Future Prospects for Scaffolding Methods and Biomaterials in Skin Tissue Engineering: A Review

Abstract

Over centuries, the field of regenerative skin tissue engineering has had several advancements to facilitate faster wound healing and thereby restoration of skin. Skin tissue regeneration is mainly based on the use of suitable scaffold matrices. There are several scaffold types, such as porous, fibrous, microsphere, hydrogel, composite and acellular, etc., with discrete advantages and disadvantages. These scaffolds are either made up of highly biocompatible natural biomaterials, such as collagen, chitosan, etc., or synthetic materials, such as polycaprolactone (PCL), and poly-ethylene-glycol (PEG), etc. Composite scaffolds, which are a combination of natural or synthetic biomaterials, are highly biocompatible with improved tensile strength for effective skin tissue regeneration. Appropriate knowledge of the properties, advantages and disadvantages of various biomaterials and scaffolds will accelerate the production of suitable scaffolds for skin tissue regeneration applications. At the same time, emphasis on some of the leading challenges in the field of skin tissue engineering, such as cell interaction with scaffolds, faster cellular proliferation/differentiation, and vascularization of engineered tissues, is inevitable. In this review, we discuss various types of scaffolding approaches and biomaterials used in the field of skin tissue engineering and more importantly their future prospects in skin tissue regeneration efforts.

Keywords: biomaterials; natural; polymer; scaffolds; skin; synthetic; tissue engineering; wound healing.

Figure 1

Cell sheets that secret extracellular matrix (ECM). Cells are seeded on the sheets and allowed to secret ECM that facilitates growth and proliferation. Multiple cell seeded sheets capable of secreting ECM are used for implantation at the wound site.

Figure 2

Porous scaffolding using various biomaterials. Various natural, synthetic and biodegradable materials are used for generation of highly porous scaffolds. These scaffolds provide a suitable environment for cell growth and proliferation. The porous nature of such scaffolds facilitates the regular supply of nutrients and oxygen for the skin cells, such as keratinocytes and fibroblasts. The full thickness skin grown on such scaffolds is used for wound transplant.

Figure 3

Acellular scaffolding approach. In this approach, complete de-cellularization of the organ is performed to create extracellular (ECM) based matrices. The cells of interest, such as skin cells, liver cells or any other organ specific cells can be then effectively grown on such scaffolds.

Figure 4

Hydrogel approach. Monomer mixture of a polymeric solution, for example, polyethylene glycol, poly-caprolactone, chitosan, cellulose, etc., are mixed with the skin cells, such as keratinocytes and fibroblasts to generate injectable hydrogels at the wound sites to facilitate wound healing and skin regeneration.