Solution-Based Processing for Scaffold Fabrication in Tissue Engineering Applications: A Brief Review

Abstract

The fabrication of 3D scaffolds is under wide investigation in tissue engineering (TE) because of its incessant development of new advanced technologies and the improvement of traditional processes. Currently, scientific and clinical research focuses on scaffold characterization to restore the function of missing or damaged tissues. A key for suitable scaffold production is the guarantee of an interconnected porous structure that allows the cells to grow as in native tissue. The fabrication techniques should meet the appropriate requirements, including feasible reproducibility and time- and cost-effective assets. This is necessary for easy processability, which is associated with the large range of biomaterials supporting the use of fabrication technologies. This paper presents a review of scaffold fabrication methods starting from polymer solutions that provide highly porous structures under controlled process parameters. In this review, general information of solution-based technologies, including freeze-drying, thermally or diffusion induced phase separation (TIPS or DIPS), and electrospinning, are presented, along with an overview of their technological strategies and applications. Furthermore, the differences in the fabricated constructs in terms of pore size and distribution, porosity, morphology, and mechanical and biological properties, are clarified and critically reviewed. Then, the combination of these techniques for obtaining scaffolds is described, offering the advantages of mimicking the unique architecture of tissues and organs that are intrinsically difficult to design.

Poly-l-Lactic Acid (PLLA)-Based Biomaterials for Regenerative Medicine: A Review on Processing and Applications

“…For this reason, combined with the relatively low elastic modulus of these systems, PLLA-based electrospun scaffolds are mainly engineered for skin or blood vessel regeneration [ 65 , 84 , 85 ]. Despite the need for organic solvents in most of the solution-based processing proposed in literature, several articles ensure the achievement of a final structure without any remaining solvent trace when investigated, hence avoiding cytotoxicity [ 86 , 87 ].…”

Recent progress in 3D printing degradable polylactic acid‐based bone repair scaffold for the application of cancellous bone defect

“…moreover, the diameter of fibers can be controlled and the final form of scaffolds can be modified with a high degree of flexibility. 67 However, the electrospinning technique also has its own disadvantages, which include the thickness, porosity, and pore size of the scaffolds. It has also been proved that it is difficult for cells to penetrate inside the fibrous network of the electrospinning scaffold.…”

Effect of Polyhydroxyalkanoate (PHA) Concentration on Polymeric Scaffolds Based on Blends of Poly-L-Lactic Acid (PLLA) and PHA Prepared via Thermally Induced Phase Separation (TIPS)

“…Over the recent years, large technological and scientific interest have dealt with the possibility of controlling polymer foams products to be employed as scaffolds for tissue engineering applications [1][2][3]. Many techniques have been developed to produce porous tissue engineering scaffolds, such as porogen leaching [4,5], freeze drying [6,7], 3D printing [8][9][10], electrospinning [11][12][13], thermally induced phase separation (TIPS) [14][15][16] and any possible combinations of these [17]. Among the listed techniques, TIPS is one of the most efficient due to its ease of implementation and potential capability to produce highly porous scaffolds with tunable properties [15,17].…”

“…Many techniques have been developed to produce porous tissue engineering scaffolds, such as porogen leaching [4,5], freeze drying [6,7], 3D printing [8][9][10], electrospinning [11][12][13], thermally induced phase separation (TIPS) [14][15][16] and any possible combinations of these [17]. Among the listed techniques, TIPS is one of the most efficient due to its ease of implementation and potential capability to produce highly porous scaffolds with tunable properties [15,17]. Different parameters can be considered to obtain the required properties, such as the polymeric system (including blends), polymer concentration, solvent and nonsolvent system, and cooling rate [18].…”