No abstract

An interesting nanoscale interfacial phenomenon mediated by gold nanoparticles (Au-NPs) was found, in that co-administration with Au-NPs enables percutaneous delivery of protein drugs. The Au-NPs with a mean size of 5 nm were revealed to be skin permeable, presumably due to the nano-bio interaction with skin lipids and the consequent induction of transient and reversible openings on the stratum corneum. Importantly, when simultaneously applied with Au-NPs, the protein drugs were also granted the ability to penetrate the skin barrier and migrate into the deep layers. This indicated that co-administration with the skin-permeable Au-NPs could mediate proteins across the skin barrier. Such co-delivery effect highlights a simple yet effective method for overcoming the skin barrier for percutaneous protein drug delivery. Employing this method, a noninvasive vaccine delivery strategy was developed, and by topically co-administrating antigens with Au-NPs, robust immune responses were elicited in the tested animals. The results provide the promise for achieving a needleless and self-administrable transcutaneous vaccination.

As a primary drug for the treatment of acute lymphoblastic leukemia (ALL), encapsulation of Lasparaginase (ASNase) into red blood cells (RBC) has been popular to circumvent immunogenicity from the exogenous protein. Unlike existing methods that perturbs RBC membranes, we introduce a novel method of RBC-incorporation of proteins using the membrane-traslocating low molecular weight protamine (LMWP). Confocal study of fluorescence-labeled LMWP-ovalbumin, as a model protein conjugate, has shown significant fluorescence inside RBCs. Surface morphology by scanning electron microscopy of the RBCs loaded with LMWP-ASNase was indistinguishable with normal RBCs. These drug loaded RBCs also closely resembled the profile of the native erythrocytes in terms of osmotic fragility, oxygen dissociation and hematological parameters. The in vivo half-life of enzyme activity after administering 8 units of RBC/LMWP-ASNase in DBA/2 mice was prolonged to 4.5±0.5 days whereas that of RBCs loaded with ASNase via a hypotonic method was 2.4±0.7 days. Furthermore, the mean survival time of DBA/2 mice bearing mouse lymphoma cell L5178Y was improved by ∼44% compared to the saline control group after treatment with the RBC loaded enzymes. From these data, an innovative, novel method for encapsulating proteins into intact and fully functional erythrocytes was established for potential treatment of ALL.

Glucocorticoids are effective for treating several respiratory diseases. However, they can cause hyperglycemia. This study determined the incidence and risk factors of steroidinduced diabetes mellitus (S-DM) in patients treated with glucocorticoid for respiratory diseases. A retrospective study examined patients with respiratory diseases treated with a prednisolone-equivalent glucocorticoid dose exceeding 20 mg/day for at least 4 weeks between January 2003 and December 2008. Patients whose initial random glucose level exceeded 200 mg/dL or who had pre-existing diabetes were excluded. S-DM was defined as a fasting glucose concentration exceeding 126 mg/dL or a random glucose concentration exceeding 200 mg/dL at least twice after beginning steroid treatment. A total of 231 patients with respiratory diseases met the inclusion criteria. Their median age was 55 yr, and 139 were female. The median cumulative prednisolone-equivalent glucocorticoid dose was 4,965 mg, and the median duration of steroid treatment was 193 days. S-DM was diagnosed in 34 (14.7%) of 231 patients. Multivariate logistic regression identified older age (odds ratio 1.05, 95% confidence interval 1.02-1.09) as a risk factor for S-DM. S-DM is frequent among patients with respiratory diseases treated with glucocorticoid. Clinicians should be aware of the possibility of S-DM, especially among elderly patients.