The increasing need for drug delivery systems that improve specificity and activity and at the same time reduce toxicity to ensure maximum treatment safety has led to the development of a great variety of drug vectors. Carriers based on soft matter have particularly interesting characteristics. Herein we present the current standing of the research in this area, and focus on two main families, namely matrix systems and vesicles. We outline the structure, properties, and potential applications of these vectors, and discuss their main advantages and drawbacks in their synthesis.

Structures formed by self-assembly of α- and β-1-n-dodecyl d-maltosides in water depend on the configuration at the anomeric center. The α-anomer forms quasi-spherical aggregates, while the β-maltoside forms larger oblate ellipsoidal micelles. This difference in behavior suggests that the configuration of the head group influences the orientation of the polar residue and hence the packing of monomers during self-assembly.

Galactosylceramide (GalCer) is an alternative receptor allowing human immunodeficiency virus (HIV)-1 entry into CD4-negative cells of neural and colonic origin.Several lines of evidence suggest that this glycosphingolipid recognizes the V3 region of HIV-1 surface envelope glycoprotein gp120. Since the V3 loop plays a key role in the fusion process driven by HIV-1, we decided to synthesize soluble analogs of GalCer with the aim to develop a new class of anti-HIV-1 agents that could neutralize HIV-1 infection through masking of the V3 loop. We describe a short route, in three steps, for the synthesis of soluble analogs of GalCer, using unprotected lactose as the starting sugar. The analogs were prescreened in an assay based on the interaction between a V3 loopderived synthetic peptide and [ 3 H]suramin, a polysulfonyl compound displaying high affinity for the V3 loop. One of the soluble analogs, i.e. CA52(n15), strongly inhibited the binding of [ 3 H]suramin to the V3 peptide, with an IC 50 of 1.2 M. This molecule was also able to inhibit [ 3 H]suramin binding to recombinant gp120 with similar activity. Using a competition enzyme-linked immunosorbent assay with highly specific anti-gp120 monoclonal antibodies, the region recognized by CA52(n15) could be mapped to amino acids 318 -323, which corresponds to the highly conserved consensus motif GPGRAF. Interestingly, the region recognized by suramin, i.e. IQRGP-R-F, was partially overlapping this motif. CA52(n15) was able to inhibit HIV-1-induced cell fusion as well as HIV-1 entry into both CD4 ؉ and CD4 ؊ / GalCer ؉ cells. A structure-activity relationship study showed that: (i) the antiviral activity of soluble analogs of GalCer correlates with V3 loop binding, and (ii) the hydrophobic moiety of the molecule plays an important role in this activity. Taken together, these data show that synthetic analogs of GalCer can inhibit HIV-1 entry into both CD4 ؊ and CD4 ؉ cells through masking of the V3 loop.