Advances in Tissue Engineering and Regenerative Medicine: Biomaterials, Biofabrication, Cell-Based and Cell-Free Therapies, and Applications in Reconstructive and Aesthetic Medicine.

Tissue engineering and regenerative medicine are shifting from passive tissue replacement toward instructive platforms that regulate cellular behavior, immune responses, vascularization, and extracellular matrix remodeling. This review examines recent advances in natural, synthetic, composite, and stimuli-responsive biomaterials, biofabrication and 3D bioprinting, stem and progenitor cell therapies, extracellular vesicles and other cell-free products, immunomodulatory scaffolds, skin organoids and organ-on-a-chip systems, nanotechnology, and artificial intelligence-assisted design. Particular emphasis is placed on plastic, reconstructive, and aesthetic applications, including skin and wound repair, craniofacial bone and cartilage regeneration, peripheral nerve reconstruction, vascularization, and dental and periodontal repair. The review also considers biomodulators and skinboosters as emerging regenerative-aesthetic interventions that aim to improve dermal hydration, fibroblast activity, collagen remodeling, and skin quality rather than provide volume replacement alone. Importantly, these technologies differ substantially in translational maturity, ranging from in vitro and preclinical platforms to early clinical interventions, established clinical products, and commercially available treatments for which durable regenerative efficacy remains incompletely validated. Throughout this review, biological plausibility and preclinical efficacy are therefore distinguished from human clinical evidence, regulatory or established clinical use, and commercial availability. Progress will require standardized characterization, mechanism-linked potency assays, clinically relevant models, and outcome measures that capture functional integration, durability, safety, and aesthetic performance.