Vesosome with distinct interior (green, orange) and exterior (blue) bilayer membranes. Drugs are encapsulated within the interior compartments and are protected from blood serum components by the exterior membrane. The outer membrane can be decorated with PEG lipids (red) to prevent aggregation in the blood as well as specific labels or targeting ligands.

The extent and locus of solubilization of guest and self-assembling surfactant host molecules in aqueous solutions are influenced by a variety of hydrophobic and hydrophilic interactions, as well as by more specific interactions between the various species present. By using a combination of two-dimensional heteronuclear 13C[1H] NMR correlation experiments with pulsed-gradient NMR diffusion and proton cross-relaxation measurements, the locations and distributions of porphyrin guest molecules have been established unambiguously with respect to the hydrophobic and hydrophilic moieties of a triblock copolymer species in solution. The interactions of tetra(4-sulfonatophenyl)porphyrin with the poly(propylene oxide) (PPO) and the poly(ethylene oxide) (PEO) segments of amphiphilic PEO-PPO-PEO triblock copolymer species have been measured as functions of solution conditions, including temperature and pH. The porphyrin/PEO-PPO-PEO interactions are established to be selective and adjustable according to the different temperature-dependent hydrophilicities or hydrophobicities of the PEO and PPO triblock copolymer components. Furthermore, such interactions influence the self-assembly properties of the block-copolymer amphiphiles in solution by stabilizing molecular porphyrin/PEO-PPO-PEO complexes well above the critical micellization temperature of the triblock copolymer species under otherwise identical conditions.

Transparent silica-block copolymer composites have been used as host matrices for optically limiting dye molecules to increase dye solubility and photophysical stability. For a given concentration, tetraphenylporphyrin (TPP)-doped mesostructured EO106PO70EO106−silica composites exhibited improved optical limiting properties compared to wholely inorganic TPP-doped silica hosts. Increased TPP solubility within the PPO−PEO block copolymer allows higher concentrations of TPP to be incorporated without dye aggregation, enhancing optical absorption of incident laser light. In addition, the silica framework provides increased damage resistance to a series of intense laser pulses compared to wholely organic host matrices.

Mesostructured silica-block copolymer thin films are demonstrated to provide orientationally ordered host matrixes for stable alignment of coassembled porphyrin J-aggregates with anisotropic optical properties. Visible light at 490 nm was absorbed anisotropically (A | /A ⊥ ) 1.35) by aligned, hexagonally ordered (ethylene oxide) 20 -(propylene oxide) 70 -(ethylene oxide) 20 (P123) triblock copolymer/silica nanocomposite films containing 1-5 wt % tetrakis(4-sulfonatophenyl)porphyrin (TPPS 4 ) guest species in the form of J-aggregates. Amorphous silica prepared similarly and containing TPPS 4 J-aggregates, but without structure-directing block copolymer species, absorbed light isotropically (A | /A ⊥ ) 1.00). The porphyrin guest species were determined to be preferentially associated with the hydrophilic ethylene oxide moieties of the triblock copolymer, by using two-dimensional (2D) solid-state 1 H{ 1 H} and 13 C{ 1 H} NMR correlation experiments, including under conditions of fast (45 kHz) magic-angle spinning. Interrelationships are shown and established among synthesis conditions, the molecular, mesoscopic, and orientational structural ordering in the porphyrin-containing nanocomposite thin films, and their macroscopic optical properties.

Hadamard-encoded heteronuclear-resolved NMR diffusion and relaxation measurements allow overlapping signal decays to be resolved with substantially shorter measuring times than are generally associated with 2D heteronuclear cross-correlation experiments. Overall measuring time requirements can be reduced by approximately an order of magnitude, compared to typical 2D heteronuclear single-quantum correlation-resolved diffusion or relaxation measurements. Specifically, in cases where chemical shift correlation information provides enhanced spectral resolution, the use of Hadamard encoding can be used to overcome uniqueness challenges that are associated with the analysis of concurrent dynamic processes and the extraction of time constants from overlapping exponential signal decays. This leads to substantially improved resolution of similar time constants than can be achieved solely through the use of post-acquisition processing techniques. In the ideal case of complete spectral separation of the signal decays, the usual constraint that time constants must be sufficiently different to resolve by exponential analysis can be circumvented entirely. Hadamard-based pulse sequences have been used to determine 1H[13C]-resolved diffusion coefficients and spin-relaxation time constants for the chemically similar components of an aqueous solution of ethanol, glycerol, and poly(ethylene glycol), and a dye-containing block-copolymer solution, which exhibit significant spectral overlap in their 1H NMR spectra.