering into the future.

Brinter® bioprinter setups can be individually configured to specific research and manufacturing applications ranging from personalized tissue models for drug screening to printing complex drug formulations and ultimately to bioprinted entire functional organs from patients’ own cells for those in need of organ transplant.

Specific techniques include:

• Creating 3D tumor models for cancer research: Brinter®’s automated fabrication process allows the researcher to create complex 3D tumors in vitro by printing reproducible cancer models by carefully placing various cell types and supporting biomaterials to construct physiologically relevant cancer models across well plates in a high-throughput manner. These models allow studies concerning complex interactions such as cancer cell dynamics during vascularization or metastasis of cancer cells.
• Fully personalized models: Bioprinted tumor models can even be created using a patient’s own cancerous cells, enabling full personalization of anti-cancer drugs, along with Drug Sensitivity and Resistance Testing (DSRT). Brinter®’s brand-new integrated slicer feature allows full control of the various printouts during a single print job by setting control and experimental groups on the well plates or Petri dishes with just a few button clicks, allowing multiple anti-cancer drugs to be tested simultaneously.
• Full reproducibility: Brinter® automated precision printing technologies allow cancer models to be effortlessly printed, multiplied and repeated on any cell culture platform. Research quality improves due to reduced human error, as the production is done automatically in a controlled environment.
• Chondral repairment research: The bioprinter can be used to design and print hybrid constructs combining rigid and soft materials into a single structure. Alternatively, it is possible to print a complex tissue model with overhangs from soft cell-embedded hydrogel inside a supporting gelatin slurry and wash it off afterwards to reveal a perfect printout.
• Fully personalized chondral models: Brinter has developed new technologies to print cartilage or chondral lesion models based on CT/MRI imaging having complex geometries and small sizes. The combination of several printing technologies enables personalized cartilage constructs with controlled shape, structural integrity, and cellular composition.
• On the fly mixing: Brinter’s proprietary fluidic manipulation technology enables the control of the flow of fluids with various physicochemical properties, allowing multiple component bioinks to be actively mixed or formed into flow patterns to achieve various structures, sorting, formulations or encapsulated droplets that can be used for diverse life science engineering, cosmetics, food engineering, pharmaceutical formulation, and other applications.
• Hybrid printing: It is possible to combine hard and soft materials to mimic the mechanical properties of native cartilage and bone. This multi-material printing is enabled by Brinter®’s hot extrusion and pneumatic print heads, making it possible to fabricate complex constructs composed of both rigid, load-bearing biomaterial supporting frames and soft hydrogels carrying cells by combining several different bioprinting techniques into a single print job.

Matching Bioprinter to application

Brinter® technology features sets of proprietary fluidic controllers, actuators, high-frequency solenoids and valves, with precision sensors to allow the control of multiple flow parameters and manipulation of multiple fluids individually for active mixing, flow focusing, sorting, and structure generation.

Depending on the specific application, different combinations of Brinter® technologies can be used. Specific features that can be employed include:

• Pneuma Cooled print head: Pneumatic print head with cooling from RT to +4 °C enabling printing of low to medium viscosity hydrogels, silicones and pastes, such as collagen or Matrigel. Equipped with integrated UV/Vis LEDs.
• Pneuma Pro print head: Pneumatic print head with heating from RT to +66 °C, enabling printing of low to medium viscosity hydrogels, silicones and pastes, such as hydrogels with living cells at +37 °C. Equipped with UV/Vis LEDs.
• Visco Tool print head: The endless piston principle Visco tool enables accurate printing of various viscous fluids and pastes, such as bioinks, biopaste, silicone, acrylate, epoxy resin, light-curing adhesives, waxes, ceramics, and abrasive pastes.
• Heated & cooled print bed: Provides a temperature-controlled environment for the printed structure from +4 °C up to +80 °C.
• UV/Vis LED module: Germicidal and photocuring module equipped with 265 nm, 365 nm and 405 nm LEDs to enable automatic disinfection of the print bed before starting the actual printing process, as well as layer-by-layer photocuring of light-sensitive bioinks, such as GelMA and UV silicone.
• MicroDroplet print head: Solenoid valve actuated dosing system enabling precision dosing of droplets in the range from 10 μL to 1000 μL. Dispensing of various liquids, e.g., cell suspension, cell media, drugs, growth factors, and crosslinking agents.
• Laminar flow unit: Directed airflow ensures a sterile working area both inside and around the bioprinter cabinet, even with the door open, allowing researchers to prepare and mix bioinks in sterile conditions close to the bioprinter.

Resources

Click on Bioprinting Applications for further information.
Click on Benefits of Bioprinting for further information.