Techniques for fabrication and construction of three-dimensional scaffolds for tissue engineering

Abstract

Three-dimensional biomimetic scaffolds have widespread applications in biomedical tissue engineering because of their nanoscaled architecture, eg, nanofibers and nanopores, similar to the native extracellular matrix. In the conventional "top-down" approach, cells are seeded onto a biocompatible and biodegradable scaffold, in which cells are expected to populate in the scaffold and create their own extracellular matrix. The top-down approach based on these scaffolds has successfully engineered thin tissues, including skin, bladder, and cartilage in vitro. However, it is still a challenge to fabricate complex and functional tissues (eg, liver and kidney) due to the lack of vascularization systems and limited diffusion properties of these large biomimetic scaffolds. The emerging "bottom-up" method may hold great potential to address these challenges, and focuses on fabricating microscale tissue building blocks with a specific microarchitecture and assembling these units to engineer larger tissue constructs from the bottom up. In this review, state-of-the-art methods for fabrication of three-dimensional biomimetic scaffolds are presented, and their advantages and drawbacks are discussed. The bottom-up methods used to assemble microscale building blocks (eg, microscale hydrogels) for tissue engineering are also reviewed. Finally, perspectives on future development of the bottom-up approach for tissue engineering are addressed.

The Potential Impact of Bone Tissue Engineering in the Clinic

“…Furthermore, a workpath from patient radiological images to implant CAD software to a 3D printer is extremely efficient. These methods can be used for the preparation of patient-specific implants for use in research and/or clinical applications [85][86][87][88][89]. The primary restrictions are the requisite expertise, access to implant CAD software, access to an appropriate 3D printer, and access to FDA-approved, 3D printable, implant material.…”

Coming to terms with tissue engineering and regenerative medicine in the lung

“…The field of tissue engineering is geared toward developing clinically viable approaches to recreating or enhancing human organs and tissues that recapitulate both the structure and function of the native organ. For example, engineering of replacement skin tissues is now well recognized (68,187), and there has been substantial progress in other organ systems such as cartilage (45,54,107,159) and bladder (53,104,138,185,212). With regard to the lung, technologies that mimic lung function such as cardiopulmonary bypass and extracorporeal membrane oxygenation are well developed and routinely used in in-hospital settings, but they suffer from being of short-term, nonambula-tory use.…”

Preparation and Physicochemical Characterization of Nano- Hydroxyapatite Based 3D Porous Scaffold for Biomedical Application

“…21 This study has chosen freeze-drying because it can form highly a porous structure and offer stability and ease of handling. 22,23 This study focuses on preparing and characterizing composite scaffold synthesized from three natural-based materials-chitosan, gelatin and HA. Afterwards in combination with agarose/PVA, these three materials offer potential synergies between physical properties and bioactivity for use as bone substitutes in bone grafts, benefiting a range of surgical applications.…”