Plant-inspired implantable therapeutic systems: quantitative structure-property-function design of hierarchical...

Plant-derived architectures provide a unique reservoir of hierarchical, anisotropic, and transport-optimized design principles that can be systematically translated into functional biomaterials for regenerative implants. Unlike conventional scaffold engineering approaches that rely on artificially generated porosity and isotropic architectures, plant tissues exhibit evolutionarily optimized vascular networks, graded mechanical stiffness, and stimulus-responsive morphologies that directly address challenges in mass transport, stress distribution, and adaptive integration in biomedical implants. This review critically examines how plant structural hierarchies, from cellulose microfibril alignment to multichannel vascular bundles, are mechanistically mapped onto modern biofabrication platforms, including decellularization, extrusion-based 3D printing, direct ink writing, electrospinning, and 4D printing. Particular emphasis is placed on quantitative structure-property-function relationships, such as anisotropic modulus ratios (E||/E⊥), channel diameter-diffusion coupling, swelling-induced curvature programming, and surface energy-biofouling interactions, that govern biological outcomes including angiogenesis, osteogenesis, myogenic alignment, and anti-infective performance. Representative case studies demonstrate that plant-inspired multichannel scaffolds enhance vascular infiltration and bone regeneration in vivo, aligned cellulose-based systems enable programmable shape morphing for minimally invasive deployment, and biomimetic surface microtopographies reduce fouling without antibiotic reliance. However, critical translational challenges remain, including immunological validation of decellularized plant matrices, mechanical fatigue under cyclic physiological loading, lubricant stability in slippery interfaces, and scalability under Good Manufacturing Practice (GMP) conditions. By integrating plant biomechanics, materials science, and advanced biofabrication, plant-inspired biomaterials emerge as a promising, yet early-stage strategy for engineering adaptive, vascularized, and multifunctional implants. Future progress will depend on rigorous quantitative validation, long-term in vivo performance studies, and standardized manufacturing frameworks that bridge biomimetic design with clinical translation.