Bioinks represent the core of 3D bioprinting, as they are the carrier responsible for enabling the fabrication of anatomically precise, cell-laden constructs that replicate native tissue architecture. Indeed, their role goes beyond structural support, as they must also sustain cellular viability, proliferation, and differentiation functions, which are critical for applications in the field of regenerative medicine and personalized therapies. However, at present, a persistent challenge lies in reconciling the conflicting demands of rheological properties, which are essential for printability and biological functionality. This trade-off limits the clinical translation of bioprinted tissues, particularly for vascularized or mechanically dynamic organs. Despite huge progress during the last decade, challenges persist in standardizing bioink characterization, scaling production, and ensuring long-term biomimetic performance. Based on these challenges, this review explores the inherent trade-off faced by bioink research optimizing rheology to ensure printability, shape fidelity, and structural integrity, while simultaneously maintaining high cell viability, proliferation, and tissue maturation offering insights into designing next-generation bioinks for functional tissue engineering.

Plant fibers possess high strength, high fracture toughness and elasticity, and have proven useful because of their diversity, versatility, renewability, and sustainability. For biomedical applications, these natural fibers have been used as reinforcement for biocomposites to infer these hybrid biomaterials mechanical characteristics, such as stiffness, strength, and durability. The reinforced hybrid composites have been tested in structural and semi-structural biodevices for potential applications in orthopedics, prosthesis, tissue engineering, and wound dressings. This review introduces plant fibers, their properties and factors impacting them, in addition to their applications. Then, it discusses different methodologies used to prepare hybrid composites based on these widespread, renewable fibers and the unique properties that the obtained biomaterials possess. It also examines several examples of hybrid composites and their biomedical applications. Finally, the findings are summed up and some thoughts for future developments are provided. Overall, the focus of the present review lies in analyzing the design, requirements, and performance, and future developments of hybrid composites based on plant fibers.