## 4 Discussion
Its ability to stimulate collagen and elastin synthesis, enhance epidermal and dermal thickness, and promote angiogenesis positions carboxytherapy as a versatile and effective treatment for managing skin aging [21]. A recent scoping review by [PERSON] et al. highlighted the therapeutic potential of carboxytherapy in enhancing wound healing, emphasizing its ability to improve blood flow, increase local oxygenation, and stimulate collagen production. These mechanisms not only accelerate wound repair but also reduce inflammation, contributing to the restoration of skin integrity. While primarily studied in the context of chronic wounds, these findings underscore the broader applicability of carboxytherapy in dermatology and aesthetics. The demonstrated capacity of CO2 therapy to promote collagen synthesis and improve skin quality aligns with its established role in cosmetic procedures, such as rejuvenation and addressing skin laxity. These results further support the growing use of carboxytherapy as a versatile and minimally invasive modality in aesthetic practice [22]. The weakening of the epidermal barrier due to aging is a key factor contributing to increased skin dehydration. External environmental factors, including UV radiation and pollutants, further compromise the water-lipid bilayer, leading to a rise in transepidermal water loss (TEWL) and triggering inflammatory processes within the skin. To effectively address aesthetic concerns in the periodital region, it is vital to integrate antioxidant and moisturizing agents into skincare routines. Compounds such as ferulic acid, ascorbic acid, and lactobionic acid have demonstrated significant efficacy in reducing inflammation, enhancing hydration, and repairing the skin barrier. Although our study did not yield statistically significant differences between monotherapy and combined treatments, the combination of carboxytherapy with acids showed modest yet consistent improvements across all parameters. Interestingly, these benefits were more evident on the left side of the face, highlighting the potential of integrated treatment strategies for achieving superior results. Lactobionic acid possesses moisturizing (hygroscopic), anti-inflammatory, and antioxidant properties. It is an inhibitor of metalloproteinases, exerting an indirect effect on the dermis and vasculature, and it supports the repair of the epidermal barrier. Consequently, lactobionic acid was selected for participants presenting symptoms of chronological aging, vascular shadows, and dry skin. Among the most notable properties of lactobionic acid are its chelating abilities, which contribute to its antioxidant effects, and its remarkable capacity to bind substantial amounts of water. As a potent humectant, it enhances skin hydration, smoothing the skin's surface and diminishing the appearance of fine wrinkles [23; 24]. [PERSON] et al. evaluated the effects of formulations containing lactobionic acid versus those with glycolic acid on several skin parameters, including skin tone (measured with Mexameter), transepidermal water loss (Tewameter), electrical capacitance (Corneometer), and pH (pHmeter). Their findings demonstrated that 6% lactobionic acid was significantly more effective in moisturizing the skin compared to glycolic acid, without causing irritation or compromising the epidermal barrier [23]. [PERSON] investigated the effects of a 20% lactobionic acid peel on skin hydration, elasticity, and TEWL. Corneometer readings revealed a statistically significant increase in skin hydration following the procedure. Although Cutometer measurements for the R6 parameter were not statistically significant, they still indicated a positive trend toward improved skin viscoelasticity [24]. In our study, the combination of carboxytherapy with lactobionic acid resulted in greater improvements compared to the combination of carboxytherapy with ferulic and ascorbic acids, although these differences were not statistically significant.