Reasons for enhanced activity of doxorubicin on co-delivery with octa(3-aminopropyl)silsesquioxane

Abstract

The interaction between polyhedral oligomeric silsesquioxane (POSS) and doxorubicin, leading to formation of active complexes involving POSS functional aminopropyl groups and anthracycline functional groups.

Hydrophilic Polyhedral Oligomeric Silsesquioxane, POSS(OH)32, as a Complexing Nanocarrier for Doxorubicin and Daunorubicin

“…The novel complexes are inexpensive to prepare, more effective than free drugs at low systemic toxicity. We found POSS(OH) 32 to be another useful silsesquioxane [16] that increased the efficacy of anthracyclines. These findings leads to the hypothesis that such cage-type silsesquioxanes with various functional groups can serve as effective nanocarriers in drug delivery.…”

“…In both these reports, the authors proposed NH• • • N hydrogen bonding as a driving force for complex (aggregate) formation; however, at that time, it was only an experimentally unsupported suggestion. Our recent study revealed that not only hydrogen bonding but also electrostatic interactions and π-π stacking between DOX moieties play important roles in the formation of weak complexes [16]. Thus, studies on potential formation of active complexes involving POSS with various functional groups and the anthracycline functional groups also appear generally important for other anti-cancer drug complexing systems, once the presence of required functional groups for such interactions with POSS are identified.…”

Novel Polyhedral Silsesquioxanes [POSS(OH)32] as Anthracycline Nanocarriers—Potential Anticancer Prodrugs

“…FTIR spectroscopy was additionally used for structural characterization of the conjugates formed via ester bond between drugs and the POSS carrier. FTIR spectra of conjugates differed from that of SAMDOX/SAMDAU [ 11 ]. The spectra of conjugates 4 – 9 ( Figure 9 ) show a new absorption frequency at ~1734 cm −1 (ν C=O , ester bond) indicating formation of an ester bond between SAMDOX/SAMDAU and the POSS hydroxyl groups.…”

“…In addition, they show longer release time, which makes them potential candidates for biomedical applications in anticancer therapy. POSS type nanocarriers were proven again [ 10 , 11 ] to be useful systems in formation of nanoconjugates and nanocomplexes with anthracycline drugs. The present work shall be expanded by in vitro studies as soon as the test laboratory reopens after COVID-19 closure.…”

“…Encapsulation, complexation or conjugation of these drugs with nanocarriers leads to slow release of the active drug, extending its time of action, leading to decreased doses. Our previous studies have been devoted to the use of polyhedral oligosilsesquioxanes as nanocarriers of anti-cancer drugs [ 8 , 9 , 10 , 11 ]. Silsesquioxanes are well known to facilitate cell membrane penetration [ 12 ], an important feature in drug delivery.…”