Photoresponsive nanosystems for therapeutic applications

Oncological and bacterial diseases are certainly the most troubling illnesses of the twenty-first century, and the data in this regard are staggering. Indeed, anticancer chemotherapy is affected by low specificity/selectivity and undesired side effects, and drug resistance phenomena are responsible for the failure of many conventional treatments. Multidrug-resistant-bacteria (MDRB) infection is become another burden to modern healthcare. For such a reason, there is an increasing demand for the development of new strategies for anticancer and antibacterial treatments without antibiotics to save millions of lives every year.1 In this frame, the light-controlled generation of cytotoxic species, such as singlet oxygen (1O2) and nitric oxide (NO), by using appropriate photochemical precursors represents a fascinating and unconventional approach for the treatment of cancerous and microbial diseases in non-invasive manner. However, many precursors have a hydrophobic nature, which favors their aggregation in aqueous medium strongly precluding their photochemical behavior.2 The entrapment of drugs and pro-drugs in nanocarriers permits to overcome all these drawbacks and ensures protection from degradation, site-specific delivery, enhanced bioavailability, increased local concentration. Here in are reported studies of two different types of nanocarriers carrying different photoactivable guests. The first part of this dissertation focuses on the achievement of novel photoresponsive calix[4]arene-based nanoconstructs which vehicle, by not covalent or covalent approach, different kinds of chromophores. The second part concerns the design, synthesis, antitumoral and antibacterial activity of polymersomes containing a nitric oxide photoprecursor by covalent and non-covalent approach.