Nanotechnology strategies to address challenges in topical and cellular delivery of siRNAs in skin disease therapy

Gene therapy is one of the most advanced therapies in current medicine. In particular, interference RNA-based therapy by small interfering RNA (siRNA) has gained attention in recent years as it is a highly versatile, selective and specific therapy. In dermatological conditions, topical delivery of siRNA offers numerous therapeutic advantages, mainly by inhibiting the expression of target transcripts directly in the skin. However, crossing the stratum corneum and overcoming intracellular barriers is an inherent challenge. Substantial efforts by scientists have moved towards the use of multimodal and multifunctional nanoparticles to overcome these barriers and achieve greater bioavailability in their site of action, the cytoplasm. In this review the most innovative strategies based on nanoparticle and physical methods are presented, as well as the design principles and the main factors that contribute to the performance of these systems. This review also highlights the synergistic contributions of medicine, nanotechnology, and molecular biology to advancing translational research into siRNA-based therapeutics for skin diseases.

[Anticardiolipin antibodies in patients with cerebral vascular accident]

Through a prospective controlled study of 81 non-selected patients with acute cerebral ischemia, admitted to the hospital over the period of one year, anticardiolipin antibodies (IgG and IgM) were compared to a control group with the objective of evaluating their place as independent risk factors for stroke. Stroke patients' anticardiolipin antibodies (ACA) were again measured at 6 months and compared to the initial values. At the time of the acute ischemic event, the patients' mean ACA IgM was significantly higher than that of the controls and, at 6 months, the patients' mean ACA IgG and IgM were significantly lower than at the time of stroke. Furthermore, through logistic regression analysis and taking into account all other stroke risk factors present in the patient population, ACA IgM's association with stroke was statistically significant. We conclude that ACA may have a role in the pathogenesis of acute cerebral ischemia. Their cross-reactivity with anti-oxidised LDL antibodies may constitute a link between atherosclerosis and thrombosis.

[Hodgkin's disease in a patient with sarcoidosis]

We present the case of a 37 years old woman with mediastinal lymphadenopathy since the age of 13. At de age of 14, the patient presented a left cervical lymphadenopathy and the onset of episodic nodose erythema. One year later, histological examinations of an enlarged lymph node revealed sarcoidal granulomata. Corticotherapy was prescribed and the patient became asymptomatic. At the age of 31, the patient complained of asthenia and fever with left parotid tumefaction. Corticotherapy was therefore resumed with good response. Three years later, the patient presented left parotid tumefaction, left cervical lymphadenopathy and painful eye congestion. The patient was submitted to parotidectomy and lymphadenectomy. One month later, an ulceration with progressive enlargement developed in the surgical scar, and the patient suffered from asthenia, anorexia, weight loss, fever, nocturnal sweating and cervical and axillary lymphadenopathy. At Santa Maria Hospital, the patient's condition was diagnosed as Hodgkin's disease, mixed cellularity subtype, stage II Bb with local cutaneous involvement. The prescribed treatment was MOPP/ABV-8 cycles- and complete remission was achieved. The patient is still asymptomatic after a follow-up of 6 years. Cutaneous involvement in Hodgkin's disease is rare and generally associated with advanced disease and poor prognosis, facts that did not occur in this case. The differential diagnosis between sarcoidosis and sarcoid reaction in Hodgkin's disease, the accidental coexistence of both entities and the evolution of sarcoidosis into lymphoma are also discussed. The sarcoidosis immune defect may be the result of the same immune disorder. No relationships between sarcoidosis and cutaneous involvement in Hodgkin's disease were found in the literature.