Psoriasis is a chronic inflammatory dermatosis that remains incurable and requires continuous therapeutic control. Even with modern treatments, management is often associated with adverse effects, recurrence risk, and declining patient adherence due to complex regimens. This creates a clear demand for safer, more physiologic, and user-friendly topical solutions that can target key pathogenic mechanisms of the disease.

In the study by Elgueta E. et al. (2025), an innovative approach combining regenerative medicine and advanced delivery systems was proposed. The authors developed a topical hyaluronic acid–based sponge enriched with stem cell–derived secretome and exosomes. Let us take a closer look at how this technology works and the clinical outcomes it demonstrated [1].

Exosomes are the key active component

Modern regenerative technologies increasingly focus on the secretome of mesenchymal stem cells (MSCs), which contains a complex mixture of cytokines, growth factors, and extracellular vesicles, including exosomes. These vesicles are considered the main functional agents responsible for intercellular communication and modulation of inflammatory responses.

In the study [1], the secretome was obtained from cultured mesenchymal stem cells isolated from Wharton’s Jelly of the umbilical cord. Donor material was processed, and cells were cultured under standard conditions. The conditioned medium, containing biologically active factors secreted by the cells, was then collected. To improve reproducibility, secretomes from multiple donors were pooled. Exosomes were subsequently isolated by sequential centrifugation, including ultracentrifugation, yielding a purified extracellular vesicle fraction.

Analytical methods confirmed the presence of exosomes with an average size of approximately 164 nm and a concentration of about 1.5×10⁹ particles/mL. Functionally, these vesicles demonstrated pronounced pro-angiogenic activity, stimulating vascular structure formation in vitro and enhancing neovascularization in vivo. Thus, exosomes are a key biological component of the secretome, potentially driving regenerative and anti-inflammatory effects in psoriasis.

Sponge technology and application design

To ensure material stability without chemical crosslinking, the authors used freeze-drying (lyophilization), which forms a rigid, porous structure by physically entangling hyaluronic acid polymer chains during freezing and subsequent ice sublimation. A critical technological aspect was the use of a mixture of high-molecular-weight (500–1000 kDa) and low-molecular-weight (50 kDa) fractions at a high concentration (4.8 mg/mL).

This approach resulted in a dry sponge that, upon activation with 0.5 mL of water, does not dissolve into a liquid but instead forms a viscous, bioadhesive gel that remains on the surface of psoriatic plaques.

The incorporation of the secretome further modifies the matrix structure. Electron microscopy data showed that biological components densify the fibrous network, reduce fiber diameter to approximately 6.6 µm, and significantly slow dissolution. The secretome-containing sponge takes 3 times longer to fully disperse (200 s vs 66 s for pure hyaluronic acid), prolonging exosome contact with the affected skin.

Clinical protocol and safety

The study design included multiple stages of safety and efficacy evaluation.

Initial tolerability was assessed in patients with atopic dermatitis, a condition characterized by heightened skin sensitivity. The absence of erythema and irritation after prolonged application allowed progression to testing in healthy volunteers, where both local and systemic safety (including blood parameters) were confirmed.

The main clinical protocol involved patients with symmetrical psoriasis vulgaris plaques who applied the sponges daily for 30 days. One side of the body was treated with the active secretome formulation, while the contralateral side received a control sponge containing only hyaluronic acid.

Patients self-activated a precisely dosed sponge (approximately 5 cm²) with water and applied the resulting adhesive layer once daily to the selected lesion.

Results and clinical implications

The best clinical outcomes were observed with a combined regimen that gradually escalated the active protein over 1 month.

The researchers reported a 33% reduction in mPASI (modified Psoriasis Area and Severity Index) and a 41% decrease in plaque size. In parallel, there was a marked improvement in skin barrier function, reflected by a reduction in transepidermal water loss (TEWL) of more than 30% and a significant increase in skin elasticity. In some cases, complete symptom regression was observed.

This method represents a promising alternative to invasive procedures and complex device-based treatments. The dry sponge format ensures stability of bioactive components without special storage conditions and facilitates outpatient use. Despite the pilot nature of the study and small sample size, these findings support a broader trend in dermatology toward the use of advanced cell-derived products as a more controlled and potentially safer form of regenerative therapy.

References

1. Elgueta E., Prieto C.P., Hartmann D. et al. Novel sponge formulation of mesenchymal stem cell secretome and hyaluronic acid: a safe and effective topical therapy for psoriasis vulgaris. Stem Cell Res Ther 2025; 16(1): 348. https://doi.org/10.1186/s13287-025-04415-1