The 3D Cell Culture & Tissue Engineering

As all of us may already be aware, currently different techniques available for 3D cell culture; while each of them offers different positives and a few negatives. Before moving ahead to understand them, it is always better to first compare 3D cell culture with its conventional counterpart, the 2D technique.

3D cell culture technique is vastly privileged to facilitate cellular differentiation and tissue organization using micro-assembled, custom-designed structures, supported by a complex microenvironment. Many studies have vetoed that cells in 3D culture are very sensitive toward morphological as well as physiological changes; which not only influence genetic expression but also enhance cellular communication.

With the help of 3D cell culture, researchers can grow two different cellular populations together, which are known as cocultures and can exactly reproduce the cellular functions observed within a tissue.

Thus, unlike 2D culture, 3D culture is a relatively new technique and requires a lot of understanding, expertise, and supportive accessories like different 3D culture matrices. However, for various applications 3D cell culture is a more satisfactory model for mimicking in vivo cell behaviors and organizations. While assembling multi-layered 3D cell culture requires optimum supporting microenvironment influencing cellular morphology, and differentiation potential to the great extent.

As discussed above, scaffolds can be used as a convenient support for 3D cell culture techniques. The flow of oxygen, nutrients, and waste products largely depend upon the porosity of the scaffolds. The more porous the scaffold is, the more cellular proliferation and migration within the web of the scaffold; and they eventually adhere to the same. While cells keep growing, the mature cells interact with each other and will eventually turn into structures close to the tissue they initially originated from.

As discussed, depending upon the type of cells to be handled, at Kosheeka we have invented adequate scaffolds possessing suitable properties and shapes. These scaffold layouts match the tissue of interest while reproducing its structure, scale, and functions.

Some of our scaffolds that have gained good recognition are:

• Hydrogel scaffolds
• Nongel polymer scaffolds
• Lyophilized membranes
• The recombinant matrices

Conclusively, biomaterials are gaining promising positions in the field of tissue engineering and translational applications.

Recently, organoids generated from primary cells, especially tissue-specific stem cells are identified to be the ideal candidates for reproducible and scalable 3D models for organs on chips. These organoids have expressed similar properties during in vitro culture as that of stem cells, and originated from specific tissue; some of these properties can be listed as self-renewal, differentiation properties, property of adherence, etc. These models address different limitations of existing models including:

Similar composition and architecture as that of primary tissues

As they harbor a small population of self-renewing stem cells, further differentiating into cells of all major lineages, with comparable properties and frequencies as in physiological conditions.

Relevant models of in vivo conditions

These organoids are more biologically relevant to any other organ system and are identified to manipulate niche components and gene sequences.

Stable system for extended cultivation

These organoids can be cryopreserved for a longer duration as biobanks and expanded indefinitely by leveraging self-renewal, differentiation capability of stem cells, and intrinsic ability to self-organize.

As stated above, these organoids are produced either with primary cells or with other pluripotent stem cells like embryonic stem cells and/or induced pluripotent stem cells by appropriate physical and biochemical cues. The physical cues for cellular attachment and survival are collagen, fibronectin, entactin, and laminin; while biochemical cues are EGF, FGF-10, R-spondin, WNT3A, etc.

Out of various known applications of organoids, some of the applications mentioned herewith hold great promise in both basic research and translational medicines.

These applications are:

• Developmental Biology
• Disease pathology of infectious diseases
• Regenerative Medicine
• Drug toxicity and efficacy testing
• Personalized medicine

The products of Kosheeka supporting organoid formation are

• Organoid Dissociation Medium
• Organoid Freezing Medium
• Organoid Conditioning Medium

These 3D balls formed due spatial arrangement of primary cells during in vitro cultures are critically important in the current biomedical practices. These proliferative spheres were named in the 1970s when hamster lung cells were grown in the culture, during which they arranged themselves into perfect spheres. Studies have indicated that these spheroids can increase cellular connectivity, and facilitate more rigorous communication for understanding the cellular microenvironment; which can in turn offer realistic tissue models for studying different pathophysiology.

The applications of spheroids are especially encouraging in regenerative medicine research, cancer research, and drug screening.

Despite their great requirements, currently one of the primary challenges in their production is to find primary cells that are robust, consistent, proliferative, and mimic the exact tissue of isolation. The latter is very important for achieving physiologically relevant outcomes because the cellular functions of the spheroids show a correlation to the size of the cell cluster.

Kosheeka is on the verge of developing a range of products supporting the production of spheroids like

• Primary cells and/or stem cells including cancer stem cells
• Serum-free growth medium for optimum proliferation and growth
• GMP compliant