The Integration of Nanotechnology and Biology for Cell Engineering: Promises and Challenges

Abstract

Introduction: Successful tissue engineering strategies leading to the regeneration of a tissue depend on many factors, starting from the choice of appropriate scaffold material, tailoring the surface functionalities and topography, providing the correct amount of chemical and mechanical stimuli at the appropriate time points, and ensuring the uniform and precise localization of cells. Further challenges arise when more than one cell type has to be employed for the effective regeneration of an organ. Importance: Though the use of nanomaterials has improved tissue engineering, many pitfalls still exist that present a roadblock in the translation of tissue engineering strategies to clinical practice. Apart from employing different materials with distinct surface functionalities and mechanical properties, various strategies have been employed to manipulate the surface topography and chemistry of scaffolds to create a biomimetic microenvironment for effective tissue regeneration. Conclusion: This review provides information about the factors influencing tissue engineering, namely geometry, chemistry, mechanics and cells, and the emerging concepts that may well represent the future of regenerative medicine. Electrospinning techniques and their variants, self-assembly, cell-printing techniques and cell sheet engineering, have all been elaborated in detail. These novel techniques may serve to overcome the challenges currently faced in tissue engineering.

Development of hydrogels for regenerative engineering

“…). However, the conjugation of chemical groups and long‐term crosslinking procedures may influence the viabilities of the cells encapsulated in the hydrogels . In this section, chemically modulated hydrogels with high biocompatibility for regenerative engineering are introduced.…”

Recent cell printing systems for tissue engineering

“… Basic techniques of 3D cell printing, (a) laser-assisted 3D cell printing techniques with and without an absorbing layer,[ 17 , 22 ] (b) thermal, piezoelectric, and acoustic inkjet 3D cell printing systems,[ 22 , 28 ] and (c) microextrusion 3D cell printing systems and products[ 14 , 35 ]. …”

“…Owing to a r elatively low flow rate, the vaporization of cell-laden bioink and possibility of cell contamination can significantly increase if a scaffold is built in larger scale. In addition, the potential cell damages caused by the thermal energy of the laser is another factor to be concerned [17,22] . Therefore, the integration of techniques, such as fast gelation of droplets or bio-papers, are actively attempted to overcome the existing limitations.…”

“…In an additional hybrid application, Yeo et al [22,57] developed a hybrid fabrication of a hierarchical scaffold using an electrospinning method to align fine PCL nano-fibers on the micro-sized PCL struts created from a melt-plotting process as shown in ( ) [56] . Then, they printed alginate-based bioink with myoblasts on the electrospun fibers to examine the alignment and stretching of the myoblast cells.…”

“…Although inkjet 3D cell printing has Figure 1. Basic techniques of 3D cell printing, (a) laser-assisted 3D cell printing techniques with and without an absorbing layer, [17,22] (b) thermal, piezoelectric, and acoustic inkjet 3D cell printing systems, [22,28] and (c) microextrusion 3D cell printing systems and products [14,35] . unsolved issues, it is expected to be a v ersatile tool in broad tissue engineering application [22,28] .…”