Macrophages as Nanocarriers for Drug Delivery: Novel Therapeutics for Central Nervous System Diseases.

Many central nervous system (CNS) diseases were thought to be untreatable due to the presence of the blood-brain barrier (BBB). The chemokine gradients secreted from CNS parenchyma can induce macrophage migration to the brain, induce firm adherence to the endothelium of BBB, and eventually to enter the brain parenchyma. Macrophages migrating into CNS can promote neuron regeneration, induce inflammation and angiogenesis. These properties can potentially allow macrophages to act as carriers for drug/nano formulations across the BBB, and reach the potential target sites. Many nanomaterials cannot be used for the management of CNS diseases because of their low carrying efficiency. Macrophage which transports nanomaterials to pathological sites is rendered as an attractive tool for the transportation of drugs to previously inaccessible regions within the brain parenchyma. Nanomaterials engulfed by macrophages can be released at target sites, and be used for therapeutic or diagnostic purposes. In this review, we focus on macrophages as the cell-carrier to deliver nano-drugs into CNS, describe the biological behavior of macrophages during pathological conditions and discuss the application of cell drug delivery system in recent years.

Systematic review of decreased intracranial pressure with optimal head elevation in postcraniotomy patients: a meta-analysis.

AIM: To determine an optimal head elevation degree to decrease intracranial pressure in postcraniotomy patients by meta-analysis. BACKGROUND: A change in head position can lead to a change in intracranial pressure; however, there are conflicting data regarding the optimal degree of elevation that decreases intracranial pressure in postcraniotomy patients. DESIGN: Quantitative systematic review with meta-analysis following Cochrane methods. DATA SOURCES: The data were collected during 2014; three databases (PubMed, Embase and China National Knowledge Internet) were searched for published and unpublished studies in English. The bibliographies of the articles were also reviewed. The inclusion criteria referred to different elevation degrees and effects on intracranial pressure in postcraniotomy patients. REVIEW METHODS: According to pre-determined inclusion criteria and exclusion criteria, two reviewers extracted the eligible studies using a standard data form. RESULTS: These included a total of 237 participants who were included in the meta-analysis. (1) Compared with 0 degree: 10, 15, 30 and 45 degrees of head elevation resulted in lower intracranial pressure. (2) Intracranial pressure at 30 degrees was not significantly different in comparison to 45 degrees and was lower than that at 10 and 15 degrees. CONCLUSION: Patients with increased intracranial pressure significantly benefitted from a head elevation of 10, 15, 30 and 45 degrees compared with 0 degrees. A head elevation of 30 or 45 degrees is optimal for decreasing intracranial pressure. Research about the relationship of position changes and the outcomes of patient primary diseases is absent.