Bioprinted Recombinant Human-Collagen-Based In Vitro Skin Models for Assessing Effects of Nano-ZnO on Dermis

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Dermatology

Background:

• Collagen types I and III are crucial for skin structure, but their ratio changes with age.
• Aging disrupts the natural balance of collagen, affecting skin integrity.
• A physiologically relevant model is needed to study skin aging and treatments.

Purpose of the Study:

• To develop a biomimetic 3D skin model with vascularization potential.
• To evaluate the effects of nano-zinc oxide (nano-ZnO) on skin cells within this model.
• To mimic the collagen I/III ratios found in both children's and adults' skin.

Main Methods:

• Utilized methacrylated recombinant human collagen (RHC-MA) bioinks with adjustable collagen I/III ratios.
• 3D bioprinted full-thickness skin constructs containing dermal (fibroblasts, endothelial cells) and epidermal (keratinocytes) layers.
• Validated the model by assessing key skin markers (K10, K14, CD31) and gene expression via qRT-PCR.

Main Results:

• The RHC-MA bioinks demonstrated excellent printability and mechanical stability for 3D bioprinting.
• The 3D skin model successfully recapitulated native skin architecture and cellular markers.
• Nano-zinc oxide (nano-ZnO) significantly altered gene expression related to apoptosis, inflammation, and oxidative stress in skin cells.

Conclusions:

• A biomimetic 3D skin model using RHC-MA bioinks is effective for studying skin.
• Nano-ZnO influences key cellular pathways involved in skin aging and stress responses.
• This model provides a relevant platform for evaluating dermatological agents like nano-ZnO.