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Purpose: The purpose of this research was to evaluate the effect of ultrasound on mass transport across fetal membrane for direct fetal drug delivery and sensing of the amniotic fluid in a noninvasive manner., Methods: Post-delivery human fetal membranes (chorioamnion) were used for in vitro experiments, in which the effect of ultrasound on transport across fetal membrane of fluorescent model molecule (250 kDa) was evaluated. Ex vivo experiments were carried out on a whole rat amniotic sac. The model molecule or alpha-fetoprotein was injected into the amniotic sac through the placenta. Transport of these molecules across pre- and post-insonation of the amniotic sac was evaluated. The ultrasound enhancement's mechanism was also assessed., Results: The greatest enhancement in mass transport (43-fold) in vitro was achieved for 5 min of insonation (20 kHz, 4.6 W/cm(2), 5 mm distance). Ex vivo results showed a rapid increase (23-fold) in mass transport of the model molecule and also for alphafetoprotein following 30 s of insonation (20 kHz, 4.6 W/cm(2), 5 mm distance)., Conclusions: Mass transport across fetal membranes was enhanced post-insonation both in vitro and ex vivo in a reversible and transient manner. We suggest that exterior (to the amniotic sac) ultrasound-induced cavitation is the main mechanism of action.

Photodynamic therapy (PDT) was performed in the chick embryo chorioallantoic membrane (CAM) for the purpose of quantitative evaluation of several porphycenes as potential photosensitizers. Porphycenes are structural isomers of porphine possessing lower symmetry of the macrocycle and are characterized by 10-fold higher absorption at the therapeutic wavelengths for PDT (lambda > 630 nm). PDT-induced damage to CAM blood vessels included vasoconstriction and blanching as was monitored during irradiation and videotaped. Image analysis techniques enabled us to follow PDT-induced constriction of vessel diameter (to 50%), reduction of blood perfusion (to 40% lower optical density) and shrinkage of implanted tumours (to 10% of their original area). The observed PDT efficacy of functionalized porphycenes is positively correlated with the number of polar substituents.

The sensitivity of Day-4-blastocysts to total x-ray irradiation at a dosage of 130r is studied at developmental stages 10, 11, 12 and 17 days p. c., after the treated blastocysts could develop in synchronized foster mothers. The effects by 130r are compared to normal controls and other dosages of 90r and 250 r. A maximum of developmental failure is recorded particularly in 130 r --irradiated embryos. The following reasons are considered to being causally involved: 1. Reduced mitotic activity between Days 5 and 7. 2. Reduced growth of the embryonic disk at Days 6 and 7, such inhibiting differentiation and further formation of the embryo. 3. Increasing imbalances in the essential synchronisation demands of the embryonic and maternal systems. 4. Developmental retardation accompanied by a failure in the dissolution of the blastocyst coverings, by this resulting in a considerable number of degenerating blastocysts at Day 8 p.c. 5. Increased imbalances in the ratio of the differentiation and growth, specific for each embryonic stage. Growth of the embryo, in general, occurs more slowly than the process of differentiation. 6. Failure of adaptation to the chorionic-allantoic-placenta supply at Day 11. This investigation may be considered as a basis for further causal relationship studies to find out the reason for the more pronounced sensitivity to 130 r than to 250 r of Day 4 rabbit blastocysts.