不同分子量海藻酸钠的透皮吸收作用及其机制的研究OA

Sodium alginate exhibits great potential for use in topical preparations because of its excellent biocom-patibility and notable moisturizing and repairing properties.However,its inherently high molecular weight and viscosity severely restrict transdermal absorption efficiency.In this study,three sodium alginate samples with var-ying molecular weights were prepared via specific enzymatic degradation to investigate their transdermal behavior and elucidate the underlying mechanisms.By combining Franz diffusion cells and confocal laser scanning micros-copy(CLSM),the transdermal absorption and tissue distribution characteristics of each fraction were evaluated in an ex vivo porcine skin model.Sodium alginate of all molecular weights accumulated within the stratum corneum;however,their penetration depths varied significantly.Lower-molecular-weight fractions—2.39 and 7.00 kDa—effectively breached the stratum corneum barrier,penetrating into the viable epidermis and dermis,whereas the higher-molecular-weight fraction was predominantly retained on the skin surface.Furthermore,attenu-ated total reflection Fourier-transform infrared spectroscopy(ATR-FTIR)and hematoxylin and eosin(H&E)anal-yses elucidated the underlying permeation-enhancing mechanisms:low-molecular-weight sodium alginate effec-tively enhanced stratum corneum hydration,induced conformational changes in the keratin secondary structure,and disrupted the ordered arrangement of intercellular lipids,thereby decreasing the penetration resistance of the skin barrier.This study elucidated the regulatory effects of molecular weight on the transdermal behavior of sodium al-ginate,confirming that its low-molecular-weight fraction can markedly improve skin penetration efficiency.These findings provide practical support for the functional development and application of sodium alginate in transdermal delivery systems and cosmetics.