皮肤组织模型中吸收和散射系数对单线态氧发光特性的影响

构建由脂肪乳剂和墨水组成的皮肤组织模型,定量研究皮肤组织模型的吸收系数μa和散射系数μs对光敏化单线态氧(singlet oxygen,~1O_2)发光特性的影响。利用~1O_2发光检测系统测量含光敏剂四硫磺基酞菁氯化铝的皮肤组织模型分别在中心波长为1 230,1 270和1 310 nm处的时间分辨发光光谱,对扣除背景信号后的时间分辨~1O_2发光光谱进行积分和拟合,获得~1O_2发光积分强度以及激发三重态寿命τ_T和~1O_2寿命τ_D。结果表明在皮肤组织模型中,~1O_2发光积分强度随着μ_a和μ_s的增大而减小,μ_a对τ_T和τ_D没有影响。τ_T随着μs的增加而增加,τ_D随μ_s的增加先骤降而后缓慢上升。当μ_a1.5 mm~(-1)和μ_s32 cm~(-1)时,~1O_2发光积分强度和τ_T、τ_D均趋于稳定,其中τ_T和τ_D分别为3.4±0.6μs和3.3±0.7μs。

Effects of Absorption and Scattering Coefficients on Singlet Oxygen Luminescence in Skin Phantom

The effects of absorption coefficient and scattering coefficient on singlet oxygen (1 O2 )luminescence in skin phantoms were quantitatively studied.In this study,Aluminum phthalocyanine disulfonic acid (AlPcS)was utilized as the model photosensitizer,and India ink and 10% Intralipid were chosen as the absorber and scatter for skin phantom, respectively.A custom-built time and spectral-resolved near-infrared (NIR)detection system was used for 1 O2 lumines-cence measurements.Three bandpass-filters centered at 1 230,1 270 and 1 310 nm were selected to discriminate the 1 O2 luminescence from background luminescence signal.The integrated intensity of 1 O2 luminescence,lifetime of triplet excited-state and 1 O2 were then derived from the 1 O2 luminescencespectra after background subtraction.The results indi-cated that the integrated intensity of 1 O2 luminescenceis decreased with the increase of μa and μs ,and μa alone has no significant influence of on τT and τD is decreased with the increase of μs ,while τD is dramatically decreased and then in-creased slowly.However,the integrated intensity of 1 O2 luminescence,as well as τT and τD are quiet stable once μa >1. 5 mm-1 and μs >32 cm-1 .τT and τD of AlPcS in skin phantoms are 3.4 ±0.6 μs and 3.3 ±0.7 μs,respectively.