Title : Lipid based nanocarriers for the delivery of biomolecules
Abstract:
Lipid-based nanocarriers have emerged as a very promising, tool for the delivery of various biomolecules lacking solubility, bioavailability and stability. These systems, in fact, are capable of encapsulating and protecting drugs from degradation before they reach the target site in vivo. In particular liposomes are ideal carriers for biomolecule delivery in a wide range of applications. They consist of a phospholipid bilayer, fully biocompatible and safe, that encloses an aqueous core. Therefore, liposomes are capable of simultaneously transporting hydrophobic and hydrophilic molecules as well as amphipathic ones. They can be easily marked both with organic fluorescent molecules and quantum dots with a high quantum yield, emitting in a wide range of wavelengths, ideal for theranostic applications. In addition, liposomes can carry fully active proteins, genetic material and other biomacromolecules. Finally, liposomes can be covered with both natural and synthetic polymers that increase their steric and biological stability, adapting them to specific experimental needs. In addition, these lipid vesicles can be decorated with molecules able to selectively direct them towards a selected biological target, at tissue, cell and even sub-cellular level, such as antibodies, aptamers and other molecular recognition groups [1-3]..
In our studies micelle to vesicle transition (MVT) or exstrusion method were applied to the realization of small unilamellar liposomes (<100 nm) useful for different types of applications in the field of drug and bioactive molecule delivery. In particular, mucus-penetrating liposomes for pulmonary delivery of beclomethasone dipropionate (BDP), a known anti-inflammatory drug, were realized. The same strategy was successfully adopted to incorporate natural antioxidants, such as curcumin, aiming to obtain formulations for colon delivery of biological active compounds. To this end liposome encapsulating curcumin, coated with the pH responsive polymer Eudragit S100, were prepared and characterized. The realized polymer coverage was proved to be stable at acid and neutral pH around the vesicles and to dissolve at a slightly alkaline pH, releasing the liposomes in the conditions in which they would be found in vivo in the colon. In vitro tests demonstrated the ability of vesicles to enter in Caco-2 cells through a mechanism of endocytosis. The antioxidant activity in the cells was measured.
Finally, the possibility of assembly liposomes on Titanium to develop advanced implant surface was exploited in view of possible strategy to local delivery of bioactive molecules.
Audience take away:
• The systems we have prepared are simple and versatile, able to host, also simultaneously, hydrophobic, hydrophilic as well as amphipathic molecules and therefore useful for applications in different fields such as, for example, in drug delivery, bioimaging and food nanothecnology.
• Appropriate engineering of lipid-based nanocarriers presented can lead to the solution of experimental problems such as: stabilization, absorption and bioavailability of their payload
• The lipid systems presented were prepared by simple, easy, effective and organic-free solvent methods responding to the needs of biocompatibility and environmental sustainability
