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Three-dimensional (3D) bioprinting is an appealing and revolutionary manufacturing approach for the accurate placement of biologics, such as living cells and extracellular matrix (ECM) components, in the form of a 3D hierarchical structure to fabricate synthetic multicellular tissues. Many synthetic and natural polymers are applied as cell printing bioinks. One of them, alginate (Alg), is an inexpensive biomaterial that is among the most examined hydrogel materials intended for vascular, cartilage, and bone tissue printing. It has also been studied pertaining to the liver, kidney, and skin, due to its excellent cell response and flexible gelation preparation through divalent ions including calcium. Nevertheless, Alg hydrogels possess certain negative aspects, including weak mechanical characteristics, poor printability, poor structural stability, and poor cell attachment, which may restrict its usage along with the 3D printing approach to prepare artificial tissue. In this review paper, we prepare the accessible materials to be able to encourage and boost new Alg-based bioink formulations with superior characteristics for upcoming purposes in drug delivery systems. Moreover, the major outcomes are discussed, and the outstanding concerns regarding this area and the scope for upcoming examination are outlined.

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Chitosan (CS) has gained particular attention in biomedical applications due to its biocompatibility, antibacterial feature, and biodegradability. Hence, many studies have focused on the manufacturing of CS films, scaffolds, particulate, and inks via different production methods. Nowadays, with the possibility of the precise adjustment of porosity size and shape, fiber size, suitable interconnectivity of pores, and creation of patient-specific constructs, 3D printing has overcome the limitations of many traditional manufacturing methods. Therefore, the fabrication of 3D printed CS scaffolds can lead to promising advances in tissue engineering and regenerative medicine. A review of additive manufacturing types, CS-based printed constructs, their usages as biomaterials, advantages, and drawbacks can open doors to optimize CS-based constructions for biomedical applications. The latest technological issues and upcoming capabilities of 3D printing with CS-based biopolymers for different applications are also discussed. This review article will act as a roadmap aiming to investigate chitosan as a new feedstock concerning various 3D printing approaches which may be employed in biomedical fields. In fact, the combination of 3D printing and CS-based biopolymers is extremely appealing particularly with regard to certain clinical purposes. Complications of 3D printing coupled with the challenges associated with materials should be recognized to help make this method feasible for wider clinical requirements. This strategy is currently gaining substantial attention in terms of several industrial biomedical products. In this review, the key 3D printing approaches along with revealing historical background are initially presented, and ultimately, the applications of different 3D printing techniques for fabricating chitosan constructs will be discussed. The recognition of essential complications and technical problems related to numerous 3D printing techniques and CS-based biopolymer choices according to clinical requirements is crucial. A comprehensive investigation will be required to encounter those challenges and to completely understand the possibilities of 3D printing in the foreseeable future.

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Bone cement synthesis through combination of polymers and bioceramics leads to the enhancement of mechanical and biological performances required for osteogenic properties and apatite‐formation ability with the aim of new bone growth. The purpose of the present study is to characterize a novel poly methyl methacrylate–poly caprolactone (PCL) bone cement containing baghdadite (BAGH) for orthopedic applications. Considerable enhancement in the mechanical properties was found in the cement containing BAGH compared to the cement without BAGH. Noticeably, favorable bioactivity was found in the bone cement containing BAGH, while the cement without BAGH presented poor bioactivity. The MTT assay illustrated that the MG63 osteoblasts' viability was noticeably improved by incorporation of BAGH into the cement. In addition, higher cell attachment and spreading were observed in the cement containing BAGH compared to the cement without BAGH. Hence, the synergistic effects of the cement containing BAGH including high mechanical properties, good bioactivity, and desirable cytocompatibility make it an attractive candidate for filling bone defects in orthopedic surgeries.

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In tissue engineering, three-dimensional (3D) printing is an emerging approach to producing functioning tissue constructs to repair wounds and repair or replace sick tissue/organs. It allows for precise control of materials and other components in the tissue constructs in an automated way, potentially permitting great throughput production. An ink made using one or multiple biomaterials can be 3D printed into tissue constructs by the printing process; though promising in tissue engineering, the printed constructs have also been reported to have the ability to lead to the emergence of unforeseen illnesses and failure due to biomaterial-related infections. Numerous approaches and/or strategies have been developed to combat biomaterial-related infections, and among them, natural biomaterials, surface treatment of biomaterials, and incorporating inorganic agents have been widely employed for the construct fabrication by 3D printing. Despite various attempts to synthesize and/or optimize the inks for 3D printing, the incidence of infection in the implanted tissue constructs remains one of the most significant issues. For the first time, here we present an overview of inks with antibacterial properties for 3D printing, focusing on the principles and strategies to accomplish biomaterials with anti-infective properties, and the synthesis of metallic ion-containing ink, chitosan-containing inks, and other antibacterial inks. Related discussions regarding the mechanics of biofilm formation and antibacterial performance are also presented, along with future perspectives of the importance of developing printable inks.