Assessment of Bioprotect's Biodegradable Balloon System as a Rectal Spacer in Radiotherapy: An Animal Study on Tissue Response and Biocompatibility.

Prostate cancer is a significant health concern for men, emphasizing the need for effective treatment strategies. Dose-escalated external beam radiotherapy shows promise in improving outcomes but presents challenges due to radiation effects on nearby structures, such as the rectum. Innovative techniques, including rectal spacers, have emerged to mitigate these effects. This study comprehensively assessed tissue responses following the implantation of the Bioprotect biodegradable fillable balloon as a rectal spacer in a rat model. Evaluation occurred at multiple time points (4, 26, and 52 weeks) post-implantation. Results revealed localized tissue responses consistent with the expected reaction to biodegradable materials, characterized by mild to moderate fibrotic reactions and encapsulation, underscoring the safety and biocompatibility of the balloon. Importantly, no other adverse events occurred, and the animals remained healthy throughout the study. These findings support its potential clinical utility in radiotherapy treatments to enhance patient outcomes and minimize long-term implant-related complications, serving as a benchmark for future similar studies and offering valuable insights for researchers in the field. In conclusion, the findings from this study highlight the safety, biocompatibility, and potential clinical applicability of the Bioprotect biodegradable fillable balloon as a promising rectal spacer in mitigating radiation-induced complications during prostate cancer radiotherapy.

Protective effect of different ophthalmic viscosurgical devices on corneal endothelium during severe phacoemulsification model in rabbits.

BACKGROUND AND OBJECTIVE: To evaluate the protective effect of different ophthalmic viscosurgical devices (OVDs) on corneal endothelial cells against relatively severe phacoemulsification damage in a rabbit model. MATERIALS AND METHODS: Twenty-four rabbit eyes were randomly assigned to four similar groups: in three groups the aqueous humor was completely replaced by Visiol (TRB CHEMEDICA, München, Germany), Biolon (Bio-Technology General Ltd., Kiryat Malachi, Israel), and Viscoat (Alcon, Puurs, Belgium) and in the control group no OVD was applied. Endothelial cell counts were performed prior to initiating the study. All eyes were exposed to continuous 5 minutes of phacoemulsification. Endothelial cell counts were repeated 4 days postoperatively. RESULTS: Viscoat showed the highest endothelial cell loss (30%), followed by Biolon (25%), Visiol (22%), and the control group (19%). None of the differences between the groups were found to be statistically significant, although they were within each group (P = .028). CONCLUSION: None of the tested OVDs demonstrated protective effect on corneal endothelial cells in comparison to the control group. This model was found to be too aggressive for the demonstration of the protective effect of different OVDs even for hard cataract.

Protective effect of different ophthalmic viscosurgical devices on corneal endothelial cells during phacoemulsification: rabbit model.

PURPOSE: To evaluate the protective effect of different ophthalmic viscosurgical devices on corneal endothelial cells during phacoemulsification in a rabbit model. SETTING: Harlan Biotech Israel and Ophthalmology Department, Kaplan Medical Center, Rehovot, Israel. DESIGN: Experimental study. METHODS: Rabbit eyes were randomly assigned to 3 equally sized groups. Endothelial cell counts were performed in all eyes before initiation of the study. The aqueous humor was completely replaced by Biolon (sodium hyaluronate 1.0%) in Group A, by a combination of Viscoat (sodium chondroitin sulfate 4.0%-sodium hyaluronate 3.0%) and Provisc (sodium chondroitin sulfate 1.0%) using the soft-shell technique in Group B, and by a combination of Visiol (sodium hyaluronate 2.0%-mannitol 0.5%) and Biolon using the soft-shell technique in Group C. The eyes were exposed to alternating 10 seconds of phacoemulsification and a 10-second pause until a total exposure time of 2.5 minutes elapsed. Endothelial cell counts were repeated 3 days after surgery. RESULTS: The study used 18 rabbit eyes, 6 in each group. Group A had the highest endothelial cell loss (13%) followed by Group B (7%), and Group C (4%). The difference in cell loss between Group C and Group A was statistically significant (P = .037). CONCLUSION: The study showed the efficiency and advantages of the soft-shell technique using the combination of Visiol and Biolon over Biolon alone.

Disseminated thrombosis-induced growth plate necrosis in rat: a unique model for growth plate arrest.

Exposure of rats to 2-butoxyethanol (BE) produces early hemolytic anemia and disseminated thrombosis. This leads to infarctions in multiple organs, including bones and cartilage. BE, administered for different durations of exposure in two separate experiments, produced metaphyseal vascular thrombosis, growth plate infarction, and partial or complete physeal growth arrest. This reproducible model may serve as a useful tool in the study of some conditions that manifest growth plate damage. The suitability of this model for investigating the pathogenesis of growth plate necrosis and as a model for potential therapy for various human growth plate disorders are discussed.

The effect of short, high intensity magnetic field pulses on the healing of skin wounds in rats.

The object of this study was to examine the effect of high intensity, short duration pulsed electromagnetic fields (PEMF) on the healing of full thickness skin wounds in rats. Full thickness skin wounds were surgically created in two groups of Sprague-Dawley male rats. The rats were randomly divided into two groups, each containing 20 rats. Animals in the treatment group received treatments with the PEMF device on day 0, 3, 7, 9, 12, 14, 17, and 22, while the rats in the control group were subjected to the same procedure, but with the PEMF device not activated. Photographs of the surgically created wounds were obtained on day 0, 3, 7, 9, 12, 14, 17, and 22. Wound contraction (WC), wound epithelialization (WE), non-healed wound, and contraction-epithelialization (CE) ratio were calculated for each wound. No significant difference was found between the two groups for the parameters of WC, WE, non-healed wound, and CE ratio. A significant group x time interaction was found for WE and CE ratio. This type of PEMF did not have a significantly beneficial effect on wound healing. Wounds in the PEMF treated group were relatively less contracted and showed a compensatory increase in epithelialization in the early stages of wound repair.

2-Butoxyethanol enhances the adherence of red blood cells.

We recently presented a unique, chemically-induced rat model of hemolytic anemia and disseminated thrombosis. In this 2-butoxyethanol (BE)-induced model the organs developing infarction are comparable to those seen in human diseases, characterized by hemolysis and thrombosis (e.g., thalassemia, sickle-cell disease, paroxysmal nocturnal hemoglobinuria, disseminated intravascular coagulation, thrombotic thrombocytopenic purpura, and hemolytic uremic syndrome). Red blood cells (RBCs) have special flow properties, namely, self-aggregability, deformability, and potential adherence to endothelial cells (ECs) of the blood vessel wall, which are essential for adequate blood flow and tissue perfusion; their alteration facilitates circulatory disorders. To examine the possible contribution of alterations in RBC flow properties to the observed thrombosis in the present investigation we determined the BE-induced changes in adherence, aggregability, and deformability of RBCs from male and female Fischer F344 rats exposed to two, three, or four daily doses of BE at 250 mg BE/kg body weight. Control animals were treated with the vehicle alone. Blood was taken on days 2, 3, 4, and 29. The administration of BE did not affect the RBCs aggregability but markedly enhanced their adherence to extracellular matrix; such enhancement was correlated with adherence to cultured ECs. RBC/EC interaction has been shown to be a potent catalyst of vascular occlusion in hemolytic hemoglobinopathies; thus the enhanced RBC adherence to EC is a likely mechanism by which thrombosis and organ infarct are induced in BE-treated rats.

Ocular expression of vascular cell adhesion molecule (VCAM-1) in 2-butoxyethanol-induced hemolysis and thrombosis in female rats.

We demonstrated previously that exposure of rats to 2-butoxyethanol (BE) was associated with morphological changes in red blood cells, hemolytic anemia, and disseminated thrombosis and infarction in different organs including the eyes. In order to elucidate the mechanism of thrombosis formation, we examined in this study the histology and immunohistochemical expression of vascular cell adhesion molecule-1 (VCAM-1), endothelial intercellular adhesion molecule-1 (ICAM-1), and P-selectin in the eyes of the female F344 rat exposed to 2, 3, or 4 daily doses of BE/250 mg/kg body weight. In this BE hemolysis and thrombosis model, positive VCAM-1 expression occurred only in eyes of rats exposed to 3 and 4 doses and was localized in the iris (epithelium lining the posterior surface, anterior mesenchymal epithelium), ciliary processes (lining epithelium, stromal cells), and retina (hypertrophic retinal pigment epithelium). Only weak immunolabeling was seen in eyes exposed to 2 doses. The appearance of VCAM-1 immunostaining correlated with the development of thrombosis located in the same structures. No change in ICAM-1 or P-selectin expression was seen. This immunolabeling distribution suggests that VCAM-1 functions in the pathogenesis of BE-related thrombosis by promoting adhesion of erythrocytes to the endothelium.

A chemically induced rat model of hemolysis with disseminated thrombosis.

Although hemolytic anemia and thrombosis, which can be serious or even lethal, are often encountered in daily common practice, their pathogenesis has remained obscure, partially because of the absence of appropriate models. Here we present a unique chemically induced rat model of hemolytic anemia and disseminated thrombosis in which the organs developing infarction are comparable to those seen in humans. We exposed male and female Fischer F344 rats to two, three, or four daily doses of 2-butoxyethanol (BE) at 250 mg/kg body weight and examined for hemolysis and histopathological evidence of disseminated thrombosis on d 2, 3, 4, and 29. Time-course BErelated erythrocytic changes were statistically significant in both sexes. Evidence of thrombosis and infarction was seen mainly in females dosed more than once with widespread thrombotic crisis after two or three dosing, likely explicable by the more significant morphological changes in erythrocytes and hemolysis observed in this gender. We documented thrombosis and infarction in the heart, brain, lungs, eyes, and bones. Our model with its list of target organs similar to that observed in human diseases characterized by hemolysis and thrombosis [for example, thalassemia, sickle cell disease (SCD), paroxysmal nocturnal hemoglobinuria (PNF), disseminated intravascular coagulation (DIC), thrombotic thrombocytopenic purpura (TTP), and hemolytic uremic syndrome (HUS)] suggests that it can be an excellent tool to study the pathogenesis of such complications.