Surgical repair of traumatic isolated inferior rectus muscle avulsion.

PURPOSE:: To report our experience in the management of avulsion of the inferior rectus muscle. METHODS:: We describe the approach we have used for surgical repair of isolated avulsion of the inferior rectus muscle in two patients who suffered orbital trauma. RESULTS:: In both cases, the proximal portion of the inferior rectus muscle was located successfully by the generated muscle force duction test and sutured back into its original insertion point. Infraduction was normal and orthotropia was present in all directions of gaze during 1 year of postoperative follow-up in both cases. These favorable outcomes are attributed in part to the inferior rectus muscle pulleys system and the natural history of this type of injury, which allows the lost proximal portion to be identified by generated muscle force duction test. CONCLUSION:: Generated muscle force duction test can be used to locate the proximal portion of a lost inferior rectus muscle and restore its function in patients with traumatic avulsion injury involving an extraocular muscle.

"Smart" Nanoparticles Enhance the Cytoplasmic Delivery of Anti-RhoC Silencing RNA and Inhibit the Migration and Invasion of Aggressive Breast Cancer Cells.

Rho-GTPases are small GTP-binding proteins that contribute to the epithelial-to-mesenchymal transition by regulating several cellular processes including organization of the actin cytoskeleton, cell motility, transcription, and cell proliferation. Overexpression of RhoC-GTPases (RhoC) in breast cancer has been implicated in poor disease prognosis due to increased cancer cells invasion, migration, and motility, which warranted its consideration as a therapeutic target for inhibiting breast cancer metastasis. Using silencing RNA (siRNA) molecules to knockdown RhoC expression is a promising approach to inhibit breast cancer metastases. However, transforming anti-RhoC siRNA molecules into a viable therapy remains a challenge due to the lack of a biocompatible carrier that can selectively deliver the RNA cargo into breast cancer cells. We report the use of a degradable, pH-sensitive, ß-cyclodextrin (ßCD)-based polymeric carrier that condenses anti-RhoC siRNA forming "smart" particles. These smart anti-RhoC particles were efficiently internalized, successfully escaped the endosome, and delivered the RNA cargo into the cytoplasm of SUM149 and MDA-MB-231 breast cancer cells. Our results show that anti-RhoC particles used at a low N/P ratio of 2.5/1 suppressed RhoC protein levels by 100% and 90% in SUM149 and MDA-MB-231 cells, respectively. Further, anti-RhoC particles inhibited the invasion, motility, and migration of SUM149 and MDA-MB-231 cells by 40-47%, 57-60%, and 61.5-73%, respectively. Smart particles encapsulating the scrambled siRNA sequence did not affect RhoC protein expression or the invasion, motility, and migration of SUM149 and MDA-MB-231 cells, which indicate the biocompatibility of the polymeric carrier and selectivity of the observed RhoC knockdown. These results collectively indicate the therapeutic potential of smart anti-RhoC particles in arresting the metastatic spread of breast cancer cells.