Purpose To prepare mesoporous silica-based delivery systems capable of simultaneous delivery of drugs and nucleic acids. Methods The surface of mesoporous silica nanoparticles (MSN) was modified with poly(ethylene glycol) (PEG) and poly(2-(dimethylamino)ethylmethacrylate) (PDMAEMA) or poly (2-(diethylamino)ethylmethacrylate) (PDEAEMA). The particles were then loaded with a lysosomotropic agent chloroquine (CQ) and complexed with plasmid DNA or siRNA. The ability of the synthesized particles to deliver combinations of CQ and nucleic acids was evaluated using luciferase plasmid DNA and siRNA targeting luciferase and GAPDH. Results The results show a slow partial MSN dissolution to form hollow silica nanoparticles in aqueous solution. The biological studies show that polycation-modified MSN are able to simultaneously deliver CQ with DNA and siRNA. The co-delivery of CQ and the nucleic acids leads to a significantly increased transfection and silencing activity of the complexes compared with MSN not loaded with CQ. Conclusion PEGylated MSN modified with polycations are promising delivery vectors for combination drug/nucleic acid therapies.

efects of the cranium may result from various causes: traumatic loss, neurosurgical intervention, skull tumors, infection, and congenital abnormalities. 1 The purpose of cranioplasty is to accurately restore the integrity and surface morphology of the skull using a permanent and durable reconstruction. This is done for both cosmetic and functional purposes. 2 The choice of reconstruction in cranioplasty may be divided into two broad categories: autologous bone and alloplastic materials. Autologous bone provides reparative capabilities and the potential for at least partial consolidation and revascularization. It features superior infection resistance and is less likely to extrude. However, it is also susceptible to resorption, can be difficult to shape, and is associated with donor-site morbidity. 3,4 Alloplastic materials were designed to circumvent these problems. They provide permanent shape and volume retention, but do not incorporate into the skeleton and are more susceptible to both infection and extrusion. 5 The recent advent of computer-designed, patient-specific, three-dimensional implants has revolutionized cranioplasty. Even in experienced

BackgroundAnimal bites are typically harmless, but in rare cases infections introduced by such bites can be fatal. Capnocytophaga canimorsus, found in the normal oral flora of dogs, has the potential to cause conditions ranging from minor cellulitis to fatal sepsis. The tendency of C. canimorsus infections to present with varied symptoms, the organism’s fastidious nature, and difficulty of culturing make this a challenging diagnosis. Rarely, bacterial cytotoxins such as those produced by C. canimorsus may act as causative agents of TTP, further complicating the diagnosis. Early recognition is crucial for survival, and the variability of presentation must be appreciated. We present the first known case of C. canimorsus infection resulting in TTP that initially presented as splenic infarction.Case presentation72-year-old Caucasian male presented with a four-day history of abdominal pain, nausea, vomiting, diarrhea, and intermittent confusion. On presentation, vital signs were stable and the patient was afebrile. Physical examination was unremarkable apart from petechiae on the inner left thigh, and extreme diffuse abdominal pain to palpation and percussion along with positive rebound tenderness. Initial investigations revealed leukocytosis with left shift and thrombocytopenia, but normal liver enzymes, cardiac enzymes, lipase, INR and PTT. Abdominal CT demonstrated a non-enhancing spleen and hemoperitoneum, suggesting complete splenic infarction. Although the patient remained afebrile, he continued deteriorating over the next two days with worsening thrombocytopenia. After becoming febrile, he developed microangiopathic hemolytic anemia and hemodynamic instability, and soon after was intubated due to hypoxic respiratory failure and decreased consciousness. Plasma exchange was initiated but subsequently stopped when positive blood cultures grew a gram-negative organism. The patient progressively improved following therapy with piperacillin-tazobactam, which was switched to imipenem, then meropenem when Capnocytophaga was identified.ConclusionsThere is a common misconception amongst practitioners that the presence of systemic infection excludes the possibility of TTP and vice versa. This case emphasizes that TTP may occur secondary to a systemic infection, thereby allowing the two processes to coexist. It is important to maintain a wide differential when considering the diagnosis of either TTP or C. canimorsus infection since delays in treatment may have fatal consequences.

Although a rare entity, it is important to consider congenital calvarial hemangioma in the differential diagnosis of slow growing skull lesions due to the possibility of complications as a result of the hemangioma's intracranial extension, and the potential for treatment. En bloc resection has classically been described as a treatment for such lesions, although our case demonstrates that medical treatment with propranolol therapy may be appropriate in certain situations.