Facial Skin Density Enhancement Using Hyaluronic Acid—Based Bioactive Hydrogel: Cannula-Assisted Delivery and Ultrasound Evaluation in a Retrospective Controlled Study

<b>Background</b>: Hyaluronic acid (HA)-based bioactive hydrogels have emerged as multifunctional platforms for skin bioregeneration. While traditional mesotherapy using multicomponent substances has been widely practiced for improving skin quality, the time-consuming nature of this approach has led to exploration of alternative delivery methods. <b>Aims</b>: This study evaluated the clinical effectiveness of an HA bioactive hydrogel-based bioregeneration system (containing non-stabilized hyaluronic acid and 14 bioactive ingredients) administered via cannula and its impact on facial skin density as assessed by ultrasound imaging. <b>Methods</b>: We conducted a retrospective review of data from 20 female patients aged 30-42 years who received a single cannula-delivered injection of a bioactive hyaluronic acid hydrogel (TEOSYAL^® Redensity [I]) in the midface region. The formulation combines the structural benefits of hyaluronic acid with the biochemical stimulation provided by amino acids, antioxidants, minerals, and vitamins. Skin density was measured using high-frequency ultrasound at baseline, immediately post-procedure, and at 3-4 weeks follow-up. A control group of seven individuals received no treatment. <b>Results</b>: Ultrasound assessments revealed a statistically significant increase in skin density (92.7%, <i>p</i> < 0.001) within the treated area compared to no significant changes in the control group. This substantial improvement in dermal architecture demonstrates the efficacy of bioactive hydrogels in stimulating fibroblast function and extracellular matrix regeneration. Patient satisfaction was high, with 85% of patients reporting being satisfied or very satisfied. Side effects were minimal, with minor bruising (10%) and transient swelling (15%). <b>Conclusions</b>: Cannula-delivered bioactive hyaluronic acid hydrogel effectively enhances facial skin density with high patient satisfaction and minimal downtime, demonstrating the potential of advanced hydrogel formulations as multifunctional therapeutic platforms that extend beyond traditional applications into aesthetic and regenerative dermatology.