In situ bioprinting
One of the promising applications of bioprinting is to pattern de novo
tissue directly onto the desired location in the body, such as chronic
wounds in the skin or bone defect. With the aid of medical imaging, the
topology of printed tissue can be designed to fit into the wound/defects
such that heterotypic cellular structure, hydrogels, and soluble factors
can be precisely deposited inside the defects. This approach would
minimize the gap between implant-host interfaces and provide
well-defined structure during the healing process, which can effectively
recruit desired cells from surrounding tissues where the patient’s body
act as a natural bioreactor (Vivian and Dai, 2016). In a recent
proof-of-concept study, Albana et al 2019, demonstrated precise delivery
of autologous/allogeneic dermal fibroblasts and epidermal keratinocytes
directly into an injured area in animals, replicating the layered skin
structure. Excisional wounds bioprinted with layered autologous dermal
fibroblasts and epidermal keratinocytes in a hydrogel carrier showed
rapid wound closure, reduced contraction and accelerated
re-epithelialization. These results showed the feasibility of in situ
bioprinting of skin and its potential applications for regeneration of
various body parts. A successful in situ bioprinting technique could
rapidly accelerate healing using cell therapy, where cells can be
isolated from a small biopsy [Normand and Karasek, 1995].