The blood brain barrier is a functional barrier allowing the entry into the brain of only essential nutrients, excluding other molecules. Its structure, although essential to keep the harmful entities out, is also a major roadblock for pharmacological treatment of brain diseases. Several alternative invasive drug delivery approaches, such as transcranial drug delivery and disruption of blood brain barrier have been explored, with limited success and several challenges. Intranasal delivery is a non-invasive methodology, which bypasses the systemic circulation, and, through the intra- and extra- neuronal pathways, provides direct brain drug delivery. Colloidal drug delivery systems, particularly lipidic nanoparticles offer several unique advantages for this goal . Areas covered: This review focuses on key brain diseases such as Alzheimer's disease, Parkinson's disease, Huntington's disease and amyotrophic lateral sclerosis, and provide a detailed overview of the current lipid nanoparticle based treatment options explored thus far. The review also delves into basic preparation, challenges and evaluation methods of lipid drug delivery systems. Expert opinion: Brain diseases present complex pathophysiology, in addition to the practically inaccessible brain tissues, hence according to the authors, a two-pronged approach utilizing new target discovery coupled with new drug delivery systems such as lipid carriers must be adopted.

Poorly structured domains in proteins enhance their susceptibility to proteasomal degradation. To learn whether the presence of such a domain near either end of a protein determines its direction of entry into the proteasome, directional translocation was enforced on several proteasome substrates. Using archaeal PAN-20S complexes, mammalian 26S proteasomes and cultured cells, we identified proteins that are degraded exclusively from either the C or N terminus and some showing no directional preference. This property results from interactions of the substrate’s termini with the regulatory ATPase and could be predicted based on the calculated relative stabilities of the N and C termini. Surprisingly, the direction of entry into the proteasome affected markedly the spectrum of peptides released and consequently influenced the efficiency of MHC class I presentation. Thus, easily unfolded termini are translocated first, and the direction of translocation influences the peptides generated and presented to the immune system.

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BACKGROUND: In circulating lymphocytes of individuals with insulin resistance and overt hyperglycaemia (NIDDM patients), alterations, affecting pyruvate dehydrogenase (PDH), the key enzyme in glucose oxidative breakdown, have been observed. They include below normal enzyme activity and, in vitro, no enzyme response to insulin at low physiological levels (5 m mUaml) as well as activation up to the basal values of controls with insulin at high physiological levels (50 m mUaml), instead of activation and inhibition respectively, as in controls. OBJECTIVE: To investigate whether these alterations characterize circulating lymphocytes of individuals with insulin resistance in whom derangements of glucose homeostasis are absent (obese subjects with normal glucose tolerance), or present but still controllable (nonobese and obese newly diagnosed NIDDM patients on an appropriate diet). SUBJECTS: Thirty obese subjects (BMI 36 AE 3) responding normally to an oral glucose tolerance (OGT) test; 60 newly diagnosed NIDDM patients (30 nonobese, BMI 22 AE 4 and 30 obese, BMI 38 AE 2); 30 nonobese (BMI 21 AE 5) and nondiabetic subjects, with no family history for NIDDM, served as controls. METHODS: Evaluation of PDH activity in circulating lymphocytes before and after exposure to insulin at 5 and 50 m mUaml, and of clinical parameters before and during an OGT test. RESULTS: 1) In circulating lymphocytes of obese nondiabetic subjects as well as obese and nonobese newly diagnosed NIDDM patients, PDH activity was signi®cantly below normal. In vitro, enzyme response to insulin at 5 m mUaml was reduced in nonobese NIDDM patients with respect to controls, and absent in obese nondiabetic subjects and obese NIDDM patients. Enzyme response to insulin at 50 m mUaml was reversed in all individuals, which allowed enzyme activity to recover up to the basal level of controls. 2) In NIDDM patients and obese nondiabetic subjects, undergoing an OGT test, the area under the glycaemic curve (g-AUC) was as expected; the area under the insulinaemic curve (i-AUC) was increased in both groups with respect to controls, but signi®cantly only in the latter. CONCLUSION: In individuals with insulin resistance PDH activity in their circulating lymphocytes rises up to basal levels of controls, only if these cells are exposed to insulin at high physiological concentrations, and g-AUC is normal only in those subjects who have signi®cantly increased i-AUC. This suggests that with insulin at suf®ciently high concentrations both parameters can be corrected. We conclude that the derangements responsible for the alterations of the two parameters share common features and thus the described PDH alterations in circulating lymphocytes re¯ect systemic insulin resistance whether accompanied by hyperglycaemia or not.

Aims: Advanced melanoma is characterized by poor outcome. Despite the number of treatments having been increased over the last decade, current pharmacological strategies are only partially effective. Therefore, the improvement of the current systemic therapy is worthy of investigation. Methods: a nanotechnology-based poly-chemotherapy was tested at preclinical level. Temozolomide, rapamycin, and bevacizumab were co-loaded as injectable nanoemulsions for total parenteral nutrition (Intralipid®), due to suitable devices, and preliminarily tested in vitro on human and mouse cell models and in vivo on the B16-F10 melanoma mouse model. Results: Drug combination was efficiently loaded in the liquid lipid matrix of Intralipid®, including bevacizumab monoclonal antibody, leading to a fast internalization in tumour cells. An increased cytotoxicity towards melanoma cells, as well as an improved inhibition of tumour relapse, migration, and angiogenesis were demonstrated in cell models for the Intralipid®-loaded drug combinations. In preliminary in vivo studies, the proposed approach was able to reduce tumour growth significantly, compared to controls. A relevant efficacy towards tumour angiogenesis and mitotic index was determined and immune response was involved. Conclusions: In these preliminary studies, Intralipid® proved to be a safe and versatile poly-chemotherapy delivery system for advanced melanoma treatment, by acting on multiple mechanisms.