## 1 Introduction  
The articular cartilage is a specialised connective tissue that provides a low-friction, lubricated, and load-bearing surface for efficient joint movement. However, its compositional and structural nature is easily disrupted with overuse, trauma, or degenerative diseases [1]. Any injury to the articular cartilage can lead to progressive impairment of the joint structure, which is one of the major causes of joint pain and chronic disability that lastsfor years [2; 3]. Unlike bones, which have the natural ability to heal over time, the articular cartilage, unfortunately, has a limited capacity for self-repair due to the absence of blood vessels, making treatment efforts a challenge [1; 3]. Current treatments used in clinical practice include symptomatic and restoration procedures [2; 4]. Symptomatic treatments are generally prescribed painkillers and non-steroidal anti-inflammatory drugs (NSAIDs) that offer pain relief while restoration treatments utilise surgical approaches which involve reconstructing the damaged articular cartilage and total joint replacement. However, these treatments require prolonged rehabilitation and complications can arise, such as donor shortage and immunologic response associated with these methods [2; 4]. Research on tissue-engineered articular cartilage has led to many promising tissue constructs in vitro, however, phenotypically stable mature chondrocyte cells and functionally equivalent engineered articular cartilage constructs remain elusive and are often hampered by a limited control over the scaffold structure and mechanical and biological complexities [2; 4]. The emerging three-dimensional (3D) bioprinting technology permits a superior solution to address cartilage repair limitations. In general, 3D bioprinting is a subset of 3D printing technology that dispenses bioink by fabricating 3D scaffolds in a layer-by-layer manner. This technique allows the 3D scaffolds to mimic the native architecture of the cartilage which allows better cell-to-cell communication [5]. There are different kinds of bioprinting setup including extrusion-based, particle fusion-based, light-induced, and inkjet-based [5; 6]. The bioink consists of a selection of suitable biomaterials and living cells that can promote tissue regeneration [6]. The selection of an ideal bioink is important in order to maintain the articular cartilage tissue's organised architecture. An ideal bioink should satisfy certain requirements, such as good mechanical properties, printability, and bio-compatibility [7]. The challenge lies in formulating a bioink that meets all these requirements. For bioinks used in cartilage bioprinting, the bioink needs to be tough and load bearing while also having elastic tendencies [8]. There are two main groups of biomaterials: namely, natural polymers and synthetic polymers which are usually used in bioink formulations. Natural polymers such as alginate have been used extensively in regenerative medicine due to its intrinsic properties that are akin to human tissues [9]. Alginate also has a unique sol/gel transition that allows the conversion between semisolid and solid state, which is highly favourable in bioprinting applications [10]. However, despite its promising features, alginate possesses several disadvantages that limit its use in 3D bioprinting. Some of the major concerns include being mechanically weak, having poor stability, and lacking the capability to adhere to mammalian cells [11]. Alginate can form a hydrogel via ionic crosslinking with cations like Ca\({}^{2+}\) to improve its mechanical strength and stability. However, this physical crosslinking is unstable and not long lasting as the crosslinked alginate hydrogels can be reversed and eventually cause the alginate hydrogel to disintegrate due to the displacement of the divalent cations (Ca\({}^{2+}\)) by the monovalent cations (Na\({}^{+}\)) which are normally present in the culture medium [12].