Direct writing of chitosan scaffolds using a robotic system

Abstract

Purpose -This paper aims to present a novel rapid prototyping (RP) fabrication methods and preliminary characterization for chitosan scaffolds. Design -A desktop rapid prototyping robot dispensing (RPBOD) system has been developed to fabricate scaffolds for tissue engineering (TE) applications. The system is a computer-controlled four-axis machine with a multiple-dispenser head. Neutralization of the acetic acid by the sodium hydroxide results in a precipitate to form a gel-like chitosan strand. The scaffold properties were characterized by scanning electron microscopy, porosity calculation and compression test. An example of fabrication of a freeform hydrogel scaffold is demonstrated. The required geometric data for the freeform scaffold were obtained from CT-scan images and the dispensing path control data were converted form its volume model. The applications of the scaffolds are discussed based on its potential for TE. Findings -It is shown that the RPBOD system can be interfaced with imaging techniques and computational modeling to produce scaffolds which can be customized in overall size and shape allowing tissue-engineered grafts to be tailored to specific applications or even for individual patients. Research limitations/implications -Important challenges for further research are the incorporation of growth factors, as well as cell seeding into the 3D dispensing plotting materials. Improvements regarding the mechanical properties of the scaffolds are also necessary. Originality/value -One of the important aspects of TE is the design scaffolds. For customized TE, it is essential to be able to fabricate 3D scaffolds of various geometric shapes, in order to repair tissue defects. RP or solid free-form fabrication techniques hold great promise for designing 3D customized scaffolds; yet traditional cell-seeding techniques may not provide enough cell mass for larger constructs. This paper presents a novel attempt to fabricate 3D scaffolds, using hydrogels which in the future can be combined with cells.

Polymers for Bioprinting

“…This solubility dependency allows chitosan to be used for bioprinting [55,56]. It is a semicrystalline polymer that cannot dissolve in aqueous environments above neutral pH.…”

Characterization of printed PLA scaffolds for bone tissue engineering

“…Composites polymeric materials like PCL‐HA or PCL‐TCP have also been produced by FDM and thus been used in bone tissue engineering for their mechanical and biochemical properties . Chitosan is a well‐known biodegradable polymer used to print scaffolds for tissue engineering purposes and has been shown to modulate macrophages’ cytokine production in vitro . PLA is a hydrophobic aliphatic polyester approved by the US Food and Drug Administration (FDA) for different biomedical and clinical applications .…”

Investigation of PLA-based scaffolds fabricated via SVM rapid prototyping

“…Similarly, many in-house developing RP techniques have been considered for this application also, e.g. LDM [26], RPBOD [27], AJS [28], micro-extrusion [29], and cyrogenic prototyping [30,31].…”