Bioactive wound-healing hydrogel porphyrin-containing systems based on polycation-stabilized alginates

Sodium alginate (SA)-based hydrogels are widely used as a base for wound-healing coatings due to their unique physicochemical and rheological properties. The targeted modification of SA hydrogel by co-integration with polycations, particularly PAMAM dendrimers, allows for formulating a platform for the immobilization of bioactive agents, followed by their subsequent controlled release. The integration of porphyrins that mimic the superoxide dismutase (SOD mimetics) will suppress oxidative stress in the area of tissue damage and prevent the formation of fibrous tissue. Thus, obtaining a polycation-stabilized SA hydrogel with immobilized SOD mimetics is a promising task in the field of regenerative medicine.

The materials used in the study were SA (Mw = 1600 kDa), third- and fourth-generation PAMAM dendrimers (G3 and G4), and porphyrin with the composition C₄₄H₂₈ClMnN₄. During the first stage of the work, we assessed the concentration of SA responsible for the formation of an elastic gel. Based on the data obtained by potentiometric titration, we revealed the degree of PAMAM binding to SA to be 98% (G3) and 85.53% (G4) at pH 7.4. Next, we studied the PAMAM-SA complex using FTIR and UV spectrophotometry. During the second stage of the work, the possibility of incorporating porphyrin into PAMAM (G3 and G4) was studied. We found that there are on average six porphyrin molecules per dendrimer macromolecule at a concentration of 10^⁻3 mg/ml. We conducted a series of studies on cytocompatibility of the porphyrin-containing hydrogel systems based on the developed polycation-stabilized alginates.

The results confirmed the possibility of formulating a biocompatible porphyrin-containing system based on polycation-stabilized sodium alginate for accelerated regeneration of skin and mucous membranes.