VECTORS FOR VITAMINS DELIVERY: NANO-LIPOSOMES PRODUCTION VIA ULTRASONIC IRRADIATION

Drug delivery vectors are of critical importance for controlled and targeted release of therapeutic agents. Their biodegradability, targetability, nano- and micro- size, prolonged half-life in the bloodstream, accumulation in pathological areas and ability to cross biological barriers make them unique tools for the delivery of active molecules directly at target sites. Liposomes are an attractive class of drug delivery vectors due to their good biocompatibility, biodegradability, low intrinsic toxicity, immunogenicity and flexibility to couple with site-specific ligands to achieve active targeting [1,2]. Liposomes protect drugs by the action of degrading agents present in the blood stream and prevent their elimination by immune system, solving the problem of short drug half-life. Liposomes dimensions are of crucial importance for their performance as drug carrier systems. It was shown that liposomes much larger than 200-250 nm may not accumulate in the spleen by a filtration mechanism, or be trapped in the lung capillaries [3]; liposomes with small (<50 nm diameter) size were found to resist degradation in blood and to circulate for several hours in human cancer patients [4]. Liposomes are an ideal delivery carrier system for various types of active molecules such as peptides, vitamins, DNA and RNA fragments. In this work vitamins encapsulation in liposomal vectors was performed. B12 and α-tocopherol were chosen as hydrophilic and hydrophobic vitamin models and for their relevant important features. B12 and α-tocopherol have been shown to possess a therapeutic and preventive effect against cancer diseases: α-tocopherol, the most well-studied isomer of vitamin E, has been shown to possess an anti-cancer effect due to its antioxidant properties [5] while vitamin B12 is essential for DNA synthesis and for cellular energy production [6]. In particular, in this work nano-liposomes production via ultrasonic irradiation for a controlled and targeted vitamins release, was presented. The lipid film hydration technique followed by a tailored ultrasonic-assisted size reduction was used to produce SUVs (Small Unilamellar Vesicles) from MLVs (MultiLamellar Vesicles). This new preparative approach, based on literature conventional techniques, is a promising method to obtain nano-liposomal structures with defined size and high load.