Design and function of targeted endocannabinoid nanoparticles.

Nanoparticles and nano-delivery systems are constantly being refined and developed for biomedical applications such as imaging, gene therapy, and targeted delivery of drugs. Nanoparticles deliver beneficial effects by both release of their cargo and by liberation of their constitutive structural components. The N-acylethanolamines linoleoyl ethanolamide (LEA) and oleoyl ethanolamide (OEA) both exhibit endocannabinoid-like activity. Here, we report on their ability to form nanoparticles that when conjugated with tissue-specific molecules, are capable of localizing to specific areas of the body and reducing inflammation. The facilitation of pharmacological effects by endocannabinoids at targeted sites provides a novel biocompatible drug delivery system and a therapeutic approach to the treatment, patient management and quality of life, in conditions such as arthritis, epilepsy, and cancer.

Shear-induced alignment of self-associated hemoglobin in human erythrocytes: small angle neutron scattering studies.

Small angle neutron scattering (SANS) was performed on suspensions of actively metabolising human erythrocytes in the constant shear field induced by a Couette cell. The SANS pattern recorded on a two-dimensional detector was a function of the shear rate; at zero shear, the SANS pattern had radial symmetry around the direction of the beam. The radial average of the SANS pattern consisted of a broad intensity maximum superimposed on a decay. The intensity maximum at q = 0.1 A(-1) was attributed to isotropically oriented self-associated complexes of the tetrameric oxygen transport protein hemoglobin inside the erythrocytes. A flow curve of the cell suspension was used to identify at what shear rate a suspension of uniaxially oriented ellipsoidal cells is produced. The radial symmetry of the SANS patterns persisted until the shear rate was sufficient to produce a suspension of uniaxially oriented ellipsoidal cells. Again, an intensity maximum was present in directions parallel and orthogonal to the shear axis, but this intensity maximum was superimposed upon quite different intensity decays in each direction from that of the primary neutron beam. The angular range of the SANS instrument was limited, however the results from shear-induced structural changes is consistent with a model that involves hemoglobin complexes that are aligned with respect to the plasma membranes of the elongated cells.

Quantitation of water in membranes by neutron diffraction and X-ray techniques.

The general principle of placing neutron and X-ray scattering density profiles on an absolute scale is being applied to an increasing number of problems in structural biology. This maximizes the information from the experiments by facilitating the identification of various molecular species. The greater detail available on the membrane water distribution has been highlighted in this chapter. The quantitative analysis of water in the headgroup region and the intermembrane water layer provides valuable information on membrane structure and function. The single most important limitation of the method is the lack of resolution. Improvements in experimental techniques will improve the resolution in a number of situations.